LIPE

The protein encoded by this gene has a long and a short form, generated by use of alternative translational start codons. The long form is expressed in steroidogenic tissues such as testis, where it converts cholesteryl esters to free cholesterol for steroid hormone production. The short form is expressed in adipose tissue, among others, where it hydrolyzes stored triglycerides to free fatty acids.

Full Name

lipase E, hormone sensitive type

Function

Lipase with broad substrate specificity, catalyzing the hydrolysis of triacylglycerols (TAGs), diacylglycerols (DAGs), monoacylglycerols (MAGs), cholesteryl esters and retinyl esters (PubMed:8812477, PubMed:15955102, PubMed:15716583, PubMed:19800417).
Shows a preferential hydrolysis of DAGs over TAGs and MAGs and preferentially hydrolyzes the fatty acid (FA) esters at the sn-3 position of the glycerol backbone in DAGs (PubMed:19800417).
Preferentially hydrolyzes FA esters at the sn-1 and sn-2 positions of the glycerol backbone in TAGs (By similarity).
Catalyzes the hydrolysis of 2-arachidonoylglycerol, an endocannabinoid and of 2-acetyl monoalkylglycerol ether, the penultimate precursor of the pathway for de novo synthesis of platelet-activating factor (By similarity).
In adipose tissue and heart, it primarily hydrolyzes stored triglycerides to free fatty acids, while in steroidogenic tissues, it principally converts cholesteryl esters to free cholesterol for steroid hormone production (By similarity).

Biological Process

Cholesterol metabolic processIEA:UniProtKB-KW
Diacylglycerol catabolic processISS:UniProtKB
Ether lipid metabolic processISS:UniProtKB
Lipid catabolic processISS:UniProtKB
Protein phosphorylationManual Assertion Based On ExperimentTAS:ProtInc
Triglyceride catabolic processManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Cell membrane
Membrane, caveola
Cytoplasm, cytosol
Lipid droplet
Found in the high-density caveolae. Translocates to the cytoplasm from the caveolae upon insulin stimulation (PubMed:17026959).
Phosphorylation by AMPK reduces its translocation towards the lipid droplets (By similarity).

Involvement in disease

Lipodystrophy, familial partial, 6 (FPLD6):
A form of lipodystrophy characterized by abnormal subcutaneous fat distribution. Affected individuals have increased visceral fat, impaired lipolysis, dyslipidemia, hepatic steatosis, systemic insulin resistance, and diabetes. Some patients manifest muscular dystrophy.

PTM

Phosphorylation by AMPK reduces its translocation towards the lipid droplets.