Lpl
Developmental stage
Maximum expression in adipose tissue during early development. In heart, low levels 6 days before birth increasing 278-fold as animals reach adulthood.
Function
Key enzyme in triglyceride metabolism. Catalyzes the hydrolysis of triglycerides from circulating chylomicrons and very low density lipoproteins (VLDL), and thereby plays an important role in lipid clearance from the blood stream, lipid utilization and storage (PubMed:8675619). Although it has both phospholipase and triglyceride lipase activities it is primarily a triglyceride lipase with low but detectable phospholipase activity (By similarity). Mediates margination of triglyceride-rich lipoprotein particles in capillaries (PubMed:24726386). Recruited to its site of action on vascular endothelium by binding to GPIHBP1 and cell surface heparan sulfate proteoglycans (PubMed:20620994, PubMed:24726386, PubMed:27811232).
Post-translational modifications
Tyrosine nitration after lipopolysaccharide (LPS) challenge down-regulates the lipase activity.
N-glycosylated.
Sequence Similarities
Belongs to the AB hydrolase superfamily. Lipase family.
Tissue Specificity
Detected in white and brown adipose tissue and heart muscle, especially at the lumenal surface of capillaries (PubMed:20620994, PubMed:25066055, PubMed:27811232). Detected on capillary endothelium in the lactating mammary gland (PubMed:27811232). Detected in blood plasma (at protein level) (PubMed:17403372, PubMed:25066055). Expressed in liver, epididymal fat, heart, psoas muscle, lactating mammary gland, adrenal, lung, and ovary. Highest levels in heart and adrenal gland.
Cellular localization
- Cell membrane
- Peripheral membrane protein
- Extracellular side
- Secreted
- Secreted
- Extracellular space
- Extracellular matrix
- Newly synthesized LPL binds to cell surface heparan proteoglycans and is then released by heparanase. Subsequently, it becomes attached to heparan proteoglycan on endothelial cells (PubMed:27811232). Locates to the plasma membrane of microvilli of hepatocytes with triglyceride-rich lipoproteins (TRL). Some of the bound LPL is then internalized and located inside non-coated endocytic vesicles (By similarity).
Alternative names
Lipoprotein lipase, LPL, Phospholipase A1, rep, 1a-1b