Ras-GTPase Activating Domain of RASAL1 and similar proteins
Ras GTPase activating-like protein (RASAL) or RASAL1 is a member of the GAP1 family, and a Ca2+ sensor responding in-phase to repetitive Ca2+ signals by associating with the plasma membrane and deactivating Ras. It contains a conserved domain structure comprising N-terminal tandem C2 domains, a highly conserved central RasGAP domain, and a C-terminal pleckstrin-homology domain that is associated with a Bruton's tyrosine kinase motif. RASAL, like Ca2+ -promoted Ras inactivator (CAPRI, or RASAL4), is a cytosolic protein that undergoes a rapid translocation to the plasma membrane in response to receptor-mediated elevation in the concentration of intracellular free Ca2+, a translocation that activates its ability to function as a RasGAP. However, unlike RASAL4, RASAL undergoes an oscillatory translocation to the plasma membrane that occurs in synchrony with repetitive Ca2+ spikes.