There are more than a hundred proteins in the Ras superfamily. Based on structure, sequence and function, the Ras superfamily is divided into nine main families, each of which further divided into subfamilies: Ras, Rad, Rab, Rap, Ran, Rho, Rheb, Rit, and Arf. Miro is a recent contributor to the superfamily.
Each subfamily shares the common core G domain, which provides essential GTPase and nucleotide exchange activity.
The surrounding sequence helps determine the functional specificity of the small GTPase, for example the 'Insert Loop', common to the Rho subfamily, specifically contributes to binding to effector proteins such as IQGAP and WASP.
In general, the Ras family is responsible for cell proliferation: Rho for cell morphology, Ran for nuclear transport, and Rab and Arf for vesicle transport.
Subfamilies and members
The following is a list of human proteins belonging to the Ras superfamily:
- Wennerberg K, Rossman KL, Der CJ (March 2005). "The Ras superfamily at a glance". J. Cell. Sci. 118 (Pt 5): 843–6. doi:10.1242/jcs.01660. PMID 15731001.
- Munemitsu S, Innis M, Clark R, McCormick F, Ullrich A, Polakis P. (1990). "Molecular cloning and experssion of a G25K cDNA, the human homolog of the yeast cell cycle gene CDC42". Mol Cell Biol 10 (11): 5977–82. ISSN 0270-7306. PMC 361395. PMID 2122236.