ABCC7 p.Tyr1424Ala

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PMID: 10652362 [PubMed] Weixel KM et al: "The carboxyl terminus of the cystic fibrosis transmembrane conductance regulator binds to AP-2 clathrin adaptors."
No. Sentence Comment
4 Substitution of an alanine residue for tyrosine at position 1424 significantly reduced the ability of AP-2 to bind the carboxyl terminus of CFTR; however, mutation to a phenylalanine residue (an amino acid found at position 1424 in dogfish CFTR) did not perturb AP-2 binding.
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ABCC7 p.Tyr1424Ala 10652362:4:19
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93 To examine the contribution of Tyr1424 to the association between the carboxyl terminus of CFTR and AP-2 adaptors, Tyr1424 was mutated to Ala in the context of the GST fusion protein GST-CT (GST-CT-Y1424A).
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ABCC7 p.Tyr1424Ala 10652362:93:115
status: NEW
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ABCC7 p.Tyr1424Ala 10652362:93:198
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94 GST-CT-Y1424A preabsorbed to glutathione-Sepharose was incubated with purified adaptors, and after extensive washing, bound proteins were analyzed by immunoblot as before.
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ABCC7 p.Tyr1424Ala 10652362:94:7
status: NEW
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95 Although GST-CT-Y1424A was capable of binding AP-2 complexes (Fig. 6A), its capacity for binding was significantly reduced compared with wild-type GST-CT.
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ABCC7 p.Tyr1424Ala 10652362:95:16
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96 Densitometric analysis of the immunoblot indicates that the Y1424A mutation reduces binding to AP-2 complexes compared with the wild-type carboxyl terminus construct, GST-CT, even at higher amounts of GST-CT-Y1424A (Fig. 6B).
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ABCC7 p.Tyr1424Ala 10652362:96:60
status: NEW
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ABCC7 p.Tyr1424Ala 10652362:96:208
status: NEW
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100 When the Student`s t test was applied to the data in Fig. 6, GST-CF- Y1424A showed significant reduction of adaptor binding compared with wild-type constructs, with a p value of Ͻ0.02.
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ABCC7 p.Tyr1424Ala 10652362:100:69
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109 Mutation of tyrosine 1424 to an alanine causes marked loss of beta-structure at this site (Fig. 8).
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ABCC7 p.Tyr1424Ala 10652362:109:12
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148 Mutation of tyrosine 1424 to alanine but not phenylalanine inhibits AP-2 binding to CFTR.
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ABCC7 p.Tyr1424Ala 10652362:148:12
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150 10 or 20 ␮g of wild-type (WT, lanes 1 and 2) or Y1424A (lanes 3 and 4) constructs were incubated with purified adaptor complexes.
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ABCC7 p.Tyr1424Ala 10652362:150:55
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152 The asterisk indicates p Ͻ 0.02 for difference between Y1424A and wild type by Student`s t test.
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ABCC7 p.Tyr1424Ala 10652362:152:61
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154 20 ␮g of Y1424F protein (lane 1), Y1424A (lane 2), wild-type (lane 3), or GST alone (lane 4) were incubated with purified adaptors as described.
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ABCC7 p.Tyr1424Ala 10652362:154:41
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162 Mutation of Tyr1424 to Ala resulted in a significant inhibition of AP-2 binding to the CFTR-GST fusion protein, indicating the importance of this residue in AP-2 binding.
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ABCC7 p.Tyr1424Ala 10652362:162:12
status: NEW
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163 However, binding of AP-2 to Y1424A-CFTR was not completely abolished.
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ABCC7 p.Tyr1424Ala 10652362:163:28
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166 Of note are the observations of Collawn and colleagues (25), who have shown that a Y1424A mutation in transiently expressed CFTR results in a 40% inhibition of CFTR endocytosis rates, a finding consistent with the extent to which Y1424A mutations inhibit AP-2 binding.
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ABCC7 p.Tyr1424Ala 10652362:166:83
status: NEW
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ABCC7 p.Tyr1424Ala 10652362:166:230
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PMID: 10862786 [PubMed] Hallows KR et al: "Inhibition of cystic fibrosis transmembrane conductance regulator by novel interaction with the metabolic sensor AMP-activated protein kinase."
No. Sentence Comment
131 Interestingly, the mutation of Y1424A substantially diminished the interaction strength. Mutation of another possible trafficking motif in the vicinity, the di-leucine at 1430 and 1431 (40) (LL-1430,1431-AA) also dramatically reduced the interaction strength.
