Integrin receptors orchestrate cell adhesion and cytoskeletal reorganization. The endocytic mechanism of integrin-β3 receptor at the podosome remains unclear. Using viscous RGD-membrane as the model system, here we show that the formation of podosome-like adhesion promotes Dab2/clathrin-mediated endocytosis of integrin-β3. Integrin-β3 and RGD ligand are endocytosed from the podosome and sorted into the endosomal compartment. Inhibitions of podosome formation and knockdowns of Dab2 and clathrin reduce RGD endocytosis. F-actin assembly at the podosome core exhibits protrusive contact towards the substrate and results in plasma membrane invaginations at the podosome ring. BIN1 specifically associates with the region of invaginated membrane and recruits DNM2. During the podosome formation, BIN1 and DNM2 synchronously enrich at the podosome ring and trigger clathrin dissociation and RGD endocytosis. Knockdowns of BIN1 and DNM2 suppress RGD endocytosis. Thus, plasma membrane invagination caused by F-actin polymerization promotes BIN1-dependent DNM2 recruitment and facilitate integrin-β3 endocytosis at the podosome.

整联蛋白受体协调细胞粘附和细胞骨架重组。整合蛋白β3受体在足小体的内吞机制尚不清楚。使用粘性RGD膜作为模型系统，在这里我们显示了足小体状粘附的形成促进了Dab2 / clathrin介导的整合素β3的内吞作用。将整合素-β3和RGD配体从足小体中内吞并分选到内体区室中。抑制足小体形成以及抑制Dab2和网格蛋白可降低RGD的内吞作用。足小体核心处的F-肌动蛋白装配体向底物表现出突出的接触，并导致足小体环处质膜的内陷。BIN1专门与内膜的区域相关联，并募集DNM2。在足小体形成过程中 BIN1和DNM2在足泡环上同步富集并触发网格蛋白解离和RGD内吞。敲低BIN1和DNM2抑制RGD内吞。因此，由F-肌动蛋白聚合引起的质膜内陷促进了BIN1依赖性DNM2募集并促进了足小体的整联蛋白-β3内吞。