RAP1, GTP-GDP Dissociation Stimulator 1 (RAP1GDS1)

The RAP1GDS1 sequence in NRG started at nucleotide 5 of the coding sequence. The smg GDP dissociation stimulator (smgGDS) protein is a stimulatory GDP/GTP exchange protein with GTPase activity.

By screening a human brain cDNA library with bovine Rap1gds1 cDNA, Kikuchi et al. (1992) cloned RAP1GDS1, which encodes a 558-amino acid protein with a calculated molecular mass of 61.1 kD. Human RAP1GDS1 shares 96% amino acid identity with its bovine homolog. The product of the RAP1GDS1 gene, usually referred to as smgGDS, has guanine nucleotide exchange factor (GEF) activity (Mizuno et al., 1991). RAP1GDS1 stimulates the GDP/GTP exchange reaction of a group of small G proteins by stimulating dissociation of GDP from the subsequent binding of GTP to each small G protein.