業績情報

• Control of plasma membrane-associated actin polymerization specifies the pattern of the cell wall in xylem vessels
  Saku T. Kijima; Takema Sasaki; Yuichiro Kikushima; Daisuke Inoue; Shingo Sakamoto; Yuki Kondo; Soichi Inagaki; Masatoshi Yamaguchi; Nobutaka Mitsuda; Yoshihisa Oda
  Nature Communications, 巻：16, 号：1, 2025年02月
  Springer Science and Business Media LLC, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1038/s41467-025-56866-y
  DOI ID：10.1038/s41467-025-56866-y, eISSN：2041-1723
• The deficiency of methylglyoxal synthase promotes cell proliferation in Synechocystis sp. PCC 6803 under mixotrophic conditions　　　　　　　　　　　　　　　
  Aikeranmu Kadeer; Yuuma Ishikawa; Kaushalya Dayarathne; Atsuko Miyagi; Toshiki Ishikawa; Masatoshi Yamaguchi; Maki Kawai-Yamada
  Plant Biotechnology, 巻：41, 号：4, 開始ページ：393, 終了ページ：399, 2024年12月, ［査読有り］
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.24.0718a
  DOI ID：10.5511/plantbiotechnology.24.0718a
• The effect of light availability and light wavelength on growth, 2-MIB biosynthesis, and 2-MIB-related gene expression in Pseudanabaena foetida var. intermedia.　　　　　　　　　　　　　　　
  Kaushalya Dayarathne; Toshiki Ishikawa; Aikeranmu Kadeer; Masatoshi Yamaguchi; Maki Kawai-Yamada
  Archives of microbiology, 巻：206, 号：9, 開始ページ：367, 終了ページ：367, 2024年08月, ［国際誌］
  2-methylisoborneol (2-MIB) is an odiferous metabolite mainly produced by cyanobacteria, contributing to taste and odor problems in drinking water. The mechanisms involved in 2-MIB biosynthesis in cyanobacteria are not yet completely understood. This study investigated the effect of light availability and wavelength on growth, 2-MIB synthesis, and related gene expression in Pseudanabaena foetida var. intermedia. A significantly lower 2-MIB production was observed in P. foetida var. intermedia during the dark period of a 12-h photoperiod. Exposure to green light resulted in a significant decrease in 2-MIB production compared to white light and red light. The relative expression levels of 2-MIB-related genes in P. foetida var. intermedia were significantly lower during the dark period of a 12-h photoperiod and when cultured under green light. The expression of 2-MIB-related genes in cyanobacteria appears to be light-dependent. This study suggests that the demand for photopigment synthesis under unfavorable light conditions affects the 2-MIB synthesis in cyanobacteria.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1007/s00203-024-04099-w
  DOI ID：10.1007/s00203-024-04099-w, PubMed ID：39105810
• Heterologous expression of mtf and mtc genes of Pseudanabaena foetida var. intermedia is sufficient to produce 2-methylisoborneol in Escherichia coli.　　　　　　　　　　　　　　　
  Kaushalya Dayarathne; Toshiki Ishikawa; Satoru Watanabe; Yuuma Ishikawa; Kadeer Aikeranmu; Hina Kitagawaa; Natsumi Komatsubara; Masatoshi Yamaguchi; Maki Kawai-Yamada
  Microbiology spectrum, 巻：11, 号：5, 開始ページ：e0256123, 2023年09月, ［国際誌］
  Microbial volatile metabolite 2-methylisoborneol (2-MIB) causes odor and taste issues in drinking water, making it unappealing for human consumption. It has been suggested that 2-MIB biosynthesis consists of two main steps, namely, methylation of geranyl diphosphate into 2-methyl geranyl diphosphate by geranyl diphosphate methyl transferase (GPPMT) and subsequent cyclization into 2-MIB by 2-MIB synthase (MIBS). Pseudanabaena foetida var. intermedia is a 2-MIB-producing cyanobacterium whose GPPMT and MIBS enzymes are encoded by adjacent mtf and mtc genes. The present study identified a 2-MIB-related gene cluster composed of cnbA, mtf, mtc, and cnbB genes in P. foetida var. intermedia. The two homologous cyclic nucleotide-binding protein genes, cnbA and cnbB, were detected adjacent to the mtf and mtc genes, respectively. The nucleotide sequence of the cnbA-mtf-mtc-cnbB gene cluster showed 99.55% identity with 2-MIB synthesis-associated gene cluster of Pseudanabaena sp. dqh15. RT-PCR results revealed that mtf and mtc genes are co-expressed, while cnbA and cnbB genes are expressed independently in P. foetida var. intermedia. To investigate whether only mtf and mtc genes are sufficient for 2-MIB synthesis, the two-gene unit (mtf-mtc) was introduced into Escherichia coli strain JM109 via overexpression vector pYS1C. Gas chromatograph-mass spectrometry results showed that the E. coli strain transformed with mtf-mtc was able to produce 2-MIB. The intracellular 2-MIB level in P. foetida var. intermedia was higher than the extracellular 2-MIB level, while the transformed E. coli strain showed an opposite trend. Growth inhibition was observed in the 2-MIB-producing transformed E. coli strain. IMPORTANCE Contamination of drinking water with odiferous microbial metabolite 2-MIB is a worldwide concern. Removal of 2-MIB from drinking water burdens the water purification process. Therefore, it is important to search for alternative methods, such as suppressing the production of 2-MIB by aquatic microorganisms. For that, it is necessary to expand the current knowledge about the mechanism of 2-MIB synthesis at the genetic level. This study revealed that mtf and mtc genes of the 2-MIB-related gene cluster are transcribed as a single unit in P. foetida var. intermedia, and the expression of both mtf and mtc genes is essential and sufficient for 2-MIB synthesis in E. coli heterologous gene expression system.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1128/spectrum.02561-23
  DOI ID：10.1128/spectrum.02561-23, PubMed ID：37732762, PubMed Central ID：PMC10580876
• NAC domain transcription factors VNI2 and ATAF2 form protein complexes and regulate leaf senescence
  Isura Sumeda Priyadarshana Nagahage; Kohei Matsuda; Kyoko Miyashita; Sumire Fujiwara; Chanaka Mannapperuma; Takuya Yamada; Shingo Sakamoto; Toshiki Ishikawa; Minoru Nagano; Misato Ohtani; Ko Kato; Hirofumi Uchimiya; Nobutaka Mitsuda; Maki Kawai‐Yamada; Taku Demura; Masatoshi Yamaguchi
  Plant Direct, 巻：7, 号：9, 2023年09月, ［査読有り］, ［最終著者, 責任著者］
  Abstract
  
  The NAM, ATAF1/2, and CUC2 (NAC) domain transcription factor VND‐INTERACTING2 (VNI2) negatively regulates xylem vessel formation by interacting with another NAC domain transcription factor, VASCULAR‐RELATED NAC‐DOMAIN7 (VND7), a master regulator of xylem vessel formation. Here, we screened interacting proteins with VNI2 using yeast two‐hybrid assay and isolated two NAC domain transcription factors, Arabidopsis thaliana ACTIVATION FACTOR 2 (ATAF2) and NAC DOMAIN CONTAINING PROTEIN 102 (ANAC102). A transient gene expression assay showed that ATAF2 upregulates the expression of genes involved in leaf senescence, and VNI2 effectively inhibits the transcriptional activation activity of ATAF2. vni2 mutants accelerate leaf senescence, whereas ataf2 mutants delay leaf senescence. In addition, the accelerated leaf senescence phenotype of the vni2 mutant is recovered by simultaneous mutation of ATAF2. Our findings strongly suggest that VNI2 interacts with and inhibits ATAF2, resulting in negatively regulating leaf senescence.
  Wiley, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1002/pld3.529
  DOI ID：10.1002/pld3.529, ISSN：2475-4455, eISSN：2475-4455
• Metabolic changes associated with dark-induced leaf senescence in Arabidopsis nadk2 mutants　　　　　　　　　　　　　　　
  Chaomurilege; Atsuko Miyagi; Toshiki Ishikawa; Masatoshi Yamaguchi; Hideki Murayama; Maki Kawai-Yamada
  Plant Signaling and Behavior, 巻：18, 号：1, 開始ページ：e2215618, 2023年05月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1080/15592324.2023.2215618
  DOI ID：10.1080/15592324.2023.2215618
• Loss of peroxisomal NAD kinase 3 (NADK3) affects photorespiration metabolism in Arabidopsis　　　　　　　　　　　　　　　
  Shota Suzuki; Daimu Tanaka; Atsuko Miyagi; Kentaro Takahara; Masaru Kono; Chaomurilege; Ko Noguchi; Toshiki Ishikawa; Minoru Nagano; Masatoshi Yamaguchi; Maki Kawai-Yamada
  Journal of Plant Physiology, 巻：283, 開始ページ：153950, 2023年03月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1016/j.jplph.2023.153950
  DOI ID：10.1016/j.jplph.2023.153950
• Metabolomic analysis of rice brittle culm mutants reveals each mutant- specific metabolic pattern in each organ
  Atsuko Miyagi; Kazuhisa Mori; Toshiki Ishikawa; Satoshi Ohkubo; Shunsuke Adachi; Masatoshi Yamaguchi; Taiichiro Ookawa; Toshihisa Kotake; Maki Kawai-Yamada
  Metabolomics, 巻：18, 号：12, 2022年11月, ［査読有り］
  Springer Science and Business Media LLC, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1007/s11306-022-01958-9
  DOI ID：10.1007/s11306-022-01958-9, eISSN：1573-3890
• Loss of chloroplast-localized NAD kinase causes ROS stress in Arabidopsis thaliana　　　　　　　　　　　　　　　
  Chaomurilege; Yanhui Zu; Atsuko Miyagi; Shin-Nosuke Hashida; Toshiki Ishikawa; Masatoshi Yamaguchi; Maki Kawai-Yamada
  Journal of Plant Research, 巻：in press, 2022年11月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1007/s10265-022-01420-w
  DOI ID：10.1007/s10265-022-01420-w
• Sphingolipids with 2-hydroxy fatty acids aid in plasma membrane nanodomain organization and oxidative burst
  Tomomi Ukawa; Fumihiko Banno; Toshiki Ishikawa; Kota Kasahara; Yuuta Nishina; Rika Inoue; Keigo Tsujii; Masatoshi Yamaguchi; Takuya Takahashi; Yoichiro Fukao; Maki Kawai-Yamada; Minoru Nagano
  Plant Physiology, 巻：189, 号：2, 開始ページ：839, 終了ページ：857, 2022年06月, ［査読有り］
  Abstract
  
  Plant sphingolipids mostly possess 2-hydroxy fatty acids (HFA), the synthesis of which is catalyzed by FA 2-hydroxylases (FAHs). In Arabidopsis (Arabidopsis thaliana), two FAHs (FAH1 and FAH2) have been identified. However, the functions of FAHs and sphingolipids with HFAs (2-hydroxy sphingolipids) are still unknown because of the lack of Arabidopsis lines with the complete deletion of FAH1. In this study, we generated a FAH1 mutant (fah1c) using CRISPR/Cas9-based genome editing. Sphingolipid analysis of fah1c, fah2, and fah1cfah2 mutants revealed that FAH1 hydroxylates very long-chain FAs (VLCFAs), whereas the substrates of FAH2 are VLCFAs and palmitic acid. However, 2-hydroxy sphingolipids are not completely lost in the fah1cfah2 double mutant, suggesting the existence of other enzymes catalyzing the hydroxylation of sphingolipid FAs. Plasma membrane (PM) analysis and molecular dynamics simulations revealed that hydroxyl groups of sphingolipid acyl chains play a crucial role in the organization of nanodomains, which are nanoscale liquid-ordered domains mainly formed by sphingolipids and sterols in the PM, through hydrogen bonds. In the PM of the fah1cfah2 mutant, the expression levels of 26.7% of the proteins, including defense-related proteins such as the pattern recognition receptors (PRRs) brassinosteroid insensitive 1-associated receptor kinase 1 and chitin elicitor receptor kinase 1, NADPH oxidase respiratory burst oxidase homolog D (RBOHD), and heterotrimeric G proteins, were lower than that in the wild-type. In addition, reactive oxygen species (ROS) burst was suppressed in the fah1cfah2 mutant after treatment with the pathogen-associated molecular patterns flg22 and chitin. These results indicated that 2-hydroxy sphingolipids are necessary for the organization of PM nanodomains and ROS burst through RBOHD and PRRs during pattern-triggered immunity.
  Oxford University Press (OUP), 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/plphys/kiac134
  DOI ID：10.1093/plphys/kiac134, ISSN：0032-0889, eISSN：1532-2548
• VNI2 effectively inhibits transcriptional activities of VND7 through a conserved sequence　　　　　　　　　　　　　　　
  Aili Ailizati; Isura Sumeda Priyadarshana Nagahage; Atsuko Miyagi; Toshiki Ishikawa; Maki Kawai-Yamada; Taku Demura; Masatoshi Yamaguchi
  Plant Biotechnology, 巻：39, 号：2, 開始ページ：147, 終了ページ：153, 2022年06月, ［査読有り］, ［最終著者, 責任著者］, ［国際共著］
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.22.0122a
  DOI ID：10.5511/plantbiotechnology.22.0122a
• An Arabidopsis NAC domain transcriptional activator VND7 negatively regulates VNI2 expression.　　　　　　　　　　　　　　　
  Ailizati A; Nagahage ISP; Miyagi A; Ishikawa T; Kawai-Yamada M; Demura T; Yamaguchi M
  Plant Biotechnology, 開始ページ：in press, 2021年10月, ［査読有り］, ［最終著者, 責任著者］
• Change in expression levels of NAD kinase-encoding genes in Flaveria species　　　　　　　　　　　　　　　
  Masami Tanaka; Yuuma Ishikawa; Sayaka Suzuki; Takako Ogawa; Yukimi Y. Taniguchi; Atsuko Miyagi; Toshiki Ishikawa; Masatoshi Yamaguchi; Yuri N. Munekage; Maki Kawai-Yamada
  Journal of Plant Physiology, 巻：265, 開始ページ：153495, 終了ページ：153495, 2021年10月, ［査読有り］, ［国際誌］
  Nicotinamide adenine dinucleotides (NAD(H)) and NAD phosphates (NADP(H)) are electron carriers involved in redox reactions and metabolic processes in all organisms. NAD kinase (NADK) is the only enzyme that phosphorylates NAD+ into NADP+, using ATP as a phosphate donor. In NADP-dependent malic enzyme (NADP-ME)-type C4 photosynthesis, NADP(H) are required for dehydrogenation by NADP-dependent malate dehydrogenase (NADP-MDH) in mesophyll cells, and decarboxylation by NADP-ME in bundle sheath cells. In this study, we identified five NADK genes (FbNADK1a, 1b, 2a, 2b, and 3) from the C4 model species Flaveria bidentis. RNA-Seq database analysis revealed higher transcript abundance in one of the chloroplast-type NADK2 genes of C4F. bidentis (FbNADK2a). Comparative analysis of NADK activity in leaves of C3, C3-C4, and C4Flaveria showed that C4Flaveria (F. bidentis and F. trinervia) had higher NADK activity than the other photosynthetic-types of Flaveria. Taken together, our results suggest that chloroplastic NAD kinase appeared to increase in importance as C3 plants evolved into C4 plants in the genus Flaveria.
  Elsevier BV, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1016/j.jplph.2021.153495
  DOI ID：10.1016/j.jplph.2021.153495, ISSN：0176-1617, PubMed ID：34411985
• The NAD Kinase Slr0400 Functions as a Growth Repressor in Synechocystis sp. PCC 6803　　　　　　　　　　　　　　　
  Yuuma Ishikawa; Cedric Cassan; Aikeranmu Kadeer; Koki Yuasa; Nozomu Sato; Kintake  Sonoike; Yasuko Kaneko; Atsuko Miyagi; Hiroko Takahashi; Toshiki Ishikawa; Masatoshi Yamaguchi; Yoshitaka Nishiyama; Yukako Hihara; Yves Gibon; Maki Kawai-Yamada
  Plant and Cell Physiology, 巻：62, 号：4, 開始ページ：668, 終了ページ：677, 2021年09月, ［査読有り］
  
  NADP+, the phosphorylated form of nicotinamide adenine dinucleotide (NAD), plays an essential role in many cellular processes. NAD kinase (NADK), which is conserved in all living organisms, catalyzes the phosphorylation of NAD+ to NADP+. However, the physiological role of phosphorylation of NAD+ to NADP+ in the cyanobacterium Synechocystis remains unclear. In this study, we report that slr0400, an NADK-encoding gene in Synechocystis, functions as a growth repressor under light-activated heterotrophic growth conditions and light and dark cycle conditions in the presence of glucose. We show, via characterization of NAD(P)(H) content and enzyme activity, that NAD+ accumulation in slr0400-deficient mutant results in the unsuppressed activity of glycolysis and tricarboxylic acid (TCA) cycle enzymes. In determining whether Slr0400 functions as a typical NADK, we found that constitutive expression of slr0400 in an Arabidopsis nadk2-mutant background complements the pale-green phenotype. Moreover, to determine the physiological background behind the growth advantage of mutants lacking slr04000, we investigated the photobleaching phenotype of slr0400-deficient mutant under high-light conditions. Photosynthetic analysis found in the slr0400-deficient mutant resulted from malfunctions in the Photosystem II (PSII) photosynthetic machinery. Overall, our results suggest that NADP(H)/NAD(H) maintenance by slr0400 plays a significant role in modulating glycolysis and the TCA cycle to repress the growth rate and maintain the photosynthetic capacity.
