ABCC4 p.Thr1142Met
Predicted by SNAP2: | A: D (71%), C: N (78%), D: N (93%), E: N (93%), F: D (59%), G: D (80%), H: D (80%), I: D (91%), K: N (87%), L: N (78%), M: D (80%), N: N (97%), P: N (93%), Q: N (93%), R: N (78%), S: N (97%), V: N (82%), W: D (63%), Y: D (53%), |
Predicted by PROVEAN: | A: N, C: D, D: D, E: D, F: D, G: D, H: D, I: D, K: D, L: D, M: D, N: N, P: N, Q: D, R: D, S: N, V: D, W: D, Y: D, |
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[hide] Pharmacogenomics of MRP transporters (ABCC1-5) and... Drug Metab Rev. 2008;40(2):317-54. Gradhand U, Kim RB
Pharmacogenomics of MRP transporters (ABCC1-5) and BCRP (ABCG2).
Drug Metab Rev. 2008;40(2):317-54., [PMID:18464048]
Abstract [show]
Elucidation of the key mechanisms that confer interindividual differences in drug response remains an important focus of drug disposition and clinical pharmacology research. We now know both environmental and host genetic factors contribute to the apparent variability in drug efficacy or in some cases, toxicity. In addition to the widely studied and recognized genes involved in the metabolism of drugs in clinical use today, we now recognize that membrane-bound proteins, broadly referred to as transporters, may be equally as important to the disposition of a substrate drug, and that genetic variation in drug transporter genes may be a major contributor of the apparent intersubject variation in drug response, both in terms of attained plasma and tissue drug level at target sites of action. Of particular relevance to drug disposition are members of the ATP Binding Cassette (ABC) superfamily of efflux transporters. In this review a comprehensive assessment and annotation of recent findings in relation to genetic variation in the Multidrug Resistance Proteins 1-5 (ABCC1-5) and Breast Cancer Resistance Protein (ABCG2) are described, with particular emphasis on the impact of such transporter genetic variation to drug disposition or efficacy.
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191 MRP4 protein has been detected in human kidney (van Aubel et al., 2002), lung (Torky et al., 2005), liver (Rius et al., 2003), prostate (Lee et al., 2000), brain (Nies et al., 2004), pancreas (König et al., 2005), lymphocytes (Schuetz et al., 1999), and platelets Figure 4 Predicted membrance topology of MRP4 (ABCC4) based on hydrophobicity analysis. Locations of the non-synonymous polymorphisms are indicated with arrows. See Table 4 for allele frequencies and description of funtional consequences. NH2 COOH NBD NBD Val854Phe Ile18Leu Ile866Val Arg531Gln Tyr556Cys Thr1142Met Glu757Lys Val776Ile Gly187Trp Lys304Asn in out Membrane Cys171Gly Pro403Leu Lys498Glu Met744Val Met1272Val MRP4 (ABCC4) COOH NBD NBD Val854Phe Ile866Val Arg531Gln Tyr556Cys Thr1142Met Glu757Lys Val776Ile Gly187Trp Lys304AsnCys171Gly Pro403Leu Lys498Glu Met744Val Met1272Val COOH NBD NBD Val854Phe Ile866Val Arg531Gln Tyr556Cys Thr1142Met Glu757Lys Val776Ile Gly187Trp Lys304AsnCys171Gly Pro403Leu Lys498Glu Met744Val Met1272Val (Jedlitschky et al., 2004).
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ABCC4 p.Thr1142Met 18464048:191:574
status: NEWX
ABCC4 p.Thr1142Met 18464048:191:758
status: NEWX
ABCC4 p.Thr1142Met 18464048:191:912
status: NEW216 Polymorphisms in exons 1, 5, 12, 13, 19, 21, and 28 leading to the following amino acid exchanges Ile18Leu, Gly187Trp, Arg531Gln, Tyr556Cys, Val776Ile, Val854Phe, Ile866Val, and Thr1142Met were analysed in relation to expression and localization of MRP4 in human liver.
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ABCC4 p.Thr1142Met 18464048:216:178
status: NEW217 Some of the amino acid substitutions are located within highly conserved regions such as membrane spanning domains (Val776Ile, Val854Phe, Ile866Val) or ATP-binding domains (Tyr556Cys, Thr1142Met), others are located in intracellular regions where they might influence substrate recognition (Gly187Trp).
