PON1

PON1
Available structures
PDB	Ortholog search: PDBe RCSB
List of PDB id codes
	1V04
Identifiers
Aliases	PON1, ESA, MVCD5, PON, paraoxonase 1
External IDs	MGI: 103295 HomoloGene: 68058 GeneCards: PON1
Gene location (Human)
Chr.	Chromosome 7 (human)[1]
End	95,324,532 bp[1]
Gene location (Mouse)
Chr.	Chromosome 6 (mouse)[2]
End	5,193,946 bp[2]
RNA expression pattern
	; ;
	More reference expression data
Gene ontology
Molecular function	• calcium ion binding; • protein homodimerization activity; • metal ion binding; • aryldialkylphosphatase activity; • arylesterase activity; • hydrolase activity; • phospholipid binding; • acyl-L-homoserine-lactone lactonohydrolase activity;
Cellular component	• blood microparticle; • intracellular membrane-bounded organelle; • spherical high-density lipoprotein particle; • high-density lipoprotein particle; • extracellular exosome; • extracellular region; • extracellular;
Biological process	• response to fatty acid; • positive regulation of transporter activity; • negative regulation of plasma lipoprotein oxidation; • lipid metabolism; • carboxylic acid catabolic process; • cholesterol metabolic process; • positive regulation of binding; • response to nutrient levels; • response to fluoride; • positive regulation of cholesterol efflux; • response to external stimulus; • organophosphate catabolic process; • aromatic compound catabolic process; • phosphatidylcholine metabolic process; • response to toxic substance; • dephosphorylation; • lipoxygenase pathway;
	Sources:Amigo / QuickGO
Orthologs
	5444
	18979
	ENSG00000005421
	ENSMUSG00000002588
	P27169
	P52430
	NM_000446
	NM_011134
	NP_000437
	NP_035264
	Wikidata
View/Edit Human	View/Edit Mouse

Serum paraoxonase and arylesterase 1 (PON1) also known as A esterase , homocysteine thiolactonase or serum aryldialkylphosphatase 1 is an enzyme that in humans is encoded by the PON1 gene.[5] Paraoxonase 1 has esterase and more specifically paraoxonase activity.[6] Serum PON1 is found in all mammalian species studied so far but is not present in the serum of birds, fish and reptiles or in insects. PON1 is the first discovered member of a multigene family also containing PON2 and PON3, the genes for which are located adjacent to each other on chromosome 7.

Structure

Human PON1 is a glycoprotein composed of 354 amino acids and has a molecular weight of 43000 Daltons which associates with high-density lipoprotein (HDL, "good cholesterol") in the circulation. Serum PON1 is secreted mainly by the liver, although local synthesis occurs in several tissues and PON1 protein is found in almost all tissues. X-ray crystallography has revealed the structure of PON1 to be a 6 bladed propeller with a unique lid structure covering the active site passage which allows association with HDL.[7][8][9]

Function

PON1 is responsible for hydrolysing organophosphate pesticides and nerve gasses. Polymorphisms in the PON1 gene significantly affect the catalytic ability of the enzyme.[10]

PON1 (paraoxonase 1) is also a major anti-atherosclerotic component of high-density lipoprotein (HDL).[11][12] The PON1 gene is activated by PPAR-γ, which increases synthesis and release of paraoxonase 1 enzyme from the liver, reducing atherosclerosis.[13]

The "natural" substrates for PON1 appear to be lactones.[14] However, PON1 has evolved to be a highly promiscuous enzyme capable of hydrolysing a wide variety of substrates such as lactones (including a number of important pharmaceutical agents such as statins), glucuronide drugs, thiolactones, arylesters, cyclic carbonates, organophosphorus pesticides and nerve gases such as sarin, soman and VX, oestrogen esters and lipid peroxides (oxidised lipids).

Genetics

PON1 in humans is encoded by the PON1 gene which is located on the long arm of chromosome 7.[15] Although many nutritional, life-style and pharmaceutical modulators of PON1 are known.,[16][17] by far the biggest effect on PON1 activity levels, which can vary by over 40 fold between individuals, is through PON1 genetic polymorphisms.[8] The coding region PON1-Q192R polymorphism determines a substrate dependent effect on activity. Some substrates e.g. paraoxon are hydrolysed faster by the R- isoform while others such as diazoxon and lipid-peroxides are hydrolysed more rapidly by the Q- isoform.[8] Both the coding region PON1-L55M and the promoter region PON1-T-108C polymorphisms are associated with different serum concentrations and therefore activities. The 55L allele results in significantly higher PON1 mRNA and serum protein levels and therefore activity compared to the 55M allele.[16][17] The -108C allele has greater promoter activity than the -108T allele which results in different serum activities.[16][17]