  Oxford University Press (OUP), 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/pcp/pcab023
  DOI ID：10.1093/pcp/pcab023, ISSN：0032-0781, eISSN：1471-9053, PubMed ID：33560438, Web of Science ID：WOS:000728395500015
• The NAD Kinase Slr0400 Functions as a Growth Repressor in Synechocystis sp. PCC 6803　　　　　　　　　　　　　　　
  Yuuma Ishikawa; Cedric Cassan; Aikeranmu Kadeer; Koki Yuasa; Nozomu Sato; Kintake  Sonoike; Yasuko Kaneko; Atsuko Miyagi; Hiroko Takahashi; Toshiki Ishikawa; Masatoshi Yamaguchi; Yoshitaka Nishiyama; Yukako Hihara; Yves Gibon; Maki Kawai-Yamada
  Plant and Cell Physiology, 巻：62, 号：4, 開始ページ：668, 終了ページ：677, 2021年09月, ［査読有り］
  
  NADP+, the phosphorylated form of nicotinamide adenine dinucleotide (NAD), plays an essential role in many cellular processes. NAD kinase (NADK), which is conserved in all living organisms, catalyzes the phosphorylation of NAD+ to NADP+. However, the physiological role of phosphorylation of NAD+ to NADP+ in the cyanobacterium Synechocystis remains unclear. In this study, we report that slr0400, an NADK-encoding gene in Synechocystis, functions as a growth repressor under light-activated heterotrophic growth conditions and light and dark cycle conditions in the presence of glucose. We show, via characterization of NAD(P)(H) content and enzyme activity, that NAD+ accumulation in slr0400-deficient mutant results in the unsuppressed activity of glycolysis and tricarboxylic acid (TCA) cycle enzymes. In determining whether Slr0400 functions as a typical NADK, we found that constitutive expression of slr0400 in an Arabidopsis nadk2-mutant background complements the pale-green phenotype. Moreover, to determine the physiological background behind the growth advantage of mutants lacking slr04000, we investigated the photobleaching phenotype of slr0400-deficient mutant under high-light conditions. Photosynthetic analysis found in the slr0400-deficient mutant resulted from malfunctions in the Photosystem II (PSII) photosynthetic machinery. Overall, our results suggest that NADP(H)/NAD(H) maintenance by slr0400 plays a significant role in modulating glycolysis and the TCA cycle to repress the growth rate and maintain the photosynthetic capacity.
  Oxford University Press (OUP), 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/pcp/pcab023
  DOI ID：10.1093/pcp/pcab023, ISSN：0032-0781, eISSN：1471-9053, PubMed ID：33210985, PubMed Central ID：PMC7781788
• Altered metabolism of chloroplastic NAD kinase-overexpressing Arabidopsis in response to magnesium sulfate supplementation
  Maki Kawai-Yamada; Atsuko Miyagi; Yuki Sato; Yuki Hosoi; Shin-Nosuke Hashida; Toshiki Ishikawa; Masatoshi Yamaguchi
  Plant Signaling & Behavior, 巻：16, 号：1, 開始ページ：1844509, 終了ページ：1844509, 2021年01月, ［査読有り］
  Informa UK Limited, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1080/15592324.2020.1844509
  DOI ID：10.1080/15592324.2020.1844509, eISSN：1559-2324
• An Arabidopsis NAC domain transcription factor, ATAF2 , promotes age‐dependent and dark‐induced leaf senescence　　　　　　　　　　　　　　　
  Isura Sumeda Priyadarshana Nagahage; Shingo Sakamoto; Minoru Nagano; Toshiki Ishikawa; Nobutaka Mitsuda; Maki Kawai‐Yamada; Masatoshi Yamaguchi
  Physiologia Plantarum, 巻：170, 号：2, 開始ページ：299, 終了ページ：308, 2020年10月, ［査読有り］, ［最終著者, 責任著者］, ［国際誌］
  Leaf senescence is controlled developmentally and environmentally and is affected by numerous genes, including transcription factors. An Arabidopsis NAC domain transcription factor, ATAF2, is known to regulate biotic stress responses. Recently, we have demonstrated that ATAF2 upregulates ORE1, a key regulator of leaf senescence. Here, to investigate the function of ATAF2 in leaf senescence further, we generated and analyzed overexpressing transgenic and T-DNA inserted mutant lines. Transient expression analysis indicated that ATAF2 upregulates several NAC domain transcription factors that regulate senescence. Indeed, ATAF2 overexpression induced the expression of senescence-related genes, thereby accelerating leaf senescence, whereas the expression of such genes in ataf2 mutants was lower than that of wild-type plants. Furthermore, the ataf2 mutants exhibited significant delays in dark-induced leaf senescence. It was also found that ATAF2 induces the expression of transcription factors, which both promotes and represses leaf senescence. The present study demonstrates that ATAF2 promotes leaf senescence in response to developmental and environmental signals.
  Wiley, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1111/ppl.13156
  DOI ID：10.1111/ppl.13156, ISSN：0031-9317, eISSN：1399-3054, PubMed ID：32579231, 共同研究・競争的資金等ID：12839792;12839799
• Plant-unique cis/trans isomerism of long-chain base unsaturation is selectively required for Aluminum tolerance resulting from glucosylceramide-dependent plasma membrane fluidity　　　　　　　　　　　　　　　
  Sato M; Nagano M; Jin S; Miyagi A; Yamaguchi M; Kawai-Yamada M; Ishikawa T
  Plants, 巻：9, 号：1, 開始ページ：19, 2020年, ［査読有り］, ［招待有り］, ［国際誌］
  Cis/trans isomerism of the Δ8 unsaturation of long-chain base (LCB) is found only in plant sphingolipids. This unique geometry is generated by sphingolipid LCB Δ8 desaturase SLD which produces both isomers at various ratios, resulting in diverse cis/trans ratios in plants. However, the biological significance of this isomeric diversity remains controversial. Here, we show that the plant-specific cis unsaturation of LCB selectively contributes to glucosylceramide (GlcCer)-dependent tolerance to aluminum toxicity. We established three transgenic rice lines with altered LCB unsaturation profiles. Overexpression of SLD from rice (OsSLD-OX), which preferentially exhibits cis-activity, or Arabidopsis (AtSLD-OX), showing preference for trans-activity, facilitated Δ8 unsaturation in different manners: a slight increase of cis-unsaturated glycosylinositolphosphoceramide (GIPC) in OsSLD-OX, and a drastic increase of trans-unsaturated GlcCer and GIPC in AtSLD-OX. Disruption of LCB Δ4 desaturase (des) significantly decreased the content of GlcCer. Fluorescence imaging analysis revealed that OsSLD-OX and AtSLD-OX showed increased plasma membrane fluidity, whereas des had less fluidity, demonstrating that the isomers universally contributed to increasing membrane fluidity. However, the results of a hydroponic assay showed decreased aluminum tolerance in AtSLD-OX and des compared to OsSLD-OX and the control plants, which did not correlate with membrane fluidity. These results suggest that cis-unsaturated GlcCer, not GIPC, selectively serves to maintain the membrane fluidity specifically associated with aluminum tolerance.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.3390/plants9010019
  DOI ID：10.3390/plants9010019, PubMed ID：31877922, PubMed Central ID：PMC7020186
• The Class II KNOX genes KNAT3 and KNAT7 work cooperatively to influence deposition of secondary cell walls that provide mechanical support to Arabidopsis stems
  Shumin Wang; Masatoshi Yamaguchi; Etienne Grienenberger; Patrick T. Martone; A. Lacey Samuels; Shawn D. Mansfield
  The Plant Journal, 巻：101, 号：2, 開始ページ：293, 終了ページ：309, 2020年01月, ［査読有り］
  Wiley, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1111/tpj.14541
  DOI ID：10.1111/tpj.14541, ISSN：0960-7412, eISSN：1365-313X
• Affinity‐based high‐resolution analysis of DNA binding by VASCULAR‐RELATED NAC‐DOMAIN7 via fluorescence correlation spectroscopy　　　　　　　　　　　　　　　
  Tamura T; Endo H; Suzuki A; Sato Y; Kato K; Ontani M; Yamaguchi M; Demura T
  Plant Journal, 巻：100, 号：2, 開始ページ：298, 終了ページ：313, 2019年10月, ［査読有り］, ［責任著者］
  © 2019 The Authors The Plant Journal © 2019 John Wiley & Sons Ltd VASCULAR-RELATED NAC-DOMAIN7 (VND7) is the master transcription factor for vessel element differentiation in Arabidopsis thaliana. To identify the cis-acting sequence(s) bound by VND7, we employed fluorescence correlation spectroscopy (FCS) to find VND7–DNA interactions quantitatively. This identified an 18-bp sequence from the promoter of XYLEM CYSTEINE PEPTIDASE1 (XCP1), a direct target of VND7. A quantitative assay for binding affinity between VND7 and the 18-bp sequence revealed the core nucleotides contributing to specific binding between VND7 and the 18-bp sequence. Moreover, by combining the systematic evolution of ligands by exponential enrichment (SELEX) technique with known consensus sequences, we defined a motif termed the Ideal Core Structure for binding by VND7 (ICSV). We also used FCS to search for VND7 binding sequences in the promoter regions of other direct targets. Taking these data together, we proposed that VND7 preferentially binds to the ICSV sequence. Additionally, we found that substitutions among the core nucleotides affected transcriptional regulation by VND7 in vivo, indicating that the core nucleotides contribute to vessel-element-specific gene expression. Furthermore, our results demonstrate that FCS is a powerful tool for unveiling the DNA-binding properties of transcription factors.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1111/tpj.14443
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85070718967&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85070718967&origin=inward
  DOI ID：10.1111/tpj.14443, ISSN：0960-7412, eISSN：1365-313X, PubMed ID：31313414, SCOPUS ID：85070718967
• One of the NAD kinases, sll1415, is required for the glucose metabolism of Synechocystis sp. PCC 6803.　　　　　　　　　　　　　　　
  Yuma Ishikawa; Atsuko Miyagi; Toshiki Ishikawa; Minoru Nagano; Masatoshi Yamaguchi; Yukako Hihara; Yasuo Kaneko; Maki Kawai‐Yamada
  Plant Journal, 巻：98, 号：4, 開始ページ：654, 終了ページ：666, 2019年05月, ［査読有り］, ［国際誌］
  Pyridine nucleotides (NAD(P)(H)) are electron carriers that are the driving forces in various metabolic pathways. Phosphorylation of NAD(H) to NADP(H) is performed by the enzyme NAD kinase (NADK). Synechocystis sp. PCC 6803 harbors two genes (sll1415 and slr0400) that encode proteins with NADK homology. When genetic mutants for sll1415 and slr0400 (Δ1415 and Δ0400, respectively) were cultured under photoheterotrophic growth conditions only the Δ1415 cells showed a growth defect. In wild-type cells, the sll1415 transcript accumulated after the cells were transferred to photoheterotrophic conditions. Furthermore, NAD(P)(H) measurements demonstrated that a dynamic metabolic conversion was implemented during the adaptation from photoautotrophic to photoheterotrophic conditions. Electron microscopy observation and biochemistry quantification demonstrated the accumulation of glycogen in the Δ1415 cells under photoheterotrophic conditions at 96 h. Quantitative real-time reverse transcription PCR (qRT-PCR) demonstrated the accumulation of mRNAs that encoded glycogen biosynthesis-related enzymes in photoheterotrophic Δ1415 cells. At 96 h, enzyme activity measurement in the photoheterotrophic Δ1415 cells demonstrated that the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were decreased, but the activities of glucose dehydrogenase were increased. Furthermore, metabolomics analysis demonstrated that the Δ1415 cells showed increased glucose-6-phosphate and 6-phosphogluconate content at 96 h. Therefore, sll1415 has a significant function in the oxidative pentose phosphate (OPP) pathway for catabolism of glucose under photoheterotrophic conditions. Additionally, it is presumed that the slr0400 had a different role in glucose catabolism during growth. These results suggest that the two Synechocystis sp. PCC 6803 NADKs (Sll1415 and Slr0400) have distinct functions in photoheterotrophic cyanobacterial metabolism.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1111/tpj.14262
  DOI ID：10.1111/tpj.14262, PubMed ID：30693583
• Arabidopsis Group IIId ERF proteins positively regulate primary cell wall-type CESA genes.　　　　　　　　　　　　　　　
  Laddawan Saelim; Nobuhiro Akiyoshi; Tian Tian Tan; Ayumi Ihara; Masatoshi Yamaguchi; Ko Hirano; Makoto Matsuoka; Taku Demura; Misato Ohtani
  Journal of plant research, 巻：132, 号：1, 開始ページ：117, 終了ページ：129, 2019年01月, ［査読有り］, ［国内誌］
  The cell wall determines morphology and the environmental responses of plant cells. The primary cell wall (PCW) is produced during cell division and expansion, determining the cell shape and volume. After cell expansion, specific types of plant cells produce a lignified wall, known as a secondary cell wall (SCW). We functionally analyzed Group IIId Arabidopsis AP2/EREBP genes, namely ERF34, ERF35, ERF38, and ERF39, which are homologs of a rice ERF gene previously proposed to be related to SCW biosynthesis. Expression analysis revealed that these four genes are expressed in regions related to cell division and/or cell differentiation in seedlings (i.e., shoot apical meristems, the primordia of leaves and lateral roots, trichomes, and central cylinder of primary roots) and flowers (i.e., vascular tissues of floral organs and replums and/or valve margins of pistils). Overexpression of ERF genes significantly upregulated PCW-type, but not SCW-type, CESA genes encoding cellulose synthase catalytic subunits in Arabidopsis seedlings. Transient co-expression reporter analysis indicated that ERF35, ERF38, and ERF39 possess transcriptional activator activity, and that ERF34, ERF35, ERF38, and ERF39 upregulated the promoter activity of CESA1, a PCW-type CESA gene, through the DRECRTCOREAT elements, the core cis-acting elements known to be recognized by AP2/ERF proteins. Together, our findings show that Group IIId ERF genes are positive transcriptional regulators of PCW-type CESA genes in Arabidopsis and are possibly involved in modulating cellulose biosynthesis in response to developmental requirements and environmental stimuli.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1007/s10265-018-1074-1
  DOI ID：10.1007/s10265-018-1074-1, PubMed ID：30478480
• An NAC domain transcription factor ATAF2 acts as transcriptional activator or repressor dependent on promoter context　　　　　　　　　　　　　　　
  Isura Sumeda Priyadarshana Nagahage; Shingo Sakamoto; Minoru Nagano; Toshiki Ishikawa; Maki Kawai-Yamada; Nobutaka Mitsuda; Masatoshi Yamaguchi
  Plant Biotechnology, 巻：35, 号：3, 開始ページ：285, 終了ページ：289, 2018年09月, ［査読有り］, ［最終著者, 責任著者］
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.18.0507a
  DOI ID：10.5511/plantbiotechnology.18.0507a
• Characterization of rice KT/HAK/KUP potassium transporters and K⁺ uptake by HAK1 from oryza sativa　　　　　　　　　　　　　　　
  Tomoyuki Okada; Sousuke Yamane; Masatoshi Yamaguchi; Ko Kato; Atsuhiko Shinmyo; Yuta Tsunemitsu; Kozo Iwasaki; Daisei Ueno; Taku Demura
  Plant Biotechnology, 巻：35, 号：2, 開始ページ：101, 終了ページ：111, 2018年, ［査読有り］
  © 2018 The Japanese Society for Plant Cell and Molecular Biology. Plant high-affinity K+ (HAK) transporters are divided into four major clusters. Cluster I transporters, in particular, are thought to have high-affinity for K+. Of the 27 HAK genes in rice, eight HAK transporters belong to cluster I. In this study, we investigated the temporal expression patterns during K+ deficiency and K+ transport activity of these eight HAK transporters. The expression of seven HAK genes except OsHAK20 was detected. Expression of OsHAK1, OsHAK5 and OsHAK21 was induced in response to K+ deficiency; however, that of other genes was not. Six of the eight HAK transporters—OsHAK1, OsHAK5, OsHAK19, OsHAK20, OsHAK21, and OsHAK27—complemented the K+-transporter-deficient yeast or bacterial strain. Further, the yeast cells expressing OsHAK1 were more sensitive to Na+ than those expressing OsHAK5. Mutant analysis showed that the high-affinity K+ uptake activity was almost undetectable in oshak1 mutants in a low-K+ medium (0.02 mM). In addition, the high-affinity K+ uptake activity of wild-type plants was inhibited by mild salt stress (20 mM NaCl); however, Na+ permeability of OsHAK1 was not detected in Escherichia coli cells. The high-affinity K+ uptake activity by leaf blades was detected in wild-type plants, while it was not detected in oshak1 mutants. Our results suggest that OsHAK1 and OsHAK5 are the two important components of cluster I corresponding to low-K+ conditions, and that the transport activity of OsHAK1, unlike that of OsHAK5, is sensitive to Na+. Further, OsHAK1 is suggested to involve in foliar K+ uptake.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.18.0308a
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85050662140&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85050662140&origin=inward
  DOI ID：10.5511/plantbiotechnology.18.0308a, ISSN：1342-4580, eISSN：1347-6114, SCOPUS ID：85050662140
• Transcription Factors VND1-VND3 Contribute to Cotyledon Xylem Vessel Formation.　　　　　　　　　　　　　　　
