Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Southern University of Science and Technology, Shenzhen 518055, China.
Core Research Facilities, Southern University of Science and Technology, Shenzhen 518055, China.
J Cell Sci. 2021 Jan 13;134(1):jcs244616. doi: 10.1242/jcs.244616.
Cell migration involves front-to-rear asymmetric focal adhesion (FA) dynamics, which facilitates trailing edge detachment and directional persistence. Here, we show that kindlin-2 is crucial for FA sliding and disassembly in migrating cells. Loss of kindlin-2 markedly reduced FA number and selectively impaired rear FA sliding and disassembly, resulting in defective rear retraction and reduced directional persistence during cell migration. Kindlin-2-deficient cells failed to develop serum-induced actomyosin-dependent tension at FAs. At the molecular level, kindlin-2 directly interacted with myosin light chain kinase (MYLK, hereafter referred to as MLCK), which was enhanced in response to serum stimulation. Serum deprivation inhibited rear FA disassembly, which was released in response to serum stimulation. Overexpression of the MLCK-binding kindlin-2 F0F1 fragment (amino acid residues 1-167), which inhibits the interaction of endogenous kindlin-2 with MLCK, phenocopied kindlin-2 deficiency-induced migration defects. Inhibition of MLCK, like loss of kindlin-2, also impaired trailing-edge detachment, rear FA disassembly and directional persistence. These results suggest a role of kindlin-2 in promoting actomyosin contractility at FAs, leading to increased rear FA sliding and disassembly, and directional persistence during cell migration.
细胞迁移涉及前后不对称粘着斑（FA）动力学，这有助于后缘脱离和定向持久性。在这里，我们表明，联接蛋白-2 对于迁移细胞中 FA 的滑动和解体至关重要。联接蛋白-2 的缺失显著减少了 FA 的数量，并选择性地损害了后 FA 的滑动和解体，导致后缘回缩缺陷和细胞迁移时定向持久性降低。缺乏联接蛋白-2 的细胞无法在 FA 处产生血清诱导的肌动球蛋白依赖性张力。在分子水平上，联接蛋白-2 直接与肌球蛋白轻链激酶（MYLK，以下简称 MLCK）相互作用，而这种相互作用在血清刺激下增强。血清剥夺抑制后 FA 的解体，而血清刺激会使其释放。过表达与 MLCK 结合的联接蛋白-2 F0F1 片段（氨基酸残基 1-167），该片段抑制内源性联接蛋白-2 与 MLCK 的相互作用，可模拟联接蛋白-2 缺失引起的迁移缺陷。与缺失联接蛋白-2一样，抑制 MLCK 也损害了后缘脱离、后 FA 解体和定向持久性。这些结果表明，联接蛋白-2 在促进 FA 处的肌动球蛋白收缩中起作用，导致细胞迁移过程中后 FA 的滑动和解体以及定向持久性增加。