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ABCC7 p.Tyr1424Ala 10862786:131:31
status: NEW
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PMID: 11022033 [PubMed] Gentzsch M et al: "Localization of sequences within the C-terminal domain of the cystic fibrosis transmembrane conductance regulator which impact maturation and stability."
No. Sentence Comment
178 In addition to the lack of influence of truncation at residue 1420, alanine substitution of Tyr1424 and Leu1430 -Leu1431 also did not alter the steady state amount of nascent or mature CFTR (not shown).
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ABCC7 p.Tyr1424Ala 11022033:178:68
status: NEW
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PMID: 11237860 [PubMed] Hu W et al: "Multiple endocytic signals in the C-terminal tail of the cystic fibrosis transmembrane conductance regulator."
No. Sentence Comment
75 Alanine substitutions in the following mutants were generated by site-directed mutagenesis: K2, F1413A,L1414A; K3, Y1424A,L1430A,L1431A; K6, F1413A; K7, L1414A; K8, Y1424A; K9, L1430A; K10, F16A,F17A (see also Figure 5), by using either single-stranded (for K2, K3, K8 and K9; Muta Gene in itro mutagenesis from Bio-Rad) or double-stranded (for K10; QuickChange site-directed mutagenesis from Stratagene [35]) pcDNA3-TacT-Ct as template.
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ABCC7 p.Tyr1424Ala 11237860:75:115
status: NEW
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ABCC7 p.Tyr1424Ala 11237860:75:165
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172 The membrane-distal signals, consisting of a canonical Tyr-based motif and a di-Leu motif, were mutated together and designated as mutant K3 (Y1424A,L1430A,L1431A) (Figure 5).
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ABCC7 p.Tyr1424Ala 11237860:172:142
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200 To evaluate the involvement of single amino acid residues in the membrane-proximal and membrane-distal internalization signals, four additional constructs were prepared that disrupted the three putative endocytic signals individually, as follows: K6, F1413A; K7, L1414A; K8, Y1424A; K9, L1430A (see also Figure 5).
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ABCC7 p.Tyr1424Ala 11237860:200:275
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231 Mutation of the membrane-distal internalization signals (K8, Y1424A; K9, L1430A) did not interfere with the processing of CFTRM2, as demonstrated by the large-amplitude cAMP-dependent iodide release from cells expressing K3CFTRM2, K8CFTRM2 or K9CFTRM2 (Figure 8A).
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ABCC7 p.Tyr1424Ala 11237860:231:61
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269 Alanine substitutions of individual residues in the membrane-proximal (K6, F1413A; K7, L1414A) or the membrane-distal (K8, Y1424A; K9, L1430A) stretch revealed an additive effect on the internalization activity (Figure 7D).
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ABCC7 p.Tyr1424Ala 11237860:269:123
status: NEW
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279 In contrast, the disruption of individual components of the bipartite membrane-distal signal caused a 4-fold (K8, Y1424A) and a 3-fold (K9, L1430A) increase in the cell-surface density of the CFTRM2 (Figure 8B; see also Figure 7D).
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ABCC7 p.Tyr1424Ala 11237860:279:114
status: NEW
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PMID: 11560923 [PubMed] Weixel KM et al: "Mu 2 binding directs the cystic fibrosis transmembrane conductance regulator to the clathrin-mediated endocytic pathway."
No. Sentence Comment
155 Furthermore, peptides containing alanine substitution at tyrosine 1424 and isoleucine 1427, *ADSA, abolished the ability of the peptide to cross-link to AP-2 (Fig. 2A, lane 3).
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ABCC7 p.Tyr1424Ala 11560923:155:33
status: NEW
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331 These results strongly correlate with the reduction in endocytosis observed in CFTR Y1424A mutants (10, 35), suggesting that the interaction specifically affected is that between ␮2 and the 1424 YDSI endocytosis signal.
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ABCC7 p.Tyr1424Ala 11560923:331:84
status: NEW
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339 Moreover, the only mutation identified that affected CFTR internalization was the YXX⌽ motif in the carboxyl terminus of CFTR, Y1424A.
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ABCC7 p.Tyr1424Ala 11560923:339:134
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PMID: 12376531 [PubMed] Peter K et al: "Ablation of internalization signals in the carboxyl-terminal tail of the cystic fibrosis transmembrane conductance regulator enhances cell surface expression."
