Ras GTPase-activating protein 1 (RASA1) (RASA1)

Ras GTPase-activating protein 1 (RASA1), also known as p120GAP, is a critical negative regulator of the Ras-MAPK signaling pathway (UniProt Consortium, 2023). It functions by accelerating the hydrolysis of GTP bound to Ras proteins, effectively switching them from an active to an inactive state (Boon et al., 2005). This regulation is essential for controlling cell growth, differentiation, and particularly the development of the vascular system (Wooderchak-Donahue et al., 2012). Mutations in the RASA1 gene, typically leading to a loss of function, are the primary cause of capillary malformation-arteriovenous malformation (CM-AVM) syndrome and Parkes Weber syndrome (Revencu et al., 2013). In these conditions, the lack of RASA1 leads to overactive Ras signaling, resulting in abnormal blood vessel formation. While RASA1 itself is difficult to target directly with small molecules due to its role as a tumor suppressor, therapeutic strategies often focus on inhibiting downstream effectors like MEK or PI3K. Current clinical management of RASA1-related vascular malformations often involves the use of mTOR inhibitors like sirolimus to mitigate overactive signaling (Revencu et al., 2013). Research is also ongoing into gene replacement therapies to restore RASA1 function in affected tissues.

Other names

p120GAPp120-GAPRasGAPGAPRASACM-AVMPKWS

RASA1 functions as a negative regulator of the Ras signaling pathway by stimulating the intrinsic GTPase activity of Ras proteins, thereby converting active Ras-GTP to inactive Ras-GDP (UniProt Consortium, 2023).