Role of Mg-chelatase on intracellular signal transduction

2011 Fiscal Year Final Research Report

• Project/Area Number: 21570035
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: The University of Tokyo
• Principal Investigator: MASUDA Tatsuru 東京大学, 大学院・総合文化研究科, 准教授 (00242305)
• Project Period (FY): 2009 – 2011
• Keywords: クロロフィル / Mg-キラターゼ / 葉緑体 / Genome-uncoupled / 遺伝子

Research Abstract

Mg-chelatase, which is composed by CHLI, CHLD, and CHLH subunits, catalyzes the the first committed step of chlorophyll biosynthetic pathway. In plants, it is known that the expression of nuclear-encoded photosynthesis related genes is coupled with chloroplast functionality. In Arabidopsis, mutants termed gun (genome uncoupled) were identified in which intracellular signaling was disrupted. Screening of gun mutants revealed many mutations were originated in mis-sense mutation of CHLH, suggesting Mg-chelatase functions not only for chlorophyll biosynthesis but also for the intracellular chloroplast to nucleus signal transduction (retrograde signaling).In this study, we have constructed reconstitution system of Mg-chelatase activity and revealed that gun phenotype is mainly related to the repression of Mg-chelatase activity. However, it is not clear why such repression caused the accumulation of CHLH protein in vivo. Analysis of functionality and conformation of Mg-chelatase complex will give novel insight into the retrograde signaling pathway in plant cells.

Research Products

• [Journal Article] Deficiency in riboflavin biosynthesis affects tetrapyrrole biosynthesis by impaired cytokinin metabolism (2012)
  • Author(s): Hedtke, B., Alawady, A., Albacete, A., Kobayashi, K., Melzer, M., Roitsch,T., Masuda, T., and Grimm, B
  • Journal Title: Plant Mol. Biol Volume: 78 Pages: 77-93
• [Journal Article] Regulation of root greening by light and auxin/cytokinin signaling in Arabidopsis (2012)
  • Author(s): Kobayashi, K., Baba, S., Obayashi, T., Keranen, M., Aro, E.M., Fukaki, H., Ohta, H., and Masuda, T
  • Journal Title: Plant Cell Volume: 24 Pages: 1081-1095
• [Journal Article] Role of the G-box element for regulation of chlorophyll biosynthesis in Arabidopsis root (2012)
  • Journal Title: Plant Signal. Behavior Volume: 7 Pages: 922-926
• [Journal Article] Evaluation of unbound free heme by differential extraction method (2012)
  • Author(s): Espinas, A. N., Kobayashi, K., Takahashi, S., Mochizuki, N., and Masuda, T
  • Journal Title: Plant Cell Physiol Volume: 53 Pages: 1344-1354
• [Journal Article] Disrupting the bimolecular binding of the heme binding protein 5 (AtHBP5) with heme oxygenase I (HYI) leads to oxidative stress in Arabidopsis (2012)
  • Author(s): Lee H.-Y., Masuda, T., and Buckhout, T. J
  • Journal Title: J Exp Bot Volume: 63 Pages: 5967-5978
• [Journal Article] Tetrapyrrole metabolism in Arabidopsis thaliana (2011)
  • Author(s): Tanaka, R., Kobayashi, K., and Masuda, T
  • Journal Title: The Arabidopsis Book Volume: 9 Pages: e0145
• [Journal Article] The cell biology of tetrapyrroles: a life and death struggle (2010)
  • Author(s): Mochizuki, M., Tanaka, R., Grimm, B., Masuda, T., Moulin, M., Smith, A. G., Tanaka, A., and Terry, M. J.
  • Journal Title: Trends in Plant Sci Volume: 15 Pages: 488-498
• [Presentation] Interaction of Arabidopsis heme binding protein 5 (HBP5) with heme oxygenase 1 (HY1) in plastids (2012)
  • Author(s): Lee, H.J., Masuda, T., Mochizuki, N.,Buckhout, T
  • Organizer: 第53回日本植物生理学会
  • Place of Presentation: 京都
  • Year and Date: 20120300
• [Presentation] Mg-キラターゼのサブユニットであるCHLHのシロイヌナズナgun変異体における蓄積 (2011)
  • Author(s): 池邨、堀、増田
  • Organizer: 日本植物学会第75回大会
  • Place of Presentation: 東京
  • Year and Date: 20110900
• [Presentation] Heme regulation is strictly controlled in Arabidopsis ferrochelatase deficient mutants,fc1 and fc2 (2011)
  • Author(s): Espinas, N., Mochizuki, N., Masuda, T
  • Organizer: 日本植物学会第75回大会
  • Place of Presentation: 東京
  • Year and Date: 20110900
• [Presentation] 植物からのヘム抽出法の検討-植物細胞におけるフリーヘムプールの評価- (2011)
  • Author(s): 増田、小林、Espinas,高橋、望月
  • Organizer: 日本植物学会第75回大会
  • Place of Presentation: 東京
  • Year and Date: 20110900
• [Presentation] エンドウ葉緑体画分とシロイヌナズナ組換えタンパク質によるMg-キラターゼ活性の再構成と調節機構の解析 (2011)
  • Author(s): 池邨、増田
  • Organizer: 第52回植物生理学会年会
  • Place of Presentation: 仙台
  • Year and Date: 20110300
• [Presentation] Characterization of chloroplast biogenesis in the root of GLK (Golden-2 like) overexpressed Arabidopsis (2011)
  • Author(s): Kobayashi, K., Masuda, T
  • Organizer: 2012 International Conference on Tetrapyrrole Photoreceptors in Photosynthetic Organisms
  • Place of Presentation: Berlin, Germany
  • Year and Date: 20110000
• [Presentation] Tetrapyrrole in plants -Stories about chlorophyll and heme (2011)
  • Author(s): Masuda, T
  • Organizer: International Seminar at CNRS Strasbourg
  • Place of Presentation: Strasbourg, France
  • Year and Date: 20110000
• [Presentation] MgキラターゼのCHLHサブユニットとポルフィリン複合体は光分解を受ける (2010)
  • Author(s): 堀、池邨、望月、増田
  • Organizer: 第51回植物生理学会年会
  • Place of Presentation: 熊本
  • Year and Date: 20100300
• [Book] The Handbook of Porphyrin Science (2011)
  • Author(s): Kobayashi, K., and Masuda, T.
  • Publisher: Tetrapyrrole biosynthesis in plant systems
• [Remarks]
  • URL: http://park.itc.u-tokyo.ac.jp/masuda_lab/Masuda_Laboratory/Welcome.html