ABCB1 p.Tyr953Phe

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PMID: 18596043 [PubMed] Loo TW et al: "Arginines in the first transmembrane segment promote maturation of a P-glycoprotein processing mutant by hydrogen bond interactions with tyrosines in transmembrane segment 11."
No. Sentence Comment
7 Mutations that removed hydrogen bond acceptors (Y950F/Y950A or Y953F/Y953A) in TM11 predicted to lie close to Arg-65 or Arg-68 inhibited maturation but did not affect maturation of the G251V parent.
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ABCB1 p.Tyr953Phe 18596043:7:63
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228 Conservative replacement of Tyr-950 or Tyr-953 with Phe would only disrupt hydrogen bond interactions.
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ABCB1 p.Tyr953Phe 18596043:228:39
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229 Mutants L65R/G251V/Y950F, M68R/G251V/ Y950A/Y953A, and M68R/G251V/Y950F/Y953F were constructed, and the cDNAs were expressed in HEK 293 cells.
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ABCB1 p.Tyr953Phe 18596043:229:72
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231 Immunoblot analysis shows the Y950A/Y953A and Y950F/Y953F changes in M68R/G251V (Fig. 8A, lanes 11 and 12) or Y950F change in L65R/G251V (Fig. 8B, lane 5) reduced maturation to levels similar to that observed in the G251V parent.
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ABCB1 p.Tyr953Phe 18596043:231:52
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232 Introduction of the Y950F and Y953F FIGURE 7.
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ABCB1 p.Tyr953Phe 18596043:232:30
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308 This possibility is supported by the observations that the conservative Y950F and Y953F mutations reduced maturation of the M68R/G251V mutant to levels observed with the G251V parent.
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ABCB1 p.Tyr953Phe 18596043:308:82
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309 An arginine introduced at position 65 in TM1 only appeared to form a hydrogen bond with Tyr-950 as the Y950F mutation but not the Y953F change reduced maturation of the L65R/G251V mutant to levels observed with the G251V parent.
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ABCB1 p.Tyr953Phe 18596043:309:130
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PMID: 24366667 [PubMed] Donmez Cakil Y et al: "Pore-exposed tyrosine residues of P-glycoprotein are important hydrogen-bonding partners for drugs."
No. Sentence Comment
53 Construction of P-gp Mutants The following primers were used for generation of the Y307F, Y310F, Y307F/Y310F, Y950F, Y953F, and Y950F/Y953F mutations of hexa-His-tagged human P-gp in the entry vector pENTR4: Y307F- forward, 59-CTTTCCTGCTGATCTTTGCATCTTATGCTCTGGCC-39; Y307F-reverse, 59-GGCCAGAGCATAAGATGCAAAGATCAGCAGG AAAG-39; Y310F-forward, 59-CTTTCCTGCTGATCTATGCATCTTT TGCTCTGGCC-39; Y310F-reverse, 59-GGCCAGAGCAAAAGATGCA- TAGATCAGCAGGAAAG-39; Y307F/Y310F-forward, 59-CTTTCCTG CTGATCTTTGCATCTTTTGCTCTGGCC-39; Y307F/Y310F-reverse, 59-GGCCAGAGCAAAAGATGCAAAGATCAGCAGGAAAG-39; Y950F- forward, 59-TCACCCAGGCAATGATGTTTTTTTCCTATGCTGGATG- 39; Y950F-reverse, 59-CATCCAGCATAGGAAAAAAACATCATTGCC TGGGTGA-39; Y953F-forward, 59-ACCCAGGCAATGATGTATTTTT CCTTTGCTGGATGTTTC-39; Y953F-reverse, 59-GAAACATCCAGCAAA GGAAAAATACATCATTGCCTGGGT-39; Y950F/Y953F-forward, 59-CCTT CACCCAGGCAATGATGTTTTTTTCCTTTGCTGGATGTTTCC -39; and Y950F/Y953F-reverse, 59-GGAAACATCCAGCAAAGGAAAAAAACATCA TTGCCTGGGTGAAGG-39.
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ABCB1 p.Tyr953Phe 24366667:53:117
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ABCB1 p.Tyr953Phe 24366667:53:134
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ABCB1 p.Tyr953Phe 24366667:53:697
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ABCB1 p.Tyr953Phe 24366667:53:760
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ABCB1 p.Tyr953Phe 24366667:53:829
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ABCB1 p.Tyr953Phe 24366667:53:909
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117 Mutant Y950F showed a similar transport rate as wild-type protein, whereas mutant Y953F showed a significantly decreased rate (54% 6 12% of wild-type) (Fig. 2).
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ABCB1 p.Tyr953Phe 24366667:117:82
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118 The double mutant Y950F/Y953F showed a decrease that was comparable with that observed for the Y953F single mutant alone.
