ABCMdb

ABCC1 p.Lys1141Glu

None has been submitted yet.

Publications

PMID: 16230346 [PubMed] Conseil G et al: "Functional importance of three basic residues clustered at the cytosolic interface of transmembrane helix 15 in the multidrug and organic anion transporter MRP1 (ABCC1)."

No. Sentence Comment

6 Mutation of Lys1141 to either Glu or Arg reduced MRP1 expression, and routing to the plasma membrane was impaired. Login to comment
47 Substitutions of charged residues were generated in the pGEM-3Z- XmaI/MRP1 plasmid according to the manufacturer`s instructions with the following mutagenic primers (Integrated DNA Technologies, Inc., Coralville, IA), which also introduced an additional silent restriction site (substituted nucleotides are underlined): R1138E, 5Ј-CGT GGC TTC CTC CGA GCA ACT GAA GCG CCT CGA G-3Ј; R1138K, 5Ј-CGT GGC TTC CTC CAA GCA GCT TAA GCG CCT CGA G-3Ј; K1141E, 5Ј-CGG CAG CTG GAG CGC CTG GAG TCG GTC AGC-3Ј; K1141R, 5Ј-CCC GGC AGC TGC GGC GCC TCG AGT CGG-3Ј; R1142E, 5Ј-CCC GGC AGC TGA AGG AGC TCG AGT CGG TCA GCC G-3Ј;R1142K, 5Ј-CCC GGC AGC TGA AGA AGC TTG AGT CGG TCA GCC G-3Ј. Login to comment
118 A, membrane vesicles (1 ␮g of protein) prepared from HEK293T cells transfected with wild-type (WT-MRP1), and mutant (R1138E/K, K1141E/R, R1142E/K) MRP1 cDNAs were immunoblotted, and MRP1 was detected with monoclonal antibody QCRL-1. Login to comment
122 B, HEK293T cells were transfected with expression vectors encoding WT-MRP1 and MRP1 mutants R1138E, R1138K, K1141E, K1141R, R1142E, and R1142K, and 48 h later, cells were probed with monoclonal antibody QCRL-3 and processed for confocal fluorescence microscopy using Alexa Fluor 488 conjugated secondary antibody. Login to comment
128 In contrast, although substitution of Lys1141 with Glu decreased LTC4 transport by ϳ70%, an Arg substitution at this position did not. Login to comment
136 Photolabeling of Arg1138 , Lys1141 , and Arg1142 Mutants of MRP1 with [3 H]LTC4-To ascertain whether the decrease in LTC4 uptake by the R1138E/K, K1141E, and R1142E/K mutants was related to a decrease in substrate binding, membrane vesicles enriched for wild-type or mutant MRP1s were photolabeled with [3 H]LTC4. Login to comment
137 As shown in Fig. 4, LTC4 labeling of R1138E and K1141E was decreased by 50% or more, after correcting for differences in protein expression levels, consistent with their decreased LTC4 transport activity. Login to comment
139 Therefore, reduced substrate binding appeared to explain, at least in part, the loss of LTC4 transport for the R1138E and K1141E mutants but not the R1138K, R1142E, and R1142K mutants. Login to comment
141 Kinetic parameters (Vmax and Km) were obtained after plotting the data according to the Michaelis-Menten equation for wild-type MRP1 and the K1141E and K1141R mutants (Table 1). Login to comment
143 However, although the Vmax for the K1141E mutant was unchanged, its Km for E217betaG transport was significantly increased by 4.4-fold (8.8 Ϯ 0.7 ␮M) when compared with the K1141R mutant (2.0 Ϯ 0.3 ␮M) and wild-type MRP1 (1.9 Ϯ 0.4 ␮M). Login to comment
145 This decrease in E217betaG affinity is consistent with the reduced ability of the conjugated estrogen to inhibit LTC4 uptake by K1141E (Fig. 5). Login to comment
149 ATP-dependent uptake of 3 H-labeled organic anions was measured in membrane vesicles prepared from HEK293T cells transfected with wild-type MRP1 (WT-MRP1) and Arg1138 , His1141 and Arg1142 mutant MRP1 (R1138E/K, K1141E/R, R1141E/K) cDNAs (shown in Fig. 2). Login to comment
160 TABLE 1 Kinetic parameters of vesicular uptake of E2 17betaG by wild-type and Lys1141 mutant MRP1 Km Vmax a Vmax/Km ؋ 103 ␮M pmol mg-1 min-1 mg/l/min WT-MRP1 1.9 Ϯ 0.4 604 Ϯ 36 0.32 K1141E 8.8 Ϯ 0.7 577 Ϯ 20 0.07 K1141R 2.0 Ϯ 0.3 964 Ϯ 42 0.48 a Vmax values have been corrected for differences in protein expression of the Lys1141 mutants relative to WT-MRP1 (Fig. 2A). Login to comment
163 In contrast, when the catalytic activity of MRP1 was measured at 37 °C by the orthovanadate-induced trapping of 8-azido-[␣32 P]ADP in the post-hydrolysis state (Fig. 6B), five of the six mutants (R1138E/K, R1142E/K, and K1141E) showed substantially reduced nucleotide trapping (ϳ40-60% that of wild-type MRP1). Login to comment
178 Membrane vesicles prepared from HEK293T cells transfected with wild-type (●, WT-MRP1) and the Glu-substituted Lys1141 mutant (E, K1141E) MRP1 cDNAs were incubated for 3 min with [3 H]LTC4 at 23 °C in the presence of E217betaG (0, 12, 24, and 48 ␮M). Login to comment
205 In contrast, the transport activity of the K1141E mutant was markedly decreased. Login to comment
207 Its decreased affinity for E217betaG was further corroborated by the reduced ability of this conjugated estrogen to inhibit the residual LTC4 transport activity of the K1141E mutant. Login to comment
208 However, orthovanadate-induced trapping of azido-ADP was also reduced, suggesting that the ability of the K1141E mutant to hydrolyze ATP is impaired. Login to comment
214 However, photolabeling of the Arg1142 mutants by [3 H]LTC4 was comparable with wild-type MRP1, indicating that, in contrast to the Arg1138 mutants and the K1141E mutant, their substrate binding properties are still intact. Login to comment

