Guanine nucleotide exchange factor (GEF) that modulates the Rho family of GTPases. Promotes the conversion of some member of the Rho family GTPase from the GDP-bound to the GTP-bound form. Isoform 1 exhibits no activity toward RHOA, RAC1 or CDC42. Isoform 2 exhibits decreased GEF activity toward CDC42. Isoform 3 exhibits a weak but significant activity toward RAC1 and CDC42. Isoform 4 exhibits significant activity toward RHOA and CDC42. The truncated DBL oncogene is active toward RHOA, RAC1 and CDC42. Interacts with an array of inositol phospholipids such as phosphatidylinositol 3-phosphate (PI3P), phosphatidylinositol 4- phosphate (PI4P) and phosphatidylinositol 5-phosphate (PI5P). May interact with CCPG1. Isoform 1 is expressed only in brain. Isoform 3 is expressed in heart, kidney, spleen, liver and testis. Isoform 4 is expressed in brain, heart, kidney, testis, placenta, stomach and peripheral blood. The protein is detectable in brain, heart, kidney, intestine, muscle, lung and testis. Belongs to the MCF2 family. 4 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Apoptosis; Cell development/differentiation; GEF; GEF, Rac/Rho; Motility/polarity/chemotaxis; Oncoprotein