ABCMdb

ABCC7 p.Lys335Glu

None has been submitted yet.

Publications

PMID: 16442101 [PubMed] Frelet A et al: "Insight in eukaryotic ABC transporter function by mutation analysis."

No. Sentence Comment

395 K335E altered the whole cell anion permeability sequence by converting CFTR from a low to a high IÀ permeability pore. Login to comment
401 In contrast, K335E changed the halide permeability and/or conductance sequences [18] but did not alter the anomalous mole-fraction effects [186]. Login to comment

PMID: 10385235 [PubMed] Walsh KB et al: "Structural and ionic determinants of 5-nitro-2-(3-phenylprophyl-amino)-benzoic acid block of the CFTR chloride channel."

No. Sentence Comment

5 4 NPPB inhibition of CFTR currents in oocytes expressing the mutants K335E and R347E also occurred in a voltage-dependent manner. Login to comment
6 However, the Kds for NPPB block were increased to 371 and 1573 mM, for the K335E and R347E mutants, respectively. Login to comment
26 ), and the K335E and R347E mutants obtained from Dr K Kunzelmann (Albert-Ludwigs University, Freiburg, Germany). Login to comment
76 Eect of NPPB on K335E and R347E CFTR mutants The pKa of NPPB is close to 4.5 (Wangemann et al., 1986; Walsh & Wang, 1998), and thus the drug molecules are predominately charged (499%) in the ND-96 solution at pH 7.5. Login to comment
77 Since the negatively charged drug may interact with positively charged amino acid residues in the pore of the CFTR channel, we examined the eect of NPPB on the mutants K335E and R347E. Login to comment
90 The K335E channel displayed a more linear I/V relationship (Figure 5) and the R347E channel a more outward-rectifying I/V relationship (Figure 6) than that measured with the wild-type channel (Figure 3). Login to comment
92 NPPB was less eective in blocking the CFTR currents in oocytes expressing the K335E and R347E channels. Login to comment
93 The Kd for NPPB block of the current was increased from 166 mM for the wild-type to 371 and 1573 mM for the K335E and R347E mutants, respectively (Figures 5 and Figure 5 Eect of NPPB on the K335E CFTR channel. Left panel: I/V relationship for the CFTR current measured in the presence and absence of 100 mM NPPB. Login to comment
95 Right panel: concentration versus response curve for inhibition of the wild-type and K335E channels by NPPB. Login to comment
98 For the K335E data, each point represents the mean+s.e.mean of three to ®ve experiments. Login to comment
99 The theoretical curve for the K335E data provided a Kd of 371 mM. Login to comment
108 Although the sensitivity of the mutant channels to NPPB was reduced, both the K335E and R347E mutants displayed a voltage-dependence to NPPB block that was similar to the wild-type channel (Figure 7). Login to comment
109 The slopes of the lines obtained from the relationship between the fractional block (Id/Io) and voltage had values of 0.23 (wild-type), 0.24 (K335E) and 0.30 (R347E). Login to comment
116 Relationship between the fractional drug block (Id/I0) and the membrane potential determined for the wild-type (100 mM NPPB), K335E (400 mM NPPB) and R347E (1 mM NPPB) CFTR channels. Login to comment
117 The slopes of the straight lines had values of 0.23 (wild-type), 0.24 (K335E) and 0.30 (R347E). Login to comment
153 While the concentration versus response curves for NPPB block of mutants K335E and R347E were shifted to higher concentrations, NPPB produced a voltage-dependent block in the mutants that was almost identical to that of the wild-type channel. Login to comment
160 This is supported by our observation that a mutation of K335, a site predicted to reside closer to the external mouth of the channel (Riordan et al., 1989), resulted in a small, but signi®cant change in NPPB potency (IC50=166 mM for wild-type and 371 mM for K335E). Login to comment

PMID: 10811966 [PubMed] Zhang ZR et al: "Direct comparison of NPPB and DPC as probes of CFTR expressed in Xenopus oocytes."

No. Sentence Comment

436 Two mutants were studied by Walsh: K335E, predicted to be at the extracellular end of TM6, and R347E, predicted to be at the cytoplasmic end of TM6. Login to comment
437 Blockade of K335E-CFTR was diminished (KD ‫ס‬ 371 ␮M) while the voltage-dependence was not affected. Login to comment
440 The effect of the K335E mutation is probably representative of a through-space interaction, wherein the negative charge introduced impedes the approach of the negatively charged drug, rather than disruption of an intimate interaction between NPPB and this lysine. Login to comment

PMID: 11179391 [PubMed] Linsdell P et al: "Relationship between anion binding and anion permeability revealed by mutagenesis within the cystic fibrosis transmembrane conductance regulator chloride channel pore."

No. Sentence Comment

34 The hypothesis that anion permeability and anion binding are separable facets of the permeation process in the CFTR Cl¦ channel is supported by the fact that several mutations within the pore have been shown to alter anion binding without strongly affecting anion permeability (e.g. K335E, Anderson et al. 1991; R347D, Tabcharani et al. 1993; G314E, Mansoura et al. 1998). Login to comment
200 Several mutations within the pore of CFTR alter permeant anion binding without strongly affecting anion selectivity (in terms of permeability ratios) (e.g. K335E, Anderson et al. 1991; G314E, Mansoura et al. 1998), suggesting that these mutations affect anion binding sites not intimately involved in the anion selectivity process (Smith et al. 1999; Linsdell et al. 2000). Login to comment

PMID: 11341822 [PubMed] Zou X et al: "ATP hydrolysis-coupled gating of CFTR chloride channels: structure and function."

No. Sentence Comment

56 For instance, replacing two positively charged residues with negatively charged residues in the M1 and M2 R-helices of MSD (K95D and K335E) alters the anion selectivity sequence of CFTR (17). Login to comment

PMID: 11557589 [PubMed] McCarty NA et al: "Identification of a region of strong discrimination in the pore of CFTR."

