GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved G domain common to many GTPases.
Ras is a family of related proteins that are expressed in all animal cell lineages and organs. All Ras protein family members belong to a class of protein called small GTPase, and are involved in transmitting signals within cells. Ras is the prototypical member of the Ras superfamily of proteins, which are all related in three-dimensional structure and regulate diverse cell behaviours.
Small GTPases, also known as small G-proteins, are a family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate (GTP). They are a type of G-protein found in the cytosol that are homologous to the alpha subunit of heterotrimeric G-proteins, but unlike the alpha subunit of G proteins, a small GTPase can function independently as a hydrolase enzyme to bind to and hydrolyze a guanosine triphosphate (GTP) to form guanosine diphosphate (GDP). The best-known members are the Ras GTPases and hence they are sometimes called Ras subfamily GTPases.
Nucleotide exchange factors (NEFs) are proteins that stimulate the exchange (replacement) of nucleoside diphosphates for nucleoside triphosphates bound to other proteins.
Ran also known as GTP-binding nuclear protein Ran is a protein that in humans is encoded by the RAN gene. Ran is a small 25 kDa protein that is involved in transport into and out of the cell nucleus during interphase and also involved in mitosis. It is a member of the Ras superfamily.
In cell signalling, Son of Sevenless (SOS) refers to a set of genes encoding guanine nucleotide exchange factors that act on the Ras subfamily of small GTPases.
Guanine nucleotide exchange factors (GEFs) are proteins or protein domains that activate monomeric GTPases by stimulating the release of guanosine diphosphate (GDP) to allow binding of guanosine triphosphate (GTP). A variety of unrelated structural domains have been shown to exhibit guanine nucleotide exchange activity. Some GEFs can activate multiple GTPases while others are specific to a single GTPase.
Son of sevenless homolog 1 is a protein that in humans is encoded by the SOS1 gene.
Cell division control protein 42 homolog, also known as Cdc42, is a protein involved in regulation of the cell cycle. It was originally identified in S. cerevisiae (yeast) as a mediator of cell division, and is now known to influence a variety of signaling events and cellular processes in a variety of organisms from yeast to mammals.
T-cell lymphoma invasion and metastasis-inducing protein 1 is a protein that in humans is encoded by the TIAM1 gene.
G alpha subunits are one of the three types of subunit of guanine nucleotide binding proteins, which are membrane-associated, heterotrimeric G proteins.
RhoGAP domain is an evolutionary conserved protein domain of GTPase activating proteins towards Rho/Rac/Cdc42-like small GTPases.
RhoGEF domain describes two distinct structural domains with guanine nucleotide exchange factor (GEF) activity to regulate small GTPases in the Rho family. Rho small GTPases are inactive when bound to GDP but active when bound to GTP; RhoGEF domains in proteins are able to promote GDP release and GTP binding to activate specific Rho family members, including RhoA, Rac1 and Cdc42.
RhoG is a small monomeric GTP-binding protein, and is an important component of many intracellular signalling pathways. It is a member of the Rac subfamily of the Rho family of small G proteins and is encoded by the gene RHOG.
Rap guanine nucleotide exchange factor 2 is a protein that in humans is encoded by the RAPGEF2 gene.
RAS guanyl-releasing protein 1 is a protein that in humans is encoded by the RASGRP1 gene.
RAS guanyl-releasing protein 2 is a protein that in humans is encoded by the RASGRP2 gene.
Rap guanine nucleotide exchange factor 5 is a protein that in humans is encoded by the RAPGEF5 gene.
Ras-related GTP-binding protein B is a protein that in humans is encoded by the RRAGB gene.
GTPase-activator protein for Ras-like GTPase is a family of evolutionarily related proteins.
