LRAT Gene: Lecithin Retinol Acyltransferase
Key enzyme in vitamin A metabolism and visual cycle
Gene Information Card
| Symbol | LRAT |
|---|---|
| Full Name | Lecithin Retinol Acyltransferase |
| Gene Type | Protein coding |
| Chromosomal Location | 4q31.2 |
| NCBI Gene ID | 9227 ncbi.nlm.nih.gov/gene/9227 |
| Ensembl ID | ENSG00000138684 |
| UniProt ID | Q95237 |
| OMIM ID | 604863 |
| HGNC ID | 6687 |
| Aliases | RBP4 receptor, LCA14, RPEG, lecithin retinol acyltransferase |
Description
LRAT encodes lecithin retinol acyltransferase, a microsomal enzyme that catalyzes the esterification of all-trans-retinol into all-trans-retinyl esters, a critical step in vitamin A metabolism and the visual cycle. This enzyme is essential for retinoid storage in the liver and for the regeneration of 11-cis-retinal in the retina. Mutations in LRAT cause autosomal recessive retinal dystrophies, including Leber congenital amaurosis type 14 and early-onset severe retinal dystrophy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Leber congenital amaurosis 14 (LCA14) | Loss-of-function mutations impair retinyl ester synthesis, disrupting the visual cycle and leading to photoreceptor degeneration. | ClinVar, OMIM |
| Early-onset severe retinal dystrophy (EOSRD) | Biallelic LRAT mutations reduce or abolish enzyme activity, causing progressive vision loss from infancy. | ClinVar, OMIM |
| Retinitis pigmentosa (rare association) | Some LRAT variants may contribute to rod-cone dystrophy phenotypes. | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Retina | 8.3 | Medium |
| Kidney | 4.1 | Low |
| Small intestine | 3.8 | Low |
| Lung | 1.2 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 10.2 | Hepatocyte cell line |
| ARPE-19 | 7.5 | Retinal pigment epithelium cell line |
| HEK293 | 2.1 | Embryonic kidney cell line |
| MCF7 | 0.8 | Breast cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.262T>C (p.Ser88Pro) | Missense | Rare | Loss of enzymatic activity; associated with LCA14 |
| c.398G>A (p.Arg133Gln) | Missense | Rare | Reduced retinyl ester formation; reported in EOSRD |
| c.1A>G (p.Met1?) | Start loss | Rare | Complete loss of protein; pathogenic in LCA14 |
| c.525delC (p.Arg176Alafs*12) | Frameshift | Rare | Premature truncation; loss of function |
Mutation functional classification
Loss of Function (LOF)
Most LRAT disease-associated mutations are loss-of-function, leading to deficient retinyl ester synthesis and impaired visual cycle.
Gain of Function (GOF)
No gain-of-function mutations have been reported for LRAT.
Dominant Negative (DN)
No dominant-negative mechanisms have been described; all known pathogenic variants are recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Vitamin A and retinoid metabolism (Reactome: R-HSA-975634)
• Visual cycle (Reactome: R-HSA-2453902)
• Retinol metabolism (KEGG: hsa00830)
Protein Summary
LRAT is a 230-amino acid integral membrane protein localized to the endoplasmic reticulum. It catalyzes the transfer of an acyl group from phosphatidylcholine to all-trans-retinol, forming all-trans-retinyl esters. This reaction is essential for vitamin A storage in hepatic stellate cells and for the regeneration of 11-cis-retinal in retinal pigment epithelium. The protein contains a conserved N-terminal domain critical for catalytic activity. Deficiency leads to accumulation of unesterified retinol and disruption of the visual cycle.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| LRATD1 Knockout HEK293 Cell Line | EDJ-KQ11329 | Human | 151354 | Details Get a Quote |
| LRATD2 Knockout HEK293 Cell Line | EDJ-KQ14097 | Human | 157638 | Details Get a Quote |
| LRATD2 Knockout A-549 Cell Line | EDJ-KQ44025 | Human | 157638 | Details Get a Quote |
| LRATD2 Knockout HCT 116 Cell Line | EDJ-KQ44026 | Human | 157638 | Details Get a Quote |
| LRATD2 Knockout HeLa Cell Line | EDJ-KQ42795 | Human | 157638 | Details Get a Quote |
| LRAT Knockout HEK293 Cell Line | EDJ-KQ50854 | Human | 9227 | Details Get a Quote |
| LRAT Knockout HeLa Cell Line | EDJ-KQ55105 | Human | 9227 | Details Get a Quote |
| LRATD1 Knockout HeLa Cell Line | EDJ-KQ58687 | Human | 151354 | Details Get a Quote |
| LRAT Knockout A-549 Cell Line | EDJ-KQ63587 | Human | 9227 | Details Get a Quote |
| LRATD1 Knockout A-549 Cell Line | EDJ-KQ67170 | Human | 151354 | Details Get a Quote |
| LRAT Knockout HCT 116 Cell Line | EDJ-KQ72052 | Human | 9227 | Details Get a Quote |
| LRATD1 Knockout HCT 116 Cell Line | EDJ-KQ75572 | Human | 151354 | Details Get a Quote |
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