The distribution of the PON1 polymorphisms varies with ethnicity. The frequency of the PON1-192R allele increases the further from Europe a population originates, the frequency in Caucasians of 15-30% increases to 70-90% in Far Eastern Oriental and Sub-Saharan African populations.[18] In the southern US African-Americans are five times more likely to be RR than Caucasians.[19] In contrast the PON1-55M allele is much less frequent in Oriental and black African populations compared to Caucasians and are extremely rare or absent in some populations e.g. Thais. These ethnic differences in SNP distribution can lead to large activity differences between populations.[18]

Clinical significance

PON1 was first discovered through its ability to hydrolyse and therefore detoxify organophosphorus compounds which are widely used as pesticides and nerve gases. Despite decades of research it is only now becoming clear that PON1 protects humans from the acute and chronic harmful effects of these compounds[20][21] Low PON1 activity found in children may increase their susceptibility to organophosphates.

Oxidised-lipids are the major cause of inflammation and are responsible for the initiation and/or propagation of several inflammatory diseases including atherosclerosis (heart disease and stroke), diabetes, liver and kidney diseases, rheumatic diseases, eye diseases (macular degeneration), cancer and HIV infection . Because of its ability to destroy oxidised-lipids PON1 appears to play some role in all these diseases. However, the greatest research interest has been the role of PON1 in atherosclerosis, where, because of its ability to remove harmful oxidised-lipids, PON1 protects against the development of atherosclerosis[22] Oxidized polyunsaturated fatty acids (notably in oxidized low-density lipoprotein) form lactone-like structures that are PON substrates.[23]

PON1 also protects against bacterial infection by destroying the bacterial signalling molecules that cause gram negative bacteria to invade human tissue and form colonies, thus PON1 contributes to the bodies innate immunity[24]

Recently it has been suggested that PON1 has a role in healthy aging, however, the mechanism is currently unknown[25]

PON1 activity is low in infants compared to adults. A study of Mexican-American children showed that PON1 activity increased 3.5 times between birth and age seven.[26]

An association between PON1 gene polymorphism and susceptibility to Parkinson's disease was not found in a Chinese population.[27]