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ABCB1 p.Tyr953Phe 24366667:118:24
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ABCB1 p.Tyr953Phe 24366667:118:95
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121 The effect of the Y953F mutation on rh123 efflux should be abolished by introducing selector residue R132 and should be more pronounced when deselecting site 1 by introducing selector residue R773.
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ABCB1 p.Tyr953Phe 24366667:121:18
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125 This is illustrated by comparable transport activity of the Q132R/Y950F, Q132R/Y953F, and Q132R/ Y950F/Y953F mutants.
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ABCB1 p.Tyr953Phe 24366667:125:79
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ABCB1 p.Tyr953Phe 24366667:125:103
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128 By contrast, transport rates were found to be lower in the Q773R/Y953F mutant compared with the Q773R mutant alone, although this decrease did not reach statistical significance.
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ABCB1 p.Tyr953Phe 24366667:128:65
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137 Q773R/Y950F/Y953F was expressed at the surface, but no rh123 efflux was detectable.
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ABCB1 p.Tyr953Phe 24366667:137:12
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146 The wild-type showed an IC50 value of 518 6 141 nM, whereas the values for the single mutants Y950F and Y953F were 1348 6 229 and 1207 6 362 nM, respectively.
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ABCB1 p.Tyr953Phe 24366667:146:104
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148 An analogous pattern was seen for GPV031 (wild-type, 85 6 22 nM; Y950F, 238 6 84 nM; Y953F, 287 6 109 nM; and Y950F/Y953F, 630 6 87 nM) (Fig. 3C).
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ABCB1 p.Tyr953Phe 24366667:148:85
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ABCB1 p.Tyr953Phe 24366667:148:116
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152 In contrast with protonatable propafenones, a higher IC50 value was observed for the Y953F, but not for the Y950F, single mutant.
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ABCB1 p.Tyr953Phe 24366667:152:85
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153 The fold change for the double mutant was comparable with that observed for the Y953F single mutant (wild-type, 2239 6 391 nM; Y950F, 2984 6 79 nM, n.s.; Y953F, 15,946 6 2941 nM, 7.1-fold change relative to wild-type; and Y950F/Y953F, 17,819 6 2106 nM, 8-fold change).
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ABCB1 p.Tyr953Phe 24366667:153:80
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ABCB1 p.Tyr953Phe 24366667:153:154
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ABCB1 p.Tyr953Phe 24366667:153:228
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159 (A) Open diamonds, wild-type; filled circles, Y950F/Y953F; triangles, Y950F; squares, Y953F.
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ABCB1 p.Tyr953Phe 24366667:159:52
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ABCB1 p.Tyr953Phe 24366667:159:86
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164 However, IC50 values were still higher in the Q132R/Y953F mutation.
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ABCB1 p.Tyr953Phe 24366667:164:52
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168 For the nonprotonatable acid amide GPV366, a higher IC50 value was observed in the Q132R/Y953F mutant (Q132R, 1074 6 282 nM; and Q132R/Y953F, 3261 6 965 nM), whereas the Y950F mutation in the same background did not affect potency (966 6 259 nM) (Fig. 4C).
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ABCB1 p.Tyr953Phe 24366667:168:89
status: NEW
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ABCB1 p.Tyr953Phe 24366667:168:135
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171 The higher IC50 values in the Q132R/Y950F/Y953F mutant were not due to an additive effect of the two tyrosine mutations on binding of propafenones.
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ABCB1 p.Tyr953Phe 24366667:171:42
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173 Certainly, the effect is not brought about by a global perturbance of protein structure and function, because the Q132R mutant and the Q132R/Y950F/Y953F triple mutant showed comparable rh123 transport rates (Fig. 2).
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ABCB1 p.Tyr953Phe 24366667:173:147
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193 Identical transport rates were found for the Q132R and the Y953F mutants in the Q132R background.
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ABCB1 p.Tyr953Phe 24366667:193:59
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198 As expected, the double mutant showed an IC50 value that was comparable with that of the Y953F mutant.
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ABCB1 p.Tyr953Phe 24366667:198:89
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202 However, higher IC50 values were found for the Y953F mutant, although less pronounced than in the wild-type background.
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ABCB1 p.Tyr953Phe 24366667:202:47
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212 For GPV005, mutant Q132R/Y953F showed a 1.5-fold higher IC50 value than the Q132R mutation, whereas the fold changes were 2.1-fold for GPV031 and 3.0-fold for uncharged GPV366.
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ABCB1 p.Tyr953Phe 24366667:212:25
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217 The triple Q132R/Y950F/Y953F mutant showed a further increase in IC50 values for all compounds, which is obviously not due to interaction with tyrosines.
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ABCB1 p.Tyr953Phe 24366667:217:23
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