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.

细胞迁移涉及从前到后的不对称焦点粘附（FA）动力学，这有利于后缘脱离和定向持久性。在这里，我们证明 kindlin-2 对于迁移细胞中 FA 的滑动和分解至关重要。kindlin-2的丢失显着减少了FA数量并选择性地损害了后部FA的滑动和分解，导致细胞迁移过程中后部回缩缺陷和方向持久性降低。Kindlin-2 缺陷细胞未能在 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，kindlin-2直接与肌球蛋白轻链激酶（MYLK，以下简称MLCK）相互作用，这种作用在血清刺激下增强。血清剥夺抑制了后部 FA 分解，该分解是响应血清刺激而释放的。MLCK 结合 kindlin-2 F0F1 片段（氨基酸残基 1-167）的过度表达，抑制内源 kindlin-2 与 MLCK 的相互作用，表型复制 kindlin-2 缺陷引起的迁移缺陷。MLCK 的抑制，就像 kindlin-2 的丢失一样，也会损害后缘分离、后 FA 分解和方向持久性。这些结果表明 kindlin-2 在促进 FA 肌动球蛋白收缩性方面发挥作用，导致后 FA 滑动和分解增加，以及细胞迁移过程中的定向持久性。