Notes

References

GRCh38: Ensembl release 89: ENSG00000005421 - Ensembl, May 2017
GRCm38: Ensembl release 89: ENSMUSG00000002588 - Ensembl, May 2017
"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
Primo-Parmo SL, Sorenson RC, Teiber J, La Du BN (May 1996). "The human serum paraoxonase/arylesterase gene (PON1) is one member of a multigene family". Genomics. 33 (3): 498–507. doi:10.1006/geno.1996.0225. PMID 8661009.
van Himbergen TM, van Tits LJ, Roest M, Stalenhoef AF (Feb 2006). "The story of PON1: how an organophosphate-hydrolysing enzyme is becoming a player in cardiovascular medicine". The Netherlands Journal of Medicine. 64 (2): 34–8. PMID 16517986.
Harel M, Aharoni A, Gaidukov L, Brumshtein B, Khersonsky O, Meged R, Dvir H, Ravelli RB, McCarthy A, Toker L, Silman I, Sussman JL, Tawfik DS (May 2004). "Structure and evolution of the serum paraoxonase family of detoxifying and anti-atherosclerotic enzymes". Nature Structural & Molecular Biology. 11 (5): 412–9. doi:10.1038/nsmb767. PMID 15098021. S2CID 52874893.
Mackness B, Durrington PN, Mackness MI (Sep 1998). "Human serum paraoxonase". General Pharmacology. 31 (3): 329–36. doi:10.1016/s0306-3623(98)00028-7. PMID 9703197.
Deakin SP, James RW (Nov 2004). "Genetic and environmental factors modulating serum concentrations and activities of the antioxidant enzyme paraoxonase-1". Clinical Science. 107 (5): 435–47. doi:10.1042/CS20040187. PMID 15265000. S2CID 18754293.
Costa LG, Cole TB, Vitalone A, Furlong CE (Feb 2005). "Measurement of paraoxonase (PON1) status as a potential biomarker of susceptibility to organophosphate toxicity". Clinica Chimica Acta; International Journal of Clinical Chemistry. 352 (1–2): 37–47. doi:10.1016/j.cccn.2004.09.019. PMID 15653099.
Getz GS, Reardon CA (Jun 2004). "Paraoxonase, a cardioprotective enzyme: continuing issues". Current Opinion in Lipidology. 15 (3): 261–7. doi:10.1097/00041433-200406000-00005. PMID 15166781. S2CID 23497678.
Mackness M, Mackness B (Nov 2004). "Paraoxonase 1 and atherosclerosis: is the gene or the protein more important?". Free Radical Biology & Medicine. 37 (9): 1317–23. doi:10.1016/j.freeradbiomed.2004.07.034. PMID 15454272.
Khateeb J, Gantman A, Kreitenberg AJ, Aviram M, Fuhrman B (Jan 2010). "Paraoxonase 1 (PON1) expression in hepatocytes is upregulated by pomegranate polyphenols: a role for PPAR-gamma pathway". Atherosclerosis. 208 (1): 119–25. doi:10.1016/j.atherosclerosis.2009.08.051. PMID 19783251.
Khersonsky O, Tawfik DS (Apr 2005). "Structure-reactivity studies of serum paraoxonase PON1 suggest that its native activity is lactonase". Biochemistry. 44 (16): 6371–82. doi:10.1021/bi047440d. PMID 15835926.
Clendenning JB, Humbert R, Green ED, Wood C, Traver D, Furlong CE (Aug 1996). "Structural organization of the human PON1 gene". Genomics. 35 (3): 586–9. doi:10.1006/geno.1996.0401. PMID 8812495.
Costa LG, Vitalone A, Cole TB, Furlong CE (Feb 2005). "Modulation of paraoxonase (PON1) activity". Biochemical Pharmacology. 69 (4): 541–50. doi:10.1016/j.bcp.2004.08.027. PMID 15670573.
Schrader C, Graeser AC, Huebbe P, Wagner AE, Rimbach G (Feb 2012). "Allyl isothiocyanate as a potential inducer of paraoxonase-1--studies in cultured hepatocytes and in mice". IUBMB Life. 64 (2): 162–8. doi:10.1002/iub.587. PMID 22131196. S2CID 26735383.
La Du B (1992). "Human serum paraoxonase/arylesterase". In Kalow W (ed.). Pharmacogenetics of Drug Metabolism. New York: Pergamon Press. pp. 51–91.
McDaniel CY, Dail MB, Wills RW, Chambers HW, Chambers JE (Dec 2014). "Paraoxonase 1 polymorphisms within a Mississippi USA population as possible biomarkers of enzyme activities associated with disease susceptibility". Biochemical Genetics. 52 (11–12): 509–23. doi:10.1007/s10528-014-9663-8. PMID 25027835. S2CID 16649798.
Costa LG, Giordano G, Cole TB, Marsillach J, Furlong CE (May 2013). "Paraoxonase 1 (PON1) as a genetic determinant of susceptibility to organophosphate toxicity". Toxicology. 307: 115–22. doi:10.1016/j.tox.2012.07.011. PMC 3516631. PMID 22884923.
Mackness M, Mackness B (2014). "Current aspects of paraoxonase-1 research". In Komoda T (ed.). The HDL handbook : biological functions and clinical implications (Second ed.). Amsterdam: Academic Press. ISBN 978-0-12-407867-3.
Costa LG, Cole TB, Jarvik GP, Furlong CE (2003). "Functional genomic of the paraoxonase (PON1) polymorphisms: effects on pesticide sensitivity, cardiovascular disease, and drug metabolism". Annual Review of Medicine. 54: 371–92. doi:10.1146/annurev.med.54.101601.152421. PMID 12525679.
Chistiakov DA, Melnichenko AA, Orekhov AN, Bobryshev YV (2017). "Paraoxonase and atherosclerosis-related cardiovascular diseases". Biochimie. 132: 19–27. doi:10.1016/j.biochi.2016.10.010. PMID 27771368.
Camps J, Pujol I, Ballester F, Joven J, Simó JM (Apr 2011). "Paraoxonases as potential antibiofilm agents: their relationship with quorum-sensing signals in Gram-negative bacteria". Antimicrobial Agents and Chemotherapy. 55 (4): 1325–31. doi:10.1128/AAC.01502-10. PMC 3067127. PMID 21199929.
Lee YS, Park CO, Noh JY, Jin S, Lee NR, Noh S, Lee JH, Lee KH (Sep 2012). "Knockdown of paraoxonase 1 expression influences the ageing of human dermal microvascular endothelial cells". Experimental Dermatology. 21 (9): 682–7. doi:10.1111/j.1600-0625.2012.01555.x. PMID 22897574. S2CID 12440057.
Huen K, Harley K, Bradman A, Eskenazi B, Holland N (Apr 2010). "Longitudinal changes in PON1 enzymatic activities in Mexican-American mothers and children with different genotypes and haplotypes". Toxicology and Applied Pharmacology. 244 (2): 181–9. doi:10.1016/j.taap.2009.12.031. PMC 2846980. PMID 20045427.
Wang J, Liu Z (Nov 2000). "No association between paraoxonase 1 (PON1) gene polymorphisms and susceptibility to Parkinson's disease in a Chinese population". Movement Disorders. 15 (6): 1265–7. doi:10.1002/1531-8257(200011)15:6<1265::AID-MDS1034>3.0.CO;2-0. PMID 11104219.