ABCC7 p.Cys1355Ser
| Predicted by SNAP2: | A: D (59%), D: D (91%), E: D (85%), F: D (91%), G: D (75%), H: D (85%), I: D (91%), K: D (91%), L: D (91%), M: D (85%), N: D (71%), P: D (91%), Q: D (85%), R: D (91%), S: D (59%), T: D (71%), V: D (85%), W: D (91%), Y: D (91%), |
| Predicted by PROVEAN: | A: D, D: D, E: D, F: D, G: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: D, |
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[hide] Insight in eukaryotic ABC transporter function by ... FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19. Frelet A, Klein M
Insight in eukaryotic ABC transporter function by mutation analysis.
FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19., 2006-02-13 [PMID:16442101]
Abstract [show]
With regard to structure-function relations of ATP-binding cassette (ABC) transporters several intriguing questions are in the spotlight of active research: Why do functional ABC transporters possess two ATP binding and hydrolysis domains together with two ABC signatures and to what extent are the individual nucleotide-binding domains independent or interacting? Where is the substrate-binding site and how is ATP hydrolysis functionally coupled to the transport process itself? Although much progress has been made in the elucidation of the three-dimensional structures of ABC transporters in the last years by several crystallographic studies including novel models for the nucleotide hydrolysis and translocation catalysis, site-directed mutagenesis as well as the identification of natural mutations is still a major tool to evaluate effects of individual amino acids on the overall function of ABC transporters. Apart from alterations in characteristic sequence such as Walker A, Walker B and the ABC signature other parts of ABC proteins were subject to detailed mutagenesis studies including the substrate-binding site or the regulatory domain of CFTR. In this review, we will give a detailed overview of the mutation analysis reported for selected ABC transporters of the ABCB and ABCC subfamilies, namely HsCFTR/ABCC7, HsSUR/ABCC8,9, HsMRP1/ABCC1, HsMRP2/ABCC2, ScYCF1 and P-glycoprotein (Pgp)/MDR1/ABCB1 and their effects on the function of each protein.
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No. Sentence Comment
307 [138] A455E, P574H cAMP-stimulated apical membrane Cl-currents but current magnitudes were reduced compared to wild-type Electrophysiology of epithelial cells [139] C491S, C1344S, C1355S C491S channels opened almost exclusively to a 3-pS subconductance.
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ABCC7 p.Cys1355Ser 16442101:307:180
status: NEW309 C1344S and C1355S (NBD2) reduced the frequency of the subconductance openings .
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ABCC7 p.Cys1355Ser 16442101:309:11
status: NEW[hide] The DeltaF508 mutation disrupts packing of the tra... J Biol Chem. 2004 Sep 17;279(38):39620-7. Epub 2004 Jul 21. Chen EY, Bartlett MC, Loo TW, Clarke DM
The DeltaF508 mutation disrupts packing of the transmembrane segments of the cystic fibrosis transmembrane conductance regulator.
J Biol Chem. 2004 Sep 17;279(38):39620-7. Epub 2004 Jul 21., 2004-09-17 [PMID:15272010]
Abstract [show]
The most common mutation in cystic fibrosis (deletion of Phe-508 in the first nucleotide binding domain (DeltaF508)) in the cystic fibrosis transmembrane conductance regulator (CFTR) causes retention of the mutant protein in the endoplasmic reticulum. We previously showed that the DeltaF508 mutation causes the CFTR protein to be retained in the endoplasmic reticulum in an inactive and structurally altered state. Proper packing of the transmembrane (TM) segments is critical for function because the TM segments form the chloride channel. Here we tested whether the DeltaF508 mutation altered packing of the TM segments by disulfide cross-linking analysis between TM6 and TM12 in wild-type and DeltaF508 CFTRs. These TM segments were selected because TM6 appears to line the chloride channel, and cross-linking between these TM segments has been observed in the CFTR sister protein, the multidrug resistance P-glycoprotein. We first mapped potential contact points in wild-type CFTR by cysteine mutagenesis and thiol cross-linking analysis. Disulfide cross-linking was detected in CFTR mutants M348C(TM6)/T1142C(TM12), T351C(TM6)/T1142C(TM12), and W356C(TM6)/W1145C(TM12) in a wild-type background. The disulfide cross-linking occurs intramolecularly and was reducible by dithiothreitol. Introduction of the DeltaF508 mutation into these cysteine mutants, however, abolished cross-linking. The results suggest that the DeltaF508 mutation alters interactions between the TM domains. Therefore, a potential target to correct folding defects in the DeltaF508 mutant of CFTR is to identify compounds that promote correct folding of the TM domains.
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No. Sentence Comment
57 The construction of Cys-less CFTR (C76S/C126S/C225S/C276S/C343S/C491S/C524S/C590S/C592S/C657S/C832S/C866S/C1344S/C1355S/C1395S/C1400S/C1410S/C1458S) was performed using the following cDNA fragments.
