Molecular mechanisms of the redirection of the secretory pathway to form lineage-unique organelles

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14738
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: National Institute for Basic Biology
• Principal Investigator: Kanazawa Takehiko 基礎生物学研究所, 細胞動態研究部門, 助教 (60802783)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 油体 / 細胞板 / オルガネラ / 細胞骨格 / 膜交通 / 分泌経路 / ゼニゴケ

Outline of Final Research Achievements

The membrane traffic is the fundamental system to correctly localized the molecules via membrane-bounded intermediates. Although some lineages of eukaryotes are reported to have acquired lineage-specific organelles, the molecular mechanisms to pioneer the novel membrane trafficking pathways are unclear.
As a model of newly-acquired organelles, I analyzed the cell plates in dividing cells and the liverwort-specific oil body in Marchantia polymorpha. I identified that these organelles are formed by periodic redirection of the secretory pathway, which responsible for the transport to the extracellular space. The cytoskeleton is also re-organized in each process as well. By the mutant screening of the oil body biogenesis, MpERF13 was isolated as a master transcription factor to form oil bodies and to re-organize the cytoskeleton.

Free Research Field

植物細胞生物学

Academic Significance and Societal Importance of the Research Achievements

単膜系オルガネラの進化と多様化は、膜交通の鍵因子の遺伝子重複による数の増加とその後の機能分化が新しいオルガネラの獲得に繋がるというオルガネラパラロジー仮説が提唱されているが、この仮説を支持する実験的な証拠はほとんど示されていない。
全く機能の異なる細胞板と油体が、共通の膜交通経路の転用により形成されるという発見は、上述の仮説を強く支持しており、単膜系オルガネラの獲得原理の理解に向けた基礎生物学的な重要な知見が得られた。
また、苔類の油体は、生理活性の高い様々な化合物を蓄積しており、本研究で明らかになった油体形成の仕組みを活用することで、有用化合物の効率的な産生への貢献も期待される。