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Lipoprotein lipase
Identifiers
Symbols LPL; LIPD
External IDs OMIM: 238600 MGI: 96820 HomoloGene: 200 GeneCards: LPL Gene
RNA expression pattern
PBB GE LPL 203549 s at tn.png
PBB GE LPL 203548 s at tn.png
More reference expression data
Orthologs
Species Human Mouse
Entrez 4023 16956
Ensembl ENSG00000175445 n/a
UniProt P06858 n/a
RefSeq (mRNA) NM_000237 XM_977885
RefSeq (protein) NP_000228 XP_982979
Location (UCSC) Chr 8:
19.84 - 19.87 Mb		 n/a
PubMed search [1] [2]

Lipoprotein lipase (EC 3.1.1.34) is an enzyme that hydrolyzes lipids in lipoproteins, such as those found in chylomicrons and very low-density lipoproteins (VLDL), into two free fatty acids and one monoacylglycerol 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]

Contents

Regulation

Insulin is known to induce 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]

Diets high in refined carbohydrates 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.

Interactions

Lipoprotein lipase has been shown to interact with LRP1.[4][5][6]

References

  1. ^ 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.  
  2. ^ "Entrez Gene: LPL lipoprotein lipase". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=4023.  
  3. ^ 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.  
  4. ^ Williams, S E; Inoue I, Tran H, Fry G L, Pladet M W, Iverius P H, Lalouel J M, Chappell D A, Strickland D K (Mar. 1994). "The carboxyl-terminal domain of lipoprotein lipase binds to the low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor (LRP) and mediates binding of normal very low density lipoproteins to LRP". J. Biol. Chem. (UNITED STATES) 269 (12): 8653–8. ISSN 0021-9258. PMID 7510694.  
  5. ^ Nykjaer, A; Nielsen M, Lookene A, Meyer N, Røigaard H, Etzerodt M, Beisiegel U, Olivecrona G, Gliemann J (Dec. 1994). "A carboxyl-terminal fragment of lipoprotein lipase binds to the low density lipoprotein receptor-related protein and inhibits lipase-mediated uptake of lipoprotein in cells". J. Biol. Chem. (UNITED STATES) 269 (50): 31747–55. ISSN 0021-9258. PMID 7989348.  
  6. ^ Chappell, D A; Fry G L, Waknitz M A, Iverius P H, Williams S E, Strickland D K (Dec. 1992). "The low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor binds and mediates catabolism of bovine milk lipoprotein lipase". J. Biol. Chem. (UNITED STATES) 267 (36): 25764–7. ISSN 0021-9258. PMID 1281473.  

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. doi:10.1097/00041433-199704000-00005. 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. doi:10.1016/S0021-9150(97)00199-8. 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. doi:10.1161/hq0102.101551. 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.  
  • Lichtenstein L, "et al." (2007). "Angptl4 up-regulates cholesterol synthesis in liver via inhibition of LPL- and HL-dependent hepatic cholesterol uptake.". Arterioscler Thromb Vasc Biol. 27 (11): 2420–27. doi:10.1161/ATVBAHA.107.151894. PMID 17761937.  

External links

Hydrolase: esterases (EC 3.1)
3.1.1: Carboxylic ester hydrolases
3.1.2: Thioesterase
3.1.3: Phosphatase
3.1.4: Phosphodiesterase
3.1.6: Sulfatase
Nuclease (includes
deoxyribonuclease and
ribonuclease)
3.1.11-16: Exonuclease
3.1.21-31: Endonuclease
RNase III · RNase H (1, 2A, 2B, 2C) · RNase P · RNase A (1, 2, 3, 4/5) · RNase T1 · RNA-induced silencing complex
either deoxy- or ribo-
Lipids: lipoprotein metabolism
Apolipoproteins
APOA (1, 2, 4, 5) · APOB · APOC (1, 2, 3, 4) · APOD · APOE · APOH
Lipoproteins
HDL
LDL
Other
Lipoprotein lipase · SAA

see also disorders







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