Opsins are members of the guanine nucleotide-binding protein (G protein)-coupled receptor superfamily. This opsin gene is expressed in the eye, brain, testes, and spinal cord. This gene belongs to the seven-exon subfamily of mammalian opsin genes that includes peropsin (RRH) and retinal G protein coupled receptor (RGR). Like these other seven-exon opsin genes, this family member may encode a protein with photoisomerase activity. Alternative splicing results in multiple transcript variants. OPN5 (Opsin 5) is a Protein Coding gene. Among its related pathways are Peptide ligand-binding receptors and Signaling by GPCR. GO annotations related to this gene include G-protein coupled receptor activity and 11-cis retinal binding. An important paralog of this gene is OPN4.