ABCC1 p.Phe594Tyr
| Predicted by SNAP2: | A: D (59%), C: D (63%), D: D (85%), E: D (80%), G: D (75%), H: D (75%), I: D (53%), K: D (80%), L: D (59%), M: N (66%), N: D (63%), P: D (85%), Q: D (66%), R: D (75%), S: D (71%), T: D (59%), V: D (71%), W: D (85%), Y: N (53%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: D, G: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: N, |
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[hide] Molecular modeling correctly predicts the function... J Biol Chem. 2004 Jan 2;279(1):463-8. Epub 2003 Oct 15. Campbell JD, Koike K, Moreau C, Sansom MS, Deeley RG, Cole SP
Molecular modeling correctly predicts the functional importance of Phe594 in transmembrane helix 11 of the multidrug resistance protein, MRP1 (ABCC1).
J Biol Chem. 2004 Jan 2;279(1):463-8. Epub 2003 Oct 15., 2004-01-02 [PMID:14561746]
Abstract [show]
The human ATP-binding cassette (ABC) transporter, multidrug resistance protein 1 (MRP1/ABCC1), confers resistance to a broad range of anti-cancer agents and transports a variety of organic anions. At present, essentially no structural data exists for MRP1 that might be used to elucidate its mechanism of transport. Consequently, we have applied a modeling strategy incorporating crystal and indirect structural data from other ABC transporters to construct a model of the transmembrane domains of the core region of MRP1 that includes the amino acid side chains. Three conserved Trp residues and one non-conserved Tyr residue, shown previously to be of functional importance (Koike, K., Oleschuk, C. J., Haimeur, A., Olsen, S. L., Deeley, R. G., and Cole, S. P. C. (2002) J. Biol. Chem. 277, 49495-49503), were found to line the "pore" in our model proximal to the membrane cytosol interface. A fifth aromatic residue (Phe594) was identified that, with the Trp and Tyr residues, completed a ring or "basket" of aromatic amino acids and, accordingly, we postulated that it would also be of functional importance. To test this idea, MRP1-Phe594 mutants were expressed in human embryonic kidney cells, and their properties were examined using membrane vesicles. Substitution of Phe594 with Ala substantially reduced or eliminated the transport of five organic anion substrates by MRP1 and abrogated the binding of leukotriene C4. On the other hand, the conservatively substituted F594W and F594Y mutants remained transport competent, although significant substrate- and substitution-specific changes were observed. These studies provide some structural insight into a possible substrate binding/transport site of MRP1 at the beginning of a putative substrate translocation pathway and demonstrate the usefulness of modeling for directing structure-function analyses of this transporter.
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No. Sentence Comment
7 On the other hand, the conservatively substituted F594W and F594Y mutants remained transport competent, although significant substrate- and substitution-specific changes were observed.
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ABCC1 p.Phe594Tyr 14561746:7:60
status: NEW69 Phe594 substitutions were generated in the pBluescriptSK(ϩ) plasmid above according to the manufacturer`s instructions with the following mutagenic primers (substituted nucleotides are underlined): F594A, 5Ј-G TTC AAC ATC CTC CGG GCT CCC CTG AAC ATT CTC C-3Ј; F594W, 5Ј-C TTG TTC AAC ATC CTC CGC TGG CCC CTG AAC ATT CTC CCC-3Ј; and F594Y, 5Ј-G TTC AAC ATC CTC CGC TAT CCC CTG AAC ATT CTC C-3Ј.
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ABCC1 p.Phe594Tyr 14561746:69:362
status: NEW99 LTC4 Transport and Photo-labeling Is Eliminated by Ala Substitution of Phe594 -As shown in Fig. 2A, all three mutants generated (F594A, F594W, and F594Y) were expressed at levels 60-100% of those of wild-type MRP1 in transfected HEK cells.
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ABCC1 p.Phe594Tyr 14561746:99:147
status: NEW102 After correcting for differences in MRP1 protein expression levels, ATP-dependent LTC4 uptake by the F594A mutant was reduced by more than 90%, whereas uptake by the F594W and F594Y mutants was comparable with that by wild-type MRP1.
