Asymmetry in the Mitotic Exit Network in the budding yeasts

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06641
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44010:Cell biology-related
• Research Institution: Kyushu University
• Principal Investigator: Maekawa Hiromi 九州大学, 農学研究院, 講師 (80399683)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: Mitotic Exit Network / yeast / Ogataea polymorpha / SPOC

Outline of Final Research Achievements

The Mitotic exit network (MEN) is a conserved signalling pathway essential for termination of mitosis in budding yeast Saccharomyces cerevisiae. Most of MEN components are highly conserved in the methylotrophic budding yeast Ogataea polymorpha, but two essential kinases were identified, instead of Cdc15 kinase. The analysis of the conditional mutants for OpHCD1 and OpHcd2 revealed their roles in mitotic exit and cytokinesis. Unlike ScCdc15, the association of these two kinases with the SPBs is restricted to the SPB in the mother cell body, which suggests that the activation of these kinases may occur exclusively in the mother cell body. Such asymmetric SPB localisations are subject to different regulations to ensure the coordination of mitotic exit (ME)-signalling and cell cycle progression. Our study suggests that the diversity of the composition and molecular mechanisms to control the ME-signalling pathway occurred relatively recently during the evolution of budding yeast.

Free Research Field

分子細胞生物学

Academic Significance and Societal Importance of the Research Achievements

モデル酵母Saccharomyces cerevisiaeの細胞周期制御に重要なMEN、SPOCの分子制御機構については長年にわたり詳細に研究されてきたが、他の出芽酵母種での進化的保存性については十分な検証は行われてこなかった。本研究により、同じ子嚢菌出芽酵母であってもシグナル伝達経路の分子構成・活性制御機構に違いが見られること、これらの違いが進化過程の比較的最近起こったことが明らかになったことは、分子機構の進化の理解に貢献するだけでなく、非モデル酵母の産業利用に向けた基礎生物学的研究の重要性を示したことに意義があった。