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ABCC4 p.Thr1142Met 18464048:217:184
status: NEW236 Following the discovery and Table 4 MRP4 (ABCC4) Single nucleotide polymorphisms. Location, allele frequency and functional effects. Position in coding sequence Amino acid exchange Location Allele frequency Effect NCBI ID ReferenceAf Ca Jp others 52A>C Ile18Leu Exon 1 - 1.1 [1] 0 [2] - No influence on expression and localization in liver [1] rs11568681 511T>G Cys171Gly Exon 4 - 0 [1] [2] - - rs4148460 559G>T Gly187Trp Exon 5 - 2.2 [1] 0 [2] - No influence on expression and localization in liver [1] rs11568658 912G>T Lys304Asn Exon 8 - 9.9 [1] [2] - No influence on expression and localization in liver [1] rs2274407 1208T>C Pro403Leu Exon 9 - - - - - rs11568705 1492A>G Lys498Glu Exon 11 - - - - - rs11568669 1592G>A Arg531Gln Exon 12 - 0.6 [1] 0 [2] - No influence on expression and localization in liver [1] 1667A>G Tyr556Cys Exon 13 - 0.6 [1] 0 [2] - No influence on expression and localization in liver [1] 2230A>G Met744Val Exon 18 - - - - - rs9282570 2269G>A Glu757Lys Exon 18 - 0.6 [1] [2] - No influence on expression and localization in liver [1] rs3765534 2326G>A Val776Ile Exon 19 - 0.6 [1] 0 [2] - No influence on expression and localization in liver [1] 2560G>T Val854Phe Exon 21 - 1.7 [1] 0 [2] - No influence on expression and localization in liver [1] rs11568694 2596A>G Ile866Val Exon 21 - 2.8 [1] 0 [2] - No influence on expression and localization in liver [1] 3425C>T Thr1142Met Exon 27 - 1.6 [1] 0 [2] - No influence on expression and localization in liver [1] rs11568644 3814A>G Met1272Val Exon 30 - - - - - rs1134217 Reference without frequency means that SNP was detected but no frequency determined.
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ABCC4 p.Thr1142Met 18464048:236:1394
status: NEW[hide] Pharmacogenetics of drug transporters in the enter... Pharmacogenomics. 2011 May;12(5):611-31. Stieger B, Meier PJ
Pharmacogenetics of drug transporters in the enterohepatic circulation.
Pharmacogenomics. 2011 May;12(5):611-31., [PMID:21619426]
Abstract [show]
This article summarizes the impact of the pharmacogenetics of drug transporters expressed in the enterohepatic circulation on the pharmacokinetics and pharmacodynamics of drugs. The role of pharmacogenetics in the function of drug transporter proteins in vitro is now well established and evidence is rapidly accumulating from in vivo pharmacokinetic studies, which suggests that genetic variants of drug transporter proteins can translate into clinically relevant phenotypes. However, a large amount of conflicting information on the clinical relevance of drug transporter proteins has so far precluded the emergence of a clear picture regarding the role of drug transporter pharmacogenetics in medical practice. This is very well exemplified by the case of P-glycoprotein (MDR1, ABCB1). The challenge is now to develop pharmacogenetic models with sufficient predictive power to allow for translation into drug therapy. This will require a combination of pharmacogenetics of drug transporters, drug metabolism and pharmacodynamics of the respective drugs.
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117 Gene name Transporter SNP Protein Population size (n) In vitro function Ref. Liver efflux transporters (cont.) SLC47A1 (cont.) MATE1 (cont.) c.1490G>C c.149G>T p.C497S p.C497F N/A Reduced, unchanged or increased transport activities (substrate dependent) [170,229] c.1557G>C p.Q519H N/A Unchanged [170] ABCC4 MRP4 c.232C>G p.P78A N/A Increased intracellular drug accumulation (substrate dependent), lower transport protein expression [161] c.559C>T p.G187W N/A Increased intracellular drug accumulation, reduced transport protein expression Slightly reduced function [161] [162] c.877A>G p.K293E N/A Unchanged [161] c.912G>T p.K304N N/A Unchanged Unchanged [161] [162] c.1208C>T p.P403L N/A Increased intracellular drug accumulation [161] c.1460G>A p.G487E N/A Increased intracellular drug accumulation Reduced transport activity (substrate dependent) [161] [162] c.1492A>G p.K498E N/A Unaltered [161] c.1667A>G p.Y556C N/A Increased transport activity [162] c.2269G>A p.E575K N/A Increased transport activity [162] c.2230A>G p.M744V N/A Unchanged [161] c.2326G>A p.V776I N/A Reduced transport activity [162] c.2459G>T p.R820I N/A Reduced transport activity [162] c.2560G>T p.V854F N/A Unchanged [162] c.2596A>G p.I866V N/A Unchanged [162] c.2867G>C p.C956S N/A Reduced intracellular drug accumulation [161] c.3211G>A p.V1071I N/A Unchanged [161] c.3425C>T p.T1142M N/A Increased transport activity [162] For more information on members of the SLC superfamily of transporters please consult [301] and for more information of ABC transporters please consult [302].
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ABCC4 p.Thr1142Met 21619426:117:1359
status: NEW[hide] Xenobiotic, bile acid, and cholesterol transporter... Pharmacol Rev. 2010 Mar;62(1):1-96. Epub 2010 Jan 26. Klaassen CD, Aleksunes LM
Xenobiotic, bile acid, and cholesterol transporters: function and regulation.