No. Sentence Comment

60 Mutants K335E, K335F, T338A, T339A, S341A, S341T, T1134A, and T1134F were prepared as previously described (33). Login to comment
143 Relative permeabilities for WT and mutant CFTRs for monovalent anions CFTR n NO3 Br SCN I ClO4 Acetate Isethionate Glutamate Gluconate WT 16 1.35Ϯ0.01 1.19Ϯ0.02 2.42Ϯ0.06 0.36Ϯ0.01 0.10Ϯ0.01 0.15Ϯ0.00* 0.24Ϯ0.01 0.24Ϯ0.01 0.18Ϯ0.01 K335A 5 1.35Ϯ0.01 1.36Ϯ0.03 3.10Ϯ0.11† 0.75Ϯ0.02† 0.12Ϯ0.01 0.06Ϯ0.01† 0.07Ϯ0.01† 0.07Ϯ0.01† 0.08Ϯ0.01† K335F 7 1.51Ϯ0.03† 1.36Ϯ0.02† 2.73Ϯ0.14 0.99Ϯ0.03† 0.20Ϯ0.02† 0.13Ϯ0.01 0.18Ϯ0.03 0.30Ϯ0.02 0.20Ϯ0.02 K335E 5 1.24Ϯ0.04 1.17Ϯ0.02 2.60Ϯ0.06 1.10Ϯ0.03† 0.23Ϯ0.01† 0.10Ϯ0.01† 0.11Ϯ0.01† 0.10Ϯ0.01† 0.11Ϯ0.01† T338A 5 1.74Ϯ0.07† 1.59Ϯ0.02† 4.35Ϯ0.24† 2.56Ϯ0.13† 1.84Ϯ0.08† 0.07Ϯ0.01† 0.06Ϯ0.01† 0.08Ϯ0.01† 0.08Ϯ0.01† T338E 3 3.65Ϯ0.19† 1.94Ϯ0.04† 4.29Ϯ0.13† 2.41Ϯ0.24† 1.18Ϯ0.06† 0.16Ϯ0.03 0.37Ϯ0.05† 0.36Ϯ0.01† 0.22Ϯ0.03 T339A 5 1.47Ϯ0.01 1.29Ϯ0.03 2.65Ϯ0.06 0.57Ϯ0.02† 0.24Ϯ0.04 0.10Ϯ0.02 0.19Ϯ0.02 0.18Ϯ0.01 0.15Ϯ0.01 S341A 6 1.91Ϯ0.02† 1.42Ϯ0.01† 3.10Ϯ0.09† 0.59Ϯ0.00*† 0.09Ϯ0.00* 0.11Ϯ0.01† 0.12Ϯ0.00*† 0.11Ϯ0.00*† 0.12Ϯ0.00*† S341E 12 2.01Ϯ0.10† 1.46Ϯ0.05† 2.81Ϯ0.18 0.84Ϯ0.00*† 0.31Ϯ0.03† 0.20Ϯ0.01 0.23Ϯ0.02 0.19Ϯ0.01 0.19Ϯ0.02 S341T 5 1.81Ϯ0.05† 1.39Ϯ0.03 3.15Ϯ0.15† 0.41Ϯ0.01 0.07Ϯ0.00* 0.05Ϯ0.00*† 0.06Ϯ0.00*† 0.03Ϯ0.01† 0.06Ϯ0.01† T1134A 6 1.43Ϯ0.02 1.30Ϯ0.02 2.66Ϯ0.02 0.46Ϯ0.00*† 0.06Ϯ0.00*† 0.08Ϯ0.01† 0.10Ϯ0.01† 0.11Ϯ0.01† 0.10Ϯ0.00*† T1134F 5 1.31Ϯ0.07 1.17Ϯ0.05 2.50Ϯ0.10 0.63Ϯ0.01† 0.08Ϯ0.00* 0.13Ϯ0.01 0.09Ϯ0.01† 0.18Ϯ0.02 0.13Ϯ0.01 T1134E 4 1.68Ϯ0.02† 1.39Ϯ0.05† 2.37Ϯ0.18 0.19Ϯ0.03† 0.20Ϯ0.03 0.06Ϯ0.01† 0.09Ϯ0.01† 0.08Ϯ0.01† 0.10Ϯ0.01† Values are means Ϯ SE with only data from the hyperpolarizing ramp protocol; n, no. of oocytes. Relative permeability, permeability of anion x to that of Cl. Anions are listed in order of increasing ionic radius. Login to comment
167 Selectivity sequences for WT and mutant CFTRs CFTR Selectivity Sequence by Relative Permeability WT SCNϾϾNO3 ϾBrϾClϾϾIϾisethionateϭglutamateϾgluconateϭacetateϾClO4 K335A SCNϾϾBrϭNO3 ϾClϾIϾϾClO4 Ͼgluconateϭisethionateϭglutamateϭacetate K335F SCNϾϾNO3 ϾBrϾClϭIϾϾglutamateϾgluconateϭClO4 ϭisethionateϾacetate K335E SCNϾϾNO3 ϾBrϭIϾClϾϾClO4 Ͼgluconateϭisethionateϭglutamateϭacetate T338A SCNϾϾIϾϾClO4 ϭNO3 ϾBrϾClϾϾgluconateϭisethionateϭglutamateϭacetate T338E SCNϾNO3 ϾIϾBrϾClO4 ϾClϾϾisethionateϭglutamateϾgluconateϭacetate T339A SCNϾϾNO3 ϾBrϾClϾϾIϾϾClO4 ϭisethionateϭglutamateϭgluconateϾacetate S341A SCNϾNO3 ϾBrϾClϾϾIϾϾgluconateϭisethionateϭglutamateϭacetateϭClO4 S341E SCNϾNO3 ϾBrϾClϾIϾϾClO4 Ͼisethionateϭacetateϭglutamateϭgluconate S341T SCNϾϾNO3 ϾBrϾClϾϾIϾϾClO4 ϭisethionateϭgluconateϭacetateϭglutamate T1134A SCNϾϾNO3 ϾBrϾClϾϾIϾϾglutamateϭisethionateϭgluconateϭacetateϭClO4 T1134F SCNϾϾNO3 ϾBrϾClϾϾIϾϾglutamateϾacetateϭgluconateϾisethionateϭClO4 T1134E SCNϾNO3 ϾBrϾClϾϾClO4 ϭIϾgluconateϭisethionateϭglutamateϭacetate L856 A REGION OF STRONG DISCRIMINATION IN THE CFTR PORE AJP-Lung Cell Mol Physiol • VOL 281 • OCTOBER 2001 • www.ajplung.org out propagation to distant sites. Login to comment
191 Relative conductances for WT and mutant CFTRs for monovalent anions CFTR n NO3 Br SCN I ClO4 Acetate Isethionate Glutamate Gluconate WT 16 0.87Ϯ0.01 0.77Ϯ0.01 0.18Ϯ0.01 0.25Ϯ0.01 0.23Ϯ0.01 0.55Ϯ0.01 0.50Ϯ0.01 0.57Ϯ0.02 0.56Ϯ0.02 K335A 5 0.88Ϯ0.04 0.77Ϯ0.02 0.30Ϯ0.02† 0.35Ϯ0.02 0.24Ϯ0.02 0.33Ϯ0.01† 0.32Ϯ0.02† 0.37Ϯ0.02† 0.38Ϯ0.02† K335F 7 1.21Ϯ0.05† 0.87Ϯ0.02† 0.55Ϯ0.02† 0.36Ϯ0.01† 0.19Ϯ0.01 0.34Ϯ0.01† 0.34Ϯ0.01† 0.41Ϯ0.01† 0.37Ϯ0.01† K335E 5 1.16Ϯ0.05† 0.91Ϯ0.02† 0.59Ϯ0.02† 0.51Ϯ0.02† 0.28Ϯ0.01 0.22Ϯ0.01† 0.25Ϯ0.01† 0.22Ϯ0.01† 0.24Ϯ0.01† T338A 5 1.20Ϯ0.13† 1.03Ϯ0.06† 0.98Ϯ0.12† 0.82Ϯ0.02† 0.50Ϯ0.04† 0.18Ϯ0.05† 0.08Ϯ0.01† 0.31Ϯ0.05† 0.29Ϯ0.05† T338E 3 3.66Ϯ0.36† 1.53Ϯ0.09† 1.80Ϯ0.12† 1.39Ϯ0.11† 0.87Ϯ0.03† 0.36Ϯ0.04† 0.56Ϯ0.17 0.44Ϯ0.03† 0.48Ϯ0.03† T339A 5 1.01Ϯ0.02† 0.77Ϯ0.03 0.22Ϯ0.01 0.31Ϯ0.03 0.23Ϯ0.01 0.38Ϯ0.02† 0.48Ϯ0.01 0.48Ϯ0.01 0.52Ϯ0.01 S341A 6 1.67Ϯ0.01† 1.08Ϯ0.01† 0.63Ϯ0.03† 0.26Ϯ0.00* 0.15Ϯ0.01† 0.63Ϯ0.01† 0.54Ϯ0.02 0.63Ϯ0.01 0.63Ϯ0.01 S341E 12 1.74Ϯ0.11† 1.14Ϯ0.02† 1.81Ϯ0.06† 0.48Ϯ0.01† 0.35Ϯ0.02† 0.28Ϯ0.01† 0.69Ϯ0.02† 0.65Ϯ0.01† 0.68Ϯ0.01† S341T 5 0.85Ϯ0.02 0.82Ϯ0.01 0.29Ϯ0.01† 0.22Ϯ0.01 0.13Ϯ0.01† 0.48Ϯ0.01 0.45Ϯ0.02 0.43Ϯ0.02 0.55Ϯ0.01 T1134A 6 0.83Ϯ0.02 0.78Ϯ0.01 0.24Ϯ0.01† 0.21Ϯ0.01 0.09Ϯ0.01† 0.39Ϯ0.01† 0.38Ϯ0.01† 0.39Ϯ0.01† 0.40Ϯ0.01 T1134F 5 0.68Ϯ0.03† 0.69Ϯ0.03† 0.36Ϯ0.01† 0.07Ϯ0.01† 0.16Ϯ0.01 0.48Ϯ0.02 0.30Ϯ0.02† 0.22Ϯ0.01† 0.32Ϯ0.02† T1134E 4 0.99Ϯ0.02† 1.00Ϯ0.02† 0.50Ϯ0.02† 0.20Ϯ0.03 0.26Ϯ0.02 0.32Ϯ0.03† 0.34Ϯ0.01† 0.34Ϯ0.03† 0.34Ϯ0.03† Values are means Ϯ SE with only data from the hyperpolarizing ramp protocol; n, no. of oocytes. Relative conductance, conductance of anion x to that of Cl. Anions are listed in order of increasing ionic radius. Login to comment
213 Vrev Cl in ND96 bath solution for WT and mutant CFTRs CFTR n Vrev Cl WT 16 -21.24Ϯ0.59 K335A 5 -22.12Ϯ0.35 K335F 7 -21.92Ϯ0.90 K335E 5 -22.88Ϯ0.36 T338A 5 -26.97Ϯ0.79* T338E 3 -20.58Ϯ1.07 T339A 5 -22.21Ϯ0.98 S341A 6 -21.21Ϯ0.56 S341E 12 -28.77Ϯ1.36* S341T 5 -26.62Ϯ1.43* T1134A 6 -28.33Ϯ1.23* T1134F 5 -19.74Ϯ0.73 T1134E 4 -27.54Ϯ1.27* Values are means Ϯ SE; n, no. of oocytes. Login to comment
278 K335E CFTR exhibited decreased Px/PCl for large anions and increased Px/PCl for the "sticky" anions I- and ClO4 - (Table 2). Login to comment
280 Gx/GCl values for most anions were altered in K335E CFTR, with decreases in Gx/GCl values for large anions and increases in Gx/GCl values for small anions (Table 4). Login to comment
281 T1134E CFTR exhibited a similar pattern, with changes in Gx/GCl values smaller in magnitude than those for K335E CFTR. Login to comment
357 Mutation K335E led to a slight decrease in GS2O3/GCl, whereas mutations T338E and S341E greatly increased GS2O3/GCl. Login to comment
388 Selectivity between Cl- and the divalent anion S2O3 2CFTR n GS2O3/GCl WT 16 0.39Ϯ0.01 K335A 5 0.37Ϯ0.01 K335F 7 0.39Ϯ0.01 K335E 5 0.34Ϯ0.01* T338A 5 0.38Ϯ0.01 T338E 3 0.70Ϯ0.08* T339A 5 0.39Ϯ0.02 S341A 6 0.27Ϯ0.01* S341E 12 0.54Ϯ0.01* S341T 5 0.38Ϯ0.01 T1134A 6 0.34Ϯ0.02 T1134F 5 0.33Ϯ0.01* T1134E 4 0.44Ϯ0.05 Values are means Ϯ SE; n, no. of oocytes. Login to comment
439 Our results with K335E (outside the region of high discrimination) and S341E (inside the region of high discrimination) show that this interpretation is feasible. Login to comment