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ABCC1 p.Phe594Tyr 14561746:102:176
status: NEW111 A, representative immunoblot of membrane vesicles prepared from HEK293T cells transfected with empty vector (pcDNA3.1(-)), wild-type (WT-MRP1), and mutant (F594A, F594W, and F594Y) MRP1 cDNAs.
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ABCC1 p.Phe594Tyr 14561746:111:174
status: NEW123 The conservatively substituted Phe594 mutants F594W and F594Y could still be photolabeled by [3 H]LTC4, although photolabeling was reduced, by ϳ50% when corrected for differences in MRP1 protein expression.
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ABCC1 p.Phe594Tyr 14561746:123:56
status: NEW128 For some substrates, uptake by the F594W mutant was up to 1.5-fold higher than that by wild-type MRP1 (GSH) and substantially higher than that by the F594Y mutant (E13SO4 and GSH).
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ABCC1 p.Phe594Tyr 14561746:128:150
status: NEW129 For other substrates the opposite effects were observed, i.e. vesicular uptake by the F594Y mutant was higher than that by wild-type MRP1 (E217betaG and MTX) and even higher than that by the F594W mutant (E217betaG and MTX).
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ABCC1 p.Phe594Tyr 14561746:129:86
status: NEW130 For example, E217betaG uptake by F594W was ϳ30% of wild-type MRP1, whereas vesicular uptake of this glucuronide conjugate by F594Y was ϳ1.4-fold higher than that by wild-type MRP1 (Fig. 3A).
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ABCC1 p.Phe594Tyr 14561746:130:131
status: NEW131 In contrast, GSH uptake by the F594Y mutant was just 15% of that of wild-type MRP1, whereas uptake of this tripeptide by the F594W mutant was ϳ1.6-fold higher than that of wild-type MRP1.
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ABCC1 p.Phe594Tyr 14561746:131:31
status: NEW161 On the other hand, conservative substitutions of Phe594 with either Tyr or Trp had little effect on LTC4 transport but, in some cases, caused some significant changes in the transport of at least two of the four other MRP1 organic anion substrates tested.
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ABCC1 p.Phe594Tyr 14561746:161:49
status: NEW162 Thus, although the aromatic properties of the residue at position 594 are critical for retaining overall activity (i.e. F594 (wild-type), F594W, and F594Y are active but F594A is not), the addition of hydrogen bonding capacity to the amino acid side chain (as in F594W and F594Y) also influences substrate specificity, as shown previously for the polar aromatic residues at positions 553, 1198, 1243, and 1246.
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ABCC1 p.Phe594Tyr 14561746:162:149
status: NEWX
ABCC1 p.Phe594Tyr 14561746:162:273
status: NEW[hide] Transmembrane helix 11 of multidrug resistance pro... Biochemistry. 2004 Jul 27;43(29):9413-25. Zhang DW, Nunoya K, Vasa M, Gu HM, Theis A, Cole SP, Deeley RG
Transmembrane helix 11 of multidrug resistance protein 1 (MRP1/ABCC1): identification of polar amino acids important for substrate specificity and binding of ATP at nucleotide binding domain 1.