  Tian Tian Tan; Hitoshi Endo; Ryosuke Sano; Tetsuya Kurata; Masatoshi Yamaguchi; Misato Ohtani; Taku Demura
  Plant physiology, 巻：176, 号：1, 開始ページ：773, 終了ページ：789, 2018年01月, ［査読有り］, ［国際誌］
  Arabidopsis (Arabidopsis thaliana) VASCULAR-RELATED NAC-DOMAIN1 (VND1) to VND7 encode a group of NAC domain transcription factors that function as master regulators of xylem vessel element differentiation. These transcription factors activate the transcription of genes required for secondary cell wall formation and programmed cell death, key events in xylem vessel element differentiation. Because constitutive overexpression of VND6 and VND7 induces ectopic xylem vessel element differentiation, functional studies of VND proteins have largely focused on these two proteins. Here, we report the roles of VND1, VND2, and VND3 in xylem vessel formation in cotyledons. Using our newly established in vitro system in which excised Arabidopsis cotyledons are stimulated to undergo xylem cell differentiation by cytokinin, auxin, and brassinosteroid treatment, we found that ectopic xylem vessel element differentiation required VND1, VND2, and VND3 but not VND6 or VND7. The importance of VND1, VND2, and VND3 also was indicated in vivo; in the vnd1 vnd2 vnd3 seedlings, xylem vessel element differentiation of secondary veins in cotyledons was inhibited under dark conditions. Furthermore, the light responsiveness of VND gene expression was disturbed in the vnd1 vnd2 vnd3 mutant, and vnd1 vnd2 vnd3 failed to recover lateral root development in response to the change of light conditions. These findings suggest that VND1 to VND3 have specific molecular functions, possibly linking light conditions to xylem vessel formation, during seedling development.
  英語
  DOI：https://doi.org/10.1104/pp.17.00461
  DOI ID：10.1104/pp.17.00461, ORCID：42523540, PubMed ID：29133368, PubMed Central ID：PMC5761765, Web of Science ID：WOS:000419675300060
• Evaluation of metabolic changes in oxalate-rich plant Rumex obtusifolius L. caused by ion beam irradiation.　　　　　　　　　　　　　　　
  Atsuko Miyagi; Sayaka Kitano; Yutaka Oono; Yoshihiro Hase; Issay Narumi; Masatoshi Yamaguchi; Hirofumi Uchimiya; Maki Kawai-Yamada
  Plant physiology and biochemistry : PPB, 巻：122, 開始ページ：40, 終了ページ：45, 2018年01月, ［査読有り］, ［国際誌］
  Some Rumex species such as sorrel are edible as baby leaf salad greens. On the other hand, Rumex plants accumulate soluble oxalate, a toxic metabolite which causes serious diseases such as renal syndrome. We attempted to produce low-oxalate plants of R. obtusifolius, a perennial weed which has higher vitamin C and amino acid content and higher tolerance to stress than many other Rumex species. Ion beams are ionising radiation with high linear energy transfer that causes a wide spectrum of mutations. Thus, in the present study we evaluated the effects of ion beams on oxalate and other primary metabolites in leaves of R. obtusifolius using CE-MS. The results showed that oxalate content was increased by irradiation with carbon ion beams. Metabolome analysis revealed that ion beams affected carbon flow to the isocitrate pathway, which is involved in oxalate synthesis. These observations suggested that modulation of carbon flow to the isocitrate pathway is important to regulate oxalate levels in plants.
  英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1016/j.plaphy.2017.11.001
  DOI ID：10.1016/j.plaphy.2017.11.001, ORCID：42523539, PubMed ID：29172104, Web of Science ID：WOS:000423895600005
• Heterologous expression and characterization of an Arabidopsis beta-L-arabinopyranosidase and alpha-D-galactosidases acting on beta-L-arabinopyranosyl residues　　　　　　　　　　　　　　　
  Chiemi Imaizumi; Harumi Tomatsu; Kiminari Kitazawa; Yoshihisa Yoshimi; Seiji Shibano; Kaoru Kikuchi; Masatoshi Yamaguchi; Satoshi Kaneko; Yoichi Tsumuraya; Toshihisa Kotake
  JOURNAL OF EXPERIMENTAL BOTANY, 巻：68, 号：16, 開始ページ：4651, 終了ページ：4661, 2017年07月, ［査読有り］
  The major plant sugar l-arabinose (L-Ara) has two different ring forms, L-arabinofuranose (L-Araf) and l-arabinopyranose (L-Arap). Although L-Ara mainly appears in the form of alpha-L-Araf residues in cell wall components, such as pectic alpha-1,3:1,5-arabinan, arabinoxylan, and arabinogalactan-proteins (AGPs), lesser amounts of it can also be found as beta-L-Arap residues of AGPs. Even though AGPs are known to be rapidly metabolized, the enzymes acting on the beta-L-Arap residues remain to be identified. In the present study, four enzymes, which we call beta-L-ARAPASE (APSE) and alpha-GALACTOSIDASE 1 (AGAL1), AGAL2, and AGAL3, are identified as those enzymes that are likely to be responsible for the hydrolysis of the beta-L-Arap residues in Arabidopsis thaliana. An Arabidopsis apse-1 mutant showed significant reduction in beta-L-arabinopyranosidase activity, and an apse-1 agal3-1 double-mutant exhibited even less activity. The apse-1 and the double-mutants both had more beta-L-Arap residues in the cell walls than wild-type plants. Recombinant APSE expressed in the yeast Pichia pastoris specifically hydrolyzed beta-L-Arap residues and released L-Ara from gum arabic and larch arabinogalactan. The recombinant AGAL3 also showed weak beta-L-arabinopyranosidase activity beside its strong alpha-galactosidase activity. It appears that the beta-L-Arap residues of AGPs are hydrolysed mainly by APSE and partially by AGALs in Arabidopsis.
  OXFORD UNIV PRESS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/jxb/erx279
  DOI ID：10.1093/jxb/erx279, ISSN：0022-0957, eISSN：1460-2431, ORCID：39147297, Web of Science ID：WOS:000412100500020
• Metabolomic analysis of NAD kinase-deficient mutants of the cyanobacterium Synechocystis sp PCC 6803　　　　　　　　　　　　　　　
  Yuuma Ishikawa; Atsuko Miyagi; Yuto Haishima; Toshiki Ishikawa; Minoru Nagano; Masatoshi Yamaguchi; Yukako Hihara; Maki Kawai-Yamada
  JOURNAL OF PLANT PHYSIOLOGY, 巻：205, 開始ページ：105, 終了ページ：112, 2016年10月, ［査読有り］
  NAD kinase (NADK) phosphorylates NAD(H) to NADP(H). The enzyme has a crucial role in the regulation of the NADP(H)/NAD(H) ratio in various organisms. The unicellular cyanobacterium Synechocystis sp. PCC 6803 possesses two NADK-encoding genes, sll1415 and slr0400. To elucidate the metabolic change in NADK-deficient mutants growing under photoautotrophic conditions, we conducted metabolomic analysis using capillary electrophoresis mass spectrometry (CE-MS). The growth curves of the wild type parent (WT) and NADK-deficient mutants (Delta 1415 and Delta 0400) did not show any differences under photoautotrophic conditions. The NAD(P)(H) balance showed abnormality in both mutants. However, only the metabolite pattern of Delta 0400 showed differences compared to WT. These results indicated that the two NADK isoforms have distinct functions in cyanobacterial metabolism. (C) 2016 Elsevier GmbH. All rights reserved.
  ELSEVIER GMBH, URBAN & FISCHER VERLAG, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1016/j.jplph.2016.09.002
  DOI ID：10.1016/j.jplph.2016.09.002, ISSN：0176-1617, eISSN：1618-1328, ORCID：39147298, Web of Science ID：WOS:000385858600014
• The expression of a rice secondary wall-specific cellulose synthase gene, OsCesA7, is directly regulated by a rice transcription factor, OsMYB58/63　　　　　　　　　　　　　　　
  Soichiro Noda; Taichi Koshiba; Takefumi Hattori; Masatoshi Yamaguchi; Shiro Suzuki; Toshiaki Umezawa
  PLANTA, 巻：242, 号：3, 開始ページ：589, 終了ページ：600, 2015年09月, ［査読有り］
  A rice MYB transcription factor, OsMYB58/63, was found to directly upregulate the expression of a rice secondary wall-specific cellulose synthase gene, cellulose synthase A7 ( OsCesA7 ); in contrast, the Arabidopsis putative orthologs AtMYB58 and AtMYB63 have been shown to specifically activate lignin biosynthesis.
  Although indirect evidence has shown that grass plants are similar to but partially different from dicotyledonous ones in transcriptional regulation of lignocellulose biosynthesis, little is known about the differences. This study showed that a rice MYB transcription factor, OsMYB58/63, directly upregulated the expression of a rice secondary wall-specific cellulose synthase gene, cellulose synthase A7 (OsCesA7). Gene co-expression analysis showed that, in rice, OsMYB58/63 and several rice MYB genes were co-expressed with genes encoding lignocellulose biosynthetic enzymes. The expression levels of OsMYB55/61, OsMYB55/61-L, OsMYB58/63, and OsMYB42/85 were commonly found to be high in culm internodes and nodes. All four MYB transcription factors functioned as transcriptional activators in yeast cells. OsMYB58/63 most strongly transactivated the expression of OsCesA7 in rice protoplasts. Moreover, recombinant OsMYB58/63 protein was bound to two distinct cis-regulatory elements, AC-II and SMRE3, in the OsCesA7 promoter. This is in sharp contrast to the role of Arabidopsis orthologs, AtMYB58 and AtMYB63, which had been reported to specifically activate lignin biosynthesis. The promoter analysis revealed that AC elements, which are the binding sites for MYB58 and MYB63, were lacking in cellulose and xylan biosynthetic genes in Arabidopsis, but present in cellulose, xylan, and lignin biosynthetic genes in rice, implying that the difference of transcriptional regulation between rice and Arabidopsis is due to the distinct composition of promoters. Our results provide a new insight into transcriptional regulation in grass lignocellulose biosynthesis.
  SPRINGER, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1007/s00425-015-2343-z
  DOI ID：10.1007/s00425-015-2343-z, ISSN：0032-0935, eISSN：1432-2048, ORCID：39147303, Web of Science ID：WOS:000359831900008
• Arabidopsis NAC domain proteins VND-INTERACTING1 and ANAC103 interact with multiple NAC domain proteins　　　　　　　　　　　　　　　
  Masatoshi Yamaguchi; Isura Sumeda Priyadarshana Nagahage; Misato Ohtani; Toshiki Ishikawa; Hirofumi Uchimiya; Maki Kawai-Yamada; Taku Demura
  PLANT BIOTECHNOLOGY, 巻：32, 号：2, 開始ページ：119, 終了ページ：U14, 2015年06月, ［査読有り］, ［筆頭著者, 責任著者］
  The Arabidopsis thaliana NAM, ATAF1/2 and CUC2 (NAC) domain transcription factor VND-INTERACTING1 (VNI1) was previously isolated as an interacting factor of VASCULAR-RELATED NAC-DOMAIN PROTEIN7 (VND7), a key regulator of xylem vessel differentiation, in a yeast two-hybrid screening. Here, we characterized VNI1 and its closest homolog, ANAC103, at the molecular level. Both VNI1 and ANAC103 interacted in vitro not only with VND proteins but also with other NAC domain proteins, such as NAC1 and CUC2. A transient expression assay showed that both VNI1 and ANAC103 are transcriptional activators. ANAC103 promoter activity was detected in vascular tissues, as well as in the trichomes, guard cells, and margins of young leaves. These data suggest that VNI1 and ANAC103 promote the differentiation of various types of cells by modulating the transcriptional activities of a wide range of NAC domain transcription factors.
  JAPANESE SOC PLANT CELL & MOLECULAR BIOLOGY, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.15.0208a
  DOI ID：10.5511/plantbiotechnology.15.0208a, ISSN：1342-4580, ORCID：39147299, Web of Science ID：WOS:000356970600002
• NAC-MYB-based transcriptional regulation of secondary cell wall biosynthesis in land plants　　　　　　　　　　　　　　　
  Yoshimi Nakano; Masatoshi Yamaguchiz; Hitoshi Endo; Nur Ardiyana Rejab; Misato Ohtani
  FRONTIERS IN PLANT SCIENCE, 巻：6, 2015年05月, ［査読有り］
  Plant cells biosynthesize primary cell walls (PCW) in all cells and produce secondary cell walls (SCWs) in specific cell types that conduct water and/or provide mechanical support, such as xylem vessels and fibers. The characteristic mechanical stiffness, chemical recalcitrance, and hydrophobic nature of SCWs result from the organization of SCW-specific biopolymers, i.e., highly ordered cellulose, hemicellulose, and lignin. Synthesis of these SCW-specific biopolymers requires SCW-specific enzymes that are regulated by SCW-specific transcription factors. In this review, we summarize our current knowledge of the transcriptional regulation of SCW formation in plant cells. Advances in research on SCW biosynthesis during the past decade have expanded our understanding of the transcriptional regulation of SCW formation, particularly the functions of the NAG and MYB transcription factors. Focusing on the NAG-MYB-based transcriptional network, we discuss the regulatory systems that evolved in land plants to modify the cell wall to serve as a key component of structures that conduct water and provide mechanical support.
  FRONTIERS MEDIA SA, 英語
  DOI：https://doi.org/10.3389/fpls.2015.00288
  DOI ID：10.3389/fpls.2015.00288, ISSN：1664-462X, ORCID：39147302, Web of Science ID：WOS:000356900500001
• Multiple Classes of Transcription Factors Regulate the Expression of VASCULAR-RELATED NAC-DOMAIN7, a Master Switch of Xylem Vessel Differentiation　　　　　　　　　　　　　　　
  Hitoshi Endo; Masatoshi Yamaguchi; Taizo Tamura; Yoshimi Nakano; Nobuyuki Nishikubo; Arata Yoneda; Ko Kato; Minoru Kubo; Shinya Kajita; Yoshihiro Katayama; Misato Ohtani; Taku Demura
  PLANT AND CELL PHYSIOLOGY, 巻：56, 号：2, 開始ページ：242, 終了ページ：254, 2015年02月, ［査読有り］
  The secondary cell walls of xylem cells, including vessel elements, provide mechanical strength and contribute to the conduction of water and minerals. VASCULAR-RELATED NAC-DOMAIN7 (VND7) is a NAC-domain transcription factor that regulates the expression of genes required for xylem vessel element formation. Transient expression assays using 68 transcription factors that are expressed during xylem vessel differentiation showed that 14 transcription factors, including VND1-VND7, are putative positive regulators of VND7 expression. Electrophoretic mobility shift assays revealed that all seven VND proteins bound to the VND7 promoter region at its SMBE/TERE motif, indicating that VND7 is a direct target of all of the VND transcription factors. Overexpression of VND1-VND5, GATA12 and ANAC075, newly identified transcription factors that function upstream of VND7, resulted in ectopic xylem vessel element formation. These data suggest that VND7 transcription is a regulatory target of multiple classes of transcription factors.
  OXFORD UNIV PRESS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/pcp/pcu134
  DOI ID：10.1093/pcp/pcu134, ISSN：0032-0781, eISSN：1471-9053, ORCID：39147301, Web of Science ID：WOS:000351514000007
• Contribution of NAC Transcription Factors to Plant Adaptation to Land　　　　　　　　　　　　　　　
  Bo Xu; Misato Ohtani; Masatoshi Yamaguchi; Kiminori Toyooka; Mayumi Wakazaki; Mayuko Sato; Minoru Kubo; Yoshimi Nakano; Ryosuke Sano; Yuji Hiwatashi; Takashi Murata; Tetsuya Kurata; Arata Yoneda; Ko Kato; Mitsuyasu Hasebe; Taku Demura
  SCIENCE, 巻：343, 号：6178, 開始ページ：1505, 終了ページ：1508, 2014年03月, ［査読有り］
  The development of cells specialized for water conduction or support is a striking innovation of plants that has enabled them to colonize land. The NAC transcription factors regulate the differentiation of these cells in vascular plants. However, the path by which plants with these cells have evolved from their nonvascular ancestors is unclear. We investigated genes of the moss Physcomitrella patens that encode NAC proteins. Loss-of-function mutants formed abnormal water-conducting and supporting cells, as well as malformed sporophyte cells, and overexpression induced ectopic differentiation of water-conducting-like cells. Our results show conservation of transcriptional regulation and cellular function between moss and Arabidopsis thaliana water-conducting cells. The conserved genetic basis suggests roles for NAC proteins in the adaptation of plants to land.
