ABCC1 p.Glu1455Asn
| Predicted by SNAP2: | A: D (95%), C: D (95%), D: D (95%), F: D (95%), G: D (95%), H: D (95%), I: D (95%), K: D (95%), L: D (95%), M: D (95%), N: D (95%), P: D (95%), Q: D (95%), R: D (95%), S: D (95%), T: D (95%), V: D (95%), W: D (95%), Y: D (95%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, F: 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: D, |
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[hide] Role of carboxylate residues adjacent to the conse... J Biol Chem. 2003 Oct 3;278(40):38537-47. Epub 2003 Jul 27. Payen LF, Gao M, Westlake CJ, Cole SP, Deeley RG
Role of carboxylate residues adjacent to the conserved core Walker B motifs in the catalytic cycle of multidrug resistance protein 1 (ABCC1).
J Biol Chem. 2003 Oct 3;278(40):38537-47. Epub 2003 Jul 27., 2003-10-03 [PMID:12882957]
Abstract [show]
MRP1 belongs to subfamily "C" of the ABC transporter superfamily. The nucleotide-binding domains (NBDs) of the C family members are relatively divergent compared with many ABC proteins. They also differ in their ability to bind and hydrolyze ATP. In MRP1, NBD1 binds ATP with high affinity, whereas NBD2 is hydrolytically more active. Furthermore, ATP binding and/or hydrolysis by NBD2 of MRP1, but not NBD1, is required for MRP1 to shift from a high to low affinity substrate binding state. Little is known of the structural basis for these functional differences. One minor structural difference between NBDs is the presence of Asp COOH-terminal to the conserved core Walker B motif in NBD1, rather than the more commonly found Glu present in NBD2. We show that the presence of Asp or Glu following the Walker B motif profoundly affects the ability of the NBDs to bind, hydrolyze, and release nucleotide. An Asp to Glu mutation in NBD1 enhances its hydrolytic capacity and affinity for ADP but markedly decreases transport activity. In contrast, mutations that eliminate the negative charge of the Asp side chain have little effect. The decrease in transport caused by the Asp to Glu mutation in NBD1 is associated with an inability of MRP1 to shift from high to low affinity substrate binding states. In contrast, mutation of Glu to Asp markedly increases the affinity of NBD2 for ATP while decreasing its ability to hydrolyze ATP and to release ADP. This mutation eliminates transport activity but potentiates the conversion from a high to low affinity binding state in the presence of nucleotide. These observations are discussed in the context of catalytic models proposed for MRP1 and other ABC drug transport proteins.
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No. Sentence Comment
78 The forward primers for D793Q, D793N, D793S, E1455Q, E1455N, E1455S, and E1455L were 5Ј-GCTGACATTTACCTCTTCGATCAACCGCTCTC- AGCAGTGGATGCC-3Ј, 5Ј-GCTGACATTTACCTCTTCGATAATCCGC- TCTCAGCAGTGGATGCC-3Ј, 5Ј-GCTGACATTTACCTCTTCGATTCT- CCCCTCTCAGCAGTGGATGCC-3Ј, 5Ј-CGAAGATCCTTGTGTTGGA- TCAGGCCACGGCGGCCGTGGACCTGG-3Ј, 5Ј-CGAAGATCCTTGTG- TTGGATA ACGCCACGGCCGCCGTGGACCTGG-3Ј, 5Ј-CGAAGATCC- TTGTGTTGGATTCGGCCACGGCAGCCGTGGACCTGG-3Ј, 5Ј-CGAA- GATCCTTGTGTTGGATTTGGCCACGGCCGCCGTGGACCTGG-3Ј, respectively.
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ABCC1 p.Glu1455Asn 12882957:78:53
status: NEW241 To determine whether there may be additional consequences to eliminating the carboxylate side chain, we mutated Asp793 and Glu1455 to Asn, Gln, and Ser as observed in cystic fibrosis transmembrane conductance regulator.
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ABCC1 p.Glu1455Asn 12882957:241:123
status: NEW249 In contrast, the NBD2 mutations (E1455S, E1455N, E1455Q, and E1455L) like E1455D completely abolished LTC4 transport (Fig. 7B).
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ABCC1 p.Glu1455Asn 12882957:249:41
status: NEW254 Mutation to Ser, Gln, and Leu essentially eliminated labeling of NBD2, whereas labeling of the E1455N mutation was similar to that of the FIG. 6.
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ABCC1 p.Glu1455Asn 12882957:254:95
status: NEW268 Like the E1455D mutant, the E1455S, E1455N, and E1455L mutations resulted in strong vanadate-independent photolabeling of NBD2 and increased vanadate-dependent photolabeling of NBD1 (Fig. 8C, lanes 3, 4, and 7-10).
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ABCC1 p.Glu1455Asn 12882957:268:36
status: NEW270 Effect of D793Q, D793N, D793S, E1455S, E1455Q, E1455N, E1455L mutations on [3 H]LTC4 transport activity.
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ABCC1 p.Glu1455Asn 12882957:270:47
status: NEW271 A, membrane proteins (1 g) from Sf21 cells expressing both halves of either MRP1 (MRP1 dh) or mutant proteins (D793Q, D793N, D793S, E1455S, E1455Q, E1455N, E1455L) were separated by SDS-PAGE on gradient gels and transferred to Immobilon-P membranes.
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ABCC1 p.Glu1455Asn 12882957:271:156
status: NEW275 B, membrane vesicles (2 g) containing MRP1 dh, D793Q, D793S, D793N, E1455Q, E1455S, E1455N, E1455L, or beta-Gus were assayed for ATP-dependent LTC4 transport activity at 23 °C for up to 3 min in transport buffer containing [3 H]LTC4 (50 nM, 0.13 Ci), as described under "Experimental Procedures."
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ABCC1 p.Glu1455Asn 12882957:275:92
status: NEW304 Comparison of nucleotide binding and vanadate trapping by wild-type MRP1 and mutant proteins (D793Q, D793N, D793S, E1455S, E1455Q, E1455N, and E1455L).
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ABCC1 p.Glu1455Asn 12882957:304:131
status: NEW305 A, at 4 °C, 8-azido- [␣-32 P]ATP photolabeling by wild-type MRP1 and mutant proteins (D793Q, D793N, D793S, E1455S, E1455Q, E1455N, and E1455L) was evaluated. Membrane vesicles (20 g) were incubated with 5 M 8-azido-[␣-32 P]ATP for 5 min on ice in transport buffer containing 5 mM MgCl2.
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ABCC1 p.Glu1455Asn 12882957:305:135
status: NEW308 The position of the labeled MRP1 NH2-half and COOH-half polypeptides are indicated, and endogenous proteins labeled are indicated by E followed by arrows. B and C, at 37 °C under trapping conditions, 8-azido-[␣-32 P]ADP trapping by wild-type MRP1 mutant proteins (D793Q, D793N, D793S, E1455S, E1455Q, E1455N, and E1455L) was studied.
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ABCC1 p.Glu1455Asn 12882957:308:313
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
261 This conclusion is further supported by mutation of the putative catalytic residue E1455 in NBD2 that all the mutants, including E1455S, E1455Q, E1455N, E1455L and E1455D, lost their abilities to transport LTC4 across membrane bilayer [62, 144].
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ABCC1 p.Glu1455Asn 17295059:261:145
status: NEW