RGS4

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.^[6] RGS proteins are able to deactivate G protein subunits of the G_i alpha, G_o alpha and G_q 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.^[7] 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.^[5]

A number of studies associate the RGS4 gene with schizophrenia,^{[8][9][10][11]} while some fail to detect an association.^[12]

RGS4 is also of interest as one of the three main RGS proteins (along with RGS9 and RGS17) involved in terminating signalling by the mu opioid receptor,^[13] and may be important in the development of tolerance to opioid drugs.^{[14][15][16][17][18]}

• cyclic peptides^[19]
• CCG-4986^[20]

RGS4 has been shown to interact with:

• COPB2,^[21]
• ERBB3,^[22] and
• GNAQ.^[23][24]