No. Sentence Comment
1 Previously, we demonstrated that Y1424A is important for CFTR endocytosis (Prince, L. S., Peter, K., Hatton, S. R., Zaliauskiene, L., Cotlin, L. F., Clancy, J. P., Marchase, R. B., and Collawn, J. F. (1999) J. Biol. Chem. 274, 3602-3609).
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ABCC7 p.Tyr1424Ala 12376531:1:33
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2 Here we show that a second substitution in the carboxyl-terminal tail of CFTR, I1427A, on Y1424A background more than doubles CFTR surface expression as monitored by surface biotinylation.
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ABCC7 p.Tyr1424Ala 12376531:2:90
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3 Internalization assays indicate that enhanced surface expression of Y1424A,I1427A CFTR is caused by a 76% inhibition of endocytosis.
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ABCC7 p.Tyr1424Ala 12376531:3:68
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4 Patch clamp recording of chloride channel activity revealed that there was a corresponding increase in chloride channel activity of Y1424A,I1427A CFTR, consistent with the elevated surface expression, and no change in CFTR channel properties.
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ABCC7 p.Tyr1424Ala 12376531:4:132
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18 We find that the substitution of Tyr1424 and Ile1427 with alanine residues resulted in a 2-fold increase in surface expression, whereas the single Y1424A mutation shows an intermediate phenotype.
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ABCC7 p.Tyr1424Ala 12376531:18:33
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:18:147
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20 Because the chloride channel activity and relative surface expression of Y1424A and I1427A CFTR are elevated to a similar extent, we propose that these substitutions affect protein trafficking but not CFTR chloride channel function.
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ABCC7 p.Tyr1424Ala 12376531:20:73
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23 The construction of the Y1424A mutant was described previously (3).
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ABCC7 p.Tyr1424Ala 12376531:23:24
status: NEW
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24 For construction of the Y1424A,I1427A mutant, a BstXI-SgrAI fragment that coded for the COOH-terminal tail region of Y1424A CFTR was subcloned into pSK-Bluescript (Stratagene).
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ABCC7 p.Tyr1424Ala 12376531:24:24
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:24:117
status: NEW
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77 COS-7 cells expressing wild-type, Y1424A, and Y1424A,I1427A CFTR were surface-biotinylated and lysed in RIPA buffer (see "Materials and Methods").
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ABCC7 p.Tyr1424Ala 12376531:77:34
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:77:46
status: NEW
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82 The levels of expression of wild-type (Wt), Y1424A, and Y1424A,I1427A CFTR were analyzed in COS-7 cells 48 h after transfection.
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ABCC7 p.Tyr1424Ala 12376531:82:44
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:82:56
status: NEW
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90 The relative amounts of wild-type (lanes 2 and 6), Y1424A (lanes 3 and 7), and Y1424A,I1427A CFTR (lanes 4 and 8) are shown.
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ABCC7 p.Tyr1424Ala 12376531:90:51
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:90:79
status: NEW
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94 The percentage CFTR at the cell surface was markedly increased for Y1424A,I1427A CFTR compared with both wild-type (108% increase, n ϭ 10, p Ͻ 0.001) and Y1424A CFTR (59% increase, n ϭ 10, p Ͻ 0.001) (Fig. 1, bottom panel).
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ABCC7 p.Tyr1424Ala 12376531:94:67
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:94:166
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97 Mutations at Tyr1424 and Ile1427 Do Not Alter CFTR Maturation Efficiency or Protein Half-life-To test the effects of these mutations on maturation efficiency and protein half-life, we performed metabolic pulse-chase experiments on COS-7 cells expressing wild-type, Y1424A, and Y1424A,I1427A CFTR.
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ABCC7 p.Tyr1424Ala 12376531:97:265
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:97:277
status: NEW
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99 The results in Fig. 2 show that the half-lives for wild-type (Wt), Y1424A, and Y1424A,I1427A CFTR were 10.3 Ϯ 2.3, 11.3 Ϯ 2.6, and 11.3 Ϯ 1.5 h (mean Ϯ S.D.).
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ABCC7 p.Tyr1424Ala 12376531:99:67
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:99:79
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102 The average maturation efficiency for wild-type (Wt), Y1424A, and Y1424A,I1427A CFTR were 32, 31, and 31%, respectively (bottom right panel).