PMID: 11741825 [PubMed] Zhang ZR et al: "Voltage-sensitive gating induced by a mutation in the fifth transmembrane domain of CFTR."

No. Sentence Comment

314 Other glutamate substitutions in TM domains 1, 5, 6, and 12 have been investigated [G91E, G314E, and K335E (16); S341E and T1134E (20)], but none of these exhibited voltage-dependent gating (McCarty and Dawson, unpublished observations). Login to comment

PMID: 18449561 [PubMed] Zhou JJ et al: "Identification of positive charges situated at the outer mouth of the CFTR chloride channel pore."

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
116 All mutants depicted (R104Q, R117Q, K335A, R104E, R117E, K335E) significantly different from wild type (asterisk P<0.05). Login to comment
145 The reduction in unitary current for Cl-efflux seen in R104Q, R104E, and K335E (Fig. 4) further suggests that these residues may play an electrostatic role in Fig. 8 Mutation of positively charged residues weakens the apparent inhibitory effect of external Pt(NO2)4 2- ions. Login to comment

PMID: 9518736 [PubMed] Briel M et al: "Cl- transport by cystic fibrosis transmembrane conductance regulator (CFTR) contributes to the inhibition of epithelial Na+ channels (ENaCs) in Xenopus oocytes co-expressing CFTR and ENaC."

No. Sentence Comment

35 The following CFTR mutations were generated: CF-associated mutations such as ÄF508, G551D and R117H as well as artificial mutations within MSD1 such as R347E and K335E (Hipper et al. 1995). Login to comment
105 Finally, two artificial mutations (R347E and K335E) in the 6th transmembrane spanning domain were initially created in order to examine properties of the putative pore of CFTR (Anderson et al. 1991). Login to comment
107 K335E generated Cl¦ conductances very similar to those of CFTR whereas G551D was almost ineffective. Login to comment
110 In contrast, other mutations, which still activated whole-cell Cl¦ conductance (R117H, R347E, K335E) downregulated ENaC currents. Login to comment

PMID: 9729613 [PubMed] Linsdell P et al: "Non-pore lining amino acid side chains influence anion selectivity of the human CFTR Cl- channel expressed in mammalian cell lines."

No. Sentence Comment

209 Inward rectification is observed in several other TM6 mutants at the single channel level, e.g. K335E (Tabcharani et al. 1993), T339V (Fig. 11B) and I332K (P. Linsdell, J. A. Tabcharani & J. W. Hanrahan, unpublished observations); however, voltage-dependent gating in T338 mutants cannot be excluded. Login to comment

PMID: 9886914 [PubMed] Schwiebert EM et al: "ABC transporter-facilitated ATP conductive transport."

No. Sentence Comment

66 Both Cl- and gluconate currents were inhibited by insertion of two well-known Cl- conduction mutations, K335E and R347D, suggesting that CFTR itself is transporting gluconate (26). Login to comment

PMID: 9922375 [PubMed] Sheppard DN et al: "Structure and function of the CFTR chloride channel."

No. Sentence Comment

102 This would suggest that like acidic residues (K95D and K335E) altered the whole cell other Cl0 channels, including ligand-gated Cl0 channels in anion permeability sequence by converting CFTR from a neurons (20) and outwardly rectifying Cl0 channels in low I0 permeability pore (Br0 ' Cl0 ú I0 ) to a high I0 epithelia (55), the CFTR pore has a ''weak field strength`` permeability pore (I0 ú Br0 ú Cl0 ) (4). Login to comment
114 However, the mutation K335E did is controversial (51, 59, 72, 93, 99, 100, 111, 129). Login to comment

PMID: 9922376 [PubMed] Dawson DC et al: "CFTR: mechanism of anion conduction."

No. Sentence Comment

432 This behavior is consistent with the notion that iodide can reside in the channel with-(TM1), K335E (TM6), R347E (TM6), and R1030E (TM10). Login to comment
434 Finkelstein and Cass (55) called attention to the factthe order of 1:10, but two of the substitutions (K95D and K335E) altered the sequence of relative anion permeabilit- that the electrical behavior of planar lipid membranes bathed by iodide-containing solutions may be strongly in-ies by increasing the ratio for iodide, PI/PCl . Login to comment
436 In the two mutant channels, this ratio was increased to Ç1.4, such that the selectivity sequence was their results suggested that the formation of the polyiodides can be effectively eliminated in the presence of aI ú Br ú Cl ú F. These substitutions, particularly K335E, also increased the apparent conductance ratio. Login to comment
441 The PI/PCl ratio was 0.44 for wild-type CFTR and increased F. Cysteine Accessibilityto 1.10 in K335E CFTR and 0.65 in K335D CFTR. Login to comment
449 The ratio PI/PCl was increased in K335E CFTR but commonly employed are metals like Hg, Cd, or Ag or derivatives of methane thiosulfonate (MTS) first intro-was nevertheless substantially less than that predicted by the general pattern (101). Login to comment
581 The K335E construct was identical to wild type with regard to apparent affinity for DPC but did important for the conformational changes that gate the pore.display slight inward rectification. Login to comment

PMID: 7947814 [PubMed] Loo TW et al: "Mutations to amino acids located in predicted transmembrane segment 6 (TM6) modulate the activity and substrate specificity of human P-glycoprotein."

