Lipoprotein lipase
| Lipoprotein lipase | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||||
| Symbols | LPL ; LIPD | ||||||||||
| External IDs | Template:OMIM5 Template:MGI HomoloGene: 200 | ||||||||||
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| RNA expression pattern | |||||||||||
| File:PBB GE LPL 203549 s at tn.png | |||||||||||
| File:PBB GE LPL 203548 s at tn.png | |||||||||||
| More reference expression data | |||||||||||
| Orthologs | |||||||||||
| Template:GNF Ortholog box | |||||||||||
| Species | Human | Mouse | |||||||||
| Entrez | n/a | n/a | |||||||||
| Ensembl | n/a | n/a | |||||||||
| UniProt | n/a | n/a | |||||||||
| RefSeq (mRNA) | n/a | n/a | |||||||||
| RefSeq (protein) | n/a | n/a | |||||||||
| Location (UCSC) | n/a | n/a | |||||||||
| PubMed search | n/a | n/a | |||||||||
Lipoprotein lipase (EC 3.1.1.34) is an enzyme that hydrolyzes lipids in lipoproteins, like those found in chylomicrons and very low-density lipoproteins (VLDL), into three free fatty acids and one glycerol molecule. It requires Apo-CII as a cofactor. [1]
Lipoprotein lipase is specifically found in endothelial cells lining the capillaries.
LPL encodes lipoprotein lipase, which is expressed in heart, muscle, and adipose tissue. LPL functions as a homodimer, and has the dual functions of triglyceride hydrolase and ligand/bridging factor for receptor-mediated lipoprotein uptake. Severe mutations that cause LPL deficiency result in type I hyperlipoproteinemia, while less extreme mutations in LPL are linked to many disorders of lipoprotein metabolism.[2]
Regulation
Insulin is known to enhance LPL synthesis in adipocytes and its placement in the capillary endothelium.
LPL has different isozymes in different tissues. The form that is in adipocytes is activated by insulin, whereas that in muscle and myocardium is not. This helps to explain why adipose cells gain fat in a well-fed state.
Pathology
Lipoprotein lipase deficiency leads to hypertriglyceridemia (elevated levels of triglycerides in the bloodstream).[3]
High-fat diets have been shown to cause tissue-specific overexpression of LPL: This has been implicated in tissue-specific insulin resistance and consequent development of type 2 diabetes mellitus.[citation needed]
References
- ↑ Kim SY, Park SM, Lee ST (2006). "Apolipoprotein C-II is a novel substrate for matrix metalloproteinases". Biochem. Biophys. Res. Commun. 339 (1): 47–54. doi:10.1016/j.bbrc.2005.10.182. PMID 16314153.
- ↑ "Entrez Gene: LPL lipoprotein lipase".
- ↑ Okubo M, Horinishi A, Saito M; et al. (2007). "A novel complex deletion-insertion mutation mediated by Alu repetitive elements leads to lipoprotein lipase deficiency". Mol. Genet. Metab. 92 (3): 229–33. doi:10.1016/j.ymgme.2007.06.018. PMID 17706445.
Further reading
- Zechner R (1997). "The tissue-specific expression of lipoprotein lipase: implications for energy and lipoprotein metabolism". Curr. Opin. Lipidol. 8 (2): 77–88. PMID 9183545.
- Fisher RM, Humphries SE, Talmud PJ (1998). "Common variation in the lipoprotein lipase gene: effects on plasma lipids and risk of atherosclerosis". Atherosclerosis. 135 (2): 145–59. PMID 9430364.
- Beisiegel U (1998). "Lipoprotein metabolism". Eur. Heart J. 19 Suppl A: A20–3. PMID 9519338.
- Pentikäinen MO, Oksjoki R, Oörni K, Kovanen PT (2002). "Lipoprotein lipase in the arterial wall: linking LDL to the arterial extracellular matrix and much more". Arterioscler. Thromb. Vasc. Biol. 22 (2): 211–7. PMID 11834518.
- Mead JR, Irvine SA, Ramji DP (2003). "Lipoprotein lipase: structure, function, regulation, and role in disease". J. Mol. Med. 80 (12): 753–69. doi:10.1007/s00109-002-0384-9. PMID 12483461.
External links
- Lipoprotein+lipase at the US National Library of Medicine Medical Subject Headings (MeSH)
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