ABCMdb

ABCC7 p.Arg117Glu

ClinVar:	c.350G>C , p.Arg117Pro ? , not provided c.349C>G , p.Arg117Gly ? , not provided c.350G>T , p.Arg117Leu ? , not provided c.349C>T , p.Arg117Cys D , Pathogenic c.350G>A , p.Arg117His D , Pathogenic
CF databases:	c.350G>A , p.Arg117His ? , Varying clinical consequence ; CFTR1: c.349C>T , p.Arg117Cys D , CF-causing ; CFTR1: The haplotype is 2-1-1-2 (XV2c-KM19-D9-J44) with seven GATT repeats. The mutation creates a new Bsml site. c.349C>G , p.Arg117Gly (CFTR1) ? , Was reported previously in one study of CBAVD. R117G/UND 7T/9T (Daudin et al., Fertility and Sterility, 74:1164-1174, 2000). c.350G>C , p.Arg117Pro (CFTR1) ? , A new missense mutation was found in exon 4 : R 117 P. The mutation was detected by DGGE analysis and identified by remplacement of an arginine residue by a proline at codon 117. The mutation creates new MnlI and NlaIV sites. The mutation was identified in one french CF chromosome. The patient has a mild lung disease and is sufficient pancreatic. c.350G>T , p.Arg117Leu (CFTR1) ? , This mutation was identified by DGGE and direct sequencing and was identified on one CF chromosome of Italian origin.
Predicted by SNAP2:	A: D (91%), C: D (63%), D: D (95%), E: D (95%), F: D (91%), G: D (95%), H: N (53%), I: D (85%), K: D (95%), L: D (63%), M: D (85%), N: D (95%), P: D (66%), Q: D (95%), S: D (95%), T: D (95%), V: D (91%), W: D (95%), Y: D (95%),
Predicted by PROVEAN:	A: N, C: D, D: N, E: N, F: N, G: N, H: N, I: N, K: N, L: N, M: N, N: N, P: N, Q: N, S: N, T: N, V: N, W: N, Y: N,

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Publications
[hide] Identification of positive charges situated at the... Pflugers Arch. 2008 Nov;457(2):351-60. Epub 2008 May 1. Zhou JJ, Fatehi M, Linsdell P
Identification of positive charges situated at the outer mouth of the CFTR chloride channel pore.
Pflugers Arch. 2008 Nov;457(2):351-60. Epub 2008 May 1., [PMID:18449561]

Abstract [show]
We have used site-directed mutagenesis and functional analysis to identify positively charged amino acid residues in the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel that interact with extracellular anions. Mutation of two positively charged arginine residues in the first extracellular loop (ECL) of CFTR, R104, and R117, as well as lysine residue K335 in the sixth transmembrane region, leads to inward rectification of the current-voltage relationship and decreased single channel conductance. These effects are dependent on the charge of the substituted side chain and on the Cl(-) concentration, suggesting that these positive charges normally act to concentrate extracellular Cl(-) ions near the outer mouth of the pore. Side chain charge-dependent effects are mimicked by manipulating charge in situ by mutating these amino acids to cysteine followed by covalent modification with charged cysteine-reactive reagents, confirming the location of these side chains within the pore outer vestibule. State-independent modification of R104C and R117C suggests that these residues are located at the outermost part of the pore. We suggest that ECL1 contributes to the CFTR pore external vestibule and that positively charged amino acid side chains in this region act to attract Cl(-) ions into the pore. In contrast, we find no evidence that fixed positive charges in other ECLs contribute to the permeation properties of the pore.

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No. Sentence Comment
60 As shown in Fig. 2, similar inward rectification is observed in the charge-reversing mutants R104E, R117E, and K335E and to a much lesser extent, R1128E, under symmetrical ionic conditions in excised membrane patches. Login to comment
67 In contrast to the linear I-V relationship seen in wild-type CFTR with symmetrical 154 mM Cl- solutions, mutants R104E, R117E, and K335E showed clear inward rectification. Login to comment
73 As shown in Fig. 3b, macroscopic current rectification was indeed sensitive to symmetrical Cl-concentration in R104E, R117E, and K335E, being more pronounced at low Cl-concentration. Login to comment
79 However, current amplitude was significantly reduced in R104E, R117E, and K335E (Fig. 4a, b). Login to comment
91 All mutants depicted (R104Q, R117Q, K335A, R1128Q, R104E, R117E, K335E, R1128E) showed rectification ratios significantly different from wild type (asterisk P<0.05). Login to comment
92 b The degree of rectification in R104E, R117E, and K335E is dependent on the Cl-concentration. Login to comment
95 Mean of data from four to six patches in both a and b side chains bearing different charges (Fig. 5b), with the possible exception that R117C modified by MTSES did not show the same degree of inward rectification seen in R117E. Login to comment
104 In fact, at both sites, pCMBS had a greater effect on the rectification ratio than MTSES (P<0.05), making them closer to results obtained with R104E and R117E. Login to comment
116 All mutants depicted (R104Q, R117Q, K335A, R104E, R117E, K335E) significantly different from wild type (asterisk P<0.05). Login to comment
137 The charge on the side chain is assumed to be +1 (MTSET, WT), 0 (R104/ 117C, R104/117Q), or -1 (MTSES, R104/R117E). Login to comment

