ABCG8 explained

ATP-binding cassette sub-family G member 8 is a protein that in humans is encoded by the ABCG8 gene.^{[1] [2]}

The protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the White subfamily. The protein encoded by this gene functions as a half-transporter to limit intestinal absorption and promote biliary excretion of sterols. It is expressed in a tissue-specific manner in the liver, colon, and intestine. This gene is tandemly arrayed on chromosome 2, in a head-to-head orientation with family member ABCG5. Mutations in this gene may contribute to sterol accumulation and atherosclerosis, and have been observed in patients with sitosterolemia.^[3]

See also

• ATP-binding cassette transporter

Further reading

• Schmitz G, Langmann T, Heimerl S . Role of ABCG1 and other ABCG family members in lipid metabolism. . J. Lipid Res. . 42 . 10 . 1513–20 . 2002 . 10.1016/S0022-2275(20)32205-7 . 11590207 . free .
• Lu K, Lee MH, Hazard S . Two Genes That Map to the STSL Locus Cause Sitosterolemia: Genomic Structure and Spectrum of Mutations Involving Sterolin-1 and Sterolin-2, Encoded by ABCG5 and ABCG8, Respectively . Am. J. Hum. Genet. . 69 . 2 . 278–90 . 2001 . 11452359 . 10.1086/321294 . 1201544 . etal.
• Hubacek JA, Berge KE, Cohen JC, Hobbs HH . Mutations in ATP-cassette binding proteins G5 (ABCG5) and G8 (ABCG8) causing sitosterolemia . Hum. Mutat. . 18 . 4 . 359–60 . 2002 . 11668628 . 10.1002/humu.1206 . 10011192 . free .
• Berge KE, von Bergmann K, Lutjohann D . Heritability of plasma noncholesterol sterols and relationship to DNA sequence polymorphism in ABCG5 and ABCG8 . J. Lipid Res. . 43 . 3 . 486–94 . 2002 . 10.1016/S0022-2275(20)30155-3 . 11893785 . etal. free .
• Lu K, Lee MH, Yu H . Molecular cloning, genomic organization, genetic variations, and characterization of murine sterolin genes Abcg5 and Abcg8 . J. Lipid Res. . 43 . 4 . 565–78 . 2002 . 10.1016/S0022-2275(20)31486-3 . 11907139 . 1815568 . etal.
• Iida A, Saito S, Sekine A . Catalog of 605 single-nucleotide polymorphisms (SNPs) among 13 genes encoding human ATP-binding cassette transporters: ABCA4, ABCA7, ABCA8, ABCD1, ABCD3, ABCD4, ABCE1, ABCF1, ABCG1, ABCG2, ABCG4, ABCG5, and ABCG8 . J. Hum. Genet. . 47 . 6 . 285–310 . 2002 . 12111378 . 10.1007/s100380200041 . etal. free .
• Heimerl S, Langmann T, Moehle C . Mutations in the human ATP-binding cassette transporters ABCG5 and ABCG8 in sitosterolemia . Hum. Mutat. . 20 . 2 . 151 . 2002 . 12124998 . 10.1002/humu.9047 . 23157539 . etal. free .
• Remaley AT, Bark S, Walts AD . Comparative genome analysis of potential regulatory elements in the ABCG5-ABCG8 gene cluster . Biochem. Biophys. Res. Commun. . 295 . 2 . 276–82 . 2002 . 12150943 . 10.1016/S0006-291X(02)00652-6 . etal.
• Graf GA, Li WP, Gerard RD . Coexpression of ATP-binding cassette proteins ABCG5 and ABCG8 permits their transport to the apical surface . J. Clin. Invest. . 110 . 5 . 659–69 . 2002 . 12208867 . 10.1172/JCI16000 . 151110 . etal.
• Yu L, Li-Hawkins J, Hammer RE . Overexpression of ABCG5 and ABCG8 promotes biliary cholesterol secretion and reduces fractional absorption of dietary cholesterol . J. Clin. Invest. . 110 . 5 . 671–80 . 2002 . 12208868 . 10.1172/JCI16001 . 151111 . etal.
• Strausberg RL, Feingold EA, Grouse LH . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . etal. free .
• Graf GA, Yu L, Li WP . ABCG5 and ABCG8 are obligate heterodimers for protein trafficking and biliary cholesterol excretion . J. Biol. Chem. . 278 . 48 . 48275–82 . 2004 . 14504269 . 10.1074/jbc.M310223200 . etal. free .
• Kajinami K, Brousseau ME, Nartsupha C . ATP binding cassette transporter G5 and G8 genotypes and plasma lipoprotein levels before and after treatment with atorvastatin . J. Lipid Res. . 45 . 4 . 653–6 . 2004 . 14703505 . 10.1194/jlr.M300278-JLR200 . etal. free .
• Hubácek JA, Berge KE, Stefková J . Polymorphisms in ABCG5 and ABCG8 transporters and plasma cholesterol levels . Physiological Research . 53 . 4 . 395–401 . 2005 . 15311998 . etal.
• Yu L, Gupta S, Xu F . Expression of ABCG5 and ABCG8 is required for regulation of biliary cholesterol secretion . J. Biol. Chem. . 280 . 10 . 8742–7 . 2005 . 15611112 . 10.1074/jbc.M411080200 . etal. free .
• Langheim S, Yu L, von Bergmann K . ABCG5 and ABCG8 require MDR2 for secretion of cholesterol into bile . J. Lipid Res. . 46 . 8 . 1732–8 . 2005 . 15930516 . 10.1194/jlr.M500115-JLR200 . etal. free .
• Miettinen TA, Klett EL, Gylling H . Liver Transplantation in a Patient With Sitosterolemia and Cirrhosis . Gastroenterology . 130 . 2 . 542–7 . 2006 . 16472606 . 10.1053/j.gastro.2005.10.022 . 1391914 . etal.
• Lally S, Tan CY, Owens D, Tomkin GH . Messenger RNA levels of genes involved in dysregulation of postprandial lipoproteins in type 2 diabetes: the role of Niemann-Pick C1-like 1, ATP-binding cassette, transporters G5 and G8, and of microsomal triglyceride transfer protein . Diabetologia . 49 . 5 . 1008–16 . 2006 . 16518588 . 10.1007/s00125-006-0177-8 . free .

Notes and References

1. Berge KE, Tian H, Graf GA, Yu L, Grishin NV, Schultz J, Kwiterovich P, Shan B, Barnes R, Hobbs HH . Accumulation of dietary cholesterol in sitosterolemia caused by mutations in adjacent ABC transporters . Science . 290 . 5497 . 1771–5 . Dec 2000 . 11099417 . 10.1126/science.290.5497.1771 . 2000Sci...290.1771B .
2. Grunhage F, Acalovschi M, Tirziu S, Walier M, Wienker TF, Ciocan A, Mosteanu O, Sauerbruch T, Lammert F . Increased gallstone risk in humans conferred by common variant of hepatic ATP-binding cassette transporter for cholesterol . Hepatology . 46 . 3 . 793–801 . Sep 2007 . 17626266 . 10.1002/hep.21847 . 29517167 . free .
3. Web site: Entrez Gene: ABCG8 ATP-binding cassette, sub-family G (WHITE), member 8 (sterolin 2).