Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
Grenoble institute of Neuroscience, University Grenoble Alpes, INSERM U1216, Grenoble, France.
EMBO J. 2024 Jul;43(13):2715-2732. doi: 10.1038/s44318-024-00114-4. Epub 2024 May 20.
Microtubules regulate cell polarity and migration via local activation of focal adhesion turnover, but the mechanism of this process is insufficiently understood. Molecular complexes containing KANK family proteins connect microtubules with talin, the major component of focal adhesions. Here, local optogenetic activation of KANK1-mediated microtubule/talin linkage promoted microtubule targeting to an individual focal adhesion and subsequent withdrawal, resulting in focal adhesion centripetal sliding and rapid disassembly. This sliding is preceded by a local increase of traction force due to accumulation of myosin-II and actin in the proximity of the focal adhesion. Knockdown of the Rho activator GEF-H1 prevented development of traction force and abolished sliding and disassembly of focal adhesions upon KANK1 activation. Other players participating in microtubule-driven, KANK-dependent focal adhesion disassembly include kinases ROCK, PAK, and FAK, as well as microtubules/focal adhesion-associated proteins kinesin-1, APC, and αTAT. Based on these data, we develop a mathematical model for a microtubule-driven focal adhesion disruption involving local GEF-H1/RhoA/ROCK-dependent activation of contractility, which is consistent with experimental data.
微管通过局部激活黏着斑周转来调节细胞极性和迁移,但这一过程的机制还不够清楚。含有 KANK 家族蛋白的分子复合物将微管与黏着斑的主要成分——桩蛋白连接起来。在这里,KANK1 介导的微管/桩蛋白连接的局部光遗传学激活促进了微管靶向单个黏着斑,随后微管从黏着斑撤回,导致黏着斑向心滑动和快速解体。在黏着斑滑动之前,由于肌球蛋白-II 和肌动蛋白在黏着斑附近聚集,会导致牵引力局部增加。Rho 激活物 GEF-H1 的敲低阻止了牵引力的发展,并在 KANK1 激活时阻止了黏着斑的滑动和解体。参与微管驱动的、KANK 依赖性黏着斑解体的其他参与者包括激酶 ROCK、PAK 和 FAK,以及微管/黏着斑相关蛋白驱动蛋白-1、APC 和 αTAT。基于这些数据,我们建立了一个微管驱动的黏着斑破坏的数学模型,该模型涉及局部 GEF-H1/RhoA/ROCK 依赖性收缩性的激活,这与实验数据一致。