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ABCC7 p.Tyr1424Ala 12376531:102:54
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:102:66
status: NEW
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103 This finding demonstrated that elevated surface expression of Y1424A,I1427A CFTR was not because of alterations in maturation efficiency.
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ABCC7 p.Tyr1424Ala 12376531:103:62
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114 COS-7 cells transfected with wild-type, Y1424A, or Y1424A,I1427A CFTR were analyzed 48-h post-transfection.
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ABCC7 p.Tyr1424Ala 12376531:114:40
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:114:51
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119 The percentage of wild-type, Y1424A, and Y1424A,I1427A CFTR internalized after 2.5 min was 34, 18, and 8 respectively.
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ABCC7 p.Tyr1424Ala 12376531:119:29
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:119:41
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122 attributed to alterations in the internalization rate of CFTR, we performed internalization assays on COS-7 cells expressing wild-type, Y1424A, and Y1424A,I1427A CFTR.
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ABCC7 p.Tyr1424Ala 12376531:122:136
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:122:148
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128 For Y1424A and Y1424A,I1427A CFTR, internalization dropped to 21 and 8%, respectively, during the same time period.
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ABCC7 p.Tyr1424Ala 12376531:128:4
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:128:15
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130 The Y1424A and Y1424A,I1427A CFTR Have Normal Chloride Channel Properties-Because the biochemical data suggested that a specific motif in the CFTR COOH terminus dramatically affected endocytosis and because point mutations in the NH2 terminus lead to both disruption of binding to docking machinery and changes in CFTR ion channel function, we tested whether the mutation of Tyr1424 and Ile1427 affected chloride channel function.
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ABCC7 p.Tyr1424Ala 12376531:130:4
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:130:15
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136 In agreement with the surface biotinylation assays, CFTR whole cell Cl- currents in Y1424A CFTR and Y1424A,I1427A CFTR-transfected cells were elevated compared with wild-type CFTR-expressing cells (Table I), suggesting that the elevated Cl-channel activity was the result of the elevated surface expression of CFTR.
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ABCC7 p.Tyr1424Ala 12376531:136:84
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:136:100
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140 Fig. 4, C and D, show the Y1424A and Y1424A,I1427A Cl- current- voltage relationships, respectively, and indicate that although the sensitivities to DIDS and glibenclamide remain similar to wild-type (Fig. 4B), the total current is elevated in the single and double mutants.
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ABCC7 p.Tyr1424Ala 12376531:140:26
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:140:37
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142 Single channel biophysical properties of wild-type, Y1424A, and Y1424A,I1427A CFTR were also assessed.
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ABCC7 p.Tyr1424Ala 12376531:142:52
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:142:64
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145 Representative recordings of wild-type, Y1424A, and Y1424A,I1427A CFTR at 50-60 mV (negative to pipette potential) are shown in Fig. 4E.
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ABCC7 p.Tyr1424Ala 12376531:145:40
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:145:52
status: NEW
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150 Nevertheless, the whole cell and single channel recordings together show that the difference in Cl-channel activity is attributed to elevated surface expression without a significant change in CFTR chloride channel properties among wild-type, Y1424A, and Y1424A,I1427A CFTR.
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ABCC7 p.Tyr1424Ala 12376531:150:243
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:150:244
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154 In examining the mechanism for the elevated surface expression of CFTR, we first showed that total expression levels of wild-type, Y1424A, and Y1424A,I1427A were the same.
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ABCC7 p.Tyr1424Ala 12376531:154:131
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:154:143
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155 We next demonstrated that maturation efficiency and protein half-life were unaffected, suggesting that a primary alteration caused by these substitutions involved changes in distribution TABLE I Summary of whole cell patch clamp recordings for wild-type CFTR and for CFTR mutants shows elevated activity in the mutants relative to wild type Transient transfection cAMP-activated chloride currenta Non-green Green Control Wild type Y1424A Y1424A/I1427A pA at ϩ100 mV Set 1 255 Ϯ 36b (13)c 1070 Ϯ 95 (5) 1650 Ϯ 200* (5) 2125 Ϯ 195† (5) (Fold-difference) 1.0 1.54 1.99 Set 2 201 Ϯ 68 (3) 738 Ϯ 52 (5) 986 Ϯ 24* (5) 1451 Ϯ 35† (5) (Fold-difference) 1.0 1.34 1.97 Set 3 393 Ϯ 140 (4) 1193 Ϯ 55 (7) 1767 Ϯ 164* (7) 3424 Ϯ 205† (6) (Fold-difference) 1.0 1.48 2.87 Fold-difference average 1.0 1.45 Ϯ 0.06* 2.28 Ϯ 0.30† a Three sets of transiently transfected COS-7 cells were analyzed in parallel with the protein biochemistry.
