OPN3 encodes the human gene, Opsin 3. It may also be known as: Opsin-3; Encephalopsin; Panopsin; protein phosphatase 1, regulatory subunit 116; ECPN; PPP1R116. The encoded protein has an amino acid length of 402 and a mass of 44.9 kDa. Other isoforms may exist. OPN3 is a member of the G-protein coupled receptor 1 family, Opsin subfamily. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.