retinoid isomerohydrolase; all-trans-retinyl-palmitate hydrolase; retinal pigment epithelium-specific 65 kD protein; retinol isomerase (RPE65)
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Function
- production of 11-cis retinal & in visual pigment regeneration
- soluble form binds vitamin A (all-trans-retinol), making it available for LRAT processing to all-trans-retinyl ester
- membrane form, palmitoylated by LRAT, binds all-trans-retinyl esters, making them available for isomerohydrolase processing to all-cis-retinol
- soluble form is regenerated by transferring its palmitoyl groups onto 11-cis-retinol, a reaction catalyzed by LRAT
- enzymatic activity is dependent on membrane association
- palmitoylation by LRAT regulates ligand binding specificity
- palmitoylated form (membrane form) specifically binds all-trans-retinyl-palmitate
- soluble unpalmitoylated form binds all-trans-retinol (vitamin A)
- interaction with MYO7A mediates light-dependent intracellular transport of RPE65
Structure
belongs to the carotenoid oxygenase family
Compartment
- cell membrane, lipid-anchor when palmitoylated
- cytoplasm, soluble when unpalmitoylated
- undergoes light-dependent intracellular transport to become more concentrated in the central region of the retinal pigment epithelium cells
Expression
retinal pigment epithelium specific
Pathology
- defects in RPE65 are the cause of LCA2 (Leber congenital amaurosis type 2)
- defects in RPE65 are the cause of autosomal dominant retinitis pigmentosa type 20 (RP20)[2]
- defects in RPE65 are the cause of autosomal dominant retinitis pigmentosa with choroidal involvement[3]
More general terms
Additional terms
References
Database
- Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=6121
- Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:6121
- OMIM: https://mirror.omim.org/entry/180069
- OMIM: https://mirror.omim.org/entry/204100
- OMIM: https://mirror.omim.org/entry/613794
- UniProt: http://www.uniprot.org/uniprot/Q16518.html