| Primary Identifier | IPR037777 | Type | Domain |
| Short Name | RASA4_PH |
| description | GAP1 (GTPase-activating protein 1) family members include RASA2 (GAP1m), RASAL (RASAL1), GAP1(IP4BP or RASA3), and CAPRI (RASA4). They all display Ras GAP activity. With the exception of RASA2, they all possess an arginine finger-dependent GAP activity on Rap1 [, ]. They contain N-terminal tandem C2 domain repeats, a centrally located Ras-GAP domain, and a PH (pleckstrin homology) domain containing a Btk motif [].This entry represents the PH domain of Ras GTPase-activating protein 4 (RASA4, also known as CAPRI). Both CAPRI and RASAL are calcium-activated RasGAPs that inactivate Ras at the plasma membrane. Its tandem C2 domains bind phospholipids upon an elevation in the intracellular free Ca2+ concentration ([Ca2+]i). CAPRI and RASAL differ in that CAPRI is an amplitude sensor while RASAL senses calcium oscillations [, ]. This difference between them resides not in their C2 domains, but in their PH domains leading to speculation that this might reflect an association with either phosphoinositides and/or proteins []. |
