Clarifying the fundamental principles of signal transduction mechanisms by simultaneous measurement of intracellular protein behavior and cellular responses in a single cell

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06097
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 43040:Biophysics-related
• Research Institution: Osaka University
• Principal Investigator: Fukuoka Hajime 大阪大学, 大学院生命機能研究科, 准教授 (50447190)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 走化性 / 感覚受容 / 情報伝達

Outline of Final Research Achievements

This study aimed to quantitatively understand chemotaxis signaling in a single E. coli cell by correlating with parameters among signal input, behavior of intracellular protein, and cellular response based on single-cell measurement technique. This study clarified that 1) spontaneous activation of the receptor array is caused by changes in the methylation level of the chemoreceptor by the activity of CheR and CheB. This study also found that 2) by simultaneous measurements of dynamics in CheB and cellular behavior during the repellent response, dynamic changes in CheB localization reflects chemoreceptor’s activity. This study also quantified 3) the correlation between the intracellular CheYp concentration change and cellular behavior in response to an attractant stimulus by measuring the FRET change between CheZ and CheY and the rotational direction of flagellar motor.

Free Research Field

生物学

Academic Significance and Societal Importance of the Research Achievements

『外環境情報を感知・処理し応答する』ことは最も重要な生命現象の一つである．従来は，生物種を問わず情報処理を担う生体分子の機能やそれらの相関図の解明に焦点が当てられてきた一方で，生きた細胞内での情報処理を担うタンパク質の動態（活性，相互作用，数など）を細胞の応答に直接的に結びつけて理解するには至っていない．本研究は，シンプルな情報伝達系である大腸菌の走化性システムを対象に，独自の１細胞計測技術により『シグナル入力，細胞内タンパク質の動態，細胞応答』を同時に計測し，それら計測パラメーターの関連付けによって情報伝達の定量的な理解に繋げた．本研究の成果は生物に共通の情報伝達系の定量的理解に貢献する．