ABCC7 p.Gly1127Cys

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PMID: 19381710 [PubMed] Fatehi M et al: "Novel residues lining the CFTR chloride channel pore identified by functional modification of introduced cysteines."
No. Sentence Comment
71 As described previously for modification of cysteines introduced into TM6 (Fatehi and Linsdell 2008) and the extracellular loop between TMs 1 and 2 (Zhou et al. 2008), MTSET and MTSES altered the IREL-V shape in S1118C, T1121C, T1122C, G1127C, V1129C, I1131C and I1132C.
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ABCC7 p.Gly1127Cys 19381710:71:236
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72 Of 21 cysteine mutants studied, only six significantly altered I-V relationship shape in the absence of external MTS reagents (Fig. 3a), with S1118C, T1121C, T1122C, G1127C and A1136C all causing significant inward rectification and V1129C showing outward rectification.
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ABCC7 p.Gly1127Cys 19381710:72:166
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84 Unitary currents at depolarized voltages were significantly decreased in S1118C, T1121C, T1122C and G1127C and significantly increased in V1129C (Fig. 5b).
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ABCC7 p.Gly1127Cys 19381710:84:100
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85 This resulted in changes in the shape of the i-V relationship, causing inward rectification in the case of S1118C, T1121C, T1122C and G1127C and outward rectification in the case of V1129C (Figs. 4b, 5c).
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ABCC7 p.Gly1127Cys 19381710:85:134
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91 Indeed, changes in unitary current amplitude were observed in S1118C, T1121C, T1122C, G1127C, V1129C, I1131C and I1132C, but not wild-type, when MTS reagents were included in the pipette solution (Fig. 6).
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ABCC7 p.Gly1127Cys 19381710:91:88
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118 Four mutations (S1118C, T1121C, T1122C, G1127C) led to significant decreases in unitary current amplitude (Fig. 5b), which were relatively strongly affected by MTS modification-in each case conductance was further decreased by reaction with MTSES and increased to near wild-type levels by MTSET (Fig. 9a).
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ABCC7 p.Gly1127Cys 19381710:118:40
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130 Block was not significantly altered in either T1122C or G1127C (data not shown).
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ABCC7 p.Gly1127Cys 19381710:130:56
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133 Under these conditions, SCN- permeability was significantly increased in S1118C and (to a lesser extent) T1122C and G1127C and unaltered in T1121C, V1129C, I1131C and I1132C (Fig. 11).
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ABCC7 p.Gly1127Cys 19381710:133:116
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158 Of the seven mutants that were functionally modified by MTS reagents, five (S1118C, T1121C, T1122C, G1127C, V1129C) also showed significantly altered unitary current amplitude in the absence of MTS modification (Figs. 4, 5).
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ABCC7 p.Gly1127Cys 19381710:158:100
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161 a S1118C (d), T1121C (j), T1122C (), G1127C (h); b V1129C (m), I1131C (r), I1132C (.).
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ABCC7 p.Gly1127Cys 19381710:161:38
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183 We speculate that one group of reactive mutants (S1118C, T1121C, T1122C, G1127C) is located relatively deep in the pore from the outside and that the other (V1129C, Fig. 11 Thiocyanate permeability of mutants.
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ABCC7 p.Gly1127Cys 19381710:183:73
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188 In this scenario, charge-neutral mutations deeper in the pore (S1118C, T1121C, T1122C, G1127C) (Fig. 9a) disrupt Cl- movement in the pore in a nonelectrostatic fashion, leading to reduced unitary currents at depolarized voltages, as described previously for TM6 mutations (McDonough et al. 1994; Linsdell et al. 1998; Linsdell 2001a).
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ABCC7 p.Gly1127Cys 19381710:188:87
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200 Mutations S1118C, T1122C and G1127C also altered the anion selectivity of CFTR, significantly increasing SCN- per- meability (Fig. 11), which is consistent with changes in pore structure and function.
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ABCC7 p.Gly1127Cys 19381710:200:29
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