ABCG4 explained

ATP-binding cassette sub-family G member 4 is a protein that in humans is encoded by the ABCG4 gene.^{[1] [2]}

The protein encoded by this gene is included in the ATP-binding cassette transporter (ABC protein) superfamily. 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 and is expressed predominantly in liver tissue. The function has not yet been determined but may involve cholesterol transport. Alternate splice variants have been described but their full length sequences have not been determined.^[2]

ABCG4 has demonstrated, in vitro, to participate in the efflux of desmosterol and amyloid-β peptide (Aβ). It is highly expressed in the brain, but its localization and function at the blood-brain barrier (BBB) level remain unknown.^[3]

See also

• ATP-binding cassette transporter

Further reading

• Engel T, Lorkowski S, Lueken A . The human ABCG4 gene is regulated by oxysterols and retinoids in monocyte-derived macrophages. . Biochem. Biophys. Res. Commun. . 288 . 2 . 483–8 . 2001 . 11606068 . 10.1006/bbrc.2001.5756 . etal.
• Annilo T, Tammur J, Hutchinson A . Human and mouse orthologs of a new ATP-binding cassette gene, ABCG4. . Cytogenet. Cell Genet. . 94 . 3–4 . 196–201 . 2002 . 11856881 . 10.1159/000048816 . 19897612 . etal.
• Yoshikawa M, Yabuuchi H, Kuroiwa A . Molecular and cytogenetic characterization of the mouse ATP-binding cassette transporter Abcg4. . Gene . 293 . 1–2 . 67–75 . 2002 . 12137944 . 10.1016/S0378-1119(02)00719-9 . etal.
• Oldfield S, Lowry C, Ruddick J, Lightman S . ABCG4: a novel human white family ABC-transporter expressed in the brain and eye. . Biochim. Biophys. Acta . 1591 . 1–3 . 175–9 . 2002 . 12183068 . 10.1016/S0167-4889(02)00269-0 .
• 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 .
• Cserepes J, Szentpétery Z, Seres L . Functional expression and characterization of the human ABCG1 and ABCG4 proteins: indications for heterodimerization. . Biochem. Biophys. Res. Commun. . 320 . 3 . 860–7 . 2004 . 15240127 . 10.1016/j.bbrc.2004.06.037 . etal.
• Gerhard DS, Wagner L, Feingold EA . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 . etal.
• Engel T, Bode G, Lueken A . Expression and functional characterization of ABCG1 splice variant ABCG1(666). . FEBS Lett. . 580 . 18 . 4551–9 . 2006 . 16870176 . 10.1016/j.febslet.2006.07.006 . 22947257 . etal. free .
• Vaughan AM, Oram JF . ABCA1 and ABCG1 or ABCG4 act sequentially to remove cellular cholesterol and generate cholesterol-rich HDL. . J. Lipid Res. . 47 . 11 . 2433–43 . 2007 . 16902247 . 10.1194/jlr.M600218-JLR200 . 15872767 . free .

Notes and References

1. Dean M, Rzhetsky A, Allikmets R . The human ATP-binding cassette (ABC) transporter superfamily . Genome Res . 11 . 7 . 1156–66 . Jul 2001 . 11435397 . 10.1101/gr.184901 . 9528197 . free .
2. Web site: Entrez Gene: ABCG4 ATP-binding cassette, sub-family G (WHITE), member 4.
3. Dodacki. Agnès. 2017. Expression and function of Abcg4 in the mouse blood-brain barrier: role in restricting the brain entry of amyloid-β peptide. Scientific Reports. Springer Nature. 7. 1. 13393. 10.1038/s41598-017-13750-0. 29042617. 5645361. 2017NatSR...713393D.