ABCB4 p.Ile936Ala
| Predicted by SNAP2: | A: N (61%), C: N (57%), D: D (80%), E: D (75%), F: N (57%), G: D (71%), H: D (71%), K: D (66%), L: N (87%), M: N (82%), N: D (75%), P: D (80%), Q: D (66%), R: D (66%), S: D (53%), T: N (53%), V: N (93%), W: N (78%), Y: N (72%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: D, F: D, G: D, H: D, K: D, L: N, M: N, N: D, P: D, Q: D, R: D, S: D, T: D, V: N, W: D, Y: D, |
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[hide] Biochemical, cellular, and pharmacological aspects... Annu Rev Pharmacol Toxicol. 1999;39:361-98. Ambudkar SV, Dey S, Hrycyna CA, Ramachandra M, Pastan I, Gottesman MM
Biochemical, cellular, and pharmacological aspects of the multidrug transporter.
Annu Rev Pharmacol Toxicol. 1999;39:361-98., [PMID:10331089]
Abstract [show]
Considerable evidence has accumulated indicating that the multidrug transporter or P-glycoprotein plays a role in the development of simultaneous resistance to multiple cytotoxic drugs in cancer cells. In recent years, various approaches such as mutational analyses and biochemical and pharmacological characterization have yielded significant information about the relationship of structure and function of P-glycoprotein. However, there is still considerable controversy about the mechanism of action of this efflux pump and its function in normal cells. This review summarizes current research on the structure-function analysis of P-glycoprotein, its mechanism of action, and facts and speculations about its normal physiological role.
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No. Sentence Comment
47 Table 1 List of mutations in human, mouse, and hamster P-glycoproteins that affect substrate specificitya aa mutation Region Sourceb Reference H61R, F, K, M, W, Y TM 1 Human MDR1 149, 150 ABC20c G64R TM 1 Human MDR1 150 L65R TM 1 Human MDR1 150 aa78-97 EC 1 Human MDR1 151 Q128Hd TM 2 Mouse mdr3 152 R138H IC 1 Mouse mdr3 152 Q139H, R IC 1 Mouse mdr3 152 Q141V IC 1 Human MDR1 15319, Q145H IC 1 Mouse mdr3 152 E155G, K IC 1 Mouse mdr3 152 F159I IC 1 Mouse mdr3 152 D174G IC 1 Mouse mdr3 152 S176G, P IC 1 Mouse mdr3 152 K177I IC 1 Mouse mdr3 152 N179S IC 1 Mouse mdr3 152 N183S/G185V IC 1 Human MDR1 154 G183D IC 1 Mouse mdr3 152 G185V IC 1 Human MDR1 155-157 G187V IC 1 Human MDR1 153 A192T TM 3 Mouse mdr3 152 F204S EC 2 Mouse mdr3 152 W208G EC 2 Mouse mdr3 152 K209E EC 2 Mouse mdr3 152 L210I TM 4 Mouse mdr3 152 T211P TM 4 Mouse mdr3 152 I214T TM 4 Mouse mdr3 152 P223A TM 4 Human MDR1 158 G288V IC 2 Human MDR1 153 I299M, T319S, L322I, TM 5, EC3, Human MDR1 159 G324K, S351N IC 3 F335A TM 6 Human MDR1 19 F335 TM 6 Human MDR1 160 V338A TM 6 Human MDR1 161 G338A, A339P TM 6 Hamster PGY1 162, 163 A339P TM 6 Hamster PGY1 163 G341V TM 6 Human MDR1 161 K536R, Q N-NBD Human MDR1 164 ERGA → DKGT N-NBD Mouse mdr3 165 aa 522-525 T578C N-NBD Mouse mdr3 165 (Continued) G830V IC 4 Human MDR1 P866A TM 10 Human MDR1 158 F934A TM 11 Mouse mdr3 166 G935A TM 11 Mouse mdr3 166 I936A TM 11 Mouse mdr3 166 F938A TM 11 Mouse mdr3 166 S939A TM 11 Mouse mdr3 166 S939F TM 11 Mouse mdr3 167, 168 S941F TM 11 Mouse mdr1 167, 168 T941A TM 11 Mouse mdr3 166 Q942A TM 11 Mouse mdr3 166 A943G TM 11 Mouse mdr3 166 Y946A TM 11 Mouse mdr3 166 S948A TM 11 Mouse mdr3 166 Y949A TM 11 Mouse mdr3 166 C952A TM 11 Mouse mdr3 166 F953A TM 11 Mouse mdr3 166 F983A TM 12 Human MDR1 169 L975A, V981A, F983A TM 12 Human MDR1 169 M986A, V988A, Q990A, TM 12 Human MDR1 169 V991A V981A, F983A TM 12 Human MDR1 169 L975A, F983A TM 12 Human MDR1 169 L975A, V981A TM 12 Human MDR1 169 F978A TM 12 Human MDR1 19 a aa,amino acid; EC, extracellular loop; IC, intracellular loop; TM,transmembrane domain; NBD, nucleotide binding/utilization domain.
