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Professor |
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Research Field |
Life Science / Molecular biology, Life Science / Cell biology |
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Graduating School 【 display / non-display 】
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Kyoto University Faculty of Science Graduated
1994.4 - 1998.3
Graduate School 【 display / non-display 】
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Kyoto University Graduate School, Division of Natural Science Doctor's Course
1998.4 - 2005.3
Campus Career 【 display / non-display 】
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KONAN UNIVERSITY Faculty of Science and Engineering Faculty of Science and Engineering Department of Biology Professor
2022.4
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KONAN UNIVERSITY Faculty of Science and Engineering Faculty of Science and Engineering Department of Biology Associate Professor
2017.4 - 2022.3
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KONAN UNIVERSITY Faculty of Science and Engineering Faculty of Science and Engineering Department of Biology Lecturer
2013.4 - 2017.3
External Career 【 display / non-display 】
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学校法人沖縄科学技術大学院大学 G0細胞ユニット
2011.11 - 2013.3
Country：Japan
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独立行政法人沖縄科学技術研究基盤整備機構 G0細胞ユニット
2010.4 - 2011.10
Country：Japan
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独立行政法人沖縄科学技術研究基盤整備機構 G0細胞ユニット
2005.9 - 2010.3
Country：Japan
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独立行政法人科学技術振興機構 沖縄大学院大学先行的研究事業 G0細胞ユニット
2005.4 - 2005.8
Country：Japan
Papers 【 display / non-display 】
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Phosphate uptake restriction, phosphate export, and polyphosphate synthesis contribute synergistically to cellular proliferation and survival. Reviewed International journal
Masahiro Takado, Tochi Komamura, Tomoki Nishimura, Ikkei Ohkubo, Keita Ohuchi, Tomohiro Matsumoto, Kojiro Takeda
The Journal of biological chemistry 299 ( 12 ) 105454 - 105454 2023.11
Authorship：Last author, Corresponding author
Phosphate (Pi) is a macronutrient, and Pi homeostasis is essential for life. Pi homeostasis has been intensively studied; however, many questions remain, even at the cellular level. Using Schizosaccharomyces pombe, we sought to better understand cellular Pi homeostasis and showed that three Pi regulators with SPX domains, Xpr1/Spx2, Pqr1, and the VTC complex synergistically contribute to Pi homeostasis to support cell proliferation and survival. SPX domains bind to inositol pyrophosphate and modulate activities of Pi-related proteins. Xpr1 is a plasma membrane protein and its Pi-exporting activity has been demonstrated in metazoan orthologs, but not in fungi. We first found that S. pombe Xpr1 is a Pi exporter, activity of which is regulated and accelerated in the mutants of Pqr1 and the VTC complex. Pqr1 is the ubiquitin ligase downregulating the Pi importers, Pho84 and Pho842. The VTC complex synthesizes polyphosphate in vacuoles. Triple deletion of Xpr1, Pqr1, and Vtc4, the catalytic core of the VTC complex, was nearly lethal in normal medium but survivable at lower [Pi]. All double-deletion mutants of the three genes were viable at normal Pi, but Δpqr1Δxpr1 showed severe viability loss at high [Pi], accompanied by hyper-elevation of cellular total Pi and free Pi. This study suggests that the three cellular processes, restriction of Pi uptake, Pi export, and polyP synthesis, contribute synergistically to cell proliferation through maintenance of Pi homeostasis, leading to the hypothesis that cooperation between Pqr1, Xpr1, and the VTC complex protects the cytoplasm and/or the nucleus from lethal elevation of free Pi.
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Regulation of inorganic polyphosphate is required for proper vacuolar proteolysis in fission yeast. Reviewed International journal
Naoya Sawada, Shiori Ueno, Kojiro Takeda
The Journal of biological chemistry 297 ( 1 ) 100891 - 100891 2021.7
Regulation of cellular proliferation and quiescence is a central issue in biology that has been studied using model unicellular eukaryotes, such as the fission yeast Schizosaccharomyces pombe. We previously reported that the ubiquitin/proteasome pathway and autophagy are essential to maintain quiescence induced by nitrogen deprivation in S. pombe; however, specific ubiquitin ligases that maintain quiescence are not fully understood. Here we investigated the SPX-RING-type ubiquitin ligase Pqr1, identified as required for quiescence in a genetic screen. Pqr1 is found to be crucial for vacuolar proteolysis, the final step of autophagy, through proper regulation of phosphate and its polymer polyphosphate. Pqr1 restricts phosphate uptake into the cell through ubiquitination and subsequent degradation of phosphate transporters on plasma membranes. We hypothesized that Pqr1 may act as the central regulator for phosphate control in S. pombe, through the function of the SPX domain involved in phosphate sensing. Deletion of pqr1+ resulted in hyperaccumulation of intracellular phosphate and polyphosphate and in improper autophagy-dependent proteolysis under conditions of nitrogen starvation. Polyphosphate hyperaccumulation in pqr1+-deficient cells was mediated by the polyphosphate synthase VTC complex in vacuoles. Simultaneous deletion of VTC complex subunits rescued Pqr1 mutant phenotypes, including defects in proteolysis and loss of viability during quiescence. We conclude that excess polyphosphate may interfere with proteolysis in vacuoles by mechanisms that as yet remain unknown. The present results demonstrate a connection between polyphosphate metabolism and vacuolar functions for proper autophagy-dependent proteolysis, and we propose that polyphosphate homeostasis contributes to maintenance of cellular viability during quiescence.