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ABCC7 p.Tyr1424Ala 12376531:155:431
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:155:438
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161 Moreover, we showed that Y1424A,I1427A CFTR was internalized much more slowly than the native protein (76% inhibition at 2.5 min) with an internalization rate of ϳ2%/min.
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ABCC7 p.Tyr1424Ala 12376531:161:25
status: NEW
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165 Second, the internalization rate of Y1424A,I1427A CFTR is comparable with the rate of bulk flow lipid uptake via the endocytic pathway (ϳ2%/min.)
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ABCC7 p.Tyr1424Ala 12376531:165:36
status: NEW
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175 Typical whole-cell I-V plots for wild-type CFTR (panel B), Y1424A (panel C), and Y1424A,I1427A (panel D) showing cyclic AMP-stimulated chloride currents in the absence of blockers (squares), presence of DIDS (upward triangles), and presence of glibenclamide (inverted triangles).
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ABCC7 p.Tyr1424Ala 12376531:175:59
status: NEW
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ABCC7 p.Tyr1424Ala 12376531:175:81
status: NEW
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PMID: 12777252 [PubMed] Bertrand CA et al: "The role of regulated CFTR trafficking in epithelial secretion."
No. Sentence Comment
195 Cells expressing either a dominant negative ␮2 or a CFTR lacking the tyrosine-based internalization motif at the COOH terminus (Y1424A) fail to endocytose CFTR efficiently.
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ABCC7 p.Tyr1424Ala 12777252:195:135
status: NEW
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PMID: 9920908 [PubMed] Prince LS et al: "Efficient endocytosis of the cystic fibrosis transmembrane conductance regulator requires a tyrosine-based signal."
No. Sentence Comment
6 Mutations of potential internalization signals in both cytoplasmic domains reveal that only one mutation inhibits internalization, Y1424A.
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ABCC7 p.Tyr1424Ala 9920908:6:131
status: NEW
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8 We found that both wild type and A1440X CFTR were rapidly internalized, whereas the Y1424A CFTR mutant, like the chimeric protein, had ϳ40% reduced internalization activity.
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ABCC7 p.Tyr1424Ala 9920908:8:84
status: NEW
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103 Next, we analyzed CFTR-TR chimeras that contained point mutations in potential internalization signals in both cytoplasmic tail regions: Y38A, L69A, Y1424A, and L1430A (Fig. 1).
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ABCC7 p.Tyr1424Ala 9920908:103:149
status: NEW
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104 Analysis of these mutants in internalization assays indicated that only one mutation, Y1424A, affected the internalization rate of the chimeras (Fig. 2B; ϳ40% loss of internalization activity, p Ͻ 0.05), suggesting that this residue might be a part of an internalization signal.
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ABCC7 p.Tyr1424Ala 9920908:104:86
status: NEW
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116 A1440X contains a stop mutation at residue 1440, and Y1424A contains an alanine substitution for tyrosine.
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ABCC7 p.Tyr1424Ala 9920908:116:53
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123 Comparison of the CFTR-(1391-1440) with the Y1424A mutant showed little or no difference (not shown).
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ABCC7 p.Tyr1424Ala 9920908:123:44
status: NEW
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134 Tyrosine 1424 Is Important for CFTR Endocytosis-Next, we tested the only point mutation that affected internalization of the chimeras, Y1424A.
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ABCC7 p.Tyr1424Ala 9920908:134:135
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144 B, internalization of CFTR and Y1424A in COS-7 cells.
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ABCC7 p.Tyr1424Ala 9920908:144:31
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145 Cells transfected with wild-type CFTR (pGT-CFTR) or Y1424A were analyzed as described in A for percentage CFTR internalized from the cell surface during the warm-up period.
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ABCC7 p.Tyr1424Ala 9920908:145:52
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146 C, percentage of CFTR or Y1424A at the cell surface under steady-state conditions.
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ABCC7 p.Tyr1424Ala 9920908:146:25
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147 Cells transfected with CFTR or Y1424A were analyzed for total CFTR expression by performing the two-step biotinylation reaction without a warm-up step.