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ABCB4 p.Ile936Ala 10331089:47:1380
status: NEW[hide] Mutagenesis of transmembrane domain 11 of P-glycop... Biochemistry. 1996 Mar 19;35(11):3625-35. Hanna M, Brault M, Kwan T, Kast C, Gros P
Mutagenesis of transmembrane domain 11 of P-glycoprotein by alanine scanning.
Biochemistry. 1996 Mar 19;35(11):3625-35., 1996-03-19 [PMID:8639515]
Abstract [show]
The biochemical and genetic analyses of P-glycoprotein (P-gp) have indicated that the membrane-associated regions of P-gp play an important role in drug recognition and drug transport. Predicted transmembrane domain 11 (TM11) maps near a major drug binding site revealed by photoaffinity labeling, and mutations in this domain alter the substrate specificity of P-gp. To investigate further the role of TM11 in P-gp function in general, and substrate specificity in particular, each of the 21 residues of TM11 of the P-gp isoform encoded by the mouse mdr3 gene was independently mutated to alanine, or to glycine in the case of endogenous alanines. After transfection and overexpression in Chinese hamster ovary cells, pools of stable transfectants were analyzed for qualitative or quantitative deviations from the profile of resistance to vinblastine, adriamycin, colchicine, and actinomycin D displayed by the wild-type protein. While mutations at eight of the positions had no effect on P-gp function, 13 mutants showed a 2-10-fold reduction of activity against one of the four drugs tested. Although the phenotype of individual mutants was varied, replacements at most mutation-sensitive positions seemed to affect the drug resistance profiles rather than the overall activity of the mutant P-gp. When TM11 was projected in a alpha-helical configuration, the distribution of deleterious and neutral mutations was not random but segregated with a more hydrophobic (mutation-insensitive) face and a more hydrophilic (mutation-sensitive) face of a putative amphipathic helix. The alternate clustering pattern of deleterious vs neutral mutations in TM11 together with the altered drug resistance profile of deleterious mutants suggest that the more hydrophilic face of the TM11 helix may play an important structural or functional role in drug recognition and transport by P-gp. Finally, the conservation of the two residues most sensitive to mutations (Y949 and Y953) in TM11, and in the homologous TM5, of all mammalian P-gps and also in other ABC transporters, suggests that these residues and domains may play an important role in structural as well as mechanistic aspects common to this family of proteins.
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No. Sentence Comment
125 Eleven of the mutations (F934A, G935A, I936A, F938A, S939A, T941A, Q942A, A943G, Y946A, S948A, and C952A) caused a moderate but reproducible 2-3-fold decrease in resistance to one or more of the drugs.
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ABCB4 p.Ile936Ala 8639515:125:39
status: NEW156 These two mutations are also predicted to map near the top half of TM11, within the outer lipid leaflet of Table 1: Drug Survival Characteristics of Mass Populations Cells Stably Transfected with Wild-Type or Mutant mdr3 cDNAsa mdr3 ACT ADR COL VBL V933A 32 ( 3 (17×) 370 ( 200 (19×) 590 ( 180 (21×) 200 ( 20 (24×) F934A 37 ( 2 (19×) 110 ( 40 (6×) 240 ( 80 (9×) 200 ( 30 (24×) G935A 26 ( 3 (14×) 200 ( 110 (10×) 350 ( 20 (13×) 120 ( 20 (14×) I936A 23 ( 5 (12×) 100 ( 40 (5×) 170 ( 40 (6×) 80 ( 13 (10×) T937A 50 ( 10 (27×) 280 ( 110 (15×) 620 ( 100 (23×) 160 ( 6 (20×) F938A 42 ( 6 (22×) 140 ( 60 (7×) 360 ( 80 (13×) 260 ( 20 (32×) S939A 46 ( 1 (24×) 160 ( 80 (8×) 280 ( 30 (10×) 160 ( 30 (20×) F940A 43 ( 4 (22×) 380 ( 130 (20×) 980 ( 210 (36×) 240 ( 30 (29×) T941A 48 ( 3 (25×) 100 ( 40 (5×) 140 ( 20 (5×) 130 ( 40 (16×) Q942A 60 ( 6 (32×) 100 ( 40 (5×) 190 ( 10 (7×) 270 ( 70 (33×) A943G 41 ( 4 (22×) 90 ( 10 (5×) 350 ( 60 (13×) 380 ( 40 (46×) M944A 29 ( 6 (15×) 450 ( 190 (23×) 730 ( 90 (27×) 200 ( 40 (24×) M945A 56 ( 2 (29×) 180 ( 50 (9×) 340 ( 80 (13×) 210 ( 50 (26×) Y946A 16 ( 2 (8×) 310 ( 160 (16×) 350 ( 30 (13×) 100 ( 8 (13×) F947A 32 ( 2 (17×) 