LRAT

The protein encoded by this gene is a microsomal enzyme that catalyzes the esterification of all-trans-retinol into all-trans-retinyl ester, an essential reaction for the retinoid cycle in visual system and vitamin A status in liver. Mutations in this gene have been associated with early-onset severe retinal dystrophy. [provided by RefSeq]

Full Name

lecithin retinol acyltransferase (phosphatidylcholine--retinol O-acyltransferase)

Function

Transfers the acyl group from the sn-1 position of phosphatidylcholine to all-trans retinol, producing all-trans retinyl esters (PubMed:9920938).
Retinyl esters are storage forms of vitamin A (Probable). LRAT plays a critical role in vision (Probable). It provides the all-trans retinyl ester substrates for the isomerohydrolase which processes the esters into 11-cis-retinol in the retinal pigment epithelium; due to a membrane-associated alcohol dehydrogenase, 11 cis-retinol is oxidized and converted into 11-cis-retinaldehyde which is the chromophore for rhodopsin and the cone photopigments (Probable). Required for the survival of cone photoreceptors and correct rod photoreceptor cell morphology (By similarity).

Biological Process

Cellular response to leukemia inhibitory factorIEA:Ensembl
Positive regulation of lipid transportIEA:Ensembl
Response to bacteriumIEA:Ensembl
Response to retinoic acidIEA:Ensembl
Response to vitamin AIEA:Ensembl
Retinoid metabolic processTAS:Reactome
Retinol metabolic processManual Assertion Based On ExperimentIDA:UniProtKB
Visual perceptionIEA:UniProtKB-KW
Vitamin A metabolic processISS:UniProtKB

Cellular Location

Endoplasmic reticulum membrane
Rough endoplasmic reticulum
Endosome, multivesicular body
Cytoplasm, perinuclear region
Present in the rough endoplasmic reticulum and multivesicular body in hepatic stellate cells. Present in the rough endoplasmic reticulum and perinuclear region in endothelial cells (By similarity).

Involvement in disease

Leber congenital amaurosis 14 (LCA14):
A severe dystrophy of the retina, typically becoming evident in the first years of life. Visual function is usually poor and often accompanied by nystagmus, sluggish or near-absent pupillary responses, photophobia, high hyperopia and keratoconus.

Topology

Cytoplasmic: 1-194
Helical: 195-215
Lumenal: 216-230