ABCC7 p.Cys225Ala
| ClinVar: |
c.673T>C
,
p.Cys225Arg
?
, not provided
c.675T>A , p.Cys225* ? , not provided |
| CF databases: |
c.673T>C
,
p.Cys225Arg
(CFTR1)
D
, This mutation was found on one CF chromosome, in association with haplotype D. The patient (13 years old) is compound heterozygote. He carries [delta]F508 on the other chormosome and has pancreatic insufficiency.
|
| Predicted by SNAP2: | A: D (63%), D: D (95%), E: D (95%), F: D (91%), G: D (91%), H: D (95%), I: D (91%), K: D (95%), L: D (91%), M: D (95%), N: D (95%), P: D (95%), Q: D (95%), R: D (71%), S: D (75%), T: D (85%), V: D (85%), W: D (91%), Y: D (91%), |
| Predicted by PROVEAN: | A: N, 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] Interhelical packing in detergent micelles. Foldin... J Biol Chem. 2002 Feb 22;277(8):6067-72. Epub 2001 Dec 17. Therien AG, Deber CM
Interhelical packing in detergent micelles. Folding of a cystic fibrosis transmembrane conductance regulator construct.
J Biol Chem. 2002 Feb 22;277(8):6067-72. Epub 2001 Dec 17., 2002-02-22 [PMID:11748233]
Abstract [show]
Using a helix-loop-helix construct consisting of the adjacent transmembrane segments 3 and 4 of the cystic fibrosis transmembrane conductance regulator (CFTR) labeled with pyrene at both N and C termini, we describe a system for the study of intramolecular helix-helix interactions within a polytopic membrane protein. Through measurement of pyrene excimer band intensity as a determinant of helix-helix proximity, we show that the helices retain tertiary contacts in detergent micelles. Notably, the nature of the micellar detergent can alter the stability of these contacts, with perfluorooctanoate highly supportive, lysophosphatidylcholine and lysophosphatidylglycerol somewhat less tolerant, and SDS largely intolerant of such interactions. This construct is further employed to study the role of the acyl chain length of micellar detergents in modulating interhelical packing; detergents having acyl chains of 9 carbons display the greatest extent of helical packing. These results provide important information regarding the role of lipids on membrane protein folding and conformation as well as demonstrate the usefulness of a pyrene-based system in studying the forces that govern interhelical packing.
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No. Sentence Comment
20 It should be noted that Cys-225 was mutated to Ala, and two cysteines (underlined) * This work was supported by grants (to C. M. D.) from the Canadian Cystic Fibrosis Foundation, the Canadian Institutes of Health Research, and the NIDDK, National Institutes of Health.
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ABCC7 p.Cys225Ala 11748233:20:24
status: NEW44 Because pyrene is available commercially as a cysteine-reactive molecule (pyrene iodoacetamide), we mutated TM 3-4 in the following ways (see also Ref. 21): (i) Cys-225 was mutated to Ala to remove any other possible reactive sites, and (ii) Cys residues were inserted at the ends of TM segments 3 and 4.
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ABCC7 p.Cys225Ala 11748233:44:161
status: NEW[hide] Polar residues in membrane domains of proteins: mo... Biochemistry. 2002 Mar 19;41(11):3647-53. Partridge AW, Melnyk RA, Deber CM
Polar residues in membrane domains of proteins: molecular basis for helix-helix association in a mutant CFTR transmembrane segment.
Biochemistry. 2002 Mar 19;41(11):3647-53., 2002-03-19 [PMID:11888281]
Abstract [show]
Polar side chains constitute over 20% of residues in the transmembrane (TM) helices of membrane proteins, where they may serve as hydrogen bond interaction sites for phenotypic polar mutations that arise in membrane protein-related diseases. To systematically explore the structural consequences of H-bonds between TM helices, we focused on TM4 of the cystic fibrosis conductance regulator (CFTR) and its cystic fibrosis- (CF-) phenotypic mutation, V232D, as a model system. Synthetic peptides corresponding to wild-type (TM4-wt) (residues 219-242: LQASAFCGLGFLIVLALFQAGLGR) and mutant (TM4-V232D) sequences both adopt helical structures in SDS micelles and display dimer bands on SDS-PAGE arising from disulfide bond formation via wild-type residue Cys-225. However, the TM4-V232D peptide additionally forms a ladder of noncovalent oligomers, including tetramers, hexamers, and octamers, mediated by a hydrogen bond network involving Asp-Gln side chain-side chain interactions. Ala-scanning mutagenesis of the TM4 sequence indicated that ladder formation minimally required the simultaneous presence of the Cys-225, Asp-232, and Gln-237 residues. As random hydrophobic sequences containing these three residues at TM4 equivalent positions did not oligomerize, specific van der Waals packing interactions between helix side chains were also shown to play a crucial role. Overall, the results suggest that polar mutations in membrane domains, in conjunction with critically positioned polar partner residues, potentially constitute a source of aberrant helix interactions that could contribute to loss of function when they arise in protein transmembrane domains.