310 ( 100 (16×) 660 ( 120 (24×) 170 ( 30 (20×) S948A 25 ( 3 (13×) 210 ( 80 (11×) 370 ( 60 (13×) 210 ( 40 (26×) Y949A 18 ( 2 (9×) 60 ( 20 (3×) 180 ( 20 (6×) 190 ( 15 (23×) A950G 46 ( 6 (24×) 280 ( 70 (15×) 520 ( 120 (19×) 200 ( 30 (25×) A951G 60 ( 10 (32×) 300 ( 30 (16×) 560 ( 120 (21×) 280 ( 30 (34×) C952A 24 ( 5 (12×) 360 ( 180 (19×) 500 ( 50 (18×) 140 ( 50 (18×) F953A 8 ( 1 (4×) 28 ( 7 (1×) 45 ( 9 (2×) 100 ( 13 (13×) WT 50 ( 10 (25×) 290 ( 80 (15×) 450 ( 100 (16×) 210 ( 40 (25×) LR73 2 ( 0.1 (1×) 19 ( 6 (1×) 27 ( 4 (1×) 8 ( 2 (1×) a The drug survival of Chinese hamster ovary drug-sensitive cells (LR73) and of cell clones transfected with either wild-type or mutant mdr3 is expressed as the D50 (in nanograms per milliliter), or the dose necessary to reduce the plating efficiency of the control and transfected cells by 50%.
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ABCB4 p.Ile936Ala 8639515:156:502
status: NEW68 Untransfected LR73 cells and G418R mass populations of LR73 transfected with WT and I936A, Q942A, Y949A, and F953A mutant mdr3 cDNAs were plated in medium without drug (2.5 × 103 cells) or in medium containing ACT, ADR, COL, or VBL at three different concentrations (2.5 × 104 cells) in 24-well plates (15-mm wells).
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ABCB4 p.Ile936Ala 8639515:68:84
status: NEW127 Among mutants with reduced activity, only F953A and I936A displayed an overall decrease in resistance to all drugs analyzed.
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ABCB4 p.Ile936Ala 8639515:127:52
status: NEW145 Among the amino acids on the more hydrophobic side of the helix, I936A showed the greatest sensitivity to alanine substitution, resulting in an overall 2-3-fold reduction in activity against the four drugs tested.
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ABCB4 p.Ile936Ala 8639515:145:65
status: NEW146 The somewhat lower level of expression of the I936A mutant in the membrane fraction of transfectants might have partly contributed to the reduced activity of this mutant.
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ABCB4 p.Ile936Ala 8639515:146:46
status: NEW187 For this, mass populations of G418R cells cotransfected with individual mutants I936A, Q942A, Y949A, and F953A, showing unique deviations from wild type in their drug resistance profiles (Figure 3), were plated directly in medium containing increasing concentrations of VBL, ADR, COL, and ACT.
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ABCB4 p.Ile936Ala 8639515:187:80
status: NEW205 As opposed to other mutation-sensitive positions, the I936A mutation caused an overall reduction by a factor of 2-3-fold in activity of the mutant P-gp, reduction which could not be totally explained by a lower amount of protein produced in the clone analyzed (compare expression and activity to that of G935A).
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ABCB4 p.Ile936Ala 8639515:205:54
status: NEW216 Approximately 2.5 × 103 cells (no drug) or 2.5 × 104 cells (with drug) from mass populations of G418R clones stably transfected with either wild-type mdr3 (columns 1) or mdr3 mutants I936A (2), Q942A (3), Y949A (4), F953A (5), or untransfected LR73 control cells (6) were plated in medium containing increasing concentrations of the drugs actinomycin D (ACT), adriamycin (ADR), colchicine (COL), or vinblastine (VBL).
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ABCB4 p.Ile936Ala 8639515:216:193
status: NEW220 Table 2: Drug Survival Characteristics of Mass Populations of G418R Cell Clones Transfected with Mouse mdr3 mutants in TM11a ACT ADM COL VBL REV 7.5 52.6 71.9 8.0 I936A 59.7 (8.0×) 121.3 (2.3×) 367.1 (5.1×) 70.5 (8.8×) Q942A 54.1 (7.2×) 82.6 (1.6×) 128.1 (1.8×) 81.7 (10.2×) Y949A 31.6 (4.2×) 80.4 (1.5×) 163.3 (2.3×) 81.0 (10.1×) F953A 9.4 (1.2×) 51.6 (1×) 85.9 (1.2×) 78.9 (9.9×) WT 67.2 (9.0×) 249.4 (4.7×) 493.7 (6.9×) 67.6 (8.5×) a The drug cytotoxicity for each mass population of G418R cell clones is expressed as the D50 (nanograms per milliliter), or the dose necessary to reduce the plating efficiency of the control and transfected cell clones by 50%.
