Regulator of G protein-coupled receptor (GPCR) signaling. Regulatory subunit of the R7-Gbeta5 complexes that acts by controlling the subcellular location of the R7-Gbeta5 complexes. When palmitoylated, it targets the R7-Gbeta5 complexes to the plasma membrane, leading to inhibit G protein alpha subunits. When it is unpalmitoylated, the R7-Gbeta5 complexes undergo a nuclear/cypolasmic shuttling. May also act by controlling the proteolytic stability of R7 proteins, probably by protecting them from degradation (By similarity).