Retinal is a polyene chromophore. Retinal, bound to proteins called opsins, is the chemical basis of visual phototransduction, the light-detection stage of visual perception (vision).
Dihydrolipoamide dehydrogenase (DLD), also known as dihydrolipoyl dehydrogenase, mitochondrial, is an enzyme that in humans is encoded by the DLD gene. DLD is a flavoprotein enzyme that oxidizes dihydrolipoamide to lipoamide.
The visual cycle is a process in the retina that replenishes the molecule retinal for its use in vision. Retinal is the chromophore of most visual opsins, meaning it captures the photons to begin the phototransduction cascade. When the photon is absorbed, the 11-cis retinal photoisomerizes into all-trans retinal as it is ejected from the opsin protein. Each molecule of retinal must travel from the photoreceptor cell to the RPE and back in order to be refreshed and combined with another opsin. This closed enzymatic pathway of 11-cis retinal is sometimes called Wald's visual cycle after George Wald (1906–1997), who received the Nobel Prize in 1967 for his work towards its discovery.
In enzymology, a retinol dehydrogenase (RDH) (EC 1.1.1.105) is an enzyme that catalyzes the chemical reaction
UDP-glucose 6-dehydrogenase is a cytosolic enzyme that in humans is encoded by the UGDH gene.
Peptidyl-prolyl cis-trans isomerase FKBP1A is an enzyme that in humans is encoded by the FKBP1A gene. It is also commonly referred to as FKBP-12 or FKBP12 and is a member of a family of FK506-binding proteins (FKBPs).
In enzymology, a retinal dehydrogenase, also known as retinaldehyde dehydrogenase (RALDH), catalyzes the chemical reaction converting retinal to retinoic acid. This enzyme belongs to the family of oxidoreductases, specifically the class acting on aldehyde or oxo- donor groups with NAD+ or NADP+ as acceptor groups, the systematic name being retinal:NAD+ oxidoreductase. This enzyme participates in retinol metabolism. The general scheme for the reaction catalyzed by this enzyme is:
RPE-retinal G protein-coupled receptor also known as RGR-opsin is a protein that in humans is encoded by the RGR gene. RGR-opsin is a member of the rhodopsin-like receptor subfamily of GPCR. Like other opsins which bind retinaldehyde, it contains a conserved lysine residue in the seventh transmembrane domain. RGR-opsin comes in different isoforms produced by alternative splicing.
Retinal pigment epithelium-specific 65 kDa protein, also known as retinoid isomerohydrolase, is an enzyme of the vertebrate visual cycle that is encoded in humans by the RPE65 gene. 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. RPE65 belongs to the carotenoid oxygenase family of enzymes.
Retinaldehyde-binding protein 1 (RLBP1) also known as cellular retinaldehyde-binding protein (CRALBP) is a 36-kD water-soluble protein that in humans is encoded by the RLBP1 gene.
11-cis retinol dehydrogenase is an enzyme that in humans is encoded by the RDH5 gene.
Peptidyl-prolyl cis-trans isomerase FKBP1B is an enzyme that in humans is encoded by the FKBP1B gene.
Isocitrate dehydrogenase [NAD] subunit alpha, mitochondrial (IDH3α) is an enzyme that in humans is encoded by the IDH3A gene.
Alcohol dehydrogenase class 4 mu/sigma chain is an enzyme that in humans is encoded by the ADH7 gene.
Isocitrate dehydrogenase [NAD] subunit beta, mitochondrial is an enzyme that in humans is encoded by the IDH3B gene.
Retinol dehydrogenase 12 is an enzyme that in humans is encoded by the RDH12 gene.
Lecithin retinol acyltransferase is an enzyme that in humans is encoded by the LRAT gene.
NADP-retinol dehydrogenase (EC 1.1.1.300, all-trans retinal reductase, all-trans-retinol dehydrogenase, NADP(H)-dependent retinol dehydrogenase/reductase, RDH11, RDH12, RDH13, RDH14, retinol dehydrogenase 12, retinol dehydrogenase 14, retinol dehydrogenase (NADP+), RalR1, PSDR1) is an enzyme with systematic name retinol:NADP+ oxidoreductase. This enzyme catalyses the following chemical reaction
Lipoate–protein ligase (EC 2.7.7.63, LplA, lipoate protein ligase, lipoate–protein ligase A, LPL, LPL-B) is an enzyme with systematic name ATP:lipoate adenylyltransferase. This enzyme catalyses the following chemical reaction
Retinol dehydrogenase 13 (all-trans/9-cis) is a protein that in humans is encoded by the RDH13 gene. This gene encodes a mitochondrial short-chain dehydrogenase/reductase, which catalyzes the reduction and oxidation of retinoids. The encoded enzyme may function in retinoic acid production and may also protect the mitochondria against oxidative stress. Alternatively spliced transcript variants have been described.