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ABCB4 p.Ile936Ala 8639515:220:163
status: NEW[hide] Molecular genetic analysis and biochemical charact... Semin Cell Dev Biol. 2001 Jun;12(3):247-56. Hrycyna CA
Molecular genetic analysis and biochemical characterization of mammalian P-glycoproteins involved in multidrug resistance.
Semin Cell Dev Biol. 2001 Jun;12(3):247-56., [PMID:11428917]
Abstract [show]
A variety of human cancers become resistant or are intrinsically resistant to treatment with conventional drug therapies. This phenomenon is due in large part to the overexpression of a 170 kDa plasma membrane ATP-dependent pump known as the multidrug resistance transporter or P-glycoprotein. P-glycoprotein is a member of the large ATP binding cassette (ABC) superfamily of membrane transporters. This review focuses on the use of structure-function analyses to elucidate further the mechanism of action of mammalian P-glycoproteins. Ultimately, a complete understanding of the mechanism is important for the development of novel strategies for the treatment of many human cancers.
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No. Sentence Comment
27 List of mutations in human, mouse and hamster P-gp`s that affect substrate specificity f aaa Mutation Regionb Sourcec Reference aa 78-97 EC 1 human MDR1 78 (ABC20)d Q128He TM 2 mouse mdr3 79 R138H IC 1 mouse mdr3 79 Q139H, R IC 1 mouse mdr3 79 G141V IC 1 human MDR1 25,80 Q145H IC 1 mouse mdr3 79 E155G, K IC 1 mouse mdr3 79 F159I IC 1 mouse mdr3 79 D174G IC 1 mouse mdr3 79 S176F, P IC 1 mouse mdr3 79 K177I IC 1 mouse mdr3 79 N179S IC1 mouse mdr3 79 N183S/G185V IC 1 human MDR1 81 G183D IC1 mouse mdr3 79 G185V IC 1 human MDR1 82-84 G187V IC 1 human MDR1 80 A192T TM 3 mouse mdr3 79 F204S EC 2 mouse mdr3 79 W208G EC 2 mouse mdr3 79 K209E EC 2 mouse mdr3 79 L210I TM 4 mouse mdr3 79 T211P TM 4 mouse mdr3 79 I214T TM 4 mouse mdr3 79 P223A TM 4 human MDR1 85 K285T IC 2 human MDR1 1 G288V IC 2 human MDR1 80 I299M, T319S, L322I, TM 5, EC3, IC 3 human MDR1 86 G324K, S351N V334 TM 6 human MDR1 1 F335A TM 6 human MDR1 25 F335 TM 6 human MDR1 87 V338A TM 6 human MDR1 88 G338A, A339P TM 6 hamster PGY 1 89,90 A339P TM 6 hamster PGY 1 90 G341V TM 6 human MDR1 88 K536R,Q N-NBD human MDR1 91 ERGA→DKGT N-NBD mouse mdr3 92 (aa 522-525) T578C N-NBD mouse mdr3 92 G812V IC 4 human MDR1 80 G830V IC 4 human MDR1 25,80 P866A TM 10 human MDR1 85 F934A TM 11 mouse mdr3 93 G935A TM 11 mouse mdr3 93 I936A TM 11 mouse mdr3 93 F938A TM 11 mouse mdr3 93 S939A TM 11 mouse mdr3 93 S939F TM 11 mouse mdr3 94,95 S941F TM 11 mouse mdr1 94,95 T941A TM 11 mouse mdr3 93 Q942A TM 11 mouse mdr3 93 Table 1-continued aaa Mutation Regionb Sourcec Reference A943G TM 11 mouse mdr3 93 Y946A TM 11 mouse mdr3 93 S948A TM 11 mouse mdr3 93 Y949A TM 11 mouse mdr3 93 C952A TM 11 mouse mdr3 93 F953A TM 11 mouse mdr3 93 F983A TM 12 human MDR1 96 L975A, V981A, F983A TM 12 human MDR1 96 M986A, V988A, TM 12 human MDR1 96 Q990A, V991A V981A, F983A TM 12 human MDR1 96 L975A, F983A TM 12 human MDR1 96 L975A, V981A TM 12 human MDR1 96 F978 TM 12 human MDR1 1 F978A TM 12 human MDR1 25 a aa, amino acid.
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ABCB4 p.Ile936Ala 11428917:27:1296
status: NEW