Brefeldin A Inhibited Guanine Nucleotide Exchange Protein 3 (BIG3)

ARFGEF3 a single-pass membrane protein. Promotes the activation of ARF G-proteins through replacement of GDP with GTP. Four alternatively spliced human isoforms have been described.Contains 1 SEC7 domain. Domain named after the S. cerevisiae SEC7 gene product, which is required for proper protein transport through the Golgi. The domain facilitates guanine nucleotide exchange on the small GTPases, ARFs (ADP ribosylation factors).The SEC7 domain was named after the first protein found to contain such a region . It has been shown to be linked with guanine nucleotide exchange function. The 3D structure of the domain displays several alpha-helices. It was found to be associated with other domains involved in guanine nucleotide exchange in mammalian factors.