Environmental adaptation in response to extracellular signals in fungal growth

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05545
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38060:Applied molecular and cellular biology-related
• Research Institution: University of Tsukuba
• Principal Investigator: TAKESHITA Norio 筑波大学, 生命環境系, 准教授 (20745038)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 糸状菌 / 菌糸 / カルシウム / アクチン / カルモジュリン

Outline of Final Research Achievements

Filamentous fungi are composed of tubular cells called mycelium, which grow by extending their tips. The apical growth of mycelium is caused by the cyclic influx of Ca2+, which synchronizes actin polymerization and enzyme secretion to gradually elongate the mycelium. In this study, we visualized the intracellular Ca2+ conduction by live imaging and analyzed its characteristics. In addition, to investigate how Ca2+ signals are transmitted downstream, we constructed strains expressing fusion proteins of Calmodulin CaM or Calmodulin-dependent kinase, CmkA, CmkB, and CmkC, to which GFP was added. We purified the interacting proteins by immunoprecipitation with GFP antibody. They were subjected to LC-MS/MS mass spectrometry to identify 20-60 candidate targets for CaM, CmkA, CmkB, and CmkC, respectively. Interestingly, there was little overlap among them, suggesting that each protein uses different signaling strategies by targeting different proteins.

Free Research Field

微生物学

Academic Significance and Societal Importance of the Research Achievements

本研究では、細胞内のCa2+の伝導をライブイメージングで可視化しその特性を解析した。さらに、Ca2+のシグナルがどのように下流に伝わるかを調べるため、CalmodulinまたはCalmodulin-dependent kinaseのターゲット候補をそれぞれ20-60個同定した。それらの重複はほとんど見られず、それぞれが異なるタンパク質をターゲットとすることで、シグナル伝達を使い分けていることが示唆された。本研究は、カビが関わる醸造・発酵、動植物への病原機構の解明、カビの高い環境適応能の理解と人間生活におけるカビ対策に貢献する。