Showing metabocard for Retinal (BMDB0001358)

General function:

Involved in prostaglandin-D synthase activity

Specific function:

Catalyzes the conversion of PGH2 to PGD2, a prostaglandin involved in smooth muscle contraction/relaxation and a potent inhibitor of platelet aggregation. Involved in a variety of CNS functions, such as sedation, NREM sleep and PGE2-induced allodynia, and may have an anti-apoptotic role in oligodendrocytes. Binds small non-substrate lipophilic molecules, including biliverdin, bilirubin, retinal, retinoic acid and thyroid hormone, and may act as a scavenger for harmful hydrophobic molecules and as a secretory retinoid and thyroid hormone transporter. Possibly involved in development and maintenance of the blood-brain, blood-retina, blood-aqueous humor and blood-testis barrier. It is likely to play important roles in both maturation and maintenance of the central nervous system and male reproductive system (By similarity).

Gene Name:

PTGDS

Uniprot ID:

O02853

Molecular weight:

21229.0

General function:

Energy production and conversion

Specific function:

Can convert/oxidize retinaldehyde to retinoic acid. Binds free retinal and cellular retinol-binding protein-bound retinal. May have a broader specificity and oxidize other aldehydes in vivo.

Gene Name:

ALDH1A1

Uniprot ID:

P48644

Molecular weight:

54806.0

General function:

Lipid transport and metabolism

Specific function:

NAD-dependent oxidoreductase with broad substrate specificity that shows both oxidative and reductive activity (in vitro). Has 17-beta-hydroxysteroid dehydrogenase activity towards various steroids (in vitro). Converts 5-alpha-androstan-3-alpha,17-beta-diol to androsterone and estradiol to estrone (in vitro). Has 3-alpha-hydroxysteroid dehydrogenase activity towards androsterone (in vitro). Has retinol dehydrogenase activity towards all-trans-retinol (in vitro). Can convert androsterone to epi-androsterone. Androsterone is first oxidized to 5-alpha-androstane-3,17-dione and then reduced to epi-andosterone. Can act on both C-19 and C-21 3-alpha-hydroxysteroids (By similarity).

Gene Name:

HSD17B6

Uniprot ID:

Q3T001

Molecular weight:

36198.0

General function:

Lipid transport and metabolism

Specific function:

Retinol dehydrogenase with a clear preference for NADP. Converts all-trans-retinal to all-trans-retinol. May play a role in the regeneration of visual pigment at high light intensity.

Gene Name:

RDH8

Uniprot ID:

Q9N126

Molecular weight:

33956.0

Reactions

General function:

Lipid transport and metabolism

Specific function:

Catalyzes the oxidation of cis-isomers of retinol, including 11-cis-, 9-cis-, and 13-cis-retinol in an NAD-dependent manner (PubMed:7544779, PubMed:7836368, PubMed:9654122). Has no activity towards all-trans retinal (PubMed:9654122). Plays a significant role in 11-cis retinol oxidation in the retinal pigment epithelium cells (RPE) (By similarity). Also recognizes steroids (androsterone, androstanediol) as its substrates (By similarity).

Gene Name:

RDH5

Uniprot ID:

Q27979

Molecular weight:

35037.0

General function:

Lipid transport and metabolism

Specific function:

Retinol dehydrogenase with a clear preference for NADP. Converts all-trans-retinol to all-trans-retinal. Has no detectable activity towards 11-cis-retinol, 9-cis-retinol and 13-cis-retinol (By similarity).

Gene Name:

RDH10

Uniprot ID:

Q8HZT6

Molecular weight:

38087.0

General function:

Energy production and conversion

Specific function:

Catalyzes the oxidation of long-chain primary alcohols and the oxidation of S-(hydroxymethyl) glutathione. Also oxidizes long chain omega-hydroxy fatty acids, such as 20-HETE, producing both the intermediate aldehyde, 20-oxoarachidonate and the end product, a dicarboxylic acid, (5Z,8Z,11Z,14Z)-eicosatetraenedioate. Class-III ADH is remarkably ineffective in oxidizing ethanol.