Pharmacol Rev. 2010 Mar;62(1):1-96. Epub 2010 Jan 26., [PMID:20103563]
Abstract [show]
Transporters influence the disposition of chemicals within the body by participating in absorption, distribution, and elimination. Transporters of the solute carrier family (SLC) comprise a variety of proteins, including organic cation transporters (OCT) 1 to 3, organic cation/carnitine transporters (OCTN) 1 to 3, organic anion transporters (OAT) 1 to 7, various organic anion transporting polypeptide isoforms, sodium taurocholate cotransporting polypeptide, apical sodium-dependent bile acid transporter, peptide transporters (PEPT) 1 and 2, concentrative nucleoside transporters (CNT) 1 to 3, equilibrative nucleoside transporter (ENT) 1 to 3, and multidrug and toxin extrusion transporters (MATE) 1 and 2, which mediate the uptake (except MATEs) of organic anions and cations as well as peptides and nucleosides. Efflux transporters of the ATP-binding cassette superfamily, such as ATP-binding cassette transporter A1 (ABCA1), multidrug resistance proteins (MDR) 1 and 2, bile salt export pump, multidrug resistance-associated proteins (MRP) 1 to 9, breast cancer resistance protein, and ATP-binding cassette subfamily G members 5 and 8, are responsible for the unidirectional export of endogenous and exogenous substances. Other efflux transporters [ATPase copper-transporting beta polypeptide (ATP7B) and ATPase class I type 8B member 1 (ATP8B1) as well as organic solute transporters (OST) alpha and beta] also play major roles in the transport of some endogenous chemicals across biological membranes. This review article provides a comprehensive overview of these transporters (both rodent and human) with regard to tissue distribution, subcellular localization, and substrate preferences. Because uptake and efflux transporters are expressed in multiple cell types, the roles of transporters in a variety of tissues, including the liver, kidneys, intestine, brain, heart, placenta, mammary glands, immune cells, and testes are discussed. Attention is also placed upon a variety of regulatory factors that influence transporter expression and function, including transcriptional activation and post-translational modifications as well as subcellular trafficking. Sex differences, ontogeny, and pharmacological and toxicological regulation of transporters are also addressed. Transporters are important transmembrane proteins that mediate the cellular entry and exit of a wide range of substrates throughout the body and thereby play important roles in human physiology, pharmacology, pathology, and toxicology.
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7118 Nucleotide Change Amino Acid Change In Vitro Function Protein Expression/Localization ABCC1 MRP1 G128C C43S 1↔ Intracellular C218T T73I 1↔ Normal C257T S92F 2↔ Normal C350T T117M 2↔ Normal G689A R230Q ↔ Normal G1057A V353M N.D. N.D. G1299T R433S 2↔ Normal G1898A R633Q 2↔ Normal G2012T G671V ↔ Normal G2168A R723Q 2 Normal G2965A A989T 2↔ Normal G3140C C1047S 1↔ Normal G3173A R1058Q ↔ Normal C4535T S1512L ↔ Normal ABCC2 MRP2 C-24T N.D. N.D. G1058A R353H N.D. N.D. G1249A V417I ↔ Normal C2366T S789F 12 Intracellular T2780G L927R N.D. N.D. C3298T R1100C N.D. N.D. G3299A R1100H N.D. N.D. T3563A V1188E N.D. N.D. G4348A A1450T ↔ Normal/Intracellular G4544A C1515Y N.D. N.D. ABCC3 MRP3 G32A G11D ↔ Normal C202T H68Y N.D. N.D. G296A R99Q N.D. Normal C1037T S346F 2 Normal C1537A Q513K N.D. N.D. T1643A L548Q N.D. N.D. G1820A S607N 2 Normal C2221T Gln741STOP N.D. N.D. G2293C V765L ↔ Normal G2395A V799M N.D. N.D. C2758T P920S 1 Normal G2768A R923Q 1 Normal C3657A S1219R N.D. N.D. C3856G R1286G ↔ Normal G3890A R1297H N.D. N.D. C4042T R1348C 1 Normal A4094G Q1365R ↔ Normal C4141A R1381S ↔ Intracellular C4217T T1406M N.D. N.D. G4267A G1423R N.D. N.D. ABCC4 MRP4 C52A L18I N.D. N.D. C232G P78A 2↔ Normal T551C M184T N.D. N.D. G559T G187W 2 Reduced A877G K293E ↔ Normal G912T K304N ↔ Normal C1067T T356M N.D. N.D. C1208T P403L 2↔ Normal G1460A G487E 2 Normal A1492G K498E ↔ Normal A1875G I625M N.D. N.D. C2000T P667L N.D. N.D. A2230G M744V ↔ Normal G2269A E757K N.D. Intracellular G2459T R820I N.D. N.D. G2560T V854F N.D. N.D. G2698T V900L N.D. N.D. G2867C C956S 1↔ Normal G3211A V1071I ↔ Normal C3425T T1142M N.D. N.D. G3659A R1220Q N.D. N.D. A3941G Q1314R N.D. N.D. 2, reduced function; 1, increased function; ↔, no change in function; N.D. not determined.