  AMER ASSOC ADVANCEMENT SCIENCE, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1126/science.1248417
  DOI ID：10.1126/science.1248417, ISSN：0036-8075, eISSN：1095-9203, ORCID：39147304, Web of Science ID：WOS:000333471000046
• Culture temperature affects gene expression and metabolic pathways in the 2-methylisoborneol-producing cyanobacterium Pseudanabaena galeata　　　　　　　　　　　　　　　
  Masayuki Kakimoto; Toshiki Ishikawa; Atsuko Miyagi; Kazuaki Saito; Motonobu Miyazaki; Takashi Asaeda; Masatoshi Yamaguchi; Hirofumi Uchimiya; Maki Kawai-Yamada
  JOURNAL OF PLANT PHYSIOLOGY, 巻：171, 号：3-4, 開始ページ：292, 終了ページ：300, 2014年02月, ［査読有り］
  A volatile metabolite, 2-methylisoborneol (2-MIB), causes an unpleasant taste and odor in tap water. Some filamentous cyanobacteria produce 2-MIB via a two-step biosynthetic pathway: methylation of geranyl diphosphate (GPP) by methyl transferase (GPPMT), followed by the cyclization of methyl-GPP by monoterpene cyclase (MIBS). We isolated the genes encoding GPPMT and MIBS from Pseudanabaena galeata, a filamentous cyanobacterium known to be a major causal organism of 2-MIB production in Japanese lakes. The predicted amino acid sequence showed high similarity with that of Pseudanabaena limnetica (96% identity in GPPMT and 97% identity in MIBS). P. galeata was cultured at different temperatures to examine the effect of growth conditions on the production of 2-MIB and major metabolites. Gas chromatograph-mass spectrometry (GC-MS) measurements showed higher accumulation of 2-MIB at 30 degrees C than at 4 degrees C or 20 degrees C after 24 h of culture. Real-time-RT PCR analysis showed that the expression levels of the genes encoding GPPMT and MIBS decreased at 4 degrees C and increased at 30 degrees C, compared with at 20 degrees C. Furthermore, metabolite analysis showed dramatic changes in primary metabolite concentrations in cyanobacteria grown at different temperatures. The data indicate that changes in carbon flow in the TCA cycle affect 2-MIB biosynthesis at higher temperatures. (C) 2013 Elsevier GmbH. All rights reserved.
  ELSEVIER GMBH, URBAN & FISCHER VERLAG, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1016/j.jplph.2013.09.005
  DOI ID：10.1016/j.jplph.2013.09.005, ISSN：0176-1617, ORCID：39147305, Web of Science ID：WOS:000332052200013
• Metabolic alterations in leaves of oxalate-rich plant Rumex obtusifolius L. irradiated by gamma rays　　　　　　　　　　　　　　　
  Sayaka Kitano; Atsuko Miyagi; Yutaka Oono; Yoshihiro Hase; Issay Narumi; Masatoshi Yamaguchi; Hirofumi Uchimiya; Maki Kawai-Yamada
  Metabolomics, 巻：11, 号：1, 開始ページ：134, 終了ページ：142, 2014年, ［査読有り］
  © 2014, Springer Science+Business Media New York. Oxalate in some plants is toxic to vertebrates and causes kidney failure. In the present study, we investigated on the metabolic effectiveness of gamma ray irradiation to seeds of Rumex obtusifolius, which are known to accumulate high level of soluble oxalate, to lower oxalate accumulation in leaves. Reduced rate of germination, discoloration of cotyledons, and deformed true leaves were observed by elevated irradiation. Metabolome analysis of primary metabolites using capillary electrophoresis–mass spectrometry showed a decrease in oxalate contents in the leaves of plants from gamma ray-irradiated seeds. Moreover, organic acids such as malate and 2-oxoglutarate also decreased, whereas amino acids such as glutamate and glutamine increased. These results indicated that seed irradiation by gamma rays leads to dynamic changes in metabolic pathways as well as plant growth/development.
  研究論文（学術雑誌）
  DOI：https://doi.org/10.1007/s11306-014-0684-4
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84939895666&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84939895666&origin=inward
  DOI ID：10.1007/s11306-014-0684-4, ISSN：1573-3882, eISSN：1573-3890, ORCID：39147300, SCOPUS ID：84939895666, Web of Science ID：WOS:000348343300013
• A Computational and Experimental Approach Reveals that the 5 '-Proximal Region of the 5 '-UTR has a Cis-Regulatory Signature Responsible for Heat Stress-Regulated mRNA Translation in Arabidopsis　　　　　　　　　　　　　　　
  Hideyuki Matsuura; Shinya Takenami; Yuki Kubo; Kiyotaka Ueda; Aiko Ueda; Masatoshi Yamaguchi; Kazumasa Hirata; Taku Demura; Shigehiko Kanaya; Ko Kato
  PLANT AND CELL PHYSIOLOGY, 巻：54, 号：4, 開始ページ：474, 終了ページ：483, 2013年04月, ［査読有り］
  Translation of specific plant mRNAs is differentially regulated under certain abiotic stress conditions such as heat, oxygen deprivation and dehydration. The majority of transcripts exhibit varying degrees of translational repression, whereas a subset of transcripts escape such repression and remain actively translated. The underlying mechanisms that mediate this control, and in particular the identities of the regulatory RNA elements involved, remain poorly understood. Using a combined computational and experimental approach, we identified a novel cis-regulatory element in the 5'-untranslated region (5'-UTR) that affects differential translation in response to heat stress (HS) in Arabidopsis thaliana. First, we selected a set of genes with distinct translational responses to HS, based on our previously reported genome-wide data regarding changes in polysome loading induced by HS in A. thaliana cultured cells. We evaluated the 5'-UTRs of these messages for their ability to mediate expression, when fused to reporter mRNAs, in protoplasts under HS. The data from the reporter assay and the nucleotide sequences of the 5'-UTRs tested were used to define regulatory elements in the 5'-UTRs, with the help of a partial least square (PLS) regression model. The computational analysis using PLS and subsequent experimental characterization of a series of 5'-UTR mutants provided evidence that the 5'-proximal sequence of the 5'-UTR is a primary and position-dependent determinant of 5'-UTR-mediated differential translation in response to HS. Finally, we discuss the possible mechanism underlying HS regulation of differential mRNA translation.
  OXFORD UNIV PRESS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/pcp/pcs189
  DOI ID：10.1093/pcp/pcs189, ISSN：0032-0781, ORCID：39147306, PubMed ID：23314753, Web of Science ID：WOS:000317611700004
• ATL54, a ubiquitin ligase gene related to secondary cell wall formation, is transcriptionally regulated by MYB46　　　　　　　　　　　　　　　
  Soichiro Noda; Masatoshi Yamaguchi; Yuta Tsurumaki; Yoshinori Takahashi; Nobuyuki Nishikubo; Takefumi Hattori; Taku Demura; Shiro Suzuki; Toshiaki Umezawa
  PLANT BIOTECHNOLOGY, 巻：30, 号：5, 開始ページ：503, 終了ページ：U120, 2013年, ［査読有り］
  We previously characterized Arabidopsis Toxicos en Levadura54 (ATL54), a ubiquitin ligase associated with secondary cell wall formation. The ATL54 gene is co-expressed with secondary wall-associated genes, and the knock-out of ATL54 up-regulates the expression of cellulose, lignin, and xylan biosynthetic genes in apical stem portions of four-week-old plants. Here, we report the tissue-level localization patterns and the regulation of ATL54 expression. The beta-glucuronidase (GUS) reporter gene driven by the ATL54 promoter was significantly expressed in interfascicular fibers, xylary fibers, and vessels in inflorescence stems. A transient transfection assay using Arabidopsis T87 cells showed that the expression of the firefly luciferase gene driven by the ATL54 promoter was activated by MYB46, which is a key transcriptional activator of secondary wall formation. In addition, the electrophoretic mobility of ATL54 promoter fragments was shifted by a recombinant MYB46 protein. These results indicate that ATL54 expression is regulated by MYB46, and support the view that ATL54 has a role in secondary wall formation.
  JAPANESE SOC PLANT CELL & MOLECULAR BIOLOGY, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.13.0905b
  DOI ID：10.5511/plantbiotechnology.13.0905b, ISSN：1342-4580, ORCID：39147308, Web of Science ID：WOS:000330032000010
• ATL54, a RING-H2 domain protein selected by a gene co-expression network analysis, is associated with secondary cell wall formation in Arabidopsis　　　　　　　　　　　　　　　
  Soichiro Noda; Yoshinori Takahashi; Yuta Tsurumaki; Masaomi Yamamura; Nobuyuki Nishikubo; Masatoshi Yamaguchi; Nozomu Sakurai; Takefumi Hattori; Hideyuki Suzuki; Taku Demura; Daisuke Shibata; Shiro Suzuki; Toshiaki Umezawa
  PLANT BIOTECHNOLOGY, 巻：30, 号：2, 開始ページ：169, 終了ページ：U174, 2013年, ［査読有り］
  Biosynthesis of plant secondary cell walls is controlled by several master transcription factors. Ubiquitin ligases, which mediate ubiquitination of proteins, including transcription factors in the protein degradation pathway, are also believed to regulate secondary wall biosynthesis; however, the exact ubiquitin ligases involved in secondary wall formation have not yet been identified. We conducted a gene co-expression network analysis and found that ATL54, annotated as a RING-finger protein, was highly co-expressed with several transcription factor and enzyme genes involved in secondary wall formation. A recombinant ATL54 protein showed ubiquitin ligase activity. The expression of several biosynthetic genes of cellulose, lignin, and xylan in apical portions of in florescence stems was up-regulated by ATL54 knock-out. The expression of Xylem Cysteine Peptidase1 (XCP1), which participates in the programmed cell death process of xylem tracheary elements, was down-regulated in middle stem portions of both ATL54-knock-out and ATL54-overexpressed mutants. Alteration of ATL54 expression levels did not, however, affect lignin and polysaccharide content and composition in whole mature stems. Our results suggest that ATL54 is an E3 ubiquitin ligase involved in secondary wall biosynthesis and programmed cell death during xylogenesis.
  JAPANESE SOC PLANT CELL & MOLECULAR BIOLOGY, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.13.0304a
  DOI ID：10.5511/plantbiotechnology.13.0304a, ISSN：1342-4580, ORCID：39147307, Web of Science ID：WOS:000322867600009
• Genome-Wide Analyses of Changes in Translation State Caused by Elevated Temperature in Oryza sativa　　　　　　　　　　　　　　　
  Kiyotaka Ueda; Hideyuki Matsuura; Masatoshi Yamaguchi; Taku Demura; Ko Kato
  PLANT AND CELL PHYSIOLOGY, 巻：53, 号：8, 開始ページ：1481, 終了ページ：1491, 2012年08月, ［査読有り］
  It has been reported that the translational status of mRNAs responds dramatically to abiotic stresses. While many useful results have demonstrated translational control in dicotyledonous model plants, little is known about changes in the translation state in response to abiotic stresses in monocotyledonous plants. To understand global changes in translation of mRNAs, we performed genome-wide analyses using Oryza sativa treated with heat stress (HS). These analyses showed that most mRNAs were translationally repressed, while the translation of some mRNAs was maintained. In addition to other regulatory steps in gene expression, including transcription and processing, it is thought that translational regulation is a critical step in adaptation to new conditions because of the functional tendencies of proteins that are either translationally maintained or highly repressed upon HS. When we compared the functional tendencies of translationally regulated proteins in rice with those in Arabidopsis thaliana cells exposed to HS, some showed similar regulation, arguing for both common and different features of translational regulation in the two plants.
  OXFORD UNIV PRESS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/pcp/pcs092
  DOI ID：10.1093/pcp/pcs092, ISSN：0032-0781, CiNii Articles ID：40019389679, ORCID：39147309, PubMed ID：22722767, Web of Science ID：WOS:000307834200011
• High level expression of transgenes by use of 5 '-untranslated region of the Arabidopsis thaliana arabinogalactan-protein 21 gene in dicotyledons　　　　　　　　　　　　　　　
  Takeshi Matsui; Hideyuki Matsuura; Kazutoshi Sawada; Eiji Takita; Satoko Kinjo; Shinya Takenami; Kiyotaka Ueda; Naoya Nishigaki; Shotaro Yamasaki; Kensuke Hata; Masatoshi Yamaguchi; Taku Demura; Ko Kato
  PLANT BIOTECHNOLOGY, 巻：29, 号：3, 開始ページ：319, 終了ページ：322, 2012年, ［査読有り］
  For higher expression of a foreign gene in plant cells, it is important to optimize nucleotide sequences corresponding to 5'-untranslated region (5'-UTR), because it usually has great impacts on the expression of the gene mainly at the translational level. In this study, with an aim to find useful 5'-UTRs, thirty nine 5'-UTRs derived from Arabidopsis thaliana genes were tested by transient expression of firefly luciferase (Fluc), and that of A. thaliana arabinogalactan-protein 21 (AtAGP21) gene was selected for further analyses. Its activity was either equaling or surpassing that of known translational enhancer, A. thaliana alchol dehydrogenase (AtADH) 5'-UTR in dicotyledons, and was further improved by the optimizing sequence context of the initiating codon (-3 to -1 of AUG). Finally, we also found that the modified AtAGP21 5'-UTR was useful in recombinant expression of horseradish peroxidase (HRP) in tobacco cultured cells, and the yield was as much as 23 mgl(-1) culture medium in seven days.
  JAPANESE SOC PLANT CELL & MOLECULAR BIOLOGY, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.12.0322a
  DOI ID：10.5511/plantbiotechnology.12.0322a, ISSN：1342-4580, ORCID：39147310, Web of Science ID：WOS:000307241600020
• A NAC domain protein family contributing to the regulation of wood formation in poplar　　　　　　　　　　　　　　　
  Misato Ohtani; Nobuyuki Nishikubo; Bo Xu; Masatoshi Yamaguchi; Nobutaka Mitsuda; Nadia Goue; Fusun Shi; Masaru Ohme-Takagi; Taku Demura
  PLANT JOURNAL, 巻：67, 号：3, 開始ページ：499, 終了ページ：512, 2011年08月, ［査読有り］
  Wood harvested from trees is one of the most widely utilized natural materials on our planet. Recent environmental issues have prompted an increase in the demand for wood, especially as a cost-effective and renewable resource for industry and energy, so it is important to understand the process of wood formation. In the present study, we focused on poplar (Populus trichocarpa) NAC domain protein genes which are homologous to well-known Arabidopsis transcription factors regulating the differentiation of xylem vessels and fiber cells. From phylogenetic analysis, we isolated 16 poplar NAC domain protein genes, and named them PtVNS (VND-, NST/SND- and SMB-related proteins) genes. Expression analysis revealed that 12 PtVNS (also called PtrWND) genes including both VND and NST groups were expressed in developing xylem tissue and phloem fiber, whereas in primary xylem vessels, only PtVNS/PtrWND genes of the VND group were expressed. By using the post-translational induction system of Arabidopsis VND7, a master regulator of xylem vessel element differentiation, many poplar genes functioning in xylem vessel differentiation downstream from NAC domain protein genes were identified. Transient expression assays showed the variation in PtVNS/PtrWND transactivation activity toward downstream genes, even between duplicate gene pairs. Furthermore, overexpression of PtVNS/PtrWND genes induced ectopic secondary wall thickening in poplar leaves as well as in Arabidopsis seedlings with different levels of induction efficiency according to the gene. These results suggest that wood formation in poplar is regulated by cooperative functions of the NAC domain proteins.
  WILEY-BLACKWELL, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1111/j.1365-313X.2011.04614.x
  DOI ID：10.1111/j.1365-313X.2011.04614.x, ISSN：0960-7412, ORCID：39147311, PubMed ID：21649762, Web of Science ID：WOS:000293176600010
• VASCULAR-RELATED NAC-DOMAIN 7 directly regulates the expression of a broad range of genes for xylem vessel formation　　　　　　　　　　　　　　　
  Masatoshi Yamaguchi; Nobutaka Mitsuda; Misato Ohtani; Masaru Ohme-Takagi; Ko Kato; Taku Demura
  Plant Journal, 巻：66, 号：4, 開始ページ：579, 終了ページ：590, 2011年05月, ［査読有り］, ［筆頭著者］
  The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a key regulator of xylem vessel differentiation. In order to identify direct target genes of VND7, we performed global transcriptome analysis using Arabidopsis transgenic lines in which VND7 activity could be induced post-translationally. This analysis identified 63 putative direct target genes of VND7, which encode a broad range of proteins, such as transcription factors, IRREGULAR XYLEM proteins and proteolytic enzymes, known to be closely associated with xylem vessel formation. Recombinant VND7 protein binds to several promoter sequences present in candidate direct target genes: specifically, in the promoter of XYLEM CYSTEINE PEPTIDASE1, two distinct regions were demonstrated to be responsible for VND7 binding. We also found that expression of VND7 restores secondary cell wall formation in the fiber cells of inflorescence stems of nst1 nst3 double mutants, as well as expression of NAC SECONDARY WALL THICKENING PROMOTING FACTOR3 (NST3, however, the vessel-type secondary wall deposition was observed only as a result of VND7 expression. These findings indicated that VND7 upregulates, directly and/or indirectly, many genes involved in a wide range of processes in xylem vessel differentiation, and that its target genes are partially different from those of NSTs. © 2011 Blackwell Publishing Ltd.