No. Sentence Comment

279 Mutation of Lys335 or Arg347 to Glu in TM6 altered the permeability and/or conductance ratios for halide ions (Anderson et al., 1991). Login to comment

PMID: 12054472 [PubMed] Tan AL et al: "Biochemical implications of sequence comparisons of the cystic fibrosis transmembrane conductance regulator."

No. Sentence Comment

54 The mutation K335E effected a modification of the relative halide permeability from BrÀ > ClÀ > IÀ > FÀ to IÀ > BrÀ > ClÀ > FÀ [28]. Login to comment
58 In salmon II, the Ser residue, whose charge is intermediate between positive and negative (referring to the mutation K335E), could render the permeability to be of the order BrÀ > IÀ > ClÀ > FÀ , i.e., relatively less permeable to chloride than other forms of CFTR. Login to comment
65 If the nonhalide anions are disregarded, the trend is strikingly analogous to what was observed for K335E, suggesting that Thr338 may exert an influence on Lys335, or that the roles of these two residues with regard to pore function are related. Login to comment

PMID: 9804160 [PubMed] Vankeerberghen A et al: "Characterization of mutations located in exon 18 of the CFTR gene."

No. Sentence Comment

15 The anion selectivity 'lter itself seems to be formed by the transmembrane helices [11], since mutagenesis of lysine 95 to aspartate and of lysine 335 to glutamate changed the anion selectivity of the channel. Login to comment

PMID: 9524141 [PubMed] Linsdell P et al: "Adenosine triphosphate-dependent asymmetry of anion permeation in the cystic fibrosis transmembrane conductance regulator chloride channel."

No. Sentence Comment

18 m e t h o d s Experiments were carried out on baby hamster kidney (BHK) or Chinese hamster ovary (CHO) cells stably expressing either wild-type or mutant (K335E or R347D) CFTR (Tabcharani et al., 1991, 1993; Linsdell and Hanrahan, 1996a). Login to comment
131 To determine whether gluconate currents were carried directly via CFTR, we examined gluconate efflux mediated by two low conductance CFTR pore mutants, R347D and K335E (Tabcharani et al., 1993). Login to comment
133 Both R347D (Fig. 7 A) and K335E (Fig. 7 B) had similar permeabilities to gluconate in the intracellular solution under biionic conditions to that of wild-type CFTR (PGluconate/PCl ϭ 0.069 Ϯ 0.010, n ϭ 9, for R347D and 0.064 Ϯ 0.008, n ϭ 7, for K335E), suggesting that relative permeability to large organic anions from the intracellular solution is not disrupted in either of these mutants. Login to comment
148 3.9 fA (n ϭ 3) for R347D and 18.1 Ϯ 3.4 fA (n ϭ 5) for K335E, in both cases significantly smaller than wild type under these conditions (P Ͻ 0.05, two-tailed t test). Login to comment
160 Both R347D (A) and K335E (B) mediate macroscopic gluconate efflux with a similar apparent gluconate permeability to wild type (see Figs. 1 A, 2 B, 3, B and C, 5 D, and 8, A and B). Login to comment
161 (C and D) Relationship between mean gluconate current (I) and current variance (␴2) at -50 mV under symmetrical ionic conditions for R347D (C) and K335E (D), calculated as described in Fig. 6 A. Login to comment
210 However, anion export in BHK cell patches was due to CFTR itself and not the result of modification of an anion transporter endogenous to these cells, since the apparent unitary gluconate current amplitude was significantly reduced in two CFTR mutants with reduced Cl- conductance, R347D and K335E (Fig. 7). Login to comment
249 We thank Shu-Xian Zheng and Jie Liao for technical assistance and Dr. J.M. Rommens (Hospital for Sick Children, Toronto, Ontario, Canada) for providing R347D and K335E cDNA. Login to comment
151 To determine whether gluconate currents were carried directly via CFTR, we examined gluconate efflux mediated by two low conductance CFTR pore mutants, R347D and K335E (Tabcharani et al., 1993). Login to comment
153 Both R347D (Fig. 7 A) and K335E (Fig. 7 B) had similar permeabilities to gluconate in the intracellular solution under biionic conditions to that of wild-type CFTR (PGluconate/PCl 5 0.069 6 0.010, n 5 9, for R347D and 0.064 6 0.008, n 5 7, for K335E), suggesting that relative permeability to large organic anions from the intracellular solution is not disrupted in either of these mutants. Login to comment
168 3.9 fA (n 5 3) for R347D and 18.1 6 3.4 fA (n 5 5) for K335E, in both cases significantly smaller than wild type under these conditions (P , 0.05, two-tailed t test). Login to comment
180 Both R347D (A) and K335E (B) mediate macroscopic gluconate efflux with a similar apparent gluconate permeability to wild type (see Figs. 1 A, 2 B, 3, B and C, 5 D, and 8, A and B). Login to comment
181 (C and D) Relationship between mean gluconate current (I) and current variance (s2) at 250 mV under symmetrical ionic conditions for R347D (C) and K335E (D), calculated as described in Fig. 6 A. Login to comment
230 However, anion export in BHK cell patches was due to CFTR itself and not the result of modification of an anion transporter endogenous to these cells, since the apparent unitary gluconate current amplitude was significantly reduced in two CFTR mutants with reduced Cl2 conductance, R347D and K335E (Fig. 7). Login to comment
269 We thank Shu-Xian Zheng and Jie Liao for technical assistance and Dr. J.M. Rommens (Hospital for Sick Children, Toronto, Ontario, Canada) for providing R347D and K335E cDNA. Login to comment

PMID: 9879057 [PubMed] Gallet X et al: "Topological model of membrane domain of the cystic fibrosis transmembrane conductance regulator."

No. Sentence Comment

189 This is in agreement with experiments by Sheppard et al., that report that mutation R334W modifies the conductance.50 On the other hand, mutation K335E affects channel selectivity.51 We propose that K335 could be implicated in a salt bridge with E873 (H7) in model I and with E92 (H1) in model II, since those acidic residues are located at the same level in the membrane. Login to comment
232 Mutations associated with mild forms of cystic fibrosis (R117H, R334W, and R347P) implicate three of our inner pore residues in the chloride conductance.50 In other studies, basic amino acids of membrane helices were replaced by acidic residues (K95D, K335E, R347E, and R1030E). Login to comment
193 This is in agreement with experiments by Sheppard et al., that report that mutation R334W modifies the conductance.50 On the other hand, mutation K335E affects channel selectivity.51 We propose that K335 could be implicated in a salt bridge with E873 (H7) in model I and with E92 (H1) in model II, since those acidic residues are located at the same level in the membrane. Login to comment
236 Mutations associated with mild forms of cystic fibrosis (R117H, R334W, and R347P) implicate three of our inner pore residues in the chloride conductance.50 In other studies, basic amino acids of membrane helices were replaced by acidic residues (K95D, K335E, R347E, and R1030E). Login to comment

PMID: 9512029 [PubMed] Mansoura MK et al: "Cystic fibrosis transmembrane conductance regulator (CFTR) anion binding as a probe of the pore."

