RRAS: Proteins and Enzymes

R-Ras is a member of the Ras superfamily of GTPases. Ras proteins function as signaling focal points that are activated by convergent signaling pathways intiated by extracellular stimuli (reviewed in Mitin et al, 2005). Activated Ras proteins in turn regulate a diversity of downstream cytoplasmic signaling cascades. Many members of the Ras superfamily are implicated in the regulation of hematopoietic cells, with roles in growth, survival, differentiation, cytokine production, chemotaxis, vesicle-trafficking, and phagocytosis. The Ras superfamily of proteins includes over 150 small GTPases (distinguished from the large, heterotrimeric GTPases, the G-proteins). It comprises six subfamilies, the Ras, Rho, Ran, Rab, Arf, and Kir/Rem/Rad subfamilies. They exhibit considerable overall amino acid identities, especially in the regions interacting with the guanine nucleotide exchange factors that catalyze their activation. Recognizes R-Ras; human R-Ras is a 218 amino acid protein.