InnateDB: Systems Biology of the Innate Immune Response

Homo sapiens Protein: LCAT

Summary

InnateDB Protein

IDBP-37739.5

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

LCAT

Protein Name

lecithin-cholesterol acyltransferase

Synonyms

Species

Homo sapiens

Ensembl Protein

ENSP00000264005

InnateDB Gene

IDBG-242762 (LCAT)

Protein Structure

UniProt Annotation

Function

Central enzyme in the extracellular metabolism of plasma lipoproteins. Synthesized mainly in the liver and secreted into plasma where it converts cholesterol and phosphatidylcholines (lecithins) to cholesteryl esters and lysophosphatidylcholines on the surface of high and low density lipoproteins (HDLs and LDLs). The cholesterol ester is then transported back to the liver. Has a preference for plasma 16:0-18:2 or 18:O-18:2 phosphatidylcholines. Also produced in the brain by primary astrocytes, and esterifies free cholesterol on nascent APOE-containing lipoproteins secreted from glia and influences cerebral spinal fluid (CSF) APOE- and APOA1 levels. Together with APOE and the cholesterol transporter ABCA1, plays a key role in the maturation of glial-derived, nascent lipoproteins. Required for remodeling high-density lipoprotein particles into their spherical forms. {ECO:0000269PubMed:10722751}.

Subcellular Localization

Secreted {ECO:0000269PubMed:19065001}. Note=Secreted into blood plasma. Produced in astrocytes and secreted into cerebral spinal fluid (CSF).

Disease Associations

Lecithin-cholesterol acyltransferase deficiency (LCATD) [MIM:245900]: A disorder of lipoprotein metabolism characterized by inadequate esterification of plasmatic cholesterol. Two clinical forms are recognized: complete LCAT deficiency and fish- eye disease. LCATD is generally referred to the complete form which is associated with absence of both alpha and beta LCAT activities resulting in esterification anomalies involving both HDL (alpha-LCAT activity) and LDL (beta-LCAT activity). It causes a typical triad of diffuse corneal opacities, target cell hemolytic anemia, and proteinuria with renal failure. {ECO:0000269PubMed:11423760, ECO:0000269PubMed:12957688, ECO:0000269PubMed:15994445, ECO:0000269PubMed:16051254, ECO:0000269PubMed:16216249, ECO:0000269PubMed:1681161, ECO:0000269PubMed:1859405, ECO:0000269PubMed:2370048, ECO:0000269PubMed:7607641, ECO:0000269PubMed:7711728, ECO:0000269PubMed:8318557, ECO:0000269PubMed:8432868, ECO:0000269PubMed:8807342, ECO:0000269PubMed:9007616, ECO:0000269PubMed:9741700}. Note=The disease is caused by mutations affecting the gene represented in this entry.Fish-eye disease (FED) [MIM:136120]: A disorder of lipoprotein metabolism due to partial lecithin-cholesterol acyltransferase deficiency that affects only alpha-LCAT activity. FED is characterized by low plasma HDL and corneal opacities due to accumulation of cholesterol deposits in the cornea ('fish- eye'). {ECO:0000269PubMed:1516702, ECO:0000269PubMed:1571050, ECO:0000269PubMed:15994445, ECO:0000269PubMed:1737840, ECO:0000269PubMed:21901787, ECO:0000269PubMed:8620346, ECO:0000269PubMed:9261271}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Tissue Specificity

Expressed mainly in brain, liver and testes. Secreted into plasma and cerebral spinal fluid. Expressed in Hep- G2 cell line. {ECO:0000269PubMed:10222237, ECO:0000269PubMed:3797244}.

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 7 experimentally validated interaction(s) in this database.

Experimentally validated
Total	7 [view]
Protein-Protein	7 [view]
Protein-DNA	0
Protein-RNA	0
DNA-DNA	0
RNA-RNA	0
DNA-RNA	0

Gene Ontology

Molecular Function

Accession	GO Term
GO:0004607	phosphatidylcholine-sterol O-acyltransferase activity
GO:0005515	protein binding
GO:0008374	O-acyltransferase activity
GO:0034186	apolipoprotein A-I binding

Biological Process

GO:0006629	lipid metabolic process
GO:0006644	phospholipid metabolic process
GO:0006656	phosphatidylcholine biosynthetic process
GO:0008203	cholesterol metabolic process
GO:0030301	cholesterol transport
GO:0034372	very-low-density lipoprotein particle remodeling
GO:0034375	high-density lipoprotein particle remodeling
GO:0034435	cholesterol esterification
GO:0042157	lipoprotein metabolic process
GO:0042158	lipoprotein biosynthetic process
GO:0042632	cholesterol homeostasis
GO:0043691	reverse cholesterol transport
GO:0044281	small molecule metabolic process
GO:0090107	regulation of high-density lipoprotein particle assembly