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ABCC4 p.Thr1142Met 20103563:7118:1789
status: NEW7115 Nucleotide Change Amino Acid Change In Vitro Function Protein Expression/Localization ABCC1 MRP1 G128C C43S 1 Intracellular C218T T73I 1 Normal C257T S92F 2 Normal C350T T117M 2 Normal G689A R230Q Normal G1057A V353M N.D. N.D. G1299T R433S 2 Normal G1898A R633Q 2 Normal G2012T G671V Normal G2168A R723Q 2 Normal G2965A A989T 2 Normal G3140C C1047S 1 Normal G3173A R1058Q Normal C4535T S1512L Normal ABCC2 MRP2 C-24T N.D. N.D. G1058A R353H N.D. N.D. G1249A V417I Normal C2366T S789F 12 Intracellular T2780G L927R N.D. N.D. C3298T R1100C N.D. N.D. G3299A R1100H N.D. N.D. T3563A V1188E N.D. N.D. G4348A A1450T Normal/Intracellular G4544A C1515Y N.D. N.D. ABCC3 MRP3 G32A G11D Normal C202T H68Y N.D. N.D. G296A R99Q N.D. Normal C1037T S346F 2 Normal C1537A Q513K N.D. N.D. T1643A L548Q N.D. N.D. G1820A S607N 2 Normal C2221T Gln741STOP N.D. N.D. G2293C V765L Normal G2395A V799M N.D. N.D. C2758T P920S 1 Normal G2768A R923Q 1 Normal C3657A S1219R N.D. N.D. C3856G R1286G Normal G3890A R1297H N.D. N.D. C4042T R1348C 1 Normal A4094G Q1365R Normal C4141A R1381S Intracellular C4217T T1406M N.D. N.D. G4267A G1423R N.D. N.D. ABCC4 MRP4 C52A L18I N.D. N.D. C232G P78A 2 Normal T551C M184T N.D. N.D. G559T G187W 2 Reduced A877G K293E Normal G912T K304N Normal C1067T T356M N.D. N.D. C1208T P403L 2 Normal G1460A G487E 2 Normal A1492G K498E Normal A1875G I625M N.D. N.D. C2000T P667L N.D. N.D. A2230G M744V Normal G2269A E757K N.D. Intracellular G2459T R820I N.D. N.D. G2560T V854F N.D. N.D. G2698T V900L N.D. N.D. G2867C C956S 1 Normal G3211A V1071I Normal C3425T T1142M N.D. N.D. G3659A R1220Q N.D. N.D. A3941G Q1314R N.D. N.D. 2, reduced function; 1, increased function; , no change in function; N.D. not determined.
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ABCC4 p.Thr1142Met 20103563:7115:1762
status: NEW[hide] Clinical impact of polymorphisms of transport prot... Transplant Proc. 2009 Jun;41(5):1441-55. Rosso Felipe C, de Sandes TV, Sampaio EL, Park SI, Silva HT Jr, Medina Pestana JO
Clinical impact of polymorphisms of transport proteins and enzymes involved in the metabolism of immunosuppressive drugs.
Transplant Proc. 2009 Jun;41(5):1441-55., [PMID:19545654]
Abstract [show]
Individualization of immunosuppressive therapy after solid organ transplantation is a goal that has been pursued for a long time. Nevertheless, in clinical practice, we are still stratifying patients in subgroups in which risk is assessed using demographic information and population analysis. Then, a combination of immunosuppressive drugs is chosen and doses are individualized to compensate for intra- and interindividual variabilities in drug pharmacokinetics, to obtain similar plasma/blood concentrations that are believed to be therapeutic, again based on data derived from population analysis. One step further in this strategy is to recognize, before initiation of immunotherapy, those patients at higher risk to be either under- or overexposed to currently used immunosuppressive drugs. Several studies have been undertaken to correlate single nucleotide polymorphisms in genes encoding transport proteins and metabolizing enzymes involved in the disposition of immunosuppressive drugs. Overall, the results from these studies have been mixed. The causes of these sometimes conflicting results include methodologic, genetic, or nongenetic factors. The degree of linkage disequilibrium, the measure of nonrandom associations between polymorphisms at different loci, not necessarily on the same chromosome, is perhaps the main genetic factor. The influence of the environment, physiology (such as kidney and liver functions), disease state, use of multidrug regimens, and inherent drug-to-drug interactions are present nongenetic factors. Moreover, it is also important to increase our knowledge of the genetic factors involved in the variabilities observed in drug responses of pharmacodynamics. True individualized therapy, with the ability to improve health outcomes of each transplant recipient, will depend on our knowledge of the genetic factors involved in immunological response and drug pharmacokinetics and pharmacodynamics.
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116 This mutation is relatively common (Ͼ18%) in the Japanese population and is associated with increased sensitivity to thiopurines observed in some Japanese patients.72 In one study, 4 MRP4 missense genetic variants (Y556C, E757K, V7761, and T1142M) exhibited a 20% to 40% reduced expression level compared with the wild type.
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ABCC4 p.Thr1142Met 19545654:116:246
status: NEW[hide] Functional hot spots in human ATP-binding cassette... Protein Sci. 2010 Nov;19(11):2110-21. Kelly L, Fukushima H, Karchin R, Gow JM, Chinn LW, Pieper U, Segal MR, Kroetz DL, Sali A
Functional hot spots in human ATP-binding cassette transporter nucleotide binding domains.