Gene Name:

ADH5

Uniprot ID:

Q3ZC42

Molecular weight:

39677.0

Reactions

General function:

Lipid transport and metabolism

Specific function:

Retinoids dehydrogenase/reductase with a clear preference for NADP. Displays high activity towards 9-cis, 11-cis and all-trans-retinal. Shows very weak activity towards 13-cis-retinol. Also exhibits activity, albeit with lower affinity than for retinaldehydes, towards lipid peroxidation products (C9 aldehydes) such as 4-hydroxynonenal and trans-2-nonenal. May play an important function in photoreceptor cells to detoxify 4-hydroxynonenal and potentially other toxic aldehyde products resulting from lipid peroxidation. Has no dehydrogenase activity towards steroids.

Gene Name:

RDH12

Uniprot ID:

P59837

Molecular weight:

35171.0

Reactions

General function:

Secondary metabolites biosynthesis, transport and catabolism

Specific function:

Critical isomerohydrolase in the retinoid cycle involved in regeneration of 11-cis-retinal, the chromophore of rod and cone opsins. Catalyzes the cleavage and isomerization of all-trans-retinyl fatty acid esters to 11-cis-retinol which is further oxidized by 11-cis retinol dehydrogenase to 11-cis-retinal for use as visual chromophore (PubMed:16096063, PubMed:19805034, PubMed:20100834). Essential for the production of 11-cis retinal for both rod and cone photoreceptors. Also capable of catalyzing the isomerization of lutein to meso-zeaxanthin an eye-specific carotenoid (By similarity). The soluble form binds vitamin A (all-trans-retinol), making it available for LRAT processing to all-trans-retinyl ester. The membrane form, palmitoylated by LRAT, binds all-trans-retinyl esters, making them available for IMH (isomerohydrolase) processing to all-cis-retinol. The soluble form is regenerated by transferring its palmitoyl groups onto 11-cis-retinol, a reaction catalyzed by LRAT (PubMed:15186777).

Gene Name:

RPE65

Uniprot ID:

Q28175

Molecular weight:

60944.0

Reactions

General function:

Involved in extracellular ligand-gated ion channel acti

Specific function:

GABA, the major inhibitory neurotransmitter in the vertebrate brain, mediates neuronal inhibition by binding to the GABA/benzodiazepine receptor and opening an integral chloride channel. Rho-2 GABA receptor could play a role in retinal neurotransmission (By similarity).

Gene Name:

GABRR2

Uniprot ID:

Q0II76

Molecular weight:

54122.0

General function:

Involved in retinal binding

Specific function:

Cytosolic CRABPs may regulate the access of retinoic acid to the nuclear retinoic acid receptors.

Gene Name:

CRABP1

Uniprot ID:

P62964

Molecular weight:

15592.0

General function:

Involved in retinal binding

Specific function:

Transports retinoic acid to the nucleus. Regulates the access of retinoic acid to the nuclear retinoic acid receptors (By similarity).

Gene Name:

CRABP2

Uniprot ID:

Q5PXY7

Molecular weight:

15735.0

General function:

Involved in retinal binding

Specific function:

Intracellular transport of retinol.

Gene Name:

RBP5

Uniprot ID:

P82708

Molecular weight:

15962.0

General function:

Involved in retinal binding

Specific function:

Cytoplasmic retinol-binding protein (PubMed:7744071). Accepts retinol from the transport protein STRA6, and thereby contributes to retinol uptake, storage and retinoid homeostasis.

Gene Name:

RBP1

Uniprot ID:

P02694

Molecular weight:

15823.0

General function:

Cell wall/membrane/envelope biogenesis

Specific function:

IRBP shuttles 11-cis and all trans retinoids between the retinol isomerase in the pigment epithelium and the visual pigments in the photoreceptor cells of the retina.

Gene Name:

RBP3

Uniprot ID:

P12661

Molecular weight:

139698.0

General function:

Involved in retinal binding

Specific function:

Retinol-binding protein that mediates retinol transport in blood plasma. Delivers retinol from the liver stores to the peripheral tissues. Transfers the bound all-trans retinol to STRA6, that then facilitates retinol transport across the cell membrane.

Gene Name:

RBP4

Uniprot ID:

P18902

Molecular weight:

21069.0

General function:

Involved in G-protein coupled receptor activity

Specific function:

Receptor for all-trans- and 11-cis-retinal. Binds preferentially to the former and may catalyze the isomerization of the chromophore by a retinochrome-like mechanism.

Gene Name:

RGR

Uniprot ID:

P47803

Molecular weight:

31961.0