Arrestins recruit a variety of signaling proteins to active phosphorylated G protein-coupled receptors in the plasma membrane and to the cytoskeleton. Loss of arrestins leads to decreased cell migration, altered cell shape, and an increase in focal adhesions. Small GTPases of the Rho family are molecular switches that regulate actin cytoskeleton and affect a variety of dynamic cellular functions including cell migration and cell morphology. Here we show that non-visual arrestins differentially regulate RhoA and Rac1 activity to promote cell spreading via actin reorganization, and focal adhesion formation via two distinct mechanisms. Arrestins regulate these small GTPases independently of G-protein-coupled receptor activation.

抑制蛋白募集了多种信号蛋白，将其与质膜中的活性磷酸化G蛋白偶联受体以及细胞骨架结合在一起。抑制蛋白的损失导致细胞迁移减少，细胞形状改变和粘着斑增加。Rho家族的小GTP酶是调节肌动蛋白细胞骨架并影响多种动态细胞功能（包括细胞迁移和细胞形态）的分子开关。在这里，我们显示非视觉抑制蛋白差异调节RhoA和Rac1活性，以通过肌动蛋白重组促进细胞扩散，并通过两种不同的机制形成粘着斑。抑制蛋白独立于G蛋白偶联受体的激活而调节这些小GTP酶。