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No. Sentence Comment
107 Spectra are TM4-VD and TM4-VD(C225A).
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ABCC7 p.Cys225Ala 11888281:107:30
status: NEW[hide] Misprocessing of the CFTR protein leads to mild cy... Hum Mutat. 2005 Apr;25(4):360-71. Clain J, Lehmann-Che J, Dugueperoux I, Arous N, Girodon E, Legendre M, Goossens M, Edelman A, de Braekeleer M, Teulon J, Fanen P
Misprocessing of the CFTR protein leads to mild cystic fibrosis phenotype.
Hum Mutat. 2005 Apr;25(4):360-71., [PMID:15776432]
Abstract [show]
Cystic fibrosis (CF) is mainly caused by mutations that interfere with the biosynthetic folding of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. The aim of this study was to determine the mechanism of dysfunction of a disease-causing mutation associated with variable phenotypes. In order to attain these objectives, we studied the effect of the p.L206W mutation on CFTR protein production and function, and we examined the genotype-phenotype correlation of [p.L206W]+[p.F508del] patients. We showed that p.L206W is a processing (class II) mutation since the CFTR biosynthetic pathway was severely impaired, whereas single-channel measurements indicated ion conductance similar to the wild-type protein. These data raise the larger question of the phenotypic variability of class II mutants, including p.F508del. Since multiple potential partners could modify the processing of the CFTR protein during its course to the cell surface, environmental and other genetic factors might contribute to this variability.
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No. Sentence Comment
201 To test this possibility, these residues were replaced one at a time by Ala (p.T122A, p.C128A, p.S135A, p.C225A, and p.Q237A) together with the p.L206W mutation, and the processing at steady-state was examined.
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ABCC7 p.Cys225Ala 15776432:201:106
status: NEW[hide] Role of the extracellular loop in the folding of a... Biochemistry. 2007 Jun 19;46(24):7099-106. Epub 2007 May 22. Wehbi H, Rath A, Glibowicka M, Deber CM
Role of the extracellular loop in the folding of a CFTR transmembrane helical hairpin.
Biochemistry. 2007 Jun 19;46(24):7099-106. Epub 2007 May 22., 2007-06-19 [PMID:17516627]
Abstract [show]
The folding of membrane-spanning domains into their native functional forms depends on interactions between transmembrane (TM) helices joined by covalent loops. However, the importance of these covalent linker regions in mediating the strength of helix-helix associations has not been systematically addressed. Here we examine the potential structural impact of cystic fibrosis-phenotypic mutations in the extracellular loop 2 (ECL2) on interactions between the TM3 and TM4 helices of the cystic fibrosis transmembrane conductance regulator (CFTR) in constructs containing CFTR residues 194-241. When the effects of replacements in ECL2 (including the CF-phenotypic mutants E217G and Q220R) were evaluated in a library of wild-type and mutant TM3-ECL2-TM4 hairpin constructs, we found that SDS-PAGE gel migration rates differed over a range of nearly 40% +/- the wild-type position and that decreased migration rates correlate with increasing hairpin alpha-helical content as measured by circular dichroism spectra in sodium dodecyl sulfate micelles. The decreased mobility of TM3/4 constructs by introduction of non-native residues is interpreted in terms of an elongation or "opening" of the helical hairpin and concomitant destabilization of membrane-based helix-helix interactions. Our results support a role for short loop regions in dictating the stability of membrane protein folds and highlight the interplay between membrane-embedded helix-helix interactions and loop conformation in influencing the structure of membrane proteins.
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No. Sentence Comment
39 The resulting construct, designated TM3/4 WT in this work, contains a C225A replacement designed to prevent disulfide bond formation between different helical hairpin molecules, has a 32-residue N-terminal fusion with an S-tag epitope used for Western blot detection (sequence GSGMKETAAAKFERQHMDSP- DLGTDDDDKAM), and has an 8-residue C-terminal fusion with the hexahistidine tag used for purification by affinity chromatography (sequence LEHHHHHH).
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ABCC7 p.Cys225Ala 17516627:39:70
status: NEW