No. Sentence Comment

62 Expression levels Wild-type and 11 mutant CFTR constructs were used in this study: G91A, G91E, G91R, G314A, G314D, G314E, G314Q, K335R, K335A, K335D, and K335E. Login to comment
103 Only one mutation, K335E, significantly altered the sequence of permeability ratios derived from shifts in reversal potential. Login to comment
113 The K335D and K335E constructs also exhibited increased conductance ratios for I, a result previously reported by Anderson et al. (1991) for K335E CFTR. Login to comment
137 Permeability Ratios Wild type 4-9 3.42 Ϯ 0.28 1.42 Ϯ 0.04 1.22 Ϯ 0.02 0.39 Ϯ 0.01 0.44 Ϯ 0.03 G91A 3-6 3.24 Ϯ 0.26 1.53 Ϯ 0.04 1.27 Ϯ 0.02 0.37 Ϯ 0.04 0.40 Ϯ 0.04 G91E 3-7 3.50 Ϯ 0.54 1.59 Ϯ 0.04 1.27 Ϯ 0.01 0.35 Ϯ 0.01 0.51 Ϯ 0.04 G91R 3-4 5.26 ؎ 0.46* 1.60 Ϯ 0.03 1.40 ؎ 0.01* 0.32 Ϯ 0.04 0.64 ؎ 0.04* G314A 3-4 2.87 Ϯ 0.17 1.45 Ϯ 0.03 1.19 Ϯ 0.02 0.31 Ϯ 0.03 0.33 Ϯ 0.03 G314D 4 3.42 Ϯ 0.34 1.44 Ϯ 0.05 1.25 Ϯ 0.04 0.33 Ϯ 0.03 0.51 Ϯ 0.05 G314E 3-4 3.72 Ϯ 0.56 1.65 ؎ 0.09* 1.35 ؎ 0.03* 0.49 Ϯ 0.04 0.53 Ϯ 0.04 G314Q 3-4 3.89 Ϯ 0.37 1.62 Ϯ 0.11 1.27 Ϯ 0.04 0.36 Ϯ 0.03 0.62 Ϯ 0.05 K335R 3-5 3.44 Ϯ 0.29 1.35 Ϯ 0.04 1.22 Ϯ 0.03 0.40 Ϯ 0.05 0.41 Ϯ 0.07 K335A 5-6 5.34 ؎ 0.58* 1.48 Ϯ 0.06 1.28 Ϯ 0.04 0.37 Ϯ 0.03 0.60 Ϯ 0.06 K335D 4-6 3.02 Ϯ 0.19 1.50 Ϯ 0.03 1.10 ؎ 0.02* 0.54 ؎ 0.04* 0.65 ؎ 0.06* K335E 5-8 3.64 Ϯ 0.21 1.48 Ϯ 0.06 1.29 Ϯ 0.03 0.46 Ϯ 0.04 1.10 ؎ 0.04* B. Conductance Ratios Wild type 4-9 0.14 Ϯ 0.02 0.75 Ϯ 0.02 0.64 Ϯ 0.02 0.52 Ϯ 0.03 0.18 Ϯ 0.03 G91A 3-6 0.14 Ϯ 0.01 0.77 Ϯ 0.02 0.61 Ϯ 0.02 0.47 Ϯ 0.02 0.19 Ϯ 0.02 G91E 3-7 0.15 Ϯ 0.03 0.73 Ϯ 0.02 0.60 Ϯ 0.01 0.50 Ϯ 0.04 0.30 Ϯ 0.02 G91R 3-4 0.14 Ϯ 0.00 0.84 Ϯ 0.01 0.63 Ϯ 0.01 0.32 ؎ 0.01* 0.14 Ϯ 0.01 G314A 3-4 0.30 Ϯ 0.09 0.89 ؎ 0.01* 0.66 Ϯ 0.01 0.48 Ϯ 0.09 0.24 Ϯ 0.01 G314D 4 0.28 Ϯ 0.05 0.82 Ϯ 0.01 0.70 Ϯ 0.02 0.49 Ϯ 0.06 0.27 Ϯ 0.03 G314E 3-4 0.62 ؎ 0.07* 1.18 ؎ 0.04* 0.84 ؎ 0.05* 0.42 Ϯ 0.05 0.29 Ϯ 0.09 G314Q 3-4 0.63 ؎ 0.02* 1.01 ؎ 0.04* 0.82 ؎ 0.03* 0.50 Ϯ 0.02 0.42 ؎ 0.02* K335R 3-5 0.14 Ϯ 0.01 0.76 Ϯ 0.03 0.61 Ϯ 0.02 0.59 Ϯ 0.06 0.16 Ϯ 0.03 K335A 6 0.20 Ϯ 0.03 0.77 Ϯ 0.02 0.61 Ϯ 0.02 0.45 Ϯ 0.03 0.21 Ϯ 0.02 K335D 4-6 0.65 ؎ 0.04* 1.25 ؎ 0.02* 0.89 ؎ 0.02* 0.61 Ϯ 0.06 0.58 ؎ 0.06* K335E 5-8 0.50 ؎ 0.06* 1.19 ؎ 0.03* 0.89 ؎ 0.02* 0.53 Ϯ 0.03 0.48 ؎ 0.03* (A) The apparent permeability ratios (PS/PCl) for each substitute anion were calculated from the shift in reversal potential using the Goldman-Hodgkin-Katz relation (noted in Materials and Methods). Login to comment
144 Similar negative results were obtained for the K335R and K335A constructs, but in the K335D and K335E mutants maximal attenuation by [SCN]o was reduced by nearly 50%, although the apparent binding affinity was unaffected. Login to comment
145 The result is consistent with the notion that the affinity of anion binding was not diminished in the K335D and K335E constructs, but the impact of binding on conduction was reduced. Login to comment
146 Sensitivity to [SCN]o was identical to wtCFTR in a construct bearing a mutation in NBF2, K1250A (data not shown), which exhibits severely altered activation in the form of a highly stabilized active state (Wilkinson et al., 1996). Login to comment
158 At the K335 locus, substitution by either glutamate (K335E) or aspartate (K335D) significantly reduced the mean value of RR by 25% and 38%, respectively. Login to comment
167 In contrast, values for the K1/2(IBMX) for both K335D and K335E were significantly greater than that for wtCFTR, an indication of diminished sensitivity to activating conditions. Login to comment
169 TABLE 4 Quantitative analyses of the macroscopic I-V shape changes Mutant ⌬ Net charge n RR g(ϩ30)/g(-30) RR/RRWT Wild type 5 1.220 Ϯ 0.06 1.00 G91A 0 4 1.293 Ϯ 0.06 1.06 G91E -1 5 1.512 ؎ 0.10* 1.24 G91R 1 4 8.041 ؎ 0.87* 6.59 G314A 0 4 1.201 Ϯ 0.09 0.98 G314D -1 4 1.362 Ϯ 0.08 1.12 G314E -1 7 1.405 Ϯ 0.08 1.15 G314Q 0 5 1.376 Ϯ 0.10 1.13 K335R 0 4 1.209 Ϯ 0.06 0.99 K335A -1 4 1.295 Ϯ 0.07 1.06 K335D -2 5 0.762 ؎ 0.02* 0.62 K335E -2 4 0.919 ؎ 0.02* 0.75 The slope conductance was measured at ϩ30 mV and -30 mV with respect to the reversal potential. Login to comment
173 TABLE 5 Concentration-dependent activation of wtCFTR, G91, G314, and K335 variants by IBMX in the presence of 10 ␮M forskolin Mutant n K1/2(IBMX) (mM) Wild type 15 0.35 Ϯ 0.04 G91A 5 0.42 Ϯ 0.06 G91E 8 0.51 ؎ 0.06* G91R 5 0.49 Ϯ 0.09 G314A 10 1.21 ؎ 0.11* G314D 3 1.35 ؎ 0.16* G314E 8 6.39 ؎ 1.35* G314Q 4 14.26 ؎ 6.64* K335R 4 0.46 Ϯ 0.04 K335A 2 0.35 Ϯ 0.15 K335D 7 0.87 ؎ 0.13* K335E 3 0.95 ؎ 0.07* The steady-state slope conductance was measured at -60 mV as increasing concentrations of IBMX (0.02-5.0 mM) were added to the perfusate in the continued presence of 10 mM forskolin. Login to comment
198 The results presented here are consistent with the notion that the binding of anions within the CFTR pore is a sensitive indicator of changes in pore structure whereas permeability ratios appear to be rather insensitive to similar TABLE 6 Qualitative summary of the functional consequences of mutations at G91, G314, and K335 Property G91 (TM1) K335 (TM6) G314 (TM5) G91A G91E G91R K335R K335A K335D K335E G314A G314D G314E G314Q I-V shape - - ϩϩϩ - - ϩϩ ϩ - - - - Psub/PCl - - - - - - ϩϩ - - - - gsub/gCl - - - - - ϩϩϩ ϩϩϩ ϩϩ - ϩϩϩ ϩϩϩ SCN- binding - - - - - ϩϩϩ ϩϩϩ ϩϩ - ϩϩϩϩ ϩϩϩϩ Activation - - - - - ϩϩ ϩϩ ϩϩϩ ϩϩϩ ϩϩϩϩ ϩϩϩϩ Results are expressed as follows: -, function of the CFTR construct with the indicated substitution was indistinguishable from wild type; ϩ to ϩϩϩϩ, semiquantitative indication of the magnitude of the change in the function compared with wild type. Login to comment
229 Hipper et al. (1995) reported that the mutations R334E, R334H, K335E, K335H, R347E, and R347H did not alter CFTR conduction properties, but careful inspection of the data presented revealed that the level of CFTR expression was very low so that altered properties of mutant CFTRs might have been easily obscured. Login to comment
245 The fact that the apparent affinity of SCN binding was not affected by the addition of a negative charge but the maximal effect was reduced suggests that SCN binding in K335D or K335E CFTR is similar to that seen with wtCFTR but that the bound anion is not as effective in obstructing the conduction path. Login to comment
253 We found, as did Anderson et al. (1991), that the sequence for Cl and I was reversed in K335E CFTR. Login to comment
254 In the present study, however, the sequence for the mutant was not that predicted solely by hydration energies, suggesting that I interacts in a unique way with both wtCFTR and K335E. Login to comment
104 Only one mutation, K335E, significantly altered the sequence of permeability ratios derived from shifts in reversal potential. Login to comment
114 The K335D and K335E constructs also exhibited increased conductance ratios for I, a result previously reported by Anderson et al. (1991) for K335E CFTR. Login to comment
138 Permeability Ratios Wild type 4-9 3.42 afe; 0.28 1.42 afe; 0.04 1.22 afe; 0.02 0.39 afe; 0.01 0.44 afe; 0.03 G91A 3-6 3.24 afe; 0.26 1.53 afe; 0.04 1.27 afe; 0.02 0.37 afe; 0.04 0.40 afe; 0.04 G91E 3-7 3.50 afe; 0.54 1.59 afe; 0.04 1.27 afe; 0.01 0.35 afe; 0.01 0.51 afe; 0.04 G91R 3-4 5.26 d1e; 0.46* 1.60 afe; 0.03 1.40 d1e; 0.01* 0.32 afe; 0.04 0.64 d1e; 0.04* G314A 3-4 2.87 afe; 0.17 1.45 afe; 0.03 1.19 afe; 0.02 0.31 afe; 0.03 0.33 afe; 0.03 G314D 4 3.42 afe; 0.34 1.44 afe; 0.05 1.25 afe; 0.04 0.33 afe; 0.03 0.51 afe; 0.05 G314E 3-4 3.72 afe; 0.56 1.65 d1e; 0.09* 1.35 d1e; 0.03* 0.49 afe; 0.04 0.53 afe; 0.04 G314Q 3-4 3.89 afe; 0.37 1.62 afe; 0.11 1.27 afe; 0.04 0.36 afe; 0.03 0.62 afe; 0.05 K335R 3-5 3.44 afe; 0.29 1.35 afe; 0.04 1.22 afe; 0.03 0.40 afe; 0.05 0.41 afe; 0.07 K335A 5-6 5.34 d1e; 0.58* 1.48 afe; 0.06 1.28 afe; 0.04 0.37 afe; 0.03 0.60 afe; 0.06 K335D 4-6 3.02 afe; 0.19 1.50 afe; 0.03 1.10 d1e; 0.02* 0.54 d1e; 0.04* 0.65 d1e; 0.06* K335E 5-8 3.64 afe; 0.21 1.48 afe; 0.06 1.29 afe; 0.03 0.46 afe; 0.04 1.10 d1e; 0.04* B. Conductance Ratios Wild type 4-9 0.14 afe; 0.02 0.75 afe; 0.02 0.64 afe; 0.02 0.52 afe; 0.03 0.18 afe; 0.03 G91A 3-6 0.14 afe; 0.01 0.77 afe; 0.02 0.61 afe; 0.02 0.47 afe; 0.02 0.19 afe; 0.02 G91E 3-7 0.15 afe; 0.03 0.73 afe; 0.02 0.60 afe; 0.01 0.50 afe; 0.04 0.30 afe; 0.02 G91R 3-4 0.14 afe; 0.00 0.84 afe; 0.01 0.63 afe; 0.01 0.32 d1e; 0.01* 0.14 afe; 0.01 G314A 3-4 0.30 afe; 0.09 0.89 d1e; 0.01* 0.66 afe; 0.01 0.48 afe; 0.09 0.24 afe; 0.01 G314D 4 0.28 afe; 0.05 0.82 afe; 0.01 0.70 afe; 0.02 0.49 afe; 0.06 0.27 afe; 0.03 G314E 3-4 0.62 d1e; 0.07* 1.18 d1e; 0.04* 0.84 d1e; 0.05* 0.42 afe; 0.05 0.29 afe; 0.09 G314Q 3-4 0.63 d1e; 0.02* 1.01 d1e; 0.04* 0.82 d1e; 0.03* 0.50 afe; 0.02 0.42 d1e; 0.02* K335R 3-5 0.14 afe; 0.01 0.76 afe; 0.03 0.61 afe; 0.02 0.59 afe; 0.06 0.16 afe; 0.03 K335A 6 0.20 afe; 0.03 0.77 afe; 0.02 0.61 afe; 0.02 0.45 afe; 0.03 0.21 afe; 0.02 K335D 4-6 0.65 d1e; 0.04* 1.25 d1e; 0.02* 0.89 d1e; 0.02* 0.61 afe; 0.06 0.58 d1e; 0.06* K335E 5-8 0.50 d1e; 0.06* 1.19 d1e; 0.03* 0.89 d1e; 0.02* 0.53 afe; 0.03 0.48 d1e; 0.03* (A) The apparent permeability ratios (PS/PCl) for each substitute anion were calculated from the shift in reversal potential using the Goldman-Hodgkin-Katz relation (noted in Materials and Methods). Login to comment

