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.
Subcellular locations: Cytoplasm
Subcellular locations: Membrane
Subcellular locations: Membrane
Colocalizes with CDC42 to plasma membrane.
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.