  4, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1111/j.1365-313X.2011.04514.x
  DOI ID：10.1111/j.1365-313X.2011.04514.x, ISSN：0960-7412, ORCID：39147312, PubMed ID：21284754, SCOPUS ID：79955852269, Web of Science ID：WOS:000290456400013
• 道管分化マスター因子の発現を制御する転写因子の探索とその解析　　　　　　　　　　　　　　　
  遠藤 仁; 山口 雅利; 中野 仁美; 西窪 伸之; 大谷 美沙都; 加藤 晃; 片山 義博; 梶田 真也; 出村 拓
  日本植物生理学会年会およびシンポジウム 講演要旨集, 巻：2011, 開始ページ：0480, 終了ページ：0480, 2011年
  私たちはこれまでに、シロイヌナズナ培養細胞の道管要素への分化転換を同調的に誘導する実験系を確立し、これを用いたマイクロアレイ解析により道管要素分化誘導過程において発現が変動する遺伝子を多数同定した。さらに、これらの中で、NACドメイン転写因子をコードするVASCULAR-RELARED NAC-DOMAIN7 (VND7)が道管分化のマスター因子であることをすでに明らかにしている。本研究ではVND7の発現制御に関わる転写因子を同定するために、道管要素分化過程でVND7と同調して発現が上昇する転写因子に着目し、VND7プロモーター:ルシフェラーゼをレポーターとしたパーティクルボンバードメントによるトランジェント解析を行った。その結果、VND7を含む7種のVNDファミリー遺伝子すべてがVND7の発現を正に制御することが明らかとなった。また、VND以外の80種の転写因子について解析を行ったところ、VND7の発現を正に制御する複数の転写因子を同定した。このうち、新たに同定したNACタイプの転写因子の機能解析を進めたところ、過剰発現体において異所的な二次細胞壁形成が認められた。このことから、現在NAC転写因子について更なる機能解析を進めており、その結果についても報告したい。
  日本植物生理学会
  DOI：https://doi.org/10.14841/jspp.2011.0.0480.0
  DOI ID：10.14841/jspp.2011.0.0480.0, CiNii Articles ID：130006996826
• 植物二次細胞壁形成の転写制御機構　　　　　　　　　　　　　　　
  Masatoshi YAMAGUCHI; Misato OHTANI; Taku DEMURA
  KAGAKU TO SEIBUTSU, 巻：49, 号：11, 開始ページ：770, 終了ページ：777, 2011年, ［査読有り］, ［筆頭著者］
  Masatoshi YAMAGUCHI, Misato OHTANI, Taku DEMURA, 2011, '植物二次細胞壁形成の転写制御機構', <i>KAGAKU TO SEIBUTSU</i>, vol. 49, no. 11, pp. 770-777
  Japan Society for Bioscience, Biotechnology, and Agrochemistry, 日本語
  DOI：https://doi.org/10.1271/kagakutoseibutsu.49.770
  DOI ID：10.1271/kagakutoseibutsu.49.770, ISSN：0453-073X, CiNii Articles ID：10029873610, CiNii Books ID：AN00037573, ORCID：9105799
• A Short Period of Mannitol Stress but Not LiCl Stress Led to Global Translational Repression in Plants　　　　　　　　　　　　　　　
  Hideyuki Matsuura; Ueda Kiyotaka; Yu Ishibashi; Yuki Kubo; Masatoshi Yamaguchi; Kazumasa Hirata; Taku Demura; Ko Kato
  BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 巻：74, 号：10, 開始ページ：2110, 終了ページ：2112, 2010年10月, ［査読有り］
  In plant cells, high salinity stress induces rapid inhibition of general protein synthesis. In this study, we found that treatment with mannitol, but not lithium stress, led to rapid global translational repression, suggesting that a rapid response at the level of translation might be induced by the osmotic but not the ionic components of salinity stress.
  TAYLOR & FRANCIS LTD, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1271/bbb.100330
  DOI ID：10.1271/bbb.100330, ISSN：0916-8451, eISSN：1347-6947, CiNii Articles ID：10027560810, ORCID：39147313, Web of Science ID：WOS:000283624900025
• VASCULAR-RELATED NAC-DOMAIN6 and VASCULAR-RELATED NAC-DOMAIN7 Effectively Induce Transdifferentiation into Xylem Vessel Elements under Control of an Induction System　　　　　　　　　　　　　　　
  Masatoshi Yamaguchi; Nadia Goue; Hisako Igarashi; Misato Ohtani; Yoshimi Nakano; Jennifer C. Mortimer; Nobuyuki Nishikubo; Minoru Kubo; Yoshihiro Katayama; Koichi Kakegawa; Paul Dupree; Taku Demura
  PLANT PHYSIOLOGY, 巻：153, 号：3, 開始ページ：906, 終了ページ：914, 2010年07月, ［査読有り］, ［筆頭著者］
  We previously showed that the VASCULAR-RELATED NAC-DOMAIN6 (VND6) and VND7 genes, which encode NAM/ATAF/CUC domain protein transcription factors, act as key regulators of xylem vessel differentiation. Here, we report a glucocorticoid-mediated posttranslational induction system of VND6 and VND7. In this system, VND6 or VND7 is expressed as a fused protein with the activation domain of the herpes virus VP16 protein and hormone-binding domain of the animal glucocorticoid receptor, and the protein's activity is induced by treatment with dexamethasone (DEX), a glucocorticoid derivative. Upon DEX treatment, transgenic Arabidopsis (Arabidopsis thaliana) plants carrying the chimeric gene exhibited transdifferentiation of various types of cells into xylem vessel elements, and the plants died. Many genes involved in xylem vessel differentiation, such as secondary wall biosynthesis and programmed cell death, were up-regulated in these plants after DEX treatment. Chemical analysis showed that xylan, a major hemicellulose component of the dicot secondary cell wall, was increased in the transgenic plants after DEX treatment. This induction system worked in poplar (Populus tremula x tremuloides) trees and in suspension cultures of cells from Arabidopsis and tobacco (Nicotiana tabacum); more than 90% of the tobacco BY-2 cells expressing VND7-VP16-GR transdifferentiated into xylem vessel elements after DEX treatment. These data demonstrate that the induction systems controlling VND6 and VND7 activities can be used as powerful tools for understanding xylem cell differentiation.
  AMER SOC PLANT BIOLOGISTS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1104/pp.110.154013
  DOI ID：10.1104/pp.110.154013, ISSN：0032-0889, eISSN：1532-2548, CiNii Articles ID：80021158683, ORCID：39147316, PubMed ID：20488898, Web of Science ID：WOS:000279400200002
• VND-INTERACTING2, a NAC Domain Transcription Factor, Negatively Regulates Xylem Vessel Formation in Arabidopsis　　　　　　　　　　　　　　　
  Masatoshi Yamaguchi; Misato Ohtani; Nobutaka Mitsuda; Minoru Kubo; Masaru Ohme-Takagi; Hiroo Fukuda; Taku Demura
  PLANT CELL, 巻：22, 号：4, 開始ページ：1249, 終了ページ：1263, 2010年04月, ［査読有り］, ［筆頭著者］
  The Arabidopsis thaliana NAC domain transcription factor VASCULAR-RELATED NAC-DOMAIN7 (VND7) acts as a master regulator of xylem vessel differentiation. To understand the mechanism by which VND7 regulates xylem vessel differentiation, we used a yeast two-hybrid system to screen for proteins that interact with VND7 and identified cDNAs encoding two NAC domain proteins, VND-INTERACTING1 (VNI1) and VNI2. Binding assays demonstrated that VNI2 effectively interacts with VND7 and the VND family proteins, VND1-5, as well as with other NAC domain proteins at lower affinity. VNI2 is expressed in both xylem and phloem cells in roots and inflorescence stems. The expression of VNI2 overlaps with that of VND7 in elongating vessel precursors in roots. VNI2 contains a predicted PEST motif and a C-terminally truncated VNI2 protein, which lacks part of the PEST motif, is more stable than full-length VNI2. Transient reporter assays showed that VNI2 is a transcriptional repressor and can repress the expression of vessel-specific genes regulated by VND7. Expression of C-terminally truncated VNI2 under the control of the VND7 promoter inhibited the normal development of xylem vessels in roots and aerial organs. These data suggest that VNI2 regulates xylem cell specification as a transcriptional repressor that interacts with VND proteins and possibly also with other NAC domain proteins.
  AMER SOC PLANT BIOLOGISTS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1105/tpc.108.064048
  DOI ID：10.1105/tpc.108.064048, ISSN：1040-4651, CiNii Articles ID：80021071347, ORCID：39147317, PubMed ID：20388856, Web of Science ID：WOS:000278414900022
• Transcriptional regulation of secondary wall formation controlled by NAC domain proteins　　　　　　　　　　　　　　　
  Masatoshi Yamaguchi; Taku Demura
  PLANT BIOTECHNOLOGY, 巻：27, 号：3, 開始ページ：237, 終了ページ：242, 2010年, ［査読有り］, ［筆頭著者］
  Woody cells develop secondary wall structure that mainly consists of polysaccharides (cellulose and hemicellulose) and lignin. These components are expected to be new sources of biofuels and biomaterials. Therefore, it is important to understand the molecular mechanism underlying secondary wall formation and how it contributes to plant biomass. Plant-specific NAC domain transcription factor family has been shown to be involved in diverse biological functions. Recently, several studies reported that a subfamily of the NAC domain transcription factors plays pivotal roles in secondary wall formation. In this review, we have summarized the role of NAC domain transcription factors in controlling the secondary wall formation.
  JAPANESE SOC PLANT CELL & MOLECULAR BIOL, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.27.237
  DOI ID：10.5511/plantbiotechnology.27.237, ISSN：1342-4580, ORCID：39147315, Web of Science ID：WOS:000280085800004
• MYB transcription factors orchestrating the developmental program of xylem vessels in Arabidopsis roots　　　　　　　　　　　　　　　
  Yoshimi Nakano; Nobuyuki Nishikubo; Nadia Goue; Misato Ohtani; Masatoshi Yamaguchi; Yoshihiro Katayama; Taku Demura
  PLANT BIOTECHNOLOGY, 巻：27, 号：3, 開始ページ：267, 終了ページ：272, 2010年, ［査読有り］
  Xylem vessel elements play an important role in conducting water and nutrient in land plants. The in vitro culture system, in which subcultured Arabidopsis cells are induced to transdifferentiate into xylem vessel elements, was used to uncover the comprehensive gene expression profile by microarray analysis, which resulted in the identification of many genes encoding transcription factors including two transcriptional key regulators, VASCUAR-RELATED NAC DOMAIN6 (VND6) and VND7. Here we analyze the detailed expression pattern and function of ten genes encoding MYB transcription factors, MYB20, 43, 46, 52, 63, 83, 85, 99, 103, and 118, with the significantly up-regulated expression during the in vitro vessel element differentiation. Of these, six exhibited the specific expression in differentiating xylem vessels in Arabidopsis roots. In addition, MYB46 and MYB83 were shown to upregulate five of these MYB genes, MYB43, 52, 63, 85, and 103. Our results suggest that several MYB genes comprise a transcriptional network during xylem vessel element differentiation in roots.
  JAPANESE SOC PLANT CELL & MOLECULAR BIOL, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.5511/plantbiotechnology.27.267
  DOI ID：10.5511/plantbiotechnology.27.267, ISSN：1342-4580, ORCID：39147314, Web of Science ID：WOS:000280085800008
• Identifying New Components Participating in the Secondary Cell Wall Formation of Vessel Elements in Zinnia and Arabidopsis　　　　　　　　　　　　　　　
  Satoshi Endo; Edouard Pesquet; Masatoshi Yamaguchi; Gen Tashiro; Mayuko Sato; Kiminori Toyooka; Nobuyuki Nishikubo; Makiko Udagawa-Motose; Minoru Kubo; Hiroo Fukuda; Taku Demura
  PLANT CELL, 巻：21, 号：4, 開始ページ：1155, 終了ページ：1165, 2009年04月, ［査読有り］
  Xylem vessel elements are hollow cellular units that assemble end-to-end to form a continuous vessel throughout the plant body; the xylem vessel is strengthened by the xylem elements' reinforced secondary cell walls (SCWs). This work aims to unravel the contribution of unknown actors in xylem vessel differentiation using the model in vitro cell culture system of Zinnia elegans differentiating cell cultures and the model in vivo system of Arabidopsis thaliana plants. Tracheary Element Differentiation-Related6 (TED6) and TED7 were selected based on an RNA interference (RNAi) screen in the Zinnia system. RNAi reduction of TED6 and 7 delayed tracheary element (TE) differentiation and co-overexpression of TED6 and 7 increased TE differentiation in cultured Zinnia cells. Arabidopsis TED6 and 7 were expressed preferentially in differentiating vessel elements in seedlings. Aberrant SCW formation of root vessel elements was induced by transient RNAi of At TED7 alone and enhanced by inhibition of both TED6 and 7. Protein-protein interactions were demonstrated between TED6 and a subunit of the SCW-related cellulose synthase complex. Our strategy has succeeded in finding two novel components in SCW formation and has opened the door for in-depth analysis of their molecular functions.
  AMER SOC PLANT BIOLOGISTS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1105/tpc.108.059154
  DOI ID：10.1105/tpc.108.059154, ISSN：1040-4651, CiNii Articles ID：80020348025, ORCID：39147318, PubMed ID：19383897, Web of Science ID：WOS:000266295800015
• An isoform of Arabidopsis myosin XI interacts with small GTPases in its C-terminal tail region　　　　　　　　　　　　　　　
  Kohsuke Hashimoto; Hisako Igarashi; Shoji Mano; Chikako Takenaka; Takashi Shiina; Masatoshi Yamaguchi; Taku Demura; Mikio Nishimura; Teruo Shimmen; Etsuo Yokota
  JOURNAL OF EXPERIMENTAL BOTANY, 巻：59, 号：13, 開始ページ：3523, 終了ページ：3531, 2008年10月, ［査読有り］
  Myosin XI, a class of myosins expressed in plants is believed to be responsible for cytoplasmic streaming and the translocation of organelles and vesicles. To gain further insight into the translocation of organelles and vesicles by myosin XI, an isoform of Arabidopsis myosin XI, MYA2, was chosen and its role in peroxisome targeting was examined. Using the yeast two-hybrid screening method, two small GTPases, AtRabD1 and AtRabC2a, were identified as factors that interact with the C-terminal tail region of MYA2. Both recombinant AtRabs tagged with His bound to the recombinant C-terminal tail region of MYA2 tagged with GST in a GTP-dependent manner. Furthermore, AtRabC2a was localized on peroxisomes, when its CFP-tagged form was expressed transiently in protoplasts prepared from Arabidopsis leaf tissue. It is suggested that MYA2 targets the peroxisome through an interaction with AtRabC2a.
  OXFORD UNIV PRESS, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1093/jxb/ern202
  DOI ID：10.1093/jxb/ern202, ISSN：0022-0957, eISSN：1460-2431, CiNii Articles ID：80019971620, ORCID：39147319, PubMed ID：18703495, Web of Science ID：WOS:000259973800003
• VASCULAR-RELATED NAC-DOMAIN7 is involved in the differentiation of all types of xylem vessels in Arabidopsis roots and shoots　　　　　　　　　　　　　　　
  Masatoshi Yamaguchi; Minoru Kubo; Hiroo Fukuda; Taku Demura
  PLANT JOURNAL, 巻：55, 号：4, 開始ページ：652, 終了ページ：664, 2008年08月, ［査読有り］, ［筆頭著者］
  The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), plays a pivotal role in regulating the differentiation of root protoxylem vessels. In order to understand the mechanisms underscoring the function of VND7 in vessel differentiation in more detail, we conducted extensive molecular analyses in yeast (Saccharomyces cerevisiae), Arabidopsis, and Nicotiana tabacum L. cv. Bright Yellow 2 (tobacco BY-2) cells. The transcriptional activation activity of VND7 was confirmed in yeast and Arabidopsis, and the C-terminal region was shown to be required for VND7 transcriptional activation. Expression of the C-terminus-truncated VND7 protein under the control of the native VND7 promoter resulted in inhibition of the normal development of metaxylem vessels in roots and vessels in aerial organs, as well as protoxylem vessels in roots. The expression pattern of VND7 overlapped that of VND2 to VND5 in most of the differentiating vessels. Furthermore, a yeast two-hybrid assay revealed the ability of VND7 to form homodimers and heterodimers with other VND proteins via their N-termini, which include the NAC domain. The heterologous expression of VND7 in tobacco BY-2 cells demonstrated that the stability of VND7 could be regulated by proteasome-mediated degradation. Together these data suggest that VND7 regulates the differentiation of all types of vessels in roots and shoots, possibly in cooperation with VND2 to VND5 and other regulatory proteins.
  WILEY-BLACKWELL, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1111/j.1365-313X.2008.03533.x
  DOI ID：10.1111/j.1365-313X.2008.03533.x, ISSN：0960-7412, ORCID：39147320, PubMed ID：18445131, Web of Science ID：WOS:000258287700010
• Control of cell division and transcription by cyclin-dependent kinase-activating kinases in plants　　　　　　　　　　　　　　　
  M Umeda; A Shimotohno; M Yamaguchi
  PLANT AND CELL PHYSIOLOGY, 巻：46, 号：9, 開始ページ：1437, 終了ページ：1442, 2005年09月, ［査読有り］
  Cyclin-dependent protein kinases (CDKs) play key roles in the progression of the cell cycle in eukaryotes. A CDK-activating kinase (CAK) catalyzes the phosphorylation of CDKs to activate their enzyme activity; thus, it is involved in activation of cell proliferation. In plants, two distinct classes of CAK have been identified; CDKD is functionally related to vertebrate-type CAKs, while CDKF is a plant-specific CAK having unique enzymatic characteristics. Recently, CDKF was shown to phosphorylate and activate CDKDs in Arabidopsis. This led to a proposal that CDKD and CDKF constitute a phosphorylation cascade that mediates environmental or hormonal signals to molecular machineries that control the cell cycle and transcription. In this review, we have summarized the biochemical features of plant CAKs and discussed the manner in which they diverge from animal and yeast orthologs. We have introduced several transgenic studies in which CAK genes were used as a tool to modify the CDK activity and to analyze cell division and differentiation during organ development.
