ABCC1 p.Thr1082Ala
| Predicted by SNAP2: | A: N (78%), C: N (66%), D: D (63%), E: N (57%), F: N (53%), G: N (72%), H: N (53%), I: N (82%), K: D (63%), L: N (72%), M: N (78%), N: N (61%), P: D (66%), Q: N (57%), R: D (63%), S: N (72%), V: N (93%), W: D (59%), Y: D (63%), |
| Predicted by PROVEAN: | A: N, C: D, D: D, E: D, F: D, G: D, H: D, I: N, K: D, L: N, M: N, N: D, P: D, Q: D, R: D, S: N, V: N, W: D, Y: D, |
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[hide] Functional importance of polar and charged amino a... J Biol Chem. 2003 Nov 14;278(46):46052-63. Epub 2003 Sep 3. Zhang DW, Gu HM, Situ D, Haimeur A, Cole SP, Deeley RG
Functional importance of polar and charged amino acid residues in transmembrane helix 14 of multidrug resistance protein 1 (MRP1/ABCC1): identification of an aspartate residue critical for conversion from a high to low affinity substrate binding state.
J Biol Chem. 2003 Nov 14;278(46):46052-63. Epub 2003 Sep 3., 2003-11-14 [PMID:12954620]
Abstract [show]
Human multidrug resistance protein 1 (MRP1) confers resistance to many chemotherapeutic agents and transports diverse conjugated organic anions. We previously demonstrated that Glu1089 in transmembrane (TM) 14 is critical for the protein to confer anthracycline resistance. We have now assessed the functional importance of all polar and charged amino acids in this TM helix. Asn1100, Ser1097, and Lys1092, which are all predicted to be on the same face of the helix as to Glu1089, are involved in determining the substrate specificity of the protein. Notably, elimination of the positively charged side chain of Lys1092, increased resistance to the cationic drugs vincristine and doxorubicin, but not the electroneutral drug etoposide (VP-16). In addition, mutations S1097A and N1100A selectively decreased transport of 17beta-estradiol 17-(beta-d-glucuronide) (E217betaG) but not cysteinyl leukotriene 4 (LTC4), demonstrating the importance of multiple residues in this helix in determining substrate specificity. In contrast, mutations of Asp1084 that eliminate the carboxylate side chain markedly decreased resistance to all drugs tested, as well as transport of both E217betaG and LTC4, despite the fact that LTC4 binding was unaffected. We show that these mutations prevent the ATP-dependent transition of the protein from a high to low affinity substrate binding state and drastically diminish ADP trapping at nucleotide binding domain 2. Based on results presented here and crystal structures of prokaryotic ATP binding cassette transporters, Asp1084 may be critical for interaction between the cytoplasmic loop connecting TM13 and TM14 and a region of nucleotide binding domain 2 between the conserved Walker A and ABC signature motifs.
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No. Sentence Comment
51 They are as follows: T1082A (5Ј-C TCC AAG GAG CTC GAC GCA GTG GAC TCC-3Ј), D1084N (5Ј-CTG GAC ACA GTG AAT TCC ATG ATC CCG-3Ј), D1084A (5Ј-CTG GAC ACA GTG AAA TCG ATG ATC CCG-3Ј), D1084E (5Ј-CTG GAC ACA GTG GAC TCG ATG ATC CCG-3Ј), D1084V (5Ј-CTG GAC ACA GTG GTA TCG ATG ATC CCG-3Ј), S1085A (5Ј-CTG GAC ACA GTC GAC GCC ATG ATC CCG G-3Ј), K1092M (5Ј-C CCG GAG GTC ATC ATG ATG TTC ATG GGC-3Ј), K1092A (5Ј-C CCG GAG GTC ATC GCG ATG TTC ATG GGC-3Ј), K1092E (5Ј-C CCG GAG GTC ATC GAG ATG TTC ATG GGC-3Ј), K1092R (5Ј-C CCG GAG GTC ATC AGG ATG TTC ATG GGC-3Ј), S1097A (5Ј-G ATG TTC ATG GGC GCC CTG TTC AAC-3Ј), N1100A (5Ј-TTC ATG GGC TCG CTC TTC GCC GTC ATT GGT G-3Ј), N1100S (5Ј-TTC ATG GGC TCG CTC TTC AGT GTC ATT GGT G-3Ј).
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ABCC1 p.Thr1082Ala 12954620:51:21
status: NEW136 The levels of LTC4 uptake by vesicles prepared from HEK transfectants expressing either wild type MRP1 or mutations T1082A, S1085A, K1092M, S1097A, and N1100A were proportional to the relative expression levels of the wild type and mutant proteins.
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ABCC1 p.Thr1082Ala 12954620:136:116
status: NEW138 ATP-dependent transport of [3 H]E217betaG was unaffected by the T1082A, S1085A and K1092M mutations (Fig. 3, D-F), but substitution of Ser1097 with Ala and conversion of Asp1084 to Asn both dramatically decreased transport.
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ABCC1 p.Thr1082Ala 12954620:138:64
status: NEW142 The results are presented as relative drug resistance factors in Table I. Mutations T1082A, S1085A, and N1100A had no significant effect on drug resistance, but conversion of one polar residue, Ser1097 , to Ala caused a 2-3-fold decrease in resistance to vincristine, VP-16, and doxorubicin.
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ABCC1 p.Thr1082Ala 12954620:142:84
status: NEW