Multidrug resistance-associated protein 6 (MRP6) also known as ATP-binding cassette sub-family C member 6 (ABCC6) and multi-specific organic anion transporter E (MOAT-E) is a protein that in humans is encoded by the ABCC6gene.[1][2][3] The protein encoded by the ABCC6 gene is a member of the superfamily of ATP-binding cassette (ABC) transporters.[1]
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 MRP subfamily which is involved in multidrug resistance.[4]
Mutations in this protein cause pseudoxanthoma elasticum (PXE).[5] The most common mutations, R1141X and 23-29del, account for about 25% of the found mutations.[6][7]
Premature atherosclerosis is also associated with mutations in the ABCC6 gene, even in those without PXE.[8]
Deficiency of Abcc6 in mouse models of ischemia leads to larger infarcts, which can be rescued by Abcc6 overexpression.[9]
Location
Abcc6 gene encodes an intracellular transporter associated with mitochondrial function, located in the mitochondrial-associated membrane (MAM), whereas its substrate can be located in either MAM, cytosol or ER.[10]
Abcc6 is primarily expressed in liver and kidney,.[11][12]
Signaling pathways
It has been observed less Smad1/5/8 activation in the presence of Abcc6 than in mice lacking that gene in liver, kidney, heart, muscle, aorta and lungs.[13] ALK1, ALK2 and ALK3 expression are higher in kidneys, but lower in liver, with functional Abcc6 and its presence causes higher expression of BMP2 in kidney and a decrease in its expression in liver.[13] In the presence of Abcc6, BMP-4, BMP-6 and BMP-7 expression is increased in kidney and decreased in liver.[13]Abcc6 deficient mice show higher BMP activation in the heart.[9]
References
↑ 1.01.1Kuss BJ, O'Neill GM, Eyre H, Doggett NA, Callen DF, Davey RA (Oct 1998). "ARA, a novel ABC transporter, is located at 16p13.1, is deleted in inv(16) leukemias, and is shown to be expressed in primitive hematopoietic precursors". Genomics. 51 (3): 455–8. doi:10.1006/geno.1998.5349. PMID9721217.
↑Meloni I, Rubegni P, De Aloe G, Bruttini M, Pianigiani E, Cusano R, Seri M, Mondillo S, Federico A, Bardelli AM, Andreassi L, Fimiani M, Renieri A (Jul 2001). "Pseudoxanthoma elasticum: Point mutations in the ABCC6 gene and a large deletion including also ABCC1 and MYH11". Hum Mutat. 18 (1): 85. doi:10.1002/humu.1157. PMID11439001.
↑Le Saux O, Urban Z, Tschuch C, Csiszar K, Bacchelli B, Quaglino D, Pasquali-Ronchetti I, Pope FM, Richards A, Terry S, Bercovitch L, de Paepe A, Boyd CD (2000). "Mutations in a gene encoding an ABC transporter cause pseudoxanthoma elasticum". Nat. Genet. 25 (2): 223–7. doi:10.1038/76102. PMID10835642.
↑Trip MD, Smulders YM, Wegman JJ, Hu X, Boer JM, ten Brink JB, Zwinderman AH, Kastelein JJ, Feskens EJ, Bergen AA (2002). "Frequent mutation in the ABCC6 gene (R1141X) is associated with a strong increase in the prevalence of coronary artery disease". Circulation. 106 (7): 773–5. doi:10.1161/01.CIR.0000028420.27813.C0. PMID12176944.
↑Gorgels TG, Hu X, Scheffer GL, van der Wal AC, Toonstra J, de Jong PT, van Kuppevelt TH, Levelt CN, de Wolf A, Loves WJ, Scheper RJ, Peek R, Bergen AA (2005). "Disruption of Abcc6 in the mouse: novel insight in the pathogenesis of pseudoxanthoma elasticum". Human Molecular Genetics. 14 (13): 1763–73. doi:10.1093/hmg/ddi183. PMID15888484.
