GTPaseactiverende

GTPase activating proteins, often abbreviated as GAPs, are a class of regulatory enzymes that play a crucial role in cellular signaling pathways. Their primary function is to accelerate the intrinsic guanosine triphosphate (GTP) hydrolysis activity of small GTPases. Small GTPases are molecular switches that cycle between an inactive guanosine diphosphate (GDP)-bound state and an active GTP-bound state. This cycling is tightly regulated, and GAPs are key players in turning off the GTPase switch.

When a small GTPase is in its active GTP-bound state, it can interact with downstream effector proteins, initiating a cascade of cellular events. GAPs bind to the activated GTPase and facilitate the conversion of GTP to GDP by increasing the rate of GTP hydrolysis. This process effectively inactivates the GTPase, allowing it to return to its GDP-bound state and terminate the signaling pathway. This precise regulation by GAPs is essential for a wide range of cellular processes, including cell growth, differentiation, migration, and signal transduction. Dysregulation of GAP activity can lead to various diseases, including cancer and developmental disorders.