RASA1 gene

The RASA1 gene (RASA1 stands for: RAS P21 Protein Activator 1) is a protein coding gene located on chromosome 5q14.3. Functional pathways associated with this gene include signaling receptor binding and protein binding. Associated signaling pathways include the EPH-ephrin signaling pathway and the IL-23 signaling pathway for the immune response. Alternative splicing results in two isoforms, with the shorter isoform, which lacks the N-terminal hydrophobic region but has the same activity, apparently being abundantly expressed in placenta but not in adult tissues. An important paralog of this gene is RASAL2.

The protein encoded by this gene is located in the cytoplasm and belongs to the GAP1 family of GTPase-activating proteins. The gene product stimulates the GTPase activity of the normal RAS p21, but not of its oncogenic counterpart. The protein acts as a suppressor of RAS function by enhancing the weak intrinsic GTPase activity of RAS proteins, leading to the inactive GDP-bound form of RAS and thus enabling the control of cellular proliferation and differentiation.

Mutations that lead to changes in the binding sites of the two proteins are associated with basal cell carcinomas.

Mutations are also associated with hereditary capillary malformations (CM) with or without arteriovenous malformations (AVM) and Parkes-Weber syndrome.

Diseases associated with RASA1 include:

capillary malformation-arteriovenous malformation 1 (nevus rhodoides syndrome)

and

Servelle-Martorell syndrome (syn.: Gorham disease/phlebectasiagenuine diffuse, Bockenheimer)