ABCMdb

ABCC1 p.Trp1198Ala

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Publications

PMID: 12388549 [PubMed] Koike K et al: "Multiple membrane-associated tryptophan residues contribute to the transport activity and substrate specificity of the human multidrug resistance protein, MRP1."

No. Sentence Comment

48 Tryptophan substitutions were generated in the pGEM-3Z and pBluescriptSK(ϩ) plasmids above according to the manufacturer`s instructions with the following mutagenic primers (substituted nucleotides are underlined): MSD1 Trp mutants W40A (5Ј-G GTC CTC GTG GCC GTG CCT TG-3Ј, W47A (5Ј-GT TTT TAC CTC GCC GCC TGT TTC CCC-3Ј), W82A (5Ј-C TTG GGA TTT TTG CTG GCG ATC GTC TGC TGG GC-3Ј), W86A (5Ј-G CTG TGG ATC GTC TGC GCT GCA GAC CTC TTC TAC TC-3Ј), W94A (5Ј-C CTC TTC TAC TCT TTC GCG GAA AGA AGT CGG GGC-3Ј), W142A (5Ј-GGG ATC ATG CTC ACT TTC GCA CTG GTA GCC CTA ATG TG-3Ј), W142F (5Ј-G CTC ACT TTT TTC CTG GTA GCC C-3Ј); MSD2 Trp mutants W361A (5Ј-C ACG AAG GCC CCA GAT GCG CAG GGC TAC TTC TAC-3Ј), W445A (5Ј-G TAC ATT AAC ATG ATC GCG TCA GCC CCC CTG CAA G-3Ј), W445F (5Ј-CG TAC ATT AAC ATG ATC TTC TCA GCC CCC CTG CAA GTC-3Ј), W445Y (5Ј-CC ACG TAC ATT AAC ATG ATC TAC TCA GCG CCC CTG CAA GTC-3Ј), W459A (5Ј-GCT CTC TAC CTC CTG GCG CTG AAT CTG GGC CC-3Ј), W553A (5Ј-G GGC ACC TTC ACC GCG GTC TGC ACG CCC-3Ј), W553F (5Ј-G GGC ACC TTC ACC TTC GTC TGC ACG CCC-3Ј), W553Y (5Ј-GCC CTG GGC ACC TTC ACA TAT GTC TGC ACG CCC-3Ј; and MSD3 Trp mutants W1198A (5Ј-C GTG GCC AAC AGG GCG CTG GCC GTG CGG C-3Ј), W1198F (5Ј-GTG GCC AAC AGG TTC CTG GCC GTG CGG C-3Ј), W1198Y (5Ј-GTG GCC AAC AGG TAC CTG GCC GTG CGG C-3Ј). Login to comment
50 Construction of MRP1-GFP Fusion Proteins-Constructs encoding GFP fusion proteins of selected MRP1 Trp mutations were generated by exchanging the 1.3-kb ClaI/AflII fragment of a pcDNA3.1(-)-MRP1-GFP construct with the comparable fragments containing the W445A, W553A, and W1198A mutations generated above and designated pcDNA3.1-W445A/MRP1-GFP, pcDNA3.1-W553A/MRP1-GFP, and pcDNA3.1-W1198A/MRP1-GFP, respectively (39). Login to comment
132 When expressed in HEK cells, W1198A-MRP1 was found to be expressed at levels that were ϳ35% (range 30-40%) of those of wild-type MRP1, suggesting that MRP1 stability may be affected by this mutation. Login to comment
133 Time courses of [3 H]LTC4 uptake showed that transport of this GSH-conjugated substrate by the W1198A mutant was ϳ65% of that by wild-type MRP1 after correcting for differences in MRP1 expression levels (Fig. 5A). Login to comment
134 In contrast, ATP-dependent [3 H]E217betaG uptake by the W1198A mutant was not detectable (Fig. 5B). Login to comment
144 Transport activity of the W1198A MRP1 mutant was recovered to an even greater extent by Phe and Tyr substitutions. Login to comment
148 In contrast to the W445A and W1198A mutants, more conservative substitutions of the Ala-substituted Trp553 mutant W553A were much less effective in restoring MRP1 transport activity. Login to comment
171 C-E, relative uptake levels of 3 H-labeled organic anions by membrane vesicles enriched for wild-type MRP1 (solid bar) and Trp1198 3 Ala substituted MRP1 (W1198A; shaded bars) were determined as described under "Experimental Procedures." Login to comment
189 Ala substitution of Trp1198 in MSD3 also resulted in a broad and profound decrease in MRP1 transport activity except for FIG. 6. ATP-dependent organic anion transport activity of wild-type and mutant MRP1 containing conservative Phe and Tyr substitutions of Trp1198 in TM16 of MSD3. A, immunoblot of membrane vesicles prepared from HEK293T cells transfected with empty vector (pcDNA3.1(-)), wild-type (WT-MRP1), and mutant (W445A, W445F, and W445Y; W553A, W553F and W553Y; W1198A, W1198F, and W1198Y) MRP1 cDNAs. MRP1 proteins were detected with monoclonal antibody QCRL-1, and relative levels of expression shown under the blot were estimated by densitometry. Login to comment
191 Ala-substituted mutants (W445A, W553A, and W1198A; shaded bars) were included for comparison. Login to comment
194 The Ala-substituted Trp1246 mutant, like W553A and W1198A, also showed significantly reduced transport of multiple MRP1 substrates with the exception of LTC4 (39). Login to comment
196 However, the specific environment of the two Trp residues appears to differ, since Tyr and Phe substitutions restore the transport activity of the W1198A but not W1246A mutant (39). Login to comment
224 HEK293T cells were transfected with pcDNA3.1(-)MRP1K-GFP (WT-MRP1-GFP) (A), pcDNA3.1-W445A/MRP1-GFP (B), pcDNA3.1-W553A/MRP1-GFP (C), and pcDNA3.1-W1198A/MRP1-GFP (D), and 48 h later, cells were processed for confocal fluorescence microscopy. Login to comment

PMID: 16415113 [PubMed] Zhang DW et al: "Mutational analysis of polar amino acid residues within predicted transmembrane helices 10 and 16 of multidrug resistance protein 1 (ABCC1): effect on substrate specificity."

No. Sentence Comment

165 Mutation of Trp1198 to Ala also dramatically decreased overall transport activity (Koike et al., 2002). Login to comment