Receptor-transporting protein 4 (RTP4)

Probable chaperone protein that facilitates trafficking and functional cell surface expression of a few G-protein coupled receptors (GPCRs). Promotes functional expression of the bitter taste receptor TAS2R16 (PubMed:16720576).

Also promotes functional expression of the opioid receptor heterodimer OPRD1-OPRM1 (By similarity). .