Ras GTPase-activating protein 1 (RASA1)

Ras GTPase-activating protein 1 (RASA1) is a cytosolic enzyme that acts as a critical regulator of the Ras signaling pathway, especially by stimulating the intrinsic GTPase activity of Ras proteins, converting them from the active GTP-bound form to the inactive GDP-bound form and thereby attenuating cell proliferation and differentiation signaling. RASA1 is a member of the GAP1 family with multiple functional domains, including SH2-SH3 domains, PH domain, and C2 domains, allowing it to interact with various cellular partners and respond to intracellular calcium. It plays a pivotal role in the maintenance of vascular homeostasis, regulation of angiogenesis, and development of the lymphatic and vascular systems. Germline mutations of RASA1 are linked to inherited vascular disorders such as capillary malformation-arteriovenous malformation syndrome (CM-AVM) and Parkes Weber syndrome. Somatic or epigenetic loss of RASA1 has been documented in several cancers, highlighting its tumor suppressor function. While no drugs clinically target RASA1 directly, its activity is central to pathways that are actively pursued in oncology and vascular medicine. Deficient or dysregulated RASA1 leads to inappropriate Ras signaling, over-proliferation, survival of vascular and lymphatic cells, vessel malformation, and disease.

Other names

RAS p21 protein activator 1p120-RasGAPRasGAPGAPRASAcapillary malformation-arteriovenous malformation (CM-AVM)p120GAPp120RASGAPPKWSp120ras GTPase-activating protein 1triphosphatase-activating proteinRas p21 protein activator (GTPase activating protein) 1

Potential mechanisms (for future or investigational agents): enhancement of GAP activity, restoration of function in loss-of-function disorders, modulation of Ras hydrolysis. Effects observed with pathway-targeting drugs: inhibition of downstream Ras/MAPK signaling, modulation of cell proliferation and differentiation. Inhibition of associated receptors (e.g., VEGFR-3) can mitigate effects of RASA1 loss in animal models.