PMID: 19015228 [PubMed] Conseil G et al: "Multiple roles of charged amino acids in cytoplasmic loop 7 for expression and function of the multidrug and organic anion transporter MRP1 (ABCC1)."

No. Sentence Comment

43 Substitution of Lys1141 with Glu also impairs expression of MRP1 at the plasma membrane as well as adversely affecting transport activity (Conseil et al., 2006). Login to comment

PMID: 21143116 [PubMed] He SM et al: "Structural and functional properties of human multidrug resistance protein 1 (MRP1/ABCC1)."

No. Sentence Comment

742 Notably, mutation of Lys1141 to either Glu or Arg impaired MRP1/ABCC1 expression and routing to the plasma membrane [354]. Login to comment
743 Substitution of Lys1141 with Glu (negatively chages) at TM15/CL7 interface decreased LTC4 transport by 70%, but an Arg substitution (positively charged) at this position did not; GSH transport by both Lys1141Glu and Lys1141Arg mutants was decreased by 40%, suggesting that the presence of a positive charge at Lys1141 was sufficient for LTC4 transport, whereas the less bulky side chain of Lys itself seemed important for GSH transport [354]. Login to comment
744 The Arg1138Glu and Lys1141Glu mutants, but not the Arg1138Lys, Arg1142Glu, and Arg1142Lys mutants, showed a >50% decrease in binding to [3 H]LTC4. Login to comment
806 Replacement of Lys1141 with Glu also impaired the expression of MRP1/ABCC1 at the plasma membrane and reduced its transport activity. Login to comment