PMID: 9454574 [PubMed] Wigley WC et al: "Transmembrane domain of cystic fibrosis transmembrane conductance regulator: design, characterization, and secondary structure of synthetic peptides m1-m6."

No. Sentence Comment

287 For example, mutational data demonstrated that the substitution of glutamic acid for lysine 335 alters channel permeability of CFTR (4), and mutation of arginine 347 to histidine gives rise to pH-dependent ion selectivity of the channel (66). Login to comment

PMID: 9511930 [PubMed] Akabas MH et al: "Probing the structural and functional domains of the CFTR chloride channel."

No. Sentence Comment

140 The mutations K95D and K335E altered the halide permeability sequence, leading to the suggestion that these residues might be involved in anion binding (Anderson et al., 1991b). Login to comment
141 The mutation K335E, however,did not alter the SCN- - induced anomalous mole fraction effects (Tabcharani et al., 1993), and our data imply that Lys335 is on the opposite side of the helix from the channel-liningface (Fig. 2B) (Cheung and Akabas, 1996), making it unlikely that this residue is part of an anion binding site. Login to comment
142 More likely,the K335E mutationinduces aconfor- mational change in residues that form ananion-binding site, possibly at quite a distance from this residue. Login to comment

PMID: 9379167 [PubMed] Tabcharani JA et al: "Halide permeation in wild-type and mutant cystic fibrosis transmembrane conductance regulator chloride channels."

