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.
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.
Ras-related protein Rap-1A is a protein that in humans is encoded by the RAP1A gene.
Rap guanine nucleotide exchange factor 3 also known as exchange factor directly activated by cAMP 1 (EPAC1) or cAMP-regulated guanine nucleotide exchange factor I (cAMP-GEFI) is a protein that in humans is encoded by the RAPGEF3 gene.
Rho guanine nucleotide exchange factor 6 is a protein that, in humans, is encoded by the ARHGEF6 gene.
Ras-related protein Rap-2a is a protein that in humans is encoded by the RAP2A gene. RAP2A is a member of the Ras-related protein family.
Rho guanine nucleotide exchange factor 11 is a protein that in humans is encoded by the ARHGEF11 gene. This protein is also called RhoGEF11 or PDZ-RhoGEF.
Rho guanine nucleotide exchange factor 12 is a protein that in humans is encoded by the ARHGEF12 gene. This protein is also called RhoGEF12 or Leukemia-associated Rho guanine nucleotide exchange factor (LARG).
Ras guanyl-releasing protein 3 is a protein that in humans is encoded by the RASGRP3 gene.
Ras-related protein Rap-2b is a protein that in humans is encoded by the RAP2B gene. RAP2B belongs to the Ras-related protein family.
Ras-related protein M-Ras, also known as muscle RAS oncogene homolog and R-Ras3, is a protein that in humans is encoded by the MRAS gene on chromosome 3. It is ubiquitously expressed in many tissues and cell types. This protein functions as a signal transducer for a wide variety of signaling pathways, including those promoting neural and bone formation as well as tumor growth. The MRAS gene also contains one of 27 SNPs associated with increased risk of coronary artery disease.
Mitochondrial GTPase 1 is an enzyme that in humans is encoded by the MTG1 gene.
Rap guanine nucleotide exchange factor 2 is a protein that in humans is encoded by the RAPGEF2 gene.
Ras-specific guanine nucleotide-releasing factor 2 is a protein that in humans is encoded by the RASGRF2 gene.
RCC1 and BTB domain-containing protein 2 is a protein that in humans is encoded by the RCBTB2 gene.
Rho guanine nucleotide exchange factor 9 is a protein that in humans is encoded by the ARHGEF9 gene.
Rap guanine nucleotide exchange factor 6 is a protein that in humans is encoded by the RAPGEF6 gene.
Ras-related protein Rab-8B is a protein that in humans is encoded by the RAB8B gene.
The human ARHGEF10 gene encodes the protein Rho guanine nucleotide exchange factor 10.
Ras-related GTP-binding protein B is a protein that in humans is encoded by the RRAGB gene.