Protein Sci. 2010 Nov;19(11):2110-21., [PMID:20799350]
Abstract [show]
The human ATP-binding cassette (ABC) transporter superfamily consists of 48 integral membrane proteins that couple the action of ATP binding and hydrolysis to the transport of diverse substrates across cellular membranes. Defects in 18 transporters have been implicated in human disease. In hundreds of cases, disease phenotypes and defects in function can be traced to nonsynonymous single nucleotide polymorphisms (nsSNPs). The functional impact of the majority of ABC transporter nsSNPs has yet to be experimentally characterized. Here, we combine experimental mutational studies with sequence and structural analysis to describe the impact of nsSNPs in human ABC transporters. First, the disease associations of 39 nsSNPs in 10 transporters were rationalized by identifying two conserved loops and a small alpha-helical region that may be involved in interdomain communication necessary for transport of substrates. Second, an approach to discriminate between disease-associated and neutral nsSNPs was developed and tailored to this superfamily. Finally, the functional impact of 40 unannotated nsSNPs in seven ABC transporters identified in 247 ethnically diverse individuals studied by the Pharmacogenetics of Membrane Transporters consortium was predicted. Three predictions were experimentally tested using human embryonic kidney epithelial (HEK) 293 cells stably transfected with the reference multidrug resistance transporter 4 and its variants to examine functional differences in transport of the antiviral drug, tenofovir. The experimental results confirmed two predictions. Our analysis provides a structural and evolutionary framework for rationalizing and predicting the functional effects of nsSNPs in this clinically important membrane transporter superfamily.
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72 Predictions of the Functional Effects of 40 nsSNPs in ABC Transporters Comon name HUGO name Mutation NBD Prediction BSEP ABCB11 E592Q NBD1 Neutral BSEP ABCB11 N591S NBD1 Neutral BSEP ABCB11 Q558H NBD1 Neutral BSEP ABCB11 V444A NBD1 Neutral BSEP ABCB11 E1186K NBD2 Disease MDR1 ABCB1 P1051A NBD2 Neutral MDR1 ABCB1 S1141T NBD2 Neutral MDR1 ABCB1 T1256K NBD2 Disease MDR1 ABCB1 V1251I NBD2 Neutral MDR1 ABCB1 W1108R NBD2 Disease MRP2 ABCC2 I670T NBD1 Disease MRP2 ABCC2 L849R NBD1 Disease MRP2 ABCC2 C1515Y NBD2 Disease MRP3 ABCC3 D770N NBD1 Neutral MRP3 ABCC3 K718M NBD1 Neutral MRP3 ABCC3 T809M NBD1 Disease MRP3 ABCC3 V765L NBD1 Disease MRP3 ABCC3 Q1365R NBD2 Disease MRP3 ABCC3 R1297H NBD2 Disease MRP3 ABCC3 R1348C NBD2 Disease MRP3 ABCC3 R1381S NBD2 Disease MRP4 ABCC4 G487E NBD1 Disease MRP4 ABCC4 K498E NBD1 Neutral MRP4 ABCC4 R1220Q NBD2 Neutral MRP4 ABCC4 T1142M NBD2 Neutral MRP4 ABCC4 V1071I NBD2 Neutral MRP6 ABCC6 I1330L NBD1 Neutral MRP6 ABCC6 I742V NBD1 Neutral MRP6 ABCC6 P664S NBD1 Neutral MRP6 ABCC6 R724K NBD1 Neutral MRP6 ABCC6 R769K NBD1 Neutral MRP6 ABCC6 A1291T NBD2 Neutral MRP6 ABCC6 E1369K NBD2 Neutral MRP6 ABCC6 G1327E NBD2 Disease MRP6 ABCC6 L1416R NBD2 Disease MRP6 ABCC6 R1268Q NBD2 Disease MRP6 ABCC6 R1461H NBD2 Disease MXR ABCG2 I206L NBD1 Neutral MXR ABCG2 P269S NBD1 Disease MXR ABCG2 Q141K NBD1 Neutral nsSNPs.
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ABCC4 p.Thr1142Met 20799350:72:864
status: NEW[hide] The human multidrug resistance protein 4 (MRP4, AB... J Pharmacol Exp Ther. 2008 Jun;325(3):859-68. Epub 2008 Mar 25. Abla N, Chinn LW, Nakamura T, Liu L, Huang CC, Johns SJ, Kawamoto M, Stryke D, Taylor TR, Ferrin TE, Giacomini KM, Kroetz DL
The human multidrug resistance protein 4 (MRP4, ABCC4): functional analysis of a highly polymorphic gene.
J Pharmacol Exp Ther. 2008 Jun;325(3):859-68. Epub 2008 Mar 25., [PMID:18364470]
Abstract [show]
ABCC4 encodes multidrug resistance protein 4 (MRP4), a member of the ATP-binding cassette family of membrane transporters involved in the efflux of endogenous and xenobiotic molecules. The aims of this study were to identify single nucleotide polymorphisms of ABCC4 and to functionally characterize selected nonsynonymous variants. Resequencing was performed in a large ethnically diverse population. Ten nonsynonymous variants were selected for analysis of transport function based on allele frequencies and evolutionary conservation. The reference and variant MRP4 cDNAs were constructed by site-directed mutagenesis and transiently transfected into human embryonic kidney cells (HEK 293T). The function of MRP4 variants was compared by measuring the intracellular accumulation of two antiviral agents, azidothymidine (AZT) and adefovir (PMEA). A total of 98 variants were identified in the coding and flanking intronic regions of ABCC4. Of these, 43 variants are in the coding region, and 22 are nonsynonymous. In a functional screen of ten variants, there was no evidence for a complete loss of function allele. However, two variants (G187W and G487E) showed a significantly reduced function compared to reference with both substrates, as evidenced by higher intracellular accumulation of AZT and PMEA compared to the reference MRP4 (43 and 69% increase in accumulation for G187W compared with the reference MRP4, with AZT and PMEA, respectively). The G187W variant also showed decreased expression following transient transfection of HEK 293T cells. Further studies are required to assess the clinical significance of this altered function and expression and to evaluate substrate specificity of this functional change.
