Retinal Pigment Epithelium Specific Protein 65kDa (RPE65)

RPE65 is a protein which is located in the retinal pigment epithelium and is involved in the conversion of all-trans retinol to 11-cis retinal during phototransduction, which is then used in visual pigment regeneration in photoreceptor cells. There are two forms of this protein, a soluble form called sRPE65, and a palmitoylated, membrane-bound form known as mRPE65. mRPE65 serves as the palmitoyl donor for lecithin retinol acyl transferase (LRAT), the enzyme that catalyzes the vitamin A to all trans retinol step of the chromophore regeneration process. Both mRPE65 and sRPE65 also serve as regulatory proteins, with the ratio and concentrations of these molecules playing a role in the inhibition of 11-cis retinal synthesis. Mutations in this gene have been associated with Leber congenital amaurosis type 2 (LCA2) and retinitis pigmentosa.