FUNCTION Visual pigments are the light-absorbing molecules that mediate vision. They consist of an apoprotein, opsin, covalently linked to cis-retinal.BIOPHYSICOCHEMICAL PROPERTIES Monomer. Homodimer. Homotetramer.SUBCELLULAR LOCATION The three color pigments are found in the cone photoreceptor cells.PTM N-glycosylated (PubMed:30948514). O-glycosylated (PubMed:30948514).PTM Phosphorylated on some or all of the serine and threonine residues present in the C-terminal region.DISEASE The disease is caused by variants affecting the gene represented in this entry.DISEASE The disease is caused by variants affecting the gene represented in this entry.DISEASE The disease is caused by variants affecting the gene represented in this entry.SIMILARITY Belongs to the G-protein coupled receptor 1 family. Opsin subfamily.CAUTION Medium-wave-sensitive opsin genes vary in number among individuals and, together with a single red pigment gene, reside in a head-to-tail tandem array within the X chromosome. In the GRCh38 reference genome assembly, there are 3 genes in tandem coding for identical proteins AC P04001, AC P0DN77 and P0DN78.