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145 The P78A and P403L TABLE 2 Selected genetic variants in ABCC4a Exon Nucleotide Position Golden Path Positionb Variant Flagb Nucleotide Change Amino Acid or Intronic Position Amino Acid Change Grantham Score Allele Frequencyc AA (n ϭ 160) CA (n ϭ 160) AS (n ϭ 120) ME (n ϭ 100) 1 -49 chr13:94751618 rs3751333 C Ͼ T 5Ј-UTR - - 0.013 0.019 0.102 0.03 1 52 chr13:94751518 rs11568681 C Ͼ A 18 Leu to Ile 5 0.006 0.044 0.034 0.01 1 IVS1ϩ10 chr13:94751486 rs11568682 C Ͼ T Intronic - - 0.006 0.019 0 0 2 IVS2ϩ7 chr13:94697891 rs11568700 C Ͼ T Intronic - - 0.031 0 0 0 3 IVS3-5 chr13:94697355 rs4148437 T Ͼ C Intronic - - 0.087 0.331 0.183 0.25 3d 232 chr13:94697304 rs11568689 C Ͼ G 78 Pro to Ala 27 0 0 0.008 0 4 IVS4-10 chr13:94685099 rs11568638 C Ͼ T Intronic - - 0.025 0 0 0 4 IVS4ϩ10 chr13:94684855 rs11568637 A Ͼ G Intronic - - 0.031 0 0.117 0 5 551 chr13:94661017 rs11568657 T Ͼ C 184 Met to Thr 81 0.013 0 0 0 5 559 chr13:94661009 rs11568658 G Ͼ T 187 Gly to Trp 184 0 0.025 0.108 0.130 6 669 chr13:94659805 rs899494 C Ͼ T 223 Syn 0.219 0.200 0.125 0.090 6 717 chr13:94659757 rs11568674 T Ͼ C 239 Syn 0 0 0.008 0 7 877 chr13:94658089 rs11568684 A Ͼ G 293 Lys to Glu 56 0.006 0 0 0 8 912 chr13:94657036 rs2274407 G Ͼ T 304 Lys to Asn 94 0.181 0.087 0.225 0.160 8 951 chr13:94656997 rs2274406 G Ͼ A 317 Syn 0.619 0.406 0.458 0.390 8 969 chr13:94656979 rs2274405 G Ͼ A 323 Syn 0.312 0.406 0.458 0.320 8 1035 chr13:94656913 rs11568703 G Ͼ A 345 Syn 0 0.013 0 0 8 1067 chr13:94656881 rs11568701 C Ͼ T 356 Thr to Met 81 0 0 0 0.010 8 IVS8ϩ8 chr13:94656779 rs11568702 T Ͼ A Intronic - 0 0.013 0 0 9 1208 chr13:94645146 rs11568705 C Ͼ T 403 Pro to Leu 98 0.006 0 0 0 11 1458 chr13:94637043 rs11568670 G Ͼ A 486 Syn 0 0.006 0 0 11 1460 chr13:94637041 rs11568668 G Ͼ A 487 Gly to Glu 98 0 0 0.008 0 11 1492 chr13:94637009 rs11568669 A Ͼ G 498 Lys to Glu 56 0.025 0 0 0 11 1497 chr13:94637004 rs1557070 C Ͼ T 499 Syn 0.238 0 0 0 14 1737 chr13:94620874 rs11568664 T Ͼ C 579 Syn 0.006 0 0 0 15 IVS15-7 chr13:94616629 rs11568696 A Ͼ G Intronic - 0.031 0 0 0 15 1875 chr13:94616572 rs11568699 A Ͼ G 625 Ile to Met 10 0.006 0 0 0 15 2000 chr13:94616447 rs11568697 C Ͼ T 667 Pro to Leu 98 0 0.006 0 0 15 2001 chr13:94616446 rs11568698 C Ͼ T 667 Syn 0.013 0 0 0 16 2100 chr13:94614708 rs11568666 C Ͼ T 700 Syn 0 0.013 0 0 18 2230 chr13:94613455 rs9282570 A Ͼ G 744 Met to Val 21 0.050 0 0 0 18 2269 chr13:94613416 rs3765534 G Ͼ A 757 Glu to Lys 56 0.025 0.013 0.033 0.030 19 2364 chr13:94611535 rs11568709 C Ͼ T 788 Syn 0.006 0 0 0 20 2459 chr13:94566253 rs11568659 G Ͼ T 820 Arg to Ile 97 0.006 0 0 0 21 2560 chr13:94533521 rs11568694 G Ͼ T 854 Val to Phe 50 0.006 0 0 0 21 2577 chr13:94533504 rs11568691 C Ͼ T 859 Syn 0 0.006 0 0 22 2698 chr13:94525795 rs11568673 G Ͼ T 900 Val to Leu 32 0 0.006 0 0.010 22 2712 chr13:94525781 rs1678339 G Ͼ A 904 Syn 0.156 0.031 0.217 0.020 23 2844 chr13:94524542 rs1189466 C Ͼ T 948 Syn 0.075 0.031 0.208 0.020 23 2847 chr13:94524539 rs11568708 C Ͼ T 949 Syn 0.019 0 0 0 23 2867 chr13:94524519 rs11568707 G Ͼ C 956 Cys to Ser 112 0.006 0 0 0 26 3211 chr13:94513114 rs11568653 G Ͼ A 1071 Val to Ile 29 0.006 0 0 0 26 3255 chr13:94513070 rs11568652 C Ͼ A 1085 Syn 0.013 0 0 0.010 26 3310 chr13:94513015 rs11568655 T Ͼ C 1104 Syn 0.100 0 0 0.010 26 3348 chr13:94512977 rs1751034 A Ͼ G 1116 Syn 0.231 0.169 0.242 0.200 27 3425 chr13:94503381 rs11568644 C Ͼ T 1142 Thr