No. Sentence Comment

264 Arg347 May Contribute to a Weak Field Strength Site for Iodide High macroscopic PI/PCl ratios have been reported previously for CFTR channels in which positively charged residues in the membrane spanning regions were mutated to negatively charged residues (K95E, 1.43; K335E, 1.37; R347E, 0.9; R1030E, 0.81; Anderson et al., 1991). Login to comment
277 Halide selectivity in CFTR cannot be attributed exclusively to the region around arg347; however, because high PI/PCl ratios have been reported previously for other pore mutants (K95D and K335E; Anderson et al., 1991), and because R347D retains some preference for Br- over Cl- and selects strongly against F- (our unpublished observations). Login to comment
278 PI/PCl was altered by a mutation that abolished the anomalous mole fraction effect (AMFE, R347D); however, these properties are not strictly correlated because K335E also had high PI/PCl in a previous study (Anderson et al., 1991) and yet displays an AMFE in SCN--Cl- mixtures (Tabcharani et al., 1993). Login to comment
289 Arg347 May Contribute to a Weak Field Strength Site for Iodide High macroscopic PI/PCl ratios have been reported previously for CFTR channels in which positively charged residues in the membrane spanning regions were mutated to negatively charged residues (K95E, 1.43; K335E, 1.37; R347E, 0.9; R1030E, 0.81; Anderson et al., 1991). Login to comment
305 Halide selectivity in CFTR cannot be attributed exclusively to the region around arg347; however, because high PI/PCl ratios have been reported previously for other pore mutants (K95D and K335E; Anderson et al., 1991), and because R347D retains some preference for Br2 over Cl2 and selects strongly against F2 (our unpublished observations). Login to comment
306 PI/PCl was altered by a mutation that abolished the anomalous mole fraction effect (AMFE, R347D); however, these properties are not strictly correlated because K335E also had high PI/PCl in a previous study (Anderson et al., 1991) and yet displays an AMFE in SCN2-Cl2 mixtures (Tabcharani et al., 1993). Login to comment

PMID: 9089437 [PubMed] Cheung M et al: "Locating the anion-selectivity filter of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel."

No. Sentence Comment

21 In contrast, the mutation K335E changed the halide permeability and/or conductance sequences (Anderson et al., 1991b) but did not alter the anomalous mole-fraction effects (Tabcharani et al., 1993). Login to comment
204 Based on the effects of the mutations K95D and K335E on halide selectivity sequences, Anderson et al. (1991b) concluded that Lys95 and Lys335 were determinants of halide selectivity. Login to comment
206 Furthermore, the K335E mutation had no effect on anomalous mole-fraction effects suggesting that Lys335 is not part of an anion binding site in the channel (Tabcharani et al., 1993). Login to comment

PMID: 8913585 [PubMed] Zhao J et al: "Rectification of cystic fibrosis transmembrane conductance regulator chloride channel mediated by extracellular divalent cations."

No. Sentence Comment

190 The studies of Tabcharani et al. (1993) showed that TM6 is also involved in the conduction process of the CFTR channel, as point mutations of K335E and R347D altered the multi-ion pore behavior of the CFTR channel. Login to comment
191 The studies of Tabcharani et al. (1993) showed that TM6 is also involved in the conduction process of the CFTR channel, as point mutations of K335E and R347D altered the multi-ion pore behavior of the CFTR channel. Login to comment

PMID: 8810276 [PubMed] Price MP et al: "Function of Xenopus cystic fibrosis transmembrane conductance regulator (CFTR) Cl channels and use of human-Xenopus chimeras to investigate the pore properties of CFTR."

No. Sentence Comment

260 In MSD1, two mutations (P99L and K335E) that alter both anion permeability and conductance have been identified (15, 30); these are conserved in human and Xenopus CFTR. Login to comment
279 In MSD1, two mutations (P99L and K335E) that alter both anion permeability and conductance have been identified (15, 30); these are conserved in human and Xenopus CFTR. Login to comment

PMID: 8744306 [PubMed] Cheung M et al: "Identification of cystic fibrosis transmembrane conductance regulator channel-lining residues in and flanking the M6 membrane-spanning segment."

No. Sentence Comment

25 A mutation, K335E, in M6 altered the permeability and conductance ratios for halides (Anderson et al., 1991b). Login to comment
193 The mutation K335E, a water-accessible residue, altered the relative halide permeability and conductance sequences (Anderson et al., 199lb). Login to comment
191 The mutation K335E, a water-accessible residue, altered the relative halide permeability and conductance sequences (Anderson et al., 199lb). Login to comment

PMID: 7589561 [PubMed] Hipper A et al: "Mutations in the putative pore-forming domain of CFTR do not change anion selectivity of the cAMP activated Cl- conductance."

No. Sentence Comment

6 The following mutations were examined: K335E, R347E, R334E, K335H, R347H, R334H. Login to comment
20 (v) Mutations in the apparent 6th a-helical transmembrane domain of CFTR (K335E, R347E) resulted in changes in the halide selectivity of CFTR [1]. Login to comment
32 Synthesis of mutated CFTR-cDNA was induced by annealing of ampicillin repair oligonucleotide and oligonucleotide primers carrying the respective mutation changing positively charged to negatively charged amino acids (R334E, R347E, K335E) or replacing R and K at these positions by histidines (R334H, R347H, K335H). Login to comment
76 I R334EIIR334HI K335E...... I K335H I R347EII R347H l (n=16) n=10) (n=10) (n=24) (n=9) "° ,11 ml I'lnt;"i' ii Illll 111 0.8 X T °., I ~ 0.4 0.2 I o.o ~ ~ ~ 6!~ 6 ~ 8 ~ ,I I ~ ...... ] J I I L ...... ,j I I t 1 I * *J t........ ~,_J L * * I * *I _ J I .......... I I , * * * , (n=18) (n=lO) (n=22) (n=7) 1.o - T T (n=8) (n=14) T / T T T o.eT T T o 1 "~ 0.4-O 0.2- oo_ L__J , i I i t - - I 1 I I I ~ t J L ' t * J I__~ * I [ * * I l * * j l. Login to comment
80 Next, positively charged amino acids R334, R347, K335 located in the putative 6th pore forming transmembrane a-helical domain of CFTR, were exchanged by histidines (R334H, R347H, K335H) or by the negatively charged glutamate (R334E, R347E, K335E). Login to comment
81 Wc conductances were activated significantly by IBMX in all 6 mutants but to variable degrees (AG in/.tS): 3.2 + 0.6 (R334E, n = 20), 2.7 + 0.6 (R334H, n = 13), 7.1 + 0.9 (K335E, n-- 20), 2.8 + 0.7 (K335H, n = 10), 3.2 + 0.04 (R347E, n = 32) and 1.8 + 0.3 (R347H, n = 10). Login to comment
105 In fact, in a previous study lysine and arginine were replaced by negatively charged amino acids in the first and sixth transmembrane domain (K95D, K335E, R347E), respectively [1]. Login to comment
108 In the present study we repeated some of the published (K335E, R347E, R347H) and performed additional mutations (R334E, R334H, K335H) which are all located in the putative sixth transmembrane domain and overexpressed the respective CFTRs in oocytes. Login to comment
112 Comparable wc measurements were performed in the present study (K335E, R347E compared to R347D in [7]) with SCN- and C1- present in the extracellular bath solution at different concentration ratios. Login to comment

PMID: 7539989 [PubMed] Gadsby DC et al: "The CFTR chloride channel of mammalian heart."

No. Sentence Comment

18 For example, expression in 3T3 cells of two CFTR mutants, K95D and K335E, in which negatively charged amino acids replaced positively charged lysines in the first (Ml) and sixth (M6) putative transmembrane a-helices (Figure I) yielded Cl- channels with altered anion permeability sequences, 1- > B..- > Cl- instead of the normal Br > CI- > 1- (3). Login to comment

PMID: 7522483 [PubMed] McDonough S et al: "Novel pore-lining residues in CFTR that govern permeation and open-channel block."