  OXFORD UNIV PRESS, 英語
  DOI：https://doi.org/10.1093/pcp/pci170
  DOI ID：10.1093/pcp/pci170, ISSN：0032-0781, CiNii Articles ID：40006875958, Web of Science ID：WOS:000232223100001
• Transcription switches for protoxylem and metaxylem vessel formation　　　　　　　　　　　　　　　
  M Kubo; M Udagawa; N Nishikubo; G Horiguchi; M Yamaguchi; J Ito; T Mimura; H Fukuda; T Demura
  GENES & DEVELOPMENT, 巻：19, 号：16, 開始ページ：1855, 終了ページ：1860, 2005年08月, ［査読有り］
  Land plants evolved xylem vessels to conduct water and nutrients, and to support the plant. Microarray analysis with a newly established Arabidopsis in vitro xylem vessel element formation system and promoter analysis revealed the possible involvement of some plant-specific NAC-domain transcription factors in xylem formation. VASCULAR-RELATED NAC-DOMAIN6 (VND6) and VND7 can induce transdifferentiation of various cells into metaxylem- and protoxylem-like vessel elements, respectively, in Arabidopsis and poplar. A dominant repression of VND6 and VND7 specifically inhibits metaxylem and protoxylem vessel formation in roots, respectively. These findings suggest that these genes are transcription switches for plant metaxylem and protoxylem vessel formation.
  COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1101/gad.1331305
  DOI ID：10.1101/gad.1331305, ISSN：0890-9369, CiNii Articles ID：30018919280, PubMed ID：16103214, Web of Science ID：WOS:000231277600005
• Control of in vitro organogenesis by cyclin-dependent kinase activities in plants　　　　　　　　　　　　　　　
  M Yamaguchi; H Kato; S Yoshida; S Yamamura; H Uchimiya; M Umeda
  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 巻：100, 号：13, 開始ページ：8019, 終了ページ：8023, 2003年06月, ［査読有り］, ［筆頭著者］
  Little is known concerning the mechanisms by which auxin and cytokinin exert their effects on proliferation and differentiation. Cyclin-dependent kinases (CDKs) are major regulators of the eukaryotic cell cycle, thus they are assumed to control cell differentiation as well as proliferation in response to phytohormone signals. Here, we overexpressed rice R2 cDNA, which encodes a CDK-activating kinase, in tobacco leaf explants by using the glucocorticoid-mediated transcriptional induction system. Transient expression of R2 during the first 7 days of culture triggered callus formation in the absence of cytokinin. This phenotype was enhanced by higher expression of R2 or coexpression of cyclin H, and suppressed by treatment with roscovitine, a CDK inhibitor. R2 expression at a later stage did not prevent cells from differentiation into roots, suggesting a restricted period for sensing CDK activities that control differentiation fate of cells during organogenesis.
  NATL ACAD SCIENCES, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1073/pnas.1332637100
  DOI ID：10.1073/pnas.1332637100, ISSN：0027-8424, CiNii Articles ID：80016025487, PubMed ID：12799469, Web of Science ID：WOS:000183845800108
• Cell cycle function of a rice B2-type cyclin interacting with a B-type cyclin-dependent kinase　　　　　　　　　　　　　　　
  J Lee; A Das; M Yamaguchi; J Hashimoto; N Tsutsumi; H Uchimiya; M Umeda
  PLANT JOURNAL, 巻：34, 号：4, 開始ページ：417, 終了ページ：425, 2003年05月, ［査読有り］
  Cyclin-dependent kinases (CDKs) are involved in the control of cell cycle progression. Plant A-type CDKs are functional homologs of yeast Cdc2/Cdc28 and are expressed throughout the cell cycle. In contrast, B-type CDK (CDKB) is a family of mitotic CDKs expressed during the S/M phase, and its precise function remains unknown. Here, we identified two B2-type cyclins, CycB2;1 and CycB2;2, as a specific partner of rice CDKB2;1. The CDKB2;1-CycB2 complexes produced in insect cells showed a significant level of kinase activity in vitro , suggesting that CycB2 binds to and activates CDKB2. We then expressed green fluorescent protein (GFP)-fused CDKB2;1 and CycB2;2 in tobacco BY2 cells to investigate their subcellular localization during mitosis. Surprisingly, the fluorescence signal of CDKB2;1-GFP was tightly associated with chromosome alignment as well as with spindle structure during the metaphase. During the telophase, the signal was localized to the spindle midzone and the separating sister chromosomes, and then to the phragmoplast. On the other hand, the CycB2;2-GFP fluorescence signal was detected in nuclei during the interphase and prophase, moved to the metaphase chromosomes, and then disappeared completely after the cells passed through the metaphase. Co-localization of CDKB2;1-GFP and CycB2;2-GFP on chromosomes aligned at the center of the metaphase cells suggests that the CDKB2-CycB2 complex may function in retaining chromosomes at the metaphase plate. Overexpression of CycB2;2 in rice plants resulted in acceleration of root growth without any increase in cell size, indicating that CycB2;2 promoted cell division probably through association with CDKB2 in the root meristem.
  BLACKWELL PUBLISHING LTD, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1046/j.1365-313X.2003.01736.x
  DOI ID：10.1046/j.1365-313X.2003.01736.x, ISSN：0960-7412, PubMed ID：12753582, Web of Science ID：WOS:000182785300003
• Differential phosphorylation activities of CDK-activating kinases in Arabidopsis thaliana　　　　　　　　　　　　　　　
  A Shimotohno; S Matsubayashi; M Yamaguchi; H Uchimiya; M Umeda
  FEBS LETTERS, 巻：534, 号：1-3, 開始ページ：69, 終了ページ：74, 2003年01月, ［査読有り］
  Activation of cyclin-dependent kinases (CDKs) requires phosphorylation of a threonine residue within the T-loop by a CDK-activating kinase (CAK). Here we isolated an Arabidopsis cDNA (CAK4At) whose predicted product shows a high similarity to vertebrate CDK7/p40(MO15). Northern blot analysis showed that expressions of the four Arabidopsis CAKs (CAK1At-CAK4At) were not dependent on cell division. CAK2At- and CAK4At-immunoprecipitates of Arabidopsis crude extract phosphorylated CDK and the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II with different preferences. These results suggest the existence of differential mechanisms in Arabidopsis that control CDK and CTD phosphorylation by multiple CAKs. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.
  ELSEVIER SCIENCE BV, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1016/S0014-5793(02)03780-8
  DOI ID：10.1016/S0014-5793(02)03780-8, ISSN：0014-5793, CiNii Articles ID：80015743159, PubMed ID：12527363, Web of Science ID：WOS:000180502100012
• Activation of CDK-activating kinase is dependent on interaction with H-type cyclins in plants　　　　　　　　　　　　　　　
  M Yamaguchi; T Fabian; M Sauter; RP Bhalerao; J Schrader; G Sandberg; M Umeda; H Uchimiya
  PLANT JOURNAL, 巻：24, 号：1, 開始ページ：11, 終了ページ：20, 2000年10月, ［査読有り］, ［筆頭著者］
  cDNAs encoding cyclin H homologs were isolated from poplar (Populus tremula x tremuloides) and rice (Oryza sativa) plants, and were designated Pt;cycH;1 and Os;cycH;1, respectively. The deduced amino-acid sequences showed 40-60% similarity to human cyclin H and Schizosaccharomyces pombe Mcs2, with higher similarity in the cyclin box region. While Pt;cycH;1 and Os;cycH;1 were expressed in all tissues examined, the transcripts accumulated abundantly in dividing cells. Expression of Os;cycH;1 was abundant in the S-phase in partially synchronized suspension cells, and was induced by submergence in internodes of deepwater rice. A yeast two-hybrid assay demonstrated that both Pt;CycH;1 and Os;CycH;1 were able to interact with rice R2 kinase, which is structurally and functionally similar to cyclin-dependent kinase (CDK)-activating kinase (CAK) of vertebrates. Moreover, an in vitro pull-down assay showed that Os;CycH;1 specifically bound to R2 but not to other rice CDKs. When R2 was expressed in budding yeast CAK mutant, the suppression activity in terms of temperature-sensitivity was enhanced by co-expression with Os;cycH;1. Furthermore, in vitro kinase assay indicated that the kinase activities of R2 on CDKs and the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II were markedly elevated by binding to Os;CycH;1. Our results suggest that cyclin H is a regulatory subunit of CAK, which positively controls CDK- and CTD-kinase activities in plant cells.
  BLACKWELL SCIENCE LTD, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1046/j.1365-313X.2000.00846.x
  DOI：https://doi.org/10.1046/j.1365-313x.2000.00846.x
  DOI ID：10.1046/j.1365-313X.2000.00846.x, ISSN：0960-7412, ORCID：39147327, Web of Science ID：WOS:000089935800002
• A rice homolog of Cdk7/MO15 phosphorylates both cyclin-dependent protein kinases and the carboxy-terminal domain of RNA polymerase II　　　　　　　　　　　　　　　
  M Yamaguchi; M Umeda; H Uchimiya
  PLANT JOURNAL, 巻：16, 号：5, 開始ページ：613, 終了ページ：619, 1998年12月, ［査読有り］, ［筆頭著者］
  The activation of cyclin-dependent protein kinases (CDKs) requires phosphorylation of a threonine residue within the T-loop by a CDK-activating kinase (CAK). The R2 protein of rice is very similar to CAKs of animals and fission yeast at the amino acid level but phosphorylation by R2 has not yet been demonstrated. When R2 was overexpressed in a CAK-deficient mutant of budding yeast, it suppressed the temperature sensitivity of the mutation. Immunoprecipitates of rice proteins with the anti-R2-antibody phosphorylated human CDK2, one of the rice CDKs (Cdc2Os1), and the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II of Arabidopsis. Mutational analysis indicated that R2 phosphorylated the threonine residue within the T-loop of CDK2 and Cdc2Os1. R2 was found mainly in two protein complexes which had molecular masses of 190 kDa and 70 kDa, respectively, whilst the CDK- and CTD-kinase activities associated with R2 were identified in a complex of 105 kDa. These results indicate that R2 is closely related to CAKs of animals and fission yeast in terms of its phosphorylation activity and, moreover, that this CAK of rice is distinct from a CAK of the dicotyledonous plant Arabidopsis.
  BLACKWELL SCIENCE LTD, 英語, 研究論文（学術雑誌）
  DOI：https://doi.org/10.1046/j.1365-313X.1998.00338.x
  DOI：https://doi.org/10.1046/j.1365-313x.1998.00338.x
  DOI ID：10.1046/j.1365-313X.1998.00338.x, ISSN：0960-7412, ORCID：39147330, Web of Science ID：WOS:000077866600010

• シロイヌナズナVND遺伝子群の遺伝学的解析
  伊藤敦也; 久保稔; 大谷美沙都; 石川寿樹; 川合真紀; 出村拓; 山口雅利
  日本植物細胞分子生物学会大会・シンポジウム講演要旨集, 巻：36th, 開始ページ：153, 2018年08月15日
  日本語
  J-Global ID：201802264094945466
• イオンビームを照射した高シュウ酸植物エゾノギシギシの代謝解析
  宮城敦子; 北野沙也佳; 長谷純宏; 大野豊; 山口雅利; 川合真紀
  日本植物学会大会研究発表記録, 巻：79th, 開始ページ：134, 2015年09月01日
  日本語
  J-Global ID：201502214850620962
• NAD(P)代謝改変シロイヌナズナの作出および代謝解析　　　　　　　　　　　　　　　
  鈴木渉太; 宮城敦子; 石川寿樹; 刑部敬史; 長野稔; 山口雅利; 川合真紀
  日本植物細胞分子生物学会大会・シンポジウム講演要旨集, 巻：33rd, 開始ページ：140, 2015年07月20日
  日本語
  J-Global ID：201502202919376033
• An E3 ubiquitin ligase involved in secondary wall formation　　　　　　　　　　　　　　　
  Soichiro Noda; Masatoshi Yamaguchi; Nobuyuki Nishikubo; Nozomu Sakurai; Masaomi Yamamura; Takefumi Hattori; Hideyuki Suzuki; Daisuke Shibata; Taku Demura; Shiro Suzuki; Toshiaki Umezawa
  International Symposium on Wood Science and Technology 2015, 2015年03月
• Functional characterization of rice MYB transcription factors involved in secondary cell wall biosynthesis　　　　　　　　　　　　　　　
  Soichiro Noda; Taichi Koshiba; Masatoshi Yamaguchi; Takefumi Hattori; Shiro Suzuki; Toshiaki Umezawa
  ICP2014, XXVIIth International Conference on Polyphenols, Nagoya, 2014年09月, ［招待有り］
• 道管細胞と繊維細胞を作り分けるシス配列-転写因子結合制御の分子基盤の解明　　　　　　　　　　　　　　　
  田村泰造; 山口雅利; 遠藤仁; 米田新; 久保稔; 加藤晃; 大谷美沙都; 出村拓; 出村拓
  日本分子生物学会年会プログラム・要旨集(Web), 巻：37th, 2014年
  J-Global ID：201502208023422025
• 道管細胞分化マスター制御因子VND7はタイトにその発現が制御される　　　　　　　　　　　　　　　
  遠藤仁; 山口雅利; TAN Tian Tian; 田村泰造; 久保稔; 大谷美沙都; 出村拓; 出村拓
  日本分子生物学会年会プログラム・要旨集(Web), 巻：37th, 2014年
  J-Global ID：201502260216732643
• 道管細胞分化におけるタンパク質S-ニトロシル化修飾の役割の解明　　　　　　　　　　　　　　　
  川邊陽文; 大谷美沙都; 山口雅利; 久保稔; 倉田哲也; 坂本智昭; 米田新; 加藤晃; 出村拓; 出村拓
  日本植物学会大会研究発表記録, 巻：78th, 2014年
  J-Global ID：201402276448409810
• ガンマ線が高シュウ酸植物の代謝に及ぼす影響
  北野沙也佳; 宮城敦子; 大野豊; 長谷純弘; 鳴海一成; 山口雅利; 内宮博文; 川合真紀
  日本植物学会大会研究発表記録, 巻：77th, 開始ページ：185, 2013年08月20日
  日本語
  J-Global ID：201302255221317192
• VND7による道管要素分化誘導系を用いたキシランキシロシルトランスフェラーゼの生化学的解析　　　　　　　　　　　　　　　
  深水祐一郎; 中野仁美; 山口雅利; 石水毅; 出村拓; 出村拓
  日本植物生理学会年会要旨集, 巻：53rd, 2012年
  J-Global ID：201202213414100741
• タバコBY-2細胞を用いた道管要素分化誘導システムの構築-二次壁形成における分子機構の解明に向けて-　　　　　　　　　　　　　　　
  中野仁美; 深水祐一郎; 伊藤由希子; グエ ナディア; 五十嵐久子; 山口雅利; 石水毅; 出村拓; 出村拓
  日本植物生理学会年会要旨集, 巻：53rd, 2012年
  J-Global ID：201202283424277095
• 道管分化マスター因子の発現制御機構の解明　　　　　　　　　　　　　　　
  遠藤仁; 山口雅利; 中野仁美; 米田新; 加藤晃; 出村拓
  日本植物細胞分子生物学会大会・シンポジウム講演要旨集, 巻：30th, 2012年
  J-Global ID：201302254240186272
• 二次細胞壁形成の時空間的制御 (特集 植物細胞壁研究の新局面 : サステナブル社会構築の基盤となる循環型炭素資源)　　　　　　　　　　　　　　　
  大谷 美沙都; 山口 雅利; 出村 拓
  遺伝 : 生物の科学, 巻：66, 号：1, 開始ページ：40, 終了ページ：46, 2012年01月
  エヌ・ティー・エス, 日本語
  ISSN：0387-0022, CiNii Articles ID：40019142214, CiNii Books ID：AN00015468
• 道管分化マスター因子の発現を制御する転写因子の探索とその解析　　　　　　　　　　　　　　　
  遠藤仁; 遠藤仁; 山口雅利; 中野仁美; 西窪伸之; 大谷美沙都; 加藤晃; 片山義博; 梶田真也; 出村拓
  日本植物生理学会年会要旨集, 巻：52nd, 2011年
  J-Global ID：201102292421319805
• 非モデル樹木ヤトロファの次世代トランスクリプトーム解析　　　　　　　　　　　　　　　
  中野仁美; 坂本智昭; 大谷美沙都; 山口雅利; 倉田哲也; 出村拓; 出村拓
  日本植物学会大会研究発表記録, 巻：75th, 2011年
  J-Global ID：201102231679331797
• 植物細胞壁形成を司る遺伝子発現制御機構　　　　　　　　　　　　　　　
  山口雅利; 大谷美沙都; 中野仁美; 出村拓; 出村拓
  日本植物学会大会研究発表記録, 巻：75th, 2011年
  J-Global ID：201102236607613137
• 二次細胞壁形成の生化学的解析　　　　　　　　　　　　　　　
  山口雅利; 中野仁美; 武藤裕貴; 伊藤由希子; 深水祐一郎; 加藤晃; 石水毅; 出村拓; 出村拓
  生化学, 2011年
  ISSN：0037-1017, J-Global ID：201202226282928090
• 二次壁形成に関わるRING fingerタンパク質の局在と転写因子による発現制御　　　　　　　　　　　　　　　
  野田壮一郎; 鈴木史朗; 山口雅利; 服部武文; 西窪伸之; 出村拓; 梅澤俊明
  第61回日本木材学会大会研究発表要旨集，p. 6，2011．, 2011年
• 道管分化マスター因子の発現を制御する転写因子の探索とその解析　　　　　　　　　　　　　　　
  遠藤仁; 遠藤仁; 山口雅利; 中野仁美; 西窪伸之; 大谷美沙都; 片山義博; 出村拓; 出村拓
  日本植物生理学会年会要旨集, 巻：51st, 2010年
  J-Global ID：201002286014242795
• 転写因子を用いた道管分化誘導システム　　　　　　　　　　　　　　　
  山口雅利; 山口雅利; NADIA Goue; 五十嵐久子; 大谷美沙都; 大谷美沙都; 中野仁美; 中野仁美; MORTIMER Jennifer C; 西窪伸之; 久保稔; 片山義博; 掛川弘一; DUPREE Paul; 出村拓; 出村拓; 出村拓
  日本植物細胞分子生物学会大会・シンポジウム講演要旨集, 巻：28th, 2010年
  J-Global ID：201102284406482470
• シロイヌナズナの二次壁形成に関与するRING fingerタンパク質の機能解析　　　　　　　　　　　　　　　
  野田壮一郎; 鈴木史朗; 西窪伸之; 山口雅利; 出村拓; 服部武文; 梅澤俊明
  日本農芸化学会関西支部例会(第463回講演会),6, 2010年
• 木化初期に発現するRING fingerタンパク質の機能解析　　　　　　　　　　　　　　　
  野田壮一郎; 鈴木史朗; 西窪伸之; 山口雅利; 出村拓; 服部武文; 梅澤俊明
  第60回日本木材学会大会研究発表要旨集，p. 148，2010．, 2010年
• 機能未知遺伝子TED6・TED7は道管細胞壁形成の新規コンポーネントである　　　　　　　　　　　　　　　
  遠藤暁詩; 遠藤暁詩; 遠藤暁詩; PESQUET Edouard; 山口雅利; 田代玄; 佐藤繭子; 豊岡公徳; 西窪伸之; 本瀬真樹子; 久保稔; 福田裕穂; 福田裕穂; 出村拓
  日本植物学会大会研究発表記録, 巻：73rd, 2009年
  J-Global ID：200902280934707308
• 転写因子の活性化による効率的な道管要素分化誘導システムの開発　　　　　　　　　　　　　　　
  山口雅利; 五十嵐久子; 大谷美沙都; GOUE Nadia; 中野仁美; 中野仁美; 西窪伸之; 出村拓
  日本植物生理学会年会要旨集, 巻：49th, 2008年
  J-Global ID：200902256767883338
• FUNCTIONAL ANALYSIS OF NAC-DOMAIN PROTEINS THAT REGULATE XYLEM VESSEL DIFFERENTIATION　　　　　　　　　　　　　　　
  YAMAGUCHI Masatoshi; KUBO Minoru; FUKUDA Hiroo; DEMURA Taku
  Journal of plant research, 巻：119, 開始ページ：164, 終了ページ：164, 2006年12月01日
  英語
  ISSN：0918-9440, CiNii Articles ID：10019309878, CiNii Books ID：AA10900218
• 高等植物における道管形成のマスター制御因子であるVND6とVND7
  久保稔; 宇田川真理子; 西窪伸之; 堀口吾朗; 山口雅利; 井藤純; 三村徹郎; 福田裕穂; 出村拓
  日本分子生物学会年会講演要旨集, 巻：28th, 開始ページ：718, 2005年11月25日
  日本語
  J-Global ID：200902242102699632
• Control of cell division and transcription by cyclin-dependent kinase-activating kinases in plants　　　　　　　　　　　　　　　
  M Umeda; A Shimotohno; M Yamaguchi
  巻：46, 号：9, 開始ページ：1437, 終了ページ：1442, 2005年09月
  Cyclin-dependent protein kinases (CDKs) play key roles in the progression of the cell cycle in eukaryotes. A CDK-activating kinase (CAK) catalyzes the phosphorylation of CDKs to activate their enzyme activity; thus, it is involved in activation of cell proliferation. In plants, two distinct classes of CAK have been identified; CDKD is functionally related to vertebrate-type CAKs, while CDKF is a plant-specific CAK having unique enzymatic characteristics. Recently, CDKF was shown to phosphorylate and activate CDKDs in Arabidopsis. This led to a proposal that CDKD and CDKF constitute a phosphorylation cascade that mediates environmental or hormonal signals to molecular machineries that control the cell cycle and transcription. In this review, we have summarized the biochemical features of plant CAKs and discussed the manner in which they diverge from animal and yeast orthologs. We have introduced several transgenic studies in which CAK genes were used as a tool to modify the CDK activity and to analyze cell division and differentiation during organ development.
