LRAT
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).
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.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Cofactor metabolism; retinol metabolism.
Sequence Similarities
Belongs to the H-rev107 family.
Tissue Specificity
Hepatic stellate cells and endothelial cells (at protein level). Found at high levels in testis and liver, followed by retinal pigment epithelium, small intestine, prostate, pancreas and colon. Low expression observed in brain. In fetal tissues, expressed in retinal pigment epithelium and liver, and barely in the brain.
Cellular localization
- Endoplasmic reticulum membrane
- Single-pass membrane protein
- 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).
Alternative names
Lecithin retinol acyltransferase, Phosphatidylcholine--retinol O-acyltransferase, LRAT