Regulator of G protein signalling (RGS) family members are regulatory molecules that act as
GTPase activating proteins (GAPs) for
G alpha subunits of
heterotrimeric G proteins. RGS proteins are able to deactivate G protein subunits of the
Gi alpha,
Go alpha and
Gq alpha subtypes. They drive G proteins into their inactive
GDP-bound forms. Regulator of G protein signaling 4 belongs to this family. All RGS proteins share a conserved 120-amino acid sequence termed the RGS domain which conveys GAP activity. Regulator of G protein signaling 4 protein is 37% identical to
RGS1 and 97% identical to rat Rgs4. This protein negatively regulates signaling upstream or at the level of the heterotrimeric G protein and is localized in the
cytoplasm. == Clinical significance ==