  英語, 書評論文,書評,文献紹介等
  DOI：https://doi.org/10.1093/pcp/pci170
  DOI ID：10.1093/pcp/pci170, ISSN：0032-0781, Web of Science ID：WOS:000232223100001
• Transcription switches for protoxylem and metaxylem vessel formation　　　　　　　　　　　　　　　
  M Kubo; M Udagawa; N Nishikubo; G Horiguchi; M Yamaguchi; J Ito; T Mimura; H Fukuda; T Demura
  巻：19, 号：16, 開始ページ：1855, 終了ページ：1860, 2005年08月
  Land plants evolved xylem vessels to conduct water and nutrients, and to support the plant. Microarray analysis with a newly established Arabidopsis in vitro xylem vessel element formation system and promoter analysis revealed the possible involvement of some plant-specific NAC-domain transcription factors in xylem formation. VASCULAR-RELATED NAC-DOMAIN6 (VND6) and VND7 can induce transdifferentiation of various cells into metaxylem- and protoxylem-like vessel elements, respectively, in Arabidopsis and poplar. A dominant repression of VND6 and VND7 specifically inhibits metaxylem and protoxylem vessel formation in roots, respectively. These findings suggest that these genes are transcription switches for plant metaxylem and protoxylem vessel formation.
  英語
  DOI：https://doi.org/10.1101/gad.1331305
  DOI ID：10.1101/gad.1331305, ISSN：0890-9369, Web of Science ID：WOS:000231277600005
• Characterication of novel NAC-domain proteins interacting with VND7　　　　　　　　　　　　　　　
  M Yamaguchi; M Kubo; H Fukuda; T Demura
  巻：46, 開始ページ：S196, 終了ページ：S196, 2005年
  英語, 研究発表ペーパー・要旨（国際会議）
  ISSN：0032-0781, Web of Science ID：WOS:000228104101288
• Functional analyses of VND genes of Arabidopsis for vascular development　　　　　　　　　　　　　　　
  M Kubo; M Yamaguchi; H Fukuda; T Demura
  巻：45, 開始ページ：S61, 終了ページ：S61, 2004年
  英語, 研究発表ペーパー・要旨（国際会議）
  ISSN：0032-0781, Web of Science ID：WOS:000220592700240
• Cell cycle function of a rice B2-type cyclin interacting with a B-type cyclin-dependent kinase　　　　　　　　　　　　　　　
  J Lee; A Das; M Yamaguchi; J Hashimoto; N Tsutsumi; H Uchimiya; M Umeda
  巻：34, 号：4, 開始ページ：417, 終了ページ：425, 2003年05月
  Cyclin-dependent kinases (CDKs) are involved in the control of cell cycle progression. Plant A-type CDKs are functional homologs of yeast Cdc2/Cdc28 and are expressed throughout the cell cycle. In contrast, B-type CDK (CDKB) is a family of mitotic CDKs expressed during the S/M phase, and its precise function remains unknown. Here, we identified two B2-type cyclins, CycB2;1 and CycB2;2, as a specific partner of rice CDKB2;1. The CDKB2;1-CycB2 complexes produced in insect cells showed a significant level of kinase activity in vitro , suggesting that CycB2 binds to and activates CDKB2. We then expressed green fluorescent protein (GFP)-fused CDKB2;1 and CycB2;2 in tobacco BY2 cells to investigate their subcellular localization during mitosis. Surprisingly, the fluorescence signal of CDKB2;1-GFP was tightly associated with chromosome alignment as well as with spindle structure during the metaphase. During the telophase, the signal was localized to the spindle midzone and the separating sister chromosomes, and then to the phragmoplast. On the other hand, the CycB2;2-GFP fluorescence signal was detected in nuclei during the interphase and prophase, moved to the metaphase chromosomes, and then disappeared completely after the cells passed through the metaphase. Co-localization of CDKB2;1-GFP and CycB2;2-GFP on chromosomes aligned at the center of the metaphase cells suggests that the CDKB2-CycB2 complex may function in retaining chromosomes at the metaphase plate. Overexpression of CycB2;2 in rice plants resulted in acceleration of root growth without any increase in cell size, indicating that CycB2;2 promoted cell division probably through association with CDKB2 in the root meristem.
  英語
  DOI：https://doi.org/10.1046/j.1365-313X.2003.01736.x
  DOI ID：10.1046/j.1365-313X.2003.01736.x, ISSN：0960-7412, Web of Science ID：WOS:000182785300003
• Differential phosphorylation activities of CDK-activating kinases in Arabidopsis thaliana　　　　　　　　　　　　　　　
  A Shimotohno; S Matsubayashi; M Yamaguchi; H Uchimiya; M Umeda
  巻：534, 号：1-3, 開始ページ：69, 終了ページ：74, 2003年01月
  Activation of cyclin-dependent kinases (CDKs) requires phosphorylation of a threonine residue within the T-loop by a CDK-activating kinase (CAK). Here we isolated an Arabidopsis cDNA (CAK4At) whose predicted product shows a high similarity to vertebrate CDK7/p40(MO15). Northern blot analysis showed that expressions of the four Arabidopsis CAKs (CAK1At-CAK4At) were not dependent on cell division. CAK2At- and CAK4At-immunoprecipitates of Arabidopsis crude extract phosphorylated CDK and the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II with different preferences. These results suggest the existence of differential mechanisms in Arabidopsis that control CDK and CTD phosphorylation by multiple CAKs. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.
  英語
  DOI：https://doi.org/10.1016/S0014-5793(02)03780-8
  DOI ID：10.1016/S0014-5793(02)03780-8, ISSN：0014-5793, Web of Science ID：WOS:000180502100012
• Analysis of transgenic tobacco plants expressing rice CDK-activating kinase (CAK)　　　　　　　　　　　　　　　
  M Yamaguchi; S Yamamura; M Umeda; H Uchimiya
  巻：43, 開始ページ：S213, 終了ページ：S213, 2002年
  英語, 研究発表ペーパー・要旨（国際会議）
  ISSN：0032-0781, Web of Science ID：WOS:000174726400752
• Ara6, a plant-unique novel type Rab GTPase, functions in the endocytic pathway of Arabidopsis thaliana　　　　　　　　　　　　　　　
  T Ueda; M Yamaguchi; H Uchimiya; A Nakano
  巻：20, 号：17, 開始ページ：4730, 終了ページ：4741, 2001年09月
  Ara6 of Arabidopsis thaliana is a novel member of the Rab/Ypt GTPase family with unique structural features. It resembles Rab5 GTPases best, but lacks a large part of the C-terminal hypervariable region and the cysteine motif, and instead harbors an extra stretch of amino acid residues containing myristoylation and palmitoylation sites at the N-terminus. Ara6 is tightly associated with membranes and is expressed constitutively. In contrast, the conventional Rab5 ortholog, Ara7, is highly expressed only in actively dividing cells. Examination of green fluorescent protein (GFP)-tagged proteins indicates that both Ara6 and Ara7 are distributed on a subpopulation of endosomes and suggests their roles in endosomal fusion. The endosomal localization of Ara6 requires N-terminal fatty acylation, nucleotide binding and the C-terminal amino acid sequence coordinately. Proteins similar to Ara6 are found only in higher plants and thus represent a novel class of Rab GTPases regulating endocytic function in a plant-specific manner.
  英語
  DOI：https://doi.org/10.1093/emboj/20.17.4730
  DOI ID：10.1093/emboj/20.17.4730, ISSN：0261-4189, Web of Science ID：WOS:000170907900012
• ANALYSIS OF THE REGULATORY MECHANISM ON CDK-ACTVATING KINASE (CAK) :　　　　　　　　　　　　　　　
  YAMAGUCHI Masatoshi; YAMAMURA Saburo; UMEDA Masaaki; UCHIMIYA Hirofumi
  Plant and cell physiology, 巻：42, 開始ページ：s46, 2001年
  Japanese Society of Plant Physiologists, 英語
  ISSN：0032-0781, CiNii Articles ID：110003715320, CiNii Books ID：AA0077511X
• MECHANISM OF ENDOSOMAL LOCALIZATION AND GTPase CYCLE REGULATION OF Ara6,A NOVEL PLANT-SPECIFIC Rab/Ypt GTPase :　　　　　　　　　　　　　　　
  UEDA Takashi; YAMAGUCHI Masatoshi; UCHIMIYA Hirofumi; NAKANO Akihiko
  Plant and cell physiology, 巻：42, 開始ページ：s219, 2001年
  Japanese Society of Plant Physiologists, 英語
  ISSN：0032-0781, CiNii Articles ID：110003715997, CiNii Books ID：AA0077511X
• Molecular dissection of cell death in rice (共著)　　　　　　　　　　　　　　　
  巻：pp.365-376, 2001年
• CYCLIN H INTERACTS WITH AND ACTIVATES CDK-ACTIVATING KINASE IN RICE :　　　　　　　　　　　　　　　
  YAMAGUCHI Masatoshi; UMEDA Masaaki; UCHIMIYA Hirofumi
  Plant and cell physiology, 巻：41, 開始ページ：s134, 2000年
  Japanese Society of Plant Physiologists, 英語
  ISSN：0032-0781, CiNii Articles ID：110003722413, CiNii Books ID：AA0077511X
• Ara6,A NOVEL PLANT-SPECIFIC Rab/Ypt GTPase, RESIDES ON ENDOCYTIC MEMBRANES :　　　　　　　　　　　　　　　
  UEDA Takashi; YAMAGUCHI Masatoshi; UCHIMIYA Hirofumi; NAKANO Akihiko
  Plant and cell physiology, 巻：41, 開始ページ：s31, 2000年
  Japanese Society of Plant Physiologists, 英語
  ISSN：0032-0781, CiNii Articles ID：110003722056, CiNii Books ID：AA0077511X
• Molecular characterization of mitotic cyclins in rice plants　　　　　　　　　　　　　　　
  M Umeda; N Iwamoto; C Umeda-Hara; M Yamaguchi; J Hashimoto; H Uchimiya
  巻：262, 号：2, 開始ページ：230, 終了ページ：238, 1999年09月
  Cyclins are known to activate cyclin-dependent protein kinases, which are essential for cell cycle progression in eukaryotes. We isolated full-length cDNAs encoding rice mitotic cyclins named CycA1;os;1 and CycB2;os;1, which are related to A- and B-type cyclins, respectively, from animals. To characterize the function of these mitotic cyclins, as well as that of another B-type cyclin, CycB2;os;2, each cDNA was introduced into yeast cells. When cDNAs encoding CycAl;os;1, CycB2;os;1 or CycB2;os;2 were overexpressed in the yeast mutant DL1, which is deficient in G1 cyclins, the mutant phenotype was rescued, indicating that these mitotic cyclins are functional in yeast cells. When the cDNA encoding CycB2;os;1 was expressed in the wild-type yeast strain, the cells lost the ability to grow, whereas the expression of either cycAl;os;1 or cycB2;os;2 did not inhibit growth. In situ hybridization of these mitotic cyclin genes with rice root apices and counterstaining of chromosomes with a DNA-specific dye revealed that cycAl;os;1 is expressed from the G2 phase to the early M phase, while transcripts of cycB2, os;1 and cycB2;os;2 accumulated until the end of mitosis. Our results indicate that these B2-type cyclins may be involved in the control of mitosis, in combination with a C2/M-phase CDK.
  英語
  DOI：https://doi.org/10.1007/s004380051079
  DOI ID：10.1007/s004380051079, ISSN：0026-8925, CiNii Articles ID：30009502304, PubMed ID：10517318, Web of Science ID：WOS:000082852000004
• CHARACTERIZATION OF FACTORS INTERACTING WITH CDK-ACTIVATING KINASE OF RICE　　　　　　　　　　　　　　　
  YAMAGUCHI Masatoshi; UMEDA Masaaki; HASHIMOTO Junji; UCHIMIYA Hirofumi
  Plant and cell physiology, 巻：40, 開始ページ：s162, 終了ページ：s162, 1999年03月
  英語
  ISSN：0032-0781, CiNii Articles ID：10003758381, CiNii Books ID：AA0077511X
• Differential expression of genes for cyclin-dependent protein kinases in rice plants　　　　　　　　　　　　　　　
  M Umeda; C Umeda-Hara; M Yamaguchi; J Hashimoto; H Uchimiya
  巻：119, 号：1, 開始ページ：31, 終了ページ：40, 1999年01月
  Cyclin-dependent protein kinases (CDKs) play key roles in regulating the eukaryotic cell cycle. We have analyzed the expression of four rice (Oryza sativa) CDK genes, cdc2Os1, cdc2Os2, cdc2Os3, and R2, by in situ hybridization of sections of root apices. Transcripts of cdc2Os1, cdc2Os2, and R2 were detected uniformly in the dividing region of the root apex, cdc2Os1 and cdc2Os2 were also expressed in differentiated cells such as those in the sclerenchyma, pericycle, and parenchyma of the central cylinder. By contrast, signals corresponding to transcripts of cdc2Os3 were distributed only in patches in the dividing region. Counterstaining of sections with 4',6-diamidino-2-phenylindole and double-target in situ hybridization with a probe for histone H4 transcripts revealed that cdc2Os3 transcripts were abundant from the G(2) to the M phase, but were less abundant or absent during the S phase. The levels of the Cdc2Os3 protein and its associated histone H1-kinase activity were reduced by treatment of cultured cells with hydroxyurea, which blocks cycling cells at the onset of the S phase. Our results suggest that domains other than the conserved amino acid sequence (the PSTAIRE motif) have important roles in the function of non-PSTAIRE CDKs in distinct cell-cycle phases.
