Recombinant Human Lecithin retinol acyltransferase (LRAT) Protein

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)

Subcellular Location

Endoplasmic reticulum membrane (Single-pass membrane protein); Rough endoplasmic reticulum; Endosome, multivesicular body; Cytoplasm, perinuclear region

Disease Association

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. [The disease is caused by variants affecting the gene represented in this entry]

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

Pathway

Cofactor metabolism; retinol metabolism

• Ruiz A. et al. Molecular and biochemical characterization of lecithin retinol acyltransferase. — J. Biol. Chem. (1999)
• Zolfaghari R. et al. Cloning, gene organization and identification of an alternative splicing process in lecithin:retinol acyltransferase cDNA from human liver. — Gene (2004)
• Ota T. et al. Complete sequencing and characterization of 21,243 full-length human cDNAs. — Nat. Genet. (2004)
• Mural R.J. et al. PubMed: CI-5GBD0VIIJ7C63 (SEP-)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Mondal M.S. et al. Lecithin retinol acyltransferase contains cysteine residues essential for catalysis. — Biochemistry (2000)
• den Hollander A.I. et al. Identification of novel mutations in patients with Leber congenital amaurosis and juvenile RP by genome-wide homozygosity mapping with SNP microarrays. — Invest. Ophthalmol. Vis. Sci. (2007)
• Nagatsuma K. et al. Lecithin: retinol acyltransferase protein is distributed in both hepatic stellate cells and endothelial cells of normal rodent and human liver. — Liver Int. (2009)