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ABCC7 p.Cys1355Ser 15272010:57:113
status: NEW58 Point mutations C76/126S were generated in sequence in the PstI (bp 1) 3 XbaI (bp 573) fragment; point mutations C225S/C276S/C343S were generated in sequence in the XbaI (bp 573) 3 KpnI (bp 1370) fragment; point mutations C491S/C524S/C590S/C592S/C657S were generated in sequence in the KpnI (bp 1370) 3 ApaI (bp 2333) fragment; point mutations C832S/C866S were generated in sequence in the ApaI (bp 2333) 3 EcoRI (bp 3643) fragment; point mutations C1344S/C1355S/ C1395S/C1400S/C1410S/C1458S were generated in sequence in the EcoRI (bp 3643) 3 XhoI (bp 4560) fragment, the five insert fragments were then ligated and inserted into the PstI and XhoI sites of plasmid vector pMT21.
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ABCC7 p.Cys1355Ser 15272010:58:456
status: NEW[hide] Cystic fibrosis transmembrane conductance regulato... Biochemistry. 2009 Oct 27;48(42):10078-88. Alexander C, Ivetac A, Liu X, Norimatsu Y, Serrano JR, Landstrom A, Sansom M, Dawson DC
Cystic fibrosis transmembrane conductance regulator: using differential reactivity toward channel-permeant and channel-impermeant thiol-reactive probes to test a molecular model for the pore.
Biochemistry. 2009 Oct 27;48(42):10078-88., 2009-10-27 [PMID:19754156]
Abstract [show]
The sixth transmembrane segment (TM6) of the CFTR chloride channel has been intensively investigated. The effects of amino acid substitutions and chemical modification of engineered cysteines (cysteine scanning) on channel properties strongly suggest that TM6 is a key component of the anion-conducting pore, but previous cysteine-scanning studies of TM6 have produced conflicting results. Our aim was to resolve these conflicts by combining a screening strategy based on multiple, thiol-directed probes with molecular modeling of the pore. CFTR constructs were screened for reactivity toward both channel-permeant and channel-impermeant thiol-directed reagents, and patterns of reactivity in TM6 were mapped onto two new, molecular models of the CFTR pore: one based on homology modeling using Sav1866 as the template and a second derived from the first by molecular dynamics simulation. Comparison of the pattern of cysteine reactivity with model predictions suggests that nonreactive sites are those where the TM6 side chains are occluded by other TMs. Reactive sites, in contrast, are generally situated such that the respective amino acid side chains either project into the predicted pore or lie within a predicted extracellular loop. Sites where engineered cysteines react with both channel-permeant and channel-impermeant probes occupy the outermost extent of TM6 or the predicted TM5-6 loop. Sites where cysteine reactivity is limited to channel-permeant probes occupy more cytoplasmic locations. The results provide an initial validation of two, new molecular models for CFTR and suggest that molecular dynamics simulation will be a useful tool for unraveling the structural basis of anion conduction by CFTR.
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No. Sentence Comment
42 The Cys-less CFTR construct (C76S, C126S, C225S, C276S, C343S, C491S, C524S, C590L, C592L, C657S, C832S, C866S, C1344S, C1355S, C1395S, C1400S, C1410S, C1458S) was a gift from Drs. Martin Mense and David Gadsby and was used in their pGEMHE vector previously described (13).
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ABCC7 p.Cys1355Ser 19754156:42:120
status: NEW[hide] CFTR: Ligand exchange between a permeant anion ([A... Biophys J. 2006 Sep 1;91(5):1737-48. Epub 2006 Jun 9. Serrano JR, Liu X, Borg ER, Alexander CS, Shaw CF 3rd, Dawson DC
CFTR: Ligand exchange between a permeant anion ([Au(CN)2]-) and an engineered cysteine (T338C) blocks the pore.
Biophys J. 2006 Sep 1;91(5):1737-48. Epub 2006 Jun 9., [PMID:16766608]
Abstract [show]
Previous attempts to identify residues that line the pore of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel have utilized cysteine-substituted channels in conjunction with impermeant, thiol-reactive reagents like MTSET+ and MTSES-. We report here that the permeant, pseudohalide anion [Au(CN)2]- can also react with a cysteine engineered into the pore of the CFTR channel. Exposure of Xenopus oocytes expressing the T338C CFTR channel to as little as 100 nM [Au(CN)2]- produced a profound reduction in conductance that was not reversed by washing but was reversed by exposing the oocytes to a competing thiol like DTT (dithiothreitol) and 2-ME (2-mercaptoethanol). In detached, inside out patches single-channel currents were abolished by [Au(CN)2]- and activity was not restored by washing [Au(CN)2]- from the bath. Both single-channel and macroscopic currents were restored, however, by exposing [Au(CN)2]- -blocked channels to excess [CN]-. The results are consistent with the hypothesis that [Au(CN)2]- can participate in a ligand exchange reaction with the cysteine thiolate at 338 such that the mixed-ligand complex, with a charge of -1, blocks the anion conduction pathway.
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23 MATERIALS AND METHODS Mutagenesis and in vitro transcription The Cys-less CFTR construct (C76S, C126S, C225S, C276S, C343S, C491S, C524S, C590L, C592L, C657S, C832S, C866S, C1344S, C1355S, C1395S, C1400S, C1410S, C1458S) was a gift from Drs. Martin Mense and Submitted December 28, 2005, and accepted for publication May 19, 2006.
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ABCC7 p.Cys1355Ser 16766608:23:181
status: NEW