Biochemistry. 2004 Jul 27;43(29):9413-25., 2004-07-27 [PMID:15260484]
Abstract [show]
Human multidrug resistance protein 1 (MRP1) is an ATP binding cassette (ABC) transporter that confers resistance to many natural product chemotherapeutic agents and can transport structurally diverse conjugated organic anions. MRP1 has three polytopic transmembrane domains (TMDs) and a total of 17 TM helices. Photolabeling and mutagenesis studies of MRP1 indicate that TM11, the last helix in the second TMD, may form part of the protein's substrate binding pocket. We have demonstrated that certain polar residues within a number of TM helices, including Arg(593) in TM11, are determinants of MRP1 substrate specificity or overall activity. We have now extended these analyses to assess the functional consequences of mutating the remaining seven polar residues within and near TM11. Mutations Q580A, T581A, and S585A in the predicted outer leaflet region of the helix had no detectable effect on function, while mutation of three residues close to the membrane/cytoplasm interface altered substrate specificity. Two of these mutations affected only drug resistance. N597A increased and decreased resistance to vincristine and VP-16, respectively, while S605A decreased resistance to vincristine, VP-16 and doxorubicin. The third, S604A, selectively increased 17beta-estradiol 17-(beta-d-glucuronide) (E(2)17betaG) transport. In contrast, elimination of the polar character of the residue at position 590 (Asn in the wild-type protein) uniformly impaired the ability of MRP1 to transport potential physiological substrates and to confer resistance to three different classes of natural product drugs. Kinetic and photolabeling studies revealed that mutation N590A not only decreased the affinity of MRP1 for cysteinyl leukotriene 4 (LTC(4)) but also substantially reduced the binding of ATP to nucleotide binding domain 1 (NBD1). Thus, polar interactions involving residues in TM11 influence not only the substrate specificity of MRP1 but also an early step in the proposed catalytic cycle of the protein.
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No. Sentence Comment
287 However, unlike Asn590 , conservative substitution of Phe594 with Tyr or Trp altered the substrate specificity of the protein, suggesting that the latter residue may interact directly with substrate (35).
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ABCC1 p.Phe594Tyr 15260484:287:54
status: NEW[hide] Transmembrane transport of endo- and xenobiotics b... Physiol Rev. 2006 Jul;86(3):849-99. Deeley RG, Westlake C, Cole SP
Transmembrane transport of endo- and xenobiotics by mammalian ATP-binding cassette multidrug resistance proteins.
Physiol Rev. 2006 Jul;86(3):849-99., [PMID:16816140]
Abstract [show]
Multidrug Resistance Proteins (MRPs), together with the cystic fibrosis conductance regulator (CFTR/ABCC7) and the sulfonylurea receptors (SUR1/ABCC8 and SUR2/ABCC9) comprise the 13 members of the human "C" branch of the ATP binding cassette (ABC) superfamily. All C branch proteins share conserved structural features in their nucleotide binding domains (NBDs) that distinguish them from other ABC proteins. The MRPs can be further divided into two subfamilies "long" (MRP1, -2, -3, -6, and -7) and "short" (MRP4, -5, -8, -9, and -10). The short MRPs have a typical ABC transporter structure with two polytropic membrane spanning domains (MSDs) and two NBDs, while the long MRPs have an additional NH2-terminal MSD. In vitro, the MRPs can collectively confer resistance to natural product drugs and their conjugated metabolites, platinum compounds, folate antimetabolites, nucleoside and nucleotide analogs, arsenical and antimonial oxyanions, peptide-based agents, and, under certain circumstances, alkylating agents. The MRPs are also primary active transporters of other structurally diverse compounds, including glutathione, glucuronide, and sulfate conjugates of a large number of xeno- and endobiotics. In vivo, several MRPs are major contributors to the distribution and elimination of a wide range of both anticancer and non-anticancer drugs and metabolites. In this review, we describe what is known of the structure of the MRPs and the mechanisms by which they recognize and transport their diverse substrates. We also summarize knowledge of their possible physiological functions and evidence that they may be involved in the clinical drug resistance of various forms of cancer.
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No. Sentence Comment
847 Conservative substitutions of Phe594 with Tyr or Trp had selective effects on substrate specificity, suggesting that it may be involved in direct interaction of MRP1 with its substrates (52).
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ABCC1 p.Phe594Tyr 16816140:847:30
status: NEW846 Conservative substitutions of Phe594 with Tyr or Trp had selective effects on substrate specificity, suggesting that it may be involved in direct interaction of MRP1 with its substrates (52).
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ABCC1 p.Phe594Tyr 16816140:846:30
status: NEW848 Similarly, only Ala substitution of Asn590 (a "cavity"-creating substitution) adversely affected MRP1 activity, while replacing this residue with Asp or Gln had no effect, suggesting that the polar side chain of Asn590 may be involved in interhelical interactions that influence the conformation of the protein in the vicinity of the binding pocket (570).
