Q07912

ACK1 also known as Activated Cdc42-Associated Kinase 1, TNK2 is a tyrosine kinase that binds Cdc42Hs in its GTP-bound form and inhibits both the intrinsic and GTPase-activating protein (GAP)-stimulated GTPase activity of Cdc42Hs. ACK1 plays a crucial role in cellular signaling pathways by acting as a tyrosine kinase that specifically interacts with the GTP-bound form of Cdc42Hs, a member of the Ras-related Rho subfamily of GTP-binding proteins. This interaction inhibits the GTPase activity of Cdc42Hs, thereby promoting its active state and influencing cytoskeletal organization and cellular morphology. A unique sequence of 47 amino acids located C-terminal to the SH3 domain of ACK1 is essential for this binding, highlighting ACK1′s structural significance in maintaining the active form of Rho family GTPases.