  英語
  DOI：https://doi.org/10.1104/pp.119.1.31
  DOI ID：10.1104/pp.119.1.31, ISSN：0032-0889, CiNii Articles ID：30019360023, PubMed ID：9880343, Web of Science ID：WOS:000078048300005
• イネのCDK活性化キナーゼの機能解析　　　　　　　　　　　　　　　
  山口 雅利; 梅田 正明; 橋本 純治; 内宮 博文
  日本分子生物学会年会プログラム・講演要旨集, 巻：21, 開始ページ：507, 終了ページ：507, 1998年12月01日
  日本語
  CiNii Articles ID：10002919420, CiNii Books ID：AN10468414
• FUNCTIONAL ANALYSIS OF RICE CYCLIN-DEPENDENT KINASES　　　　　　　　　　　　　　　
  YAMAGUCHI Masatoshi; UMEDA Masaaki; UMEDA-HARA Chikage; HASHIMOTO Junji; UCHIMIYA Hirofumi
  Plant and cell physiology, 巻：39, 開始ページ：S53, 終了ページ：S53, 1998年05月
  英語
  ISSN：0032-0781, CiNii Articles ID：10003751680, CiNii Books ID：AA0077511X
• DIFFERENTIAL EXPRESSION OF cdc2-RELATED GENES IN RICE　　　　　　　　　　　　　　　
  UMEDA Masaaki; UMEDA-HARA Chikage; YAMAGUCHI Masatoshi; HASHIMOTO Junji; UCHIMIYA Hirofumi
  Plant and cell physiology, 巻：38, 開始ページ：s81, 1997年03月
  英語
  ISSN：0032-0781, CiNii Articles ID：10004345700, CiNii Books ID：AA0077511X
• ANALYSIS OF AERENCHYMA FORMATION CAUSED BY CELL DEATH IN RICE ROOT　　　　　　　　　　　　　　　
  KAWAI Maki; SAMARAJEEWA P. K.; YAMAGUCHI Masatoshi; UCHIMIYA Hirofumi
  Plant and cell physiology, 巻：37, 開始ページ：131, 終了ページ：131, 1996年03月
  英語
  ISSN：0032-0781, CiNii Articles ID：10002708306, CiNii Books ID：AA0077511X
• RING fingerタンパク質ATL54の機能解析　　　　　　　　　　　　　　　
  野田壮一郎; 鈴木史朗; 山口雅利; 西窪伸之; 櫻井望; 服部武文; 鈴木秀幸; 出村拓; 柴田大輔; 梅澤俊明
  第29回日本植物細胞分子生物学会（福岡）大会・シンポジウム講演要旨集、p. 96

• 環境共生学実験, 埼玉大学
• 生物学特講, 山形大学
• 分子細胞学, 埼玉大学
• 生物学基礎, 埼玉大学
• 生物代謝工学, 埼玉大学大学院
• 生物学序説, 埼玉大学
• バイオテクノロジー, 埼玉大学

• Canadian Society of Plant Biologist
• 日本植物学会
• 日本植物細胞分子生物学会
• 日本分子生物学会
• 日本植物生理学会

• 二次細胞壁を形成する道管要素と繊維細胞分化制御機構の解明　　　　　　　　　　　　　　　
  日本学術振興会, 科学研究費助成事業, 基盤研究(C), 2024年04月01日 - 2027年03月31日
  山口 雅利, 埼玉大学
  配分額（総額）：4680000, 配分額（直接経費）：3600000, 配分額（間接経費）：1080000
  課題番号：24K08823
• 機能性を高めるグルコマンナン高アセチル化の分子メカニズム　　　　　　　　　　　　　　　
  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 2023年04月01日 - 2027年03月31日
  小竹 敬久; 山口 雅利, 埼玉大学
  配分額（総額）：18720000, 配分額（直接経費）：14400000, 配分額（間接経費）：4320000
  課題番号：23K26827
• 超高感度光干渉法による多元的植物の環境汚染ストレス・活性の無侵襲極短時間モニタ法　　　　　　　　　　　　　　　
  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 2019年04月01日 - 2022年03月31日
  門野 博史; 山口 雅利; ラジャゴパラン ウママヘスワリ; LIM YIHENG, 埼玉大学
  配分額（総額）：17420000, 配分額（直接経費）：13400000, 配分額（間接経費）：4020000
  本研究の目的は，無侵襲・超高感度な光干渉法である統計干渉法(SIT)およびバイオスペックル光断層画像法(bOCT)に基づいて，植物の環境に対する極短時間の生理的・形態的応答を多元的に知ることにより，新しい植物の環境ストレスモニタリング技術を確立することである．本研究ではSITを用いて得られる新規な現象である植物成長の「自発的ナノメータゆらぎ」(NIF)の特性を利用する．加えて，新たに提案するbOCTを用いた植物内部の3次元的生理応答情報を統合して利用する．これらを総合して多角的に植物活性を無侵襲，迅速かつ高感度に評価することにより植物を用いた環境の毒性評価の確立を試みるものである。
  本年度はbOCTおよびSIT統合システムの基礎設計および構築を試みた。新システム設計のための基礎データを取得するための基礎実験を中心におこなった。特にbOCTについては新に提案したバイオスペックルデータの植物活性状態をモニタするための有効性について検討した。環境汚染物質として重金属である亜鉛(Zn)と酸性鉱山排水(AMD)をlentilおよびradishの種子に対して暴露実験をおこなった。
  Znの濃度は0.75から10mg/Lである。この濃度では微量栄養物質として植物に対して成長促進作用が知られている。これに対してbOCTにより得られる活性指標としてのバイオスペックルコントラストは10mg/L(Zn)に対して発芽以前の早期である僅か6時間後に2.5倍の増加を示した。
  一方、人工AMD(FeSO4)(濃度150μmol/L, 298μmol)に対する暴露においても発芽前の早期において内部活性の増加が観測された。これは主としてAMD溶液の低pHによる効果と思われる。 このようにbOCTによる内部活性のモニタの有効性を確認した。
  課題番号：19H04289
• 様々なNACドメイン転写因子と複合体を形成するVNI2の多面的な生物学的役割　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金（基盤研究(C)）, 基盤研究(C), 2018年04月 - 2021年03月
  山口 雅利, 埼玉大学, 研究代表者
  NACドメイン転写因子であるVNI2は、これまでにNACドメイン転写因子で道管形成の鍵因子であるVND7と相互作用する因子と同定されている。また、VNI2はVND7以外にも30ものNACドメイン転写因子と複合体を形成することを明らかにしており、本研究ではVNI2が複合体を形成する作用機構や生物学的意義を明らかにすることを目的として解析を行った。その結果、VNI2は葉の老化を制御する異なるNACドメイン転写因子と複合体を形成することで、多段階制御することを明らかにした。また、VNI2が相互作用因子の機能制御に重要なアミノ酸領域の特定にも成功した。
  競争的資金, 課題番号：18K06277
  論文ID：31422729
• カビ臭産出関連遺伝子の分析を用いた次世代型貯水池カビ臭対策技術の開発　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金（挑戦的萌芽研究）, 2015年04月 - 2018年03月
  浅枝 隆
  競争的資金
• 単一種のマングローブの植林による生態系と景観の改変の実態把握と改善法の開発　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金（基盤研究(B)）, 2015年04月 - 2018年03月
  浅枝 隆
  競争的資金
• NACドメイン転写因子へテロ複合体の生物学的役割　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金（基盤研究(C)）, 2015年04月 - 2018年03月
  山口 雅利, 研究代表者
  競争的資金
  論文ID：31422729
• オミクス解析による細胞外情報処理空間構築の統合的理解　　　　　　　　　　　　　　　
  日本学術振興会, 科学研究費助成事業, 新学術領域研究(研究領域提案型), 2012年06月28日 - 2017年03月31日
  出村 拓; 倉田 哲也; 米田 新; 山口 雅利; 楢本 悟史, 奈良先端科学技術大学院大学
  配分額（総額）：111670000, 配分額（直接経費）：85900000, 配分額（間接経費）：25770000
  道管分化のマスター転写因子VND7の下流で展開する二次細胞壁形成、および、プロトプラストからの細胞壁再生について、オミクス解析を行った。トランスクリプトーム/メタボローム解析により、二次細胞壁形成時に一次代謝経路の活性化が起こること、プロテオーム解析により、リグニン合成とペクチン分解に関連する酵素タンパク質の蓄積量が大きく変動すること、細胞壁再生過程のトランスクリプトーム解析からは、KOR2タンパク質の一次細胞壁再生への関与を示した。さらに、ヒメツリガネゴケのVND7遺伝子ホモログ（VNS遺伝子群）が、通水細胞ハイドロイドと支持細胞ステライドの細胞分化を制御することを示した。
  課題番号：24114002
• 転写抑制因子を活用したリグノセルロース点含有植物の作出　　　　　　　　　　　　　　　
  科学技術振興機構, 戦略的創造研究推進事業さきがけ, 2011年12月 - 2015年03月
  山口 雅利, 研究代表者
  配分額（総額）：52000000, 配分額（直接経費）：40000000, 配分額（間接経費）：12000000
  競争的資金
• NAC転写因子複合体の作用機構と生物学的な役割　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金(若手研究(B)), 若手研究(B), 2013年 - 2014年
  山口 雅利, 埼玉大学, 研究代表者
  配分額（総額）：4420000, 配分額（直接経費）：3400000, 配分額（間接経費）：1020000
  NAC転写因子ファミリーは、生物個体の成長や維持に重要な様々な制御に関わっていることが明らかになっている。本研究では、まずVNI1、および高い相同性を有するANAC103がVND7だけでなく様々なNAC転写因子と複合体を形成することを明らかにした。また、転写因子ライブラリーを用いてVNI2と相互作用する因子を探索したところ、30ものNAC転写因子が同定された。単離されたNAC転写因子には、これまで知られている二次細胞壁形成だけでなく、ストレス応答や、老化、さらに機能が解明されていないものが含まれており、NAC転写因子複合体が様々な制御機構において機能していることが強く示唆された。
  競争的資金, 課題番号：25840098
• 二次細胞壁形成の統御システムの解明　　　　　　　　　　　　　　　
  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 2010年 - 2012年
  出村 拓; 山口 雅利, 奈良先端科学技術大学院大学
  配分額（総額）：18980000, 配分額（直接経費）：14600000, 配分額（間接経費）：4380000
  木質バイオマスを構成する二次細胞壁の形成メカニズムについては、不明な点が多々残されている。本研究では、二次細胞壁形成のマスタースイッチとして同定したVND7 遺伝子を利用して、高効率な二次細胞壁誘導系を確立し、これらを用いて、二次細胞壁の主要成分であるセルロースとキシランの生合成ならびにVND7 の機能制御機構の解析を行うことで、二次細胞壁形成を統御するシステムの新たな側面を明らかにした。
  課題番号：22370020
• 道管分化マスター因子が制御する下流遺伝子発現機構の解析　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金(若手研究(B)), 若手研究(B), 2008年 - 2009年
  山口 雅利, 独立行政法人理化学研究所->奈良先端科学技術大学院大学, 研究代表者
  配分額（総額）：4420000, 配分額（直接経費）：3400000, 配分額（間接経費）：1020000
  私は、道管分化機構を分子レベルで明らかにすることを目的に、道管分化マスター因子であるVND7についての機能解析を行った。まず、マクロアレイ解析によりVND7が制御する多数の下流遺伝子を明らかにし、それらの中からVND7が直接制御する候補遺伝子を見いだした。また、VND7はVNDタンパク質とダイマーを形成することが明らかとなった。さらに、VND7と相互作用する因子として、VNI2を同定し、VND7の転写活性を負に制御することが明らかとなった。
  競争的資金, 課題番号：20770041
• 維管束メリステムからの細胞運命決定機構　　　　　　　　　　　　　　　
  日本学術振興会, 科学研究費助成事業, 特定領域研究, 2008年 - 2008年
  出村 拓; 山口 雅利; 西窪 伸之, 独立行政法人理化学研究所
  配分額（総額）：3000000, 配分額（直接経費）：3000000
  私たちはこれまでに単一のサブファミリーに属する一群のNAC転写因子(VNDl〜VND7がいずれも維管束細胞に発現し、特にVND6とVND7が道管分化を制御するマスター因子として機能することを明らかにした。本研究では、維管束メリステムからの細胞運命の決定機構を明らかする目的で、VNDファミリーの発現と機能の制御機構を詳細な解析を行っている。まず、VND7の機能解析として、転写活性化ドメインを欠失させたドミナントネガティブ体全体のあらゆる道管の分化を制御しうることが明らかとなった。そこで、VNDファミリー内の冗長性を確かめるために、多重変異体の作出を進めた。その結果、VND4/VND7二重T-DNA挿入変異体で根において顕著な道管分化の抑制が起こることが明らかとなった。また、VND7の機能を制御する新規因子を同定するために、酵母Two-hybridスクリーニングによる相互作用因子の探索を行い、新規のNAC転写因子VNI2を単離した。詳細な解析の結果、VNI2はVND7と結合し、VND7の転写活性を抑制することで、道管分化を負に制御することが明らかとなった。さらに、DEXに処理により植物型のVND7を用いた解析を行った。その結果、VND7が他のVNDファミリーと協調的に植物体全体で道管分化誘導が可能なVND7-VP16-GR発現シロイヌナズナを用いたサプレッサーのスクリーニングを行い、多数の変異体を得た。現在、導入遺伝子のインターナル変異やGRシステムヘの変異の有無について調査するとともに原因遺伝子の特定を進めている。一方、トランジェントアッセイ系により、上流でVND7の発現を制御する転写因子についても探索を行っており、現在までにVND4、VND5がVND7の発現を正に制御することを明らかにした。
  課題番号：20061029
• 維管束分化を制御するタンパク質-タンパク質相互作用因子の探索と作用機構の解析　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金(若手研究(B)), 若手研究(B), 2006年 - 2007年
  山口 雅利, 独立行政法人理化学研究所, 研究代表者
  配分額（総額）：3700000, 配分額（直接経費）：3700000
  私たちの研究室では、木質バイオマスの質的および、量的な改変を目的として、植物の維管束、特に木質器官の分化制御機構について分子レベルで明らかにすることを試みている。特に本研究では、タンパク質-タンパク質相互作用機構に焦点を置きながら、新規制御機構の解明を試みてきた。私たちはこれまでに、植物に特有な転写因子であるNACドメインタンパク質をコードするVND7(Vascular related NAC domain protein7)が、過剰発現体などの解析より、道管細胞への分化を決定するマスター遺伝子であることを明らかにした。そこで、まずこのVND7について生化学的な手法などにより解析を行ったところ、VND7はVND1からVND6と二量体を形成することが明らかとなった。また、阻害剤を用いた発現解析により、VND7は積極的なタンパク質分解制御を受けていることが明らかとなった。さらに、VND7と相互作用する因子の探索を行ったところ、NACドメインタンパク質をコートするVNDIP2(VND7-Interacting Protein2)を同定した。このVNDIP2の発現は未成熟な道管細胞においてVND7の発現と重なっているものの、発現のピークはVND7よりも早いことが明らかとなった。また、一過的に遺伝子を導入する実験において、VNDIP2はVND7の転写活性を著しく阻害すること、さらにVN...
  競争的資金, 課題番号：18770045
• 植物における細胞の分裂と分化を制御する分子機構の解析　　　　　　　　　　　　　　　
  文部科学省, 科学研究費補助金(若手研究(B)), 若手研究(B), 2004年 - 2005年
  山口 雅利, 独立行政法人理化学研究所, 研究代表者
  配分額（総額）：3700000, 配分額（直接経費）：3700000
  分化全能性を有する植物は、様々な外的・内的なシグナルに対して、細胞分裂と分化とを柔軟に制御していることが知られている。私はこれまでに、その細胞の分裂と分化の方向性は、細胞周期の進行を制御するサイクリン依存性キナーゼ(CDKs)の活性レベルによって決定されていることを明らかにした。そこで、本研究では高頻度かつ同調的に脱分化そして道管を構成する管状要素細胞へと分化を誘導することが可能なヒャクニチソウ葉肉細胞培養系に着目し、誘導過程においてCDKsの発現や活性がどのような制御を受けているか解析を行っている。昨年度までに私は、細胞周期の進行の決定に重要なCDKA(ZeCDKA)を単離した。さらに、今年度は分裂期特異的に発現し植物にのみ存在するCDKBに属するZeCDKB1;1についても単離することに成功した。これらの機能を推測する目的で、出芽酵母cdc28変異株にこのZeCDKA、およびZeCDKB1;1を導入したところ、ZeCDKAはcdc28の温度感受性を相補することができたのに対し、ZeCDKB1;1はむしろ許容条件下においても生育を阻害することが明らかとなった。また興味深いことに、CDK活性化キナーゼ(CAK)によるリン酸化部位を置換したZeCDKAを導入した場合にも、相補活性はみられなかった。これまでの発現解析結果と併せることにより、ZeCDKAは葉肉細胞が脱分化能を獲得す...
  競争的資金, 課題番号：16770047
• 植物細胞に特徴的な分裂期を制御する細胞周期関連因子に関する解析　　　　　　　　　　　　　　　
  日本学術振興会, 科学研究費助成事業, 特別研究員奨励費, 2000年 - 2001年
  山口 雅利, 東京大学
  配分額（総額）：2000000, 配分額（直接経費）：2000000
  課題番号：00J08639

• 転写抑制因子を利用した植物の二次細胞壁の量的形質を改変する方法　　　　　　　　　　　　　　　
  山口 雅利; 光田 展隆; 坂本 真吾, 特許権