Nano-mechanical Behaviors of Tension-sensoring Proteins

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13832
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Materials/Mechanics of materials
• Research Institution: Kyoto University
• Principal Investigator: Adachi Taiji 京都大学, ウイルス・再生医科学研究所, 教授 (40243323)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 張力感受センサー分子 / ナノ構造力学試験 / 原子間力顕微鏡 / ナノバイオメカニクス / αカテニン

Outline of Final Research Achievements

At adherens junctions, α-catenin is known to act as a tension sensor and accelerate the positive feedback of intercellular tension by recruiting vinculin. In this study, we aimed at elucidating the mechanism how α-catenin retains its activated state while avoiding unfolding under tension. Based on nano-tensile testing using atomic force microscopy, we found that mechanically activated α-catenin fragment exhibited higher mechanical stability than a non-activated one. Through the comparison with mutated and segmented fragments, we found that the key intramolecular interactions within α-catenin act as a conformational switch. We also demonstrated that α-catenin adaptively changes its conformation under tension to a stable intermediate state and settles into a more stable state reinforced by vinculin binding. Our findings suggest that the characteristics of α-catenin enable the functional dynamics of multicellular tissues.

Free Research Field

バイオメカニクス