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The fission yeast Greatwall-Endosulfine pathway is required for proper quiescence/G<sub>0</sub> phase entry and maintenance. Reviewed
Aono S, Haruna Y, Watanabe YH, Mochida S, Takeda K
Genes to Cells 24 ( 2 ) 172 - 186 2019.2
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Glucose restriction induces transient G2 cell cycle arrest extending cellular chronological lifespan Reviewed
Masuda, F., Ishii, M., Mori, A., Uehara, L., Yanagida, M., *Takeda, K., and *Saitoh, S. (*: corresponding author)
Sci Rep 6 19629 2016.1
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The critical glucose concentration for respiration-independent proliferation of fission yeast, Schizosaccharomyces pombe. Reviewed
*Takeda K, Starzynski C, Mori A, Yanagida M (* corresponding author)
Mitochondrion 22 91 - 95 2015.5
Review Papers (Misc) 【 display / non-display 】
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多彩な生理機能をもつ謎めいた高分子ポリリン酸 〜酵母遺伝学からの一考察〜 Invited
武田鋼二郎
放生研ニュース ( 172 ) 3 - 7 2022.8
Authorship：Lead author
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分裂酵母静止期細胞におけるプロテアソームとオートファジーの協調：ミトコンドリア品質管理と寿命維持
武田鋼二郎
細胞工学 29 429 - 430 2010
Authorship：Lead author Publishing type：Article, review, commentary, editorial, etc. (scientific journal) Publisher：秀潤社
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分裂酵母Cut8によるプロテアソームの核局在機構
武田鋼二郎, 柳田充弘
蛋白質核酸酵素 51 1241 - 1244 2006
Publishing type：Article, review, commentary, editorial, etc. (scientific journal) Publisher：共立出版
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染色体分配と蛋白質分解：セパレースによる姉妹染色分体分離とその制御〜セパレース・セキュリン・APC/C
武田鋼二郎, 柳田充弘
実験医学 22 196 - 202 2004
Publishing type：Article, review, commentary, editorial, etc. (scientific journal) Publisher：羊土社
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APC/サイクロソームによるM期制御機構
武田鋼二郎, 木全諭宇, 柳田充弘
実験医学 19 126 - 131 2001
Publishing type：Article, review, commentary, editorial, etc. (scientific journal) Publisher：羊土社
Presentations 【 display / non-display 】
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Seeking polyphosphate synthases and related proteins of higher eukaryotes by yeast genetics Invited
Kojiro Takeda
iCeMS Seminar (Kyoto University) 2022.10
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分裂酵母Xpr1依存的なリン酸排出活性
武田鋼二郎
酵母遺伝学フォーラム第５５回研究報告会 2022.9
Event date： 2022.9
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分裂酵母におけるポリリン酸の必須性の検討
藤山佳穂、野瀬夏鈴、佃楓音、武田鋼二郎
酵母遺伝学フォーラム第５５回研究報告会 2022.9
Event date： 2022.9
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分裂酵母∆xpr1∆pqr1の高リン酸濃度超感受性の多コピー抑圧因子の探索
西村智貴、佃楓音、駒村灯智、武田鋼二郎
酵母遺伝学フォーラム第５５回研究報告会 2022.9
Event date： 2022.9
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分裂酵母におけるリン酸源枯渇時のポリリン酸関連因子の働き
西村智貴、紙谷竜馬、興梠佑里香、武田鋼二郎
酵母遺伝学フォーラム第５４回研究報告会 2021.8
Event date： 2021.8
Grant-in-Aid for Scientific Research 【 display / non-display 】
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多細胞生物ポリリン酸関連酵素の探索
2022 - 2024
JSPS Grants-in-Aid for Scientific Research Grant-in-Aid for challenging Exploratory Research
Authorship：Principal investigator
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Studies on novel physiological functions and regulatory mechanisms of inorganic polyphosphate in eukaryotes
2019.4 - 2022.3
JSPS Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research(C)
Authorship：Principal investigator
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栄養環境とプロテアソーム経路を連係するシグナル伝達ネットワークの解明
2016.4 - 2019.3
JSPS Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research(C)
分裂酵母をモデルとして、栄養環境の変化をプロテアソームの制御機構に伝えるシグナル伝達ネットワークの善用と生理的意義を解明する。
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プロテアソームの空間制御を司る分子基盤と制御機構の探求
2013.4 - 2016.3
JSPS Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research(C)
プロテアソームの空間制御を司る分子基盤と制御機構の探求
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タンパク質分解マシナリーの協調によるミトコンドリア機能維持の分子基盤の解明
2011.4 - 2013.3
JSPS Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists(B)
タンパク質分解マシナリーの協調によるミトコンドリア機能維持の分子基盤の解明
Other External funds procured 【 display / non-display 】
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タンパク質分解系の協調によるミトコンドリア品質管理と静止期細胞の寿命維持
2010.4 - 2011.3
その他財団等 アステラス病態代謝研究会研究助成金
タンパク質分解系の協調によるミトコンドリア品質管理と静止期細胞の寿命維持
Preferred joint research theme 【 display / non-display 】
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細胞レベルのリン酸恒常性を維持する分子機構
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細胞内ポリリン酸の可視化
Recommended URL 【 display / non-display 】
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微生物学研究室HP
https://sites.google.com/site/microbekonan/
Biological Science