GAIN domain
The GAIN domain is a protein domain found in a number of cell surface receptors, including adhesion-GPCRs and polycystic kidney disease proteins PKD1 and Polycystic [kidney disease 2|PKD2]. The domain is involved in the self-cleavage of these transmembrane receptors, and has been shown to be crucial for their function. Point mutations within the GAIN domain of PKD1 and GPR56 are known to cause polycystic [kidney disease] and polymicrogyria, respectively.