[hide] Three charged amino acids in extracellular loop 1 ... J Gen Physiol. 2014 Aug;144(2):159-79. doi: 10.1085/jgp.201311122. Epub 2014 Jul 14. Cui G, Rahman KS, Infield DT, Kuang C, Prince CZ, McCarty NA
Three charged amino acids in extracellular loop 1 are involved in maintaining the outer pore architecture of CFTR.
J Gen Physiol. 2014 Aug;144(2):159-79. doi: 10.1085/jgp.201311122. Epub 2014 Jul 14., [PMID:25024266]

Abstract [show]
The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) bears six extracellular loops (ECL1-6); ECL1 is the site of several mutations associated with CF. Mutation R117H has been reported to reduce current amplitude, whereas D110H, E116K, and R117C/L/P may impair channel stability. We hypothesized that these amino acids might not be directly involved in ion conduction and permeation but may contribute to stabilizing the outer vestibule architecture in CFTR. We used cRNA injected oocytes combined with electrophysiological techniques to test this hypothesis. Mutants bearing cysteine at these sites were not functionally modified by extracellular MTS reagents and were blocked by GlyH-101 similarly to WT-CFTR. These results suggest that these three residues do not contribute directly to permeation in CFTR. In contrast, mutants D110R-, E116R-, and R117A-CFTR exhibited instability of the open state and significantly shortened burst duration compared with WT-CFTR and failed to be locked into the open state by AMP-PNP (adenosine 5'-(beta,gamma-imido) triphosphate); charge-retaining mutants showed mainly the full open state with comparably longer open burst duration. These interactions suggest that these ECL1 residues might be involved in maintaining the outer pore architecture of CFTR. A CFTR homology model suggested that E116 interacts with R104 in both the closed and open states, D110 interacts with K892 in the fully closed state, and R117 interacts with E1126 in the open state. These interactions were confirmed experimentally. The results suggest that D110, E116, and R117 may contribute to stabilizing the architecture of the outer pore of CFTR by interactions with other charged residues.

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No. Sentence Comment
118 Fig. S6 shows representative I-V plots of double mutants R104E/ E116R- and R117E/E1126R-CFTR and their rectification ratio. Login to comment
128 No current was detected in either inside-out patch or TEVC recording from oocytes expressing R117E-CFTR; therefore, it was not studied further. Login to comment
204 To test this hypothesis, we first made the mutants E116R/R117E-, D110R/R117E-, and D110R/E116R/R117E-CFTR and studied their single-channel properties. Login to comment
224 Tab l e 1 Reversal potentials of WT-CFTR and mutants in ND96 bath solution CFTR n Vrev mV WT 14 &#e032;27.75 &#b1; 0.78 R334A 6 &#e032;12.15 &#b1; 1.64a R117A 6 &#e032;22.51 &#b1; 0.85a E116R 5 &#e032;21.45 &#b1; 1.14a K114D 5 &#e032;24.68 &#b1; 3.22 D110R 5 &#e032;27.64 &#b1; 3.29 R104E 5 &#e032;21.15 &#b1; 1.08a R899C 4 &#e032;25.30 &#b1; 3.94 D891C 6 &#e032;25.81 &#b1; 2.44 K892E 5 &#e032;23.70 &#b1; 3.62 E1124R 5 &#e032;18.32 &#b1; 0.43a E1126R 5 &#e032;20.67 &#b1; 3.16b R117E/E1126R 6 &#e032;23.06 &#b1; 1.37b R104E/E116R 6 &#e032;27.17 &#b1; 1.08 Values are mean &#b1; SEM. Login to comment
271 (A) Representative single-channel currents of R117E/ E116R-, R117E/D110R-, and R117E/E116R/ D110R-CFTR and corresponding all-points amplitude histograms recorded under the same conditions as Fig. 2 A. Login to comment
274 (C) Mean single-channel amplitudes of WT-, R117E/ E116R-, R117E/D110R-, and R117E/E116R/ D110R-CFTR. Login to comment
380 Sample current traces for both E1126R- and R117E/ E1126R-CFTR are shown in Fig. 12 A. Login to comment
381 As mentioned previously, we did not detect current from R117E-CFTR We also tested the possibility that E116 could form an open state salt bridge with K892. Login to comment
403 We also compared the fractional burst duration represented by s1, s2, and f states for E1126R- and R117E/E1126R-CFTR and found that E1126R exhibited a significantly higher fraction of both s1 and s2 states than WT, whereas the distribution for double mutant R117E/E1126R-CFTR was similar to WT-CFTR, exhibiting mainly the f state (a nearly complete rescue; Fig. 12 D). Login to comment
406 R117E/E1126R-CFTR opened to a full open state much more often compared with R117A-CFTR (Fig. 2). Login to comment
407 Mean burst duration for both E1126R- and R117E/ E1126R-CFTR are summarized in Fig. 12 B. Login to comment
408 The mean burst duration of R117E/E1126R-CFTR was significantly longer than that of R117A- and R117C-CFTR. Login to comment
410 (A) Representative single-channel current traces of E1126R-, R117E/E1126R-, R117C-, and R117C/E1126C-CFTR recorded under the same experimental conditions as Fig. 2 and their all-points amplitude histograms (right). Login to comment
412 #, P < 0.01 indicates a significant difference between WTand R117C-CFTR; **, P < 0.01 indicates a significant difference between WTand E1126R-CFTR, between R117C and R117E/E1126R-CFTR, and between R117C and R117C/E1126C. Login to comment
413 n.d., no current detected for R117E-CFTR in Xenopus oocytes. Login to comment
417 (D) Mean fraction of open burst duration is plotted for each open conductance state of E1126R- and R117E/E1126R-CFTR. Login to comment