FIGURE 2.

Schematic model for Thy-1-dependent signaling and cytoskeleton regulation induced by α_vβ₃ integrin-binding. (A) Thy-1/CD90 nanoclusters at the neuronal plasma membrane dynamically associate or disassociate from CBP in lipid microdomains. Phosphorylated CBP serves as a docking site for active Src, which phosphorylates and activates p190RhoGAP that in turn activates the RhoA GTPase that hydrolyses GTP to GDP, inactivating RhoA. (B) Binding of α_vβ₃ integrin from astrocytes to Thy-1/CD90 induces clustering around CBP-Src-containing domains, recruiting Csk. Csk phosphorylates Src on Y527 and switches off Src activity. Inactive Src moves away from the Thy-1-CBP-Csk complex, inactivating p190RhoGAP. GAP inactivation increases RhoA activity, activating its effector ROCK, thereby leading to increased phosphorylation of cofilin and MLCII, and altering actin cytoskeleton dynamics.