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ABCC7 p.Tyr1424Ala 9920908:147:31
status: NEW
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148 Biotinylated and nonbiotinylated CFTR or Y1424A was separated on a monovalent avidin column and quantitated as described for A.
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ABCC7 p.Tyr1424Ala 9920908:148:41
status: NEW
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156 tion would imply that the steady-state distribution of Y1424A might favor a higher cell surface distribution pattern, we determined the percentage of CFTR at the cell surface using surface biotinylation at 4 °C.
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ABCC7 p.Tyr1424Ala 9920908:156:55
status: NEW
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157 As predicted, the percentage of Y1424A at the cell surface was higher than the wild-type CFTR protein (36.1 versus 23.1% (p Ͻ 0.01), respectively; Fig. 6C), supporting the idea that tyrosine 1424 was important for CFTR endocytosis.
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ABCC7 p.Tyr1424Ala 9920908:157:32
status: NEW
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163 A similar comparison between wild type CFTR (pGT) and Y1424A (pGT) revealed that the expression levels were similar (Fig. 5B).
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ABCC7 p.Tyr1424Ala 9920908:163:54
status: NEW
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178 The only mutation that we identified in our studies that affected CFTR internalization was found in the carboxyl-terminal tail, Y1424A.
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ABCC7 p.Tyr1424Ala 9920908:178:128
status: NEW
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PMID: 23045527 [PubMed] Duan Y et al: "Keratin K18 increases CFTR surface expression by binding to its C-terminal hydrophobic patch."
No. Sentence Comment
160 Mutation of Tyr1424 to alanine did not alter CFTR-C-K18 binding, arguing against a role of AP2 in mediating the interaction between CFTR and K18.
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ABCC7 p.Tyr1424Ala 23045527:160:0
status: NEW
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ABCC7 p.Tyr1424Ala 23045527:160:12
status: NEW
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151 Mutation of Tyr1424 to alanine did not alter CFTR-C-K18 binding, arguing against a role of AP2 in mediating the interaction between CFTR and K18.
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ABCC7 p.Tyr1424Ala 23045527:151:12
status: NEW
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253 In agreement with previous studies (4), substitution of Tyr1424 with an alanine in the CFTR C terminus (M4 mutation) strongly suppressed AP2-binding (Fig. 6A).
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ABCC7 p.Tyr1424Ala 23045527:253:56
status: NEW
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297 Panel a, AP2 (top blot) and K18 (middle blot) from Calu-3 cells pulled down by GST alone (GST), GST-CFTR-(1407-1480) (WT), and GST-CFTR-(1407-1480) with 1413 FLVI1416 -AAAA (M1) or Y1424A (M4) mutations; the bottom blot shows loading of GST proteins.
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ABCC7 p.Tyr1424Ala 23045527:297:181
status: NEW
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PMID: 22399289 [PubMed] Cihil KM et al: "Disabled-2 protein facilitates assembly polypeptide-2-independent recruitment of cystic fibrosis transmembrane conductance regulator to endocytic vesicles in polarized human airway epithelial cells."
No. Sentence Comment
89 Plasmids and Transient Transfection-The cDNAs encoding human full-length WT-CFTR and the CFTR Y1424A mutant in pS65T-C1 vector (GFP-CFTR WT and GFP-CFTR Y1424A, respectively) were generous gifts from Dr. Bruce A. Stanton, Department of Physiology, Dartmouth Medical School, Hanover, NH. Human Dab2 (Uniprot accession number P98082-1) was obtained from Origene (SC321375) Technologies, Inc., Rockville, MD).
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ABCC7 p.Tyr1424Ala 22399289:89:94
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:89:153
status: NEW
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255 First, we examined whether the Y1424A substitution in CFTR, previously shown to disrupt the CFTR-␮2 interaction, affects CFTR recruitment to CCVs.
X
ABCC7 p.Tyr1424Ala 22399289:255:31
status: NEW
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256 Parental CFBE41o-cells transiently transfected with the GFP-CFTR WT or the GFP-CFTR Y1424A mutant were grown in plastic tissue culture dishes for 72 h.
X
ABCC7 p.Tyr1424Ala 22399289:256:72
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:256:84
status: NEW
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258 As illustrated in Fig. 8, the abundance of the GFP-CFTR WT and GFP-CFTR Y1424A in CCVs was similar.