to Met 81 0 0.006 0 0 28 3609 chr13:94494541 rs11568695 G Ͼ A 1203 Syn 0.206 0 0 0.010 29 3659 chr13:94494013 rs11568639 G Ͼ A 1220 Arg to Gln 43 0.006 0 0 0 29 3723 chr13:94493949 rs11568640 C Ͼ T 1241 Syn 0.006 0 0 0 30 3774 chr13:94484956 rs11568704 G Ͼ A 1258 Syn 0.037 0 0 0 31 IVS31-3 chr13:94471940 rs9524765 C Ͼ T Intronic - 0.225 0 0 0.02 31 3941 chr13:94471867 rs11568688 A Ͼ G 1314 Gln to Arg 43 0.006 0 0 0 31 4016 chr13:94471792 rs3742106 T Ͼ G 3Ј-UTR - 0.287 0.388 0.467 0.470 Dashes indicate not relevant.
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ABCC4 p.Thr1142Met 18364470:145:3705
status: NEWX
ABCC4 p.Thr1142Met 18364470:145:3729
status: NEW[hide] 6-mercaptopurine and 9-(2-phosphonyl-methoxyethyl)... Hum Mutat. 2008 May;29(5):659-69. Janke D, Mehralivand S, Strand D, Godtel-Armbrust U, Habermeier A, Gradhand U, Fischer C, Toliat MR, Fritz P, Zanger UM, Schwab M, Fromm MF, Nurnberg P, Wojnowski L, Closs EI, Lang T
6-mercaptopurine and 9-(2-phosphonyl-methoxyethyl) adenine (PMEA) transport altered by two missense mutations in the drug transporter gene ABCC4.
Hum Mutat. 2008 May;29(5):659-69., [PMID:18300232]
Abstract [show]
Multiple drug resistance protein 4 (MRP4, ABCC4) belongs to the C subfamily of the ATP-binding cassette (ABC) transporter superfamily and participates in the transport of diverse antiviral and chemotherapeutic agents such as 6-mercaptopurine (6-MP) and 9-(2-phosphonyl methoxyethyl) adenine (PMEA). We have undertaken a comprehensive functional characterization of protein variants of MRP4 found in Caucasians and other ethnicities. A total of 11 MRP4 missense genetic variants (nonsynonymous SNPs), fused to green fluorescent protein (GFP), were examined in Xenopus laevis oocytes for their effect on expression, localization, and function of the transporter. Radiolabeled 6-MP and PMEA were chosen as transport substrates. All MRP4 protein variants were found to be expressed predominantly in the oocyte membrane. A total of four variants (Y556C, E757 K, V776I, and T1142 M) exhibited a 20% to 40% reduced expression level compared to the wild type. Efflux studies showed that 6-MP is transported by MRP4 in unmodified form. Compared to wild-type MRP4, the transmembrane variant V776I, revealed a significant lower activity in 6-MP transport, while the amino acid exchange Y556C in the Walker(B) motif displayed significantly higher transport of PMEA. The transport properties of the other variants were comparable to wild-type MRP4. Our study shows that Xenopus oocytes are well suited to characterize MRP4 and its protein variants. Carriers of the rare MRP4 variants Y556C and V776I may have altered disposition of MRP4 substrates.
Comments [show]
None has been submitted yet.
No. Sentence Comment
6 A total of four variants (Y556C, E757K, V776I, and T1142M) exhibited a 20% to 40% reduced expression level compared to the wild type.
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ABCC4 p.Thr1142Met 18300232:6:51
status: NEW107 The following primer pairs were applied to amplify SNP-containing fragments by PCR: * rs11568658 (c.559G4T, Gly187Trp): 50 -Biotin-CCTCTTTT ATTTCAGGCACTTCG-30 , * 50 -TGCAGCTTACCTGATCAAACTTGT-30 (117 bp) * rs2274407 (c.912G4T, Lys304Asn): 50 -Biotin-ACGATGA TTTTGCTTGCACT-30 , * 50 - CGTGAGCCACTTTATCTGGT-30 (146 bp) * rs11568644 (c.3425C4T, Thr1142Met): 50 -GGGCACTTAG GAACCTGTTTTGT-30 , * 50 -Biotin-CTCTTGTAAGGCATTCCACAGTTC-30 (101 bp).
