Retinal pigment epithelium-specific 65 kDa protein is a retinoid isomerohydrolase enzyme of the vertebrate visual cycle. RPE65 is expressed in the retinal pigment epithelium and is responsible for the conversion of all-trans-retinyl esters to 11-cis-retinol during phototransduction. 11-cis-retinol is then used in visual pigment regeneration in photoreceptor cells.
