RAS p21 protein activator 1 or RasGAP (Ras GTPase activating protein), also known as RASA1, is a 120-kDa cytosolic human protein that provides two principal activities:
- Inactivation of Ras from its active GTP-bound form to its inactive GDP-bound form by enhancing the endogenous GTPase activity of Ras, via its C-terminal GAP domain
- Mitogenic signal transmission towards downstream interacting partners through its N-terminal SH2-SH3-SH2 domains
Quick Facts RASA1, Available structures ...
RASA1 |
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Identifiers |
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Aliases | RASA1, CM-AVM, CMAVM, GAP, PKWS, RASA, RASGAP, p120GAP, p120RASGAP, RAS p21 protein activator 1, p120, CMAVM1 |
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External IDs | OMIM: 139150; MGI: 97860; HomoloGene: 2168; GeneCards: RASA1; OMA:RASA1 - orthologs |
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The protein encoded by this gene is located in the cytoplasm and is part of the GAP1 family of GTPase-activating proteins. The gene product stimulates the GTPase activity of normal RAS p21 but not its oncogenic counterpart. Acting as a suppressor of RAS function, the protein enhances the weak intrinsic GTPase activity of RAS proteins resulting in the inactive GDP-bound form of RAS, thereby allowing control of cellular proliferation and differentiation. Mutations leading to changes in the binding sites of either protein are associated with basal cell carcinomas. Alternative splicing results in two isoforms where the shorter isoform, lacking the N-terminal hydrophobic region but retaining the same activity, appears to be abundantly expressed in placental but not adult tissues.[5]
RasGAP contains one SH3 domain and two SH2 domains, a PH domain, a C2 domain, and a GAP domain.
RAS p21 protein activator 1 has been shown to interact with:
- ANXA6,[6]
- CAV2,[7]
- DNAJA3,[8]
- DOK1,[9][10][11]
- EPHB2,[12][13]
- EPHB3,[14]
- GNB2L1[15]
- HCK,[16]
- HRAS,[17][18][19]
- HTT,[20]
- IGF1R,[21]
- KHDRBS1,[22][23][24]
- NCK1,[25]
- PDGFRB,[26][27]
- PTK2B,[28][29]
- SOCS3,[30] and
- Src.[17][31]
The mRNA can interact with Mir-132 microRNA; this process is linked to angiogenesis.[32]
Dunant NM, Wisniewski D, Strife A, Clarkson B, Resh MD (May 2000). "The phosphatidylinositol polyphosphate 5-phosphatase SHIP1 associates with the dok1 phosphoprotein in bcr-Abl transformed cells". Cell. Signal. 12 (5): 317–26. doi:10.1016/s0898-6568(00)00073-5. PMID 10822173. Zisch AH, Pazzagli C, Freeman AL, Schneller M, Hadman M, Smith JW, Ruoslahti E, Pasquale EB (January 2000). "Replacing two conserved tyrosines of the EphB2 receptor with glutamic acid prevents binding of SH2 domains without abrogating kinase activity and biological responses". Oncogene. 19 (2): 177–87. doi:10.1038/sj.onc.1203304. PMID 10644995. S2CID 21872001. Hock B, Böhme B, Karn T, Feller S, Rübsamen-Waigmann H, Strebhardt K (July 1998). "Tyrosine-614, the major autophosphorylation site of the receptor tyrosine kinase HEK2, functions as multi-docking site for SH2-domain mediated interactions". Oncogene. 17 (2): 255–60. doi:10.1038/sj.onc.1201907. PMID 9674711. S2CID 25714553. Koehler JA, Moran MF (May 2001). "RACK1, a protein kinase C scaffolding protein, interacts with the PH domain of p120GAP". Biochem. Biophys. Res. Commun. 283 (4): 888–95. doi:10.1006/bbrc.2001.4889. PMID 11350068. Giglione C, Gonfloni S, Parmeggiani A (June 2001). "Differential actions of p60c-Src and Lck kinases on the Ras regulators p120-GAP and GDP/GTP exchange factor CDC25Mm". Eur. J. Biochem. 268 (11): 3275–83. doi:10.1046/j.1432-1327.2001.02230.x. PMID 11389730. Seely BL, Reichart DR, Staubs PA, Jhun BH, Hsu D, Maegawa H, Milarski KL, Saltiel AR, Olefsky JM (August 1995). "Localization of the insulin-like growth factor I receptor binding sites for the SH2 domain proteins p85, Syp, and GTPase activating protein". J. Biol. Chem. 270 (32): 19151–7. doi:10.1074/jbc.270.32.19151. PMID 7642582. Ger M, Zitkus Z, Valius M (October 2011). "Adaptor protein Nck1 interacts with p120 Ras GTPase-activating protein and regulates its activity". Cell. Signal. 23 (10): 1651–8. doi:10.1016/j.cellsig.2011.05.019. PMID 21664272. Farooqui T, Kelley T, Coggeshall KM, Rampersaud AA, Yates AJ (1999). "GM1 inhibits early signaling events mediated by PDGF receptor in cultured human glioma cells". Anticancer Res. 19 (6B): 5007–13. PMID 10697503. Ekman S, Kallin A, Engström U, Heldin CH, Rönnstrand L (March 2002). "SHP-2 is involved in heterodimer specific loss of phosphorylation of Tyr771 in the PDGF beta-receptor". Oncogene. 21 (12): 1870–5. doi:10.1038/sj.onc.1205210. PMID 11896619. S2CID 35823546. Cacalano NA, Sanden D, Johnston JA (May 2001). "Tyrosine-phosphorylated SOCS-3 inhibits STAT activation but binds to p120 RasGAP and activates Ras". Nat. Cell Biol. 3 (5): 460–5. doi:10.1038/35074525. PMID 11331873. S2CID 19179597. Anand S, Majeti BK, Acevedo LM, Murphy EA, Mukthavaram R, Scheppke L, Huang M, Shields DJ, Lindquist JN, Lapinski PE, King PD, Weis SM, Cheresh DA (2010). "MicroRNA-132–mediated loss of p120RasGAP activates the endothelium to facilitate pathological angiogenesis". Nat Med. 16 (8): 909–14. doi:10.1038/nm.2186. PMC 3094020. PMID 20676106.