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ABCC4 p.Thr1142Met 18300232:107:342
status: NEW110 Procedures of Pyrosequencing were performed according to the manufacturer`s instructions using the PSQ 96 SNP Reagent Kit (Biotage AB) and following sequencing primers: rs11568658 (Gly187Trp): 50 -CCTGTGGTTGTCTTCC-30 and rs2274407 (Lys304Asn): 50 -CTGTACTCTCTTTCAG-30 for reverse assay, rs11568644 (Thr1142Met), 50 -TGGATCCCTTTAATGAGC-30 for forward assay.
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ABCC4 p.Thr1142Met 18300232:110:299
status: NEW258 Conservation of the MRP4 Polymorphic AminoAcids Among Di¡erent ABCC Orthologs and Homologsà Protein Speciesa G187W K304N G487E Y556C E757K V776I R820I V854F I866V T1142M MRP4 Human G K G Y E V R V I T Mouse G K G Y E V R I V T Rat G K G Y G V R I L S MRP1 Human K Q D Y K ^ N C F S Mouse K Q D Y F A ^ V F S Rat K Q D Y ^ G N V V S MRP2 Human K K G Y S G R L V S Mouse R K G Y S G R L V S Rat K K G Y S G R L I S MRP3 Human R Q C F L G R L V S Rat R Q C F S G R I V S MRP5 Human ^ ^ A Y D L R V S T Mouse ^ ^ A Y D L R V S T Rat ^ ^ A Y D L R V S T MRP6 Human K G T Y G H S V V S Mouse K G T Y H G N G V T Rat K G T Y G N G V V T ÃAligned using ClustalW (www.ebi.ac.uk/clustalw).
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ABCC4 p.Thr1142Met 18300232:258:173
status: NEW[hide] Variability in human hepatic MRP4 expression: infl... Pharmacogenomics J. 2008 Feb;8(1):42-52. Epub 2007 Apr 3. Gradhand U, Lang T, Schaeffeler E, Glaeser H, Tegude H, Klein K, Fritz P, Jedlitschky G, Kroemer HK, Bachmakov I, Anwald B, Kerb R, Zanger UM, Eichelbaum M, Schwab M, Fromm MF
Variability in human hepatic MRP4 expression: influence of cholestasis and genotype.
Pharmacogenomics J. 2008 Feb;8(1):42-52. Epub 2007 Apr 3., [PMID:17404579]
Abstract [show]
The multidrug resistance protein 4 (MRP4) is an efflux transporter involved in the transport of endogenous substrates and xenobiotics. We measured MRP4 mRNA and protein expression in human livers and found a 38- and 45-fold variability, respectively. We sequenced 2 kb of the 5'-flanking region, all exons and intron/exon boundaries of the MRP4 gene in 95 patients and identified 74 genetic variants including 10 non-synonymous variations, seven of them being located in highly conserved regions. None of the detected polymorphisms was significantly associated with changes in the MRP4 mRNA or protein expression. Immunofluorescence microscopy indicated that none of the non-synonymous variations affected the cellular localization of MRP4. However, in cholestatic patients the MRP4 mRNA and protein expression both were significantly upregulated compared to non-cholestatic livers (protein: 299+/-138 vs 100+/-60a.u., P<0.001). Taken together, human hepatic MRP4 expression is highly variable. Genetic variations were not sufficient to explain this variability. In contrast, cholestasis is one major determinant of human hepatic MRP4 expression.
Comments [show]
None has been submitted yet.
No. Sentence Comment
52 MRP4 protein expression in samples carrying non-synonymous polymorphisms relative to the control group (n ¼ 8) was as follows: G187W 58% (n ¼ 2), K304N 54% (n ¼ 3), R531Q 20% (n ¼ 1), Y556C 60% (n ¼ 1), E757K 86% (n ¼ 1), V776I 161% (n ¼ 1), V854F 96% (n ¼ 1), I866V 78% (n ¼ 4) and T1142M 40% (n ¼ 2).
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ABCC4 p.Thr1142Met 17404579:52:328
status: NEW72 Prediction of functional effects of non-synonymous variations In silico analysis of all 10 detected amino acid exchanges revealed that five of them (I18L, K304N, R531Q, E757K, V776I) can be considered benign, whereas others especially near or within transmembrane regions or ATP-binding domains are possibly (G187W, Y556C, V854F, I866V) or in one case (T1142M) even very likely damaging for protein localization and/or function (Figure 3).
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ABCC4 p.Thr1142Met 17404579:72:353
status: NEW53 MRP4 protein expression in samples carrying non-synonymous polymorphisms relative to the control group (n &#bc; 8) was as follows: G187W 58% (n &#bc; 2), K304N 54% (n &#bc; 3), R531Q 20% (n &#bc; 1), Y556C 60% (n &#bc; 1), E757K 86% (n &#bc; 1), V776I 161% (n &#bc; 1), V854F 96% (n &#bc; 1), I866V 78% (n &#bc; 4) and T1142M 40% (n &#bc; 2).
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ABCC4 p.Thr1142Met 17404579:53:319
status: NEW73 Prediction of functional effects of non-synonymous variations In silico analysis of all 10 detected amino acid exchanges revealed that five of them (I18L, K304N, R531Q, E757K, V776I) can be considered benign, whereas others especially near or within transmembrane regions or ATP-binding domains are possibly (G187W, Y556C, V854F, I866V) or in one case (T1142M) even very likely damaging for protein localization and/or function (Figure 3).
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ABCC4 p.Thr1142Met 17404579:73:353
status: NEW