RASA3 (or GAP1_IP4BP) is a member of the GAP1 family and has been shown to specifically bind 1,3,4,5-tetrakisphosphate (IP4). Thus, RASA3 may function as an IP4 receptor. The members of GAP1 family are characterized by 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. Purified RASA3 stimulates GAP activity on Ras with about a five-fold lower potency than p120RasGAP, but shows no GAP-stimulating activity at all against Rac or Rab3A.
Jiyao W et al.(2023). "The conserved domain database in 2023.",