X
ABCC7 p.Tyr1424Ala 22399289:258:72
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:258:121
status: NEW
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259 Next, we examined the effect of the Y1424A substitution on CFTR endocytosis.
X
ABCC7 p.Tyr1424Ala 22399289:259:36
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:259:70
status: NEW
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260 The biotinylation-based endocytic assays were conducted in parental CFBE41o-cells expressing GFP-CFTR WT or the GFP-CFTR Y1424A mutant.
X
ABCC7 p.Tyr1424Ala 22399289:260:63
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:260:121
status: NEW
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261 As illustrated in Fig. 9, endocytosis of the GFP-CFTR WT and GFP-CFTR Y1424A was similar in the linear uptake phase, consistent with steady-state measurements (Figs. 8 and 10).
X
ABCC7 p.Tyr1424Ala 22399289:261:70
status: NEW
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262 Finally, studies were conducted to determine the effect of the Y1424A substitution on CFTR stability in the plasma membrane.
X
ABCC7 p.Tyr1424Ala 22399289:262:63
status: NEW
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275 Error bars, S.E. Dab2 Facilitates CFTR Endocytosis APRIL 27, 2012•VOLUME 287•NUMBER 18 JOURNAL OF BIOLOGICAL CHEMISTRY 15093 membrane biotinylation at °C, the disappearance of the GFP-CFTR WT or GFP-CFTR Y1424A mutant from the plasma membrane was monitored as a function of time at 37 °C.
X
ABCC7 p.Tyr1424Ala 22399289:275:36
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:275:225
status: NEW
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276 As shown in Fig. 10, the plasma membrane stability of the GFP-CFTR WT and GFP-CFTR Y1424A was similar.
X
ABCC7 p.Tyr1424Ala 22399289:276:83
status: NEW
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277 The above data demonstrate that the Y1424A mutation affects neither CFTR recruitment to CCVs, CFTR endocytosis, nor CFTR stability in the plasma membrane and suggest that the CFTR interaction with ␮2 adaptin is not essential for CFTR endocytosis in human airway epithelial cells.
X
ABCC7 p.Tyr1424Ala 22399289:277:36
status: NEW
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327 Subcellular fractionation experiments performed to determine the effect of the Y1424A mutation on CFTR recruitment CCV in CFBE41o-cells.
X
ABCC7 p.Tyr1424Ala 22399289:327:79
status: NEW
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328 The CCV fractions were prepared by density gradient and differential centrifugation in parental CFBE41o-cells 72 h after transfection with the GFP-CFTR WT or GFP-CFTR Y1424A mutant.
X
ABCC7 p.Tyr1424Ala 22399289:328:86
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:328:167
status: NEW
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330 A representative Western blot (B) and summary of experiments (C) demonstrate that the Y1424A mutation did not decrease the abundance of CFTR in CCVs.
X
ABCC7 p.Tyr1424Ala 22399289:330:86
status: NEW
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356 Endocytic assays performed to determine the effect of the Y1424A mutation on CFTR endocytosis.
X
ABCC7 p.Tyr1424Ala 22399289:356:58
status: NEW
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357 Endocytic assays were performed in parental CFBE41o-cells 72 h after transfection with the GFP-CFTR WT or GFP-CFTR Y1424A mutant.
X
ABCC7 p.Tyr1424Ala 22399289:357:91
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:357:115
status: NEW
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359 A representative Western blot (IB; A) and summary of experiments (B) demonstrates that the Y1424A mutation did not inhibit CFTR endocytosis.
X
ABCC7 p.Tyr1424Ala 22399289:359:91
status: NEW
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366 Biotinylation experiments performed to determine the effects of the Y1424A mutation on CFTR expression in the plasma membrane of CFBE41o-cells as a function of time.
X
ABCC7 p.Tyr1424Ala 22399289:366:68
status: NEW
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367 Biotinylation experiments were performed in parental CFBE41o-cells 72 h after transfection with the GFP-CFTR WT or GFP-CFTR Y1424A mutant.
X
ABCC7 p.Tyr1424Ala 22399289:367:90
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:367:124
status: NEW
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369 A representative Western blot (IB; A) and summary of experiments (B) demonstrate that the Y1424A mutation did not increase CFTR stability in the plasma membrane.
