Rap Guanine Nucleotide Exchange Factor 2 (RAPGEF2)

Members of the RAS subfamily of GTPases function in signal transduction as GTP/GDP-regulated switches that cycle between inactive GDP- and active GTP-bound states. Guanine nucleotide exchange factors (GEFs), such as RAPGEF2, serve as RAS activators by promoting acquisition of GTP to maintain the active GTP-bound state and are the key link between cell surface receptors and RAS activation. The deduced 1,499-amino acid protein has an apparent molecular mass of more than 100 kD, and it shares significant amino acid identity with RAPGEF5. RT-PCR detected high RAPGEF2 expression in kidney, placenta, and liver, intermediate expression in ovary, and low expression in small intestine, brain, and lung. No expression was detected in other tissues examined.