Plant genome plasticity resulting from the alteration of the M phase checkpoint

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06215
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Nara Institute of Science and Technology
• Principal Investigator: Komaki Shinichiro 奈良先端科学技術大学院大学, 先端科学技術研究科, 助教 (50584588)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: Survivin / CPC複合体 / M期チェックポイント / 細胞分裂

Outline of Final Research Achievements

The chromosome passenger complex (CPC) is comprised of an Aurora kinase and a scaffold built of INCENP, Borealin, and Survivin. While most CPC components are conserved across eukaryotes, orthologs of the chromatin reader Survivin have only been identified in animals and fungi. This raises the question of how its essential role is carried out in other eukaryotes.
We identified BORI1 and BORI2 as redundant Survivin-like proteins in the context of the CPC in plants. The BORIs were demonstrated to bind to phosphorylated histone H3, which is crucial for the proper association of the CPC with chromatin. However, this interaction is not mediated by a BIR domain as in previously recognized Survivin orthologs, but by an FHA domain. We propose that the unifying criterion of Survivin-type proteins is a helix that facilitates complex formation with the other two scaffold components, and that the addition of a phosphate-binding domain evolved in parallel in different eukaryotic groups.

Free Research Field

細胞分裂

Academic Significance and Societal Importance of the Research Achievements

動物のSurvivinは、アポトーシスの制御因子として同定された。このアポトーシス経路でのSurvivinは、BIRドメインによってカスパーゼを抑制することから、SurvivinはBIRドメインを持つタンパク質であると信じられてきた。そのため、BIRドメインを持つタンパク質が存在しない生物には、Survivinのホモログも無いと考えられてきた。本研究は、これまで不明であった植物でのCPC複合体の局在機構を明らかにしただけにはとどまらず、Survivinの本体がヘリックス領域であると再定義することを可能とし、全ての真核生物にSurvivin /BORIタンパク質が保存されていることを示した。