C3G Background Information C3G (RAPGEF1, Rap guanine nucleotide exchange factor (GEF) 1, GRF2) is a human guanine nucleotide releasing protein for Ras protein. C3G belongs to the adaptor-type Src homology (SH2)-containing molecules. SH2 domains are globular protein modules present in a large variety of functionally distinct proteins. Src family kinases or pervanadate treatment induces phosphorylation of C3G on Tyrosine-504. C3G can interact with Hck and undergo tyrosine phosphorylation by treatment of human myelomonocytic THP-1 cells with mercuric chloride. C3G mRNA is ubiquitous in human adult and fetal tissues. C3G-dependent activation of Rap1 is required for adhesion and spreading of embryonic fibroblasts and for the early embryogenesis of the mouse. The human C3G gene encodes several transcript variants.
