ABCC7 p.Gln1144Cys
| ClinVar: |
c.3430C>T
,
p.Gln1144*
?
, not provided
|
| Predicted by SNAP2: | A: D (63%), C: D (66%), D: D (80%), E: D (75%), F: D (66%), G: D (75%), H: D (71%), I: D (66%), K: D (80%), L: D (71%), M: D (63%), N: D (63%), P: D (85%), R: D (80%), S: D (63%), T: D (66%), V: D (63%), W: D (75%), Y: D (71%), |
| Predicted by PROVEAN: | A: D, C: D, D: N, E: N, F: D, G: N, H: N, I: D, K: N, L: D, M: D, N: N, P: D, R: N, S: N, T: N, V: D, W: D, Y: D, |
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[hide] Functional arrangement of the 12th transmembrane r... Pflugers Arch. 2011 Oct;462(4):559-71. Epub 2011 Jul 28. Qian F, El Hiani Y, Linsdell P
Functional arrangement of the 12th transmembrane region in the CFTR chloride channel pore based on functional investigation of a cysteine-less CFTR variant.
Pflugers Arch. 2011 Oct;462(4):559-71. Epub 2011 Jul 28., [PMID:21796338]
Abstract [show]
The membrane-spanning part of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel comprises 12 transmembrane (TM) alpha-helices, arranged into two pseudo-symmetrical groups of six. While TM6 in the N-terminal TMs is known to line the pore and to make an important contribution to channel properties, much less is known about its C-terminal counterpart, TM12. We have used patch clamp recording to investigate the accessibility of cytoplasmically applied cysteine-reactive reagents to cysteines introduced along the length of TM12 in a cysteine-less variant of CFTR. We find that methanethiosulfonate (MTS) reagents irreversibly modify cysteines substituted for TM12 residues N1138, M1140, S1141, T1142, Q1144, W1145, V1147, N1148, and S1149 when applied to the cytoplasmic side of open channels. Cysteines sensitive to internal MTS reagents were not modified by extracellular [2-(trimethylammonium)ethyl] MTS, consistent with MTS reagent impermeability. Both S1141C and T1142C could be modified by intracellular [2-sulfonatoethyl] MTS prior to channel activation; however, N1138C and M1140C, located deeper into the pore from its cytoplasmic end, were modified only after channel activation. Comparison of these results with previous work on CFTR-TM6 allows us to develop a model of the relative positions, functional contributions, and alignment of these two important TMs lining the CFTR pore. We also propose a mechanism by which these seemingly structurally symmetrical TMs make asymmetric contributions to the functional properties of the channel pore.
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No. Sentence Comment
80 Application of MTSES (200 μM) or MTSET (2 mM) to the intracellular solution after channel activation with PKA, ATP, and PPi significantly altered macroscopic current amplitude in nine out of 19 cysteine-substituted mutants tested (N1138C, M1140C, S1141C, T1142C, Q1144C, W1145C, V1147C, N1148C, and S1149C; Figs. 1 and 2).
X
ABCC7 p.Gln1144Cys 21796338:80:269
status: NEW84 Closer to the intracellular end of TM12 (in T1142C, Q1144C, and W1145C), macroscopic current amplitude was decreased by MTSES application but increased by MTSET (Figs. 1 and 2).
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ABCC7 p.Gln1144Cys 21796338:84:52
status: NEW[hide] Metal bridges illuminate transmembrane domain move... J Biol Chem. 2014 Oct 10;289(41):28149-59. doi: 10.1074/jbc.M114.593103. Epub 2014 Aug 20. El Hiani Y, Linsdell P
Metal bridges illuminate transmembrane domain movements during gating of the cystic fibrosis transmembrane conductance regulator chloride channel.
J Biol Chem. 2014 Oct 10;289(41):28149-59. doi: 10.1074/jbc.M114.593103. Epub 2014 Aug 20., [PMID:25143385]
Abstract [show]
Opening and closing of the cystic fibrosis transmembrane conductance regulator are controlled by ATP binding and hydrolysis by the cytoplasmic nucleotide-binding domains. Different conformational changes in the channel pore have been described during channel opening and closing; however, the relative importance of these changes to the process of gating the pore is not known. We have used patch clamp recording to identify high affinity Cd(2+) bridges formed between pairs of pore-lining cysteine residues introduced into different transmembrane alpha-helices (TMs). Seven Cd(2+) bridges were identified forming between cysteines in TMs 6 and 12. Interestingly, each of these Cd(2+) bridges apparently formed only in closed channels, and their formation stabilized the closed state. In contrast, a single Cd(2+) bridge identified between cysteines in TMs 1 and 12 stabilized the channel open state. Analysis of the pattern of Cd(2+) bridge formation in different channel states suggests that lateral separation and convergence of different TMs, rather than relative rotation or translation of different TMs, is the key conformational change that causes the channel pore to open and close.
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No. Sentence Comment
51 To investigate potential Cd2af9; bridges formed between pore-lining cysteine side chains exposed in the inner vestibule of the CFTR pore, we combined individual cysteines that we previously found to be accessible to cytoplasmically applied methanethiosulfonate reagents in three important pore-lining TMs: TM1 (K95C, Q98C) (13), TM6 (I344C, V345C, M348C, A349C) (15), and TM12 (M1140C, S1141C, T1142C, Q1144C, W1145C, V1147C, N1148C) (16), to generate a total of 50 double cysteine mutants (8 TM1:TM6; 14 TM1:TM12; 28 TM6:TM12).
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ABCC7 p.Gln1144Cys 25143385:51:405
status: NEW137 Thus, M348C is able to form Cd2af9; bridges with cysteines at multiple positions in TM12 (S1141C, Q1144C, W1145C, V1147C, N1148C) (Fig. 8B), and S1141C is able to form Cd2af9; bridges with cysteines both in TM1 (K95C) and in TM6 (I344C, V345C, M348C) (Fig. 8C).
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ABCC7 p.Gln1144Cys 25143385:137:101
status: NEW