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ABCC1 p.Phe594Tyr 16816140:848:30
status: NEW[hide] Transport of glutathione and glutathione conjugate... Trends Pharmacol Sci. 2006 Aug;27(8):438-46. Epub 2006 Jul 3. Cole SP, Deeley RG
Transport of glutathione and glutathione conjugates by MRP1.
Trends Pharmacol Sci. 2006 Aug;27(8):438-46. Epub 2006 Jul 3., [PMID:16820223]
Abstract [show]
Glutathione (GSH)-conjugated xenobiotics and GSH-conjugated metabolites (e.g. the cysteinyl leukotriene C4) must be exported from the cells in which they are formed before they can be eliminated from the body or act on their cellular targets. This efflux is often mediated by the multidrug resistance protein 1 (MRP1) transporter, which also confers drug resistance to tumour cells and can protect normal cells from toxic insults. In addition to drugs and GSH conjugates, MRP1 exports GSH and GSH disulfide, and might thus have a role in cellular responses to oxidative stress. The transport of several drugs and conjugated organic anions by MRP1 requires the presence of GSH, but it is not well understood how GSH (and its analogues) enhances transport. Site-directed mutagenesis studies and biophysical analyses have provided important insights into the structural determinants of MRP1 that influence GSH and GSH conjugate binding and transport.
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No. Sentence Comment
150 TM6 is also predicted to be adjacent to TM11, in which a conservative Tyr substitution of Phe594 adversely affects only GSH transport, whereas non-conservative Ala substitution of this residue eliminates the transport of multiple organic anions [38].
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ABCC1 p.Phe594Tyr 16820223:150:70
status: NEW[hide] A molecular understanding of ATP-dependent solute ... Cancer Metastasis Rev. 2007 Mar;26(1):15-37. Chang XB
A molecular understanding of ATP-dependent solute transport by multidrug resistance-associated protein MRP1.
Cancer Metastasis Rev. 2007 Mar;26(1):15-37., [PMID:17295059]
Abstract [show]
Over a million new cases of cancers are diagnosed each year in the United States and over half of these patients die from these devastating diseases. Thus, cancers cause a major public health problem in the United States and worldwide. Chemotherapy remains the principal mode to treat many metastatic cancers. However, occurrence of cellular multidrug resistance (MDR) prevents efficient killing of cancer cells, leading to chemotherapeutic treatment failure. Numerous mechanisms of MDR exist in cancer cells, such as intrinsic or acquired MDR. Overexpression of ATP-binding cassette (ABC) drug transporters, such as P-glycoprotein (P-gp or ABCB1), breast cancer resistance protein (BCRP or ABCG2) and/or multidrug resistance-associated protein (MRP1 or ABCC1), confers an acquired MDR due to their capabilities of transporting a broad range of chemically diverse anticancer drugs. In addition to their roles in MDR, there is substantial evidence suggesting that these drug transporters have functions in tissue defense. Basically, these drug transporters are expressed in tissues important for absorption, such as in lung and gut, and for metabolism and elimination, such as in liver and kidney. In addition, these drug transporters play an important role in maintaining the barrier function of many tissues including blood-brain barrier, blood-cerebral spinal fluid barrier, blood-testis barrier and the maternal-fetal barrier. Thus, these ATP-dependent drug transporters play an important role in the absorption, disposition and elimination of the structurally diverse array of the endobiotics and xenobiotics. In this review, the molecular mechanism of ATP-dependent solute transport by MRP1 will be addressed.
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No. Sentence Comment
156 In addition, the LTC4, GSH, E217βG or E13SO4 transport activities of conservatively substituted F594W and F594Y mutants located in TM11 were significantly different from each other [80], suggesting that they bind to different regions or different conformations of the MRP1 protein.
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ABCC1 p.Phe594Tyr 17295059:156:112
status: NEW