Homologous Superfamily

Ras guanine nucleotide exchange factor domain superfamily (IPR023578)

Short name: Ras_GEF_dom_sf


Small GTPases of the Ras family alternate between 2 conformations induced by the binding of either GTP or GDP. Guanine nucleotide exchange factors (GEFs) induce the dissociation of GDP to allow association of the more abundant GTP. The Ras-like family of small GTPases includes, among others, Ras, Rap1, R-ras, and Ral. The family is characterised by similarities in the effector domain. The Ras GTPase Rap1 is activated rapidly in response to activation of a variety of receptors. Rap1 activation is mediated by several second messengers, including calcium, diacylglycerol, and cAMP. GEFs have been identified that mediate these effects. One such GEF is Epac, an exchange protein directly activated by cAMP, which represents a novel cAMP-induced, protein kinase A-independent pathway [PMID: 10579920].

This superfamily represents a multihelical domain found in Ras GEFs. It can be subdivided in two domains: Ras GEF catalytic domain (IPR001895) and Ras GEF N-terminal domain (IPR000651). In the nucleotide exchange factor Son of sevenless (SOS), both of these domains are required for the Ras specific nucleotide exchange activity, and both of them together are referred to as SOS-cat [PMID: 15507210].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.