X
ABCC7 p.Tyr1424Ala 22399289:369:90
status: NEW
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88 Plasmids and Transient Transfection-The cDNAs encoding human full-length WT-CFTR and the CFTR Y1424A mutant in pS65T-C1 vector (GFP-CFTR WT and GFP-CFTR Y1424A, respectively) were generous gifts from Dr. Bruce A. Stanton, Department of Physiology, Dartmouth Medical School, Hanover, NH. Human Dab2 (Uniprot accession number P98082-1) was obtained from Origene (SC321375) Technologies, Inc., Rockville, MD).
X
ABCC7 p.Tyr1424Ala 22399289:88:94
status: NEW
X
ABCC7 p.Tyr1424Ala 22399289:88:153
status: NEW
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253 First, we examined whether the Y1424A substitution in CFTR, previously shown to disrupt the CFTR-òe;2 interaction, affects CFTR recruitment to CCVs.
X
ABCC7 p.Tyr1424Ala 22399289:253:31
status: NEW
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254 Parental CFBE41o-cells transiently transfected with the GFP-CFTR WT or the GFP-CFTR Y1424A mutant were grown in plastic tissue culture dishes for 72 h.
X
ABCC7 p.Tyr1424Ala 22399289:254:84
status: NEW
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257 Next, we examined the effect of the Y1424A substitution on CFTR endocytosis.
X
ABCC7 p.Tyr1424Ala 22399289:257:36
status: NEW
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273 Error bars, S.E. Dab2 Facilitates CFTR Endocytosis APRIL 27, 2012ߦVOLUME 287ߦNUMBER 18 JOURNAL OF BIOLOGICAL CHEMISTRY 15093 at SEMMELWEIS UNIV OF MEDICINE on December 5, membrane biotinylation at &#b0;C, the disappearance of the GFP-CFTR WT or GFP-CFTR Y1424A mutant from the plasma membrane was monitored as a function of time at 37 &#b0;C.
X
ABCC7 p.Tyr1424Ala 22399289:273:268
status: NEW
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274 As shown in Fig. 10, the plasma membrane stability of the GFP-CFTR WT and GFP-CFTR Y1424A was similar.
X
ABCC7 p.Tyr1424Ala 22399289:274:83
status: NEW
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325 Subcellular fractionation experiments performed to determine the effect of the Y1424A mutation on CFTR recruitment CCV in CFBE41o-cells.
X
ABCC7 p.Tyr1424Ala 22399289:325:79
status: NEW
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326 The CCV fractions were prepared by density gradient and differential centrifugation in parental CFBE41o-cells 72 h after transfection with the GFP-CFTR WT or GFP-CFTR Y1424A mutant.
X
ABCC7 p.Tyr1424Ala 22399289:326:167
status: NEW
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354 Endocytic assays performed to determine the effect of the Y1424A mutation on CFTR endocytosis.
X
ABCC7 p.Tyr1424Ala 22399289:354:58
status: NEW
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355 Endocytic assays were performed in parental CFBE41o-cells 72 h after transfection with the GFP-CFTR WT or GFP-CFTR Y1424A mutant.
X
ABCC7 p.Tyr1424Ala 22399289:355:115
status: NEW
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364 Biotinylation experiments performed to determine the effects of the Y1424A mutation on CFTR expression in the plasma membrane of CFBE41o-cells as a function of time.
X
ABCC7 p.Tyr1424Ala 22399289:364:68
status: NEW
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365 Biotinylation experiments were performed in parental CFBE41o-cells 72 h after transfection with the GFP-CFTR WT or GFP-CFTR Y1424A mutant.
X
ABCC7 p.Tyr1424Ala 22399289:365:124
status: NEW
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PMID: 11001491 [PubMed] Kleizen B et al: "Regulated trafficking of the CFTR chloride channel."
No. Sentence Comment
118 Construction of chimeras consisting of the C-terminal or N-terminal CFTR tail regions fused to the transferrin receptor (TR) followed by mutational analysis in chicken embryo fibroblasts revealed that one specific mutation within the C-terminal CFTR-TR, Y1424A, reduced the internalization rate by 40% (Prince et al., 1999).
X
ABCC7 p.Tyr1424Ala 11001491:118:254
status: NEW
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120 As expected, the C-terminal CFTR mutation Y1424A significantly reduced the AP-2 association with CFTR, confirming that the tyrosine-based signal is required for the formation of the AP-2 complex (Weixel and Bradbury, 2000) (Fig. 1).
X
ABCC7 p.Tyr1424Ala 11001491:120:42
status: NEW
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