No. Sentence Comment

71 (F) K335E mutation, indicating inward rectification and unchanged DPC binding affinity. Login to comment
78 Affinity and Voltage Dependence for Block of CFTR Variants by DPC Construct TM Ko( - 100) (PM) 0 I-V Relation n Properties Wild type Wild type low [Cl-], (10 mM) K335E 6 K335F 6 T338A 6 T339A 6 S341A 6 S341T 6 S1118A 11 T1134A 12 T1134F 12 S1141A 12 Triple 6,12 276 f 14 181 f 13" 303 -t 14 351 * 15' 220 * 14 284 * 47 1251 f 116a 530 f 80" 243 * 37 230 * 20 74 * 3" 220 * 13 325 * 26b 0.41 f 0.01 0.32 f 0.02" 0.42 f 0.01 0.42 f 0.02 0.36 f 0.02" 0.44 * 0.12 0.49 * 0.03" 0.35 f 0.09 0.40 f 0.02 0.35 * 0.02" 0.41 f 0.01 0.42 f 0.03 0.21 * O.Ol",b Linear, E,,, = -8 f 1 mV Ere\ = +48+2mV Inward rectification Linear Linear Linear Strong inward rectification Inward rectification Linear Linear Linear Linear Strong inward rectification Affinity for DPC was determined empirically at -100 mV, from whole-cell currents measured in the presence of 200 uM DPC (see Experimental Procedures). Login to comment
92 In contrast, K335E displayed slight inward rectification of unblocked currents, but this mutant had the same DPC affinity as wild-type CFTR (Figure 3F). Login to comment
156 Also in TM 6, mutation K335F slightly reduces DPC block, and mutation K335E gives inward rectification (see also Tabcharani et al., 1993). Login to comment
173 Previous studies of CFTR have found that mutations of positively charged residues in TM 1 and TM 6 (including K335E) give small changes in ionic selectivity (Anderson et al., 1991b) and that naturally occurring mutations of positively charged residues just extracellular to TM 2, or within TM 6 (R347P and R334W), reduce single-channel conductance and alter kinetics (Sheppard et al., 1993). Login to comment

PMID: 7515047 [PubMed] Akabas MH et al: "Amino acid residues lining the chloride channel of the cystic fibrosis transmembrane conductance regulator."

No. Sentence Comment

15 Mutation of Lys-95 to Asp, in M1, and Lys-335 and Arg-347 to Glu, in M6, altered the permeability andlor conductance ratios for halides (6). Login to comment

PMID: 7515441 [PubMed] Cuthbert A et al: "Cystic fibrosis gene update."

No. Sentence Comment

14 (c) Directed mutagenesis (ie conversion oflysine 95 to aspartate and lysine 335 to glutamate) altered the ion selectivity of CFTR chloride channels from Br>Cl->I->Fto I->Br->Cl->F-6. Login to comment

PMID: 7508414 [PubMed] Cuppens H et al: "Detection of 98.5% of the mutations in 200 Belgian cystic fibrosis alleles by reverse dot-blot and sequencing of the complete coding region and exon/intron junctions of the CFTR gene."

No. Sentence Comment

80 It has been shown that mutagenesis of the neighboring amino acid 335 from a basic amino acid to an acidic amino acid (K335E) results in a CFTR protein with altered anion permeability sequence and conductivity sequence properties of the different halides (2). Login to comment
79 It has been shown that mutagenesis of the neighboring amino acid 335 from a basic amino acid to an acidic amino acid (K335E) results in a CFTR protein with altered anion permeability sequence and conductivity sequence properties of the different halides (2). Login to comment

PMID: 1281220 [PubMed] Sheppard DN et al: "Effect of ATP-sensitive K+ channel regulators on cystic fibrosis transmembrane conductance regulator chloride currents."

No. Sentence Comment

48 We also transiently expressed another mutant (CFI'R-K335E, in which lysine 335 in the first transmembrane domain was changed to glutamic acid) in HeLa cells using the vaccinia virus-T7 hybrid expression system (Rich et al., 1990; Elroy-Stein, Fuerst, and Moss, 1989). Login to comment
161 We therefore examined the effect of glibenclamide, the most potent inhibitor we had identified, on CI- currents generated by several CFFR mutants. We studied 100 • 1992 CFTR containing mutations that affect each of the three types of domains of CFTR: CFFP~R where part of the R domain has been deleted (amino acids 708-835); CVFR-K335E, which contains a mutation in the sixth putative membrane-spanning sequence; and CFTR-K1250M, which contains a mutation in the second NBD. Login to comment
171 CFFR-K335E forms CI- channels that are similar to wild-type channels, except that the anion selectivity is altered such that I- > Br- > C1- and currents show some outward rectification (Anderson et al., 1991b and Fig. 7, D and F). Login to comment
172 Glibenclamide inhibited CFTR-K335E CI- currents, and the effect was similar to that observed with wild-type CFTR (Fig. 7, E and F). Login to comment
176 +SO mV 0 m V ~ -go mV CFTFI~ A~ ......~-1 baseline D CFTR-K335E I ii..i.Iii cAMP .... 13, CFTR-K1250M 1cAMP baseline + gllbenclamlde 250 pA L 50 ms C 1500 1000 5OO -500 o1~0 -100 -75 -50 -25 0 V (mV) ---o-- baseline ---4-- gllbenclamlde E) I cAMP + gllbenclamlde / tp----e F 1000 750 5OO -100 -75 -50 -25 0 V (mV) H ) 1000 PAL__ 50 ms I i cAMP + gllbenclamlde --o-- cAMP --e-- gllbanclamlde / _~_ _ 4OOO 3OOO ~q]O0 I000 0 I000 2OOO 30OO mOO -100 -75 -50 -25 0 V (mV) 25 50 25 50 25 50 FIGURE 7. Login to comment
178 Traces are from C127 cells stably expressing CFTP-~R (A-C), HeLa cells transiently expressing CFFR-K335E (D-F), and NIH 3T3 cells stably expressing CFIR-K1250M (G-I). Login to comment
180 CFFRAR currents were recorded in the absence of cAMP, but for CFFR-K335E and CFTR-K1250M currents cAMP agonists were present. Login to comment
185 Data for steady-state current values measured at +50 and -90 mV are shown for wild-type CF-FR (A), CFTRAR (B), CFFR-K335E (C), and CFTR-K1250M (D). Login to comment
186 The dose-response curves for wild-type CFFR, CFTR-K335E, and CFTR-K1250M were similar. Login to comment
187 Although the effect was not marked, in each case inhibition was slightly more potent at -90 mV than at +50 inV. A 100 8O O 60 c g 20 B 100 8O o 6o eo o m 20 THE JOURNAL OF GENERAL PHYSIOLOGY • VOLUME 100 • 1992 C CFTR 100 ' --o-- 50mV 80 e 6o C g,m 2O 0 20 40 60 80 1C10 0 gllbenclamlde (,aM) D CFTRAR 100 80 2 60 c i 2O 1 ~ ~ 866o o glil~nclamlde (gM) CFTR-K335E 0 20 40 ~ 80 100 glibenclamlda (,ttM) CFTR-K1250M "il o 2i~ ,o 6i) 8o lOO glibenclamlde (i.tM) FIGURE 8. Login to comment
191 (A) Wild-type CFTR; (B) CFTR~R; (C) CFTR-K335E; (D) CFFR-K1250M. Login to comment
196 Half-maximal inhibition by glibenclamide was similar in all cases, occurring at ~ 20 TABLE I1 Effect of Glibenclamide on CFTR Mutants 4-50 mV -90 mV Mutant Experiments Ki n Ki n my/ u2v/ CFTR 21.8 ± 5.2 0.8 - 0.1 19.0 - 5.6* 0.7 ± 0.1 7 CFTR-K335E 25.9 ± 4.1 0.9 ± 0.I 20.4 +--3.7* 0.9 ± 0.1 6 CFTR-K1250M 16.8 _ 4.2 0.8 ± 0.1 31.2 ± 2.5 1.0 - 0.1 5 Ki and n values were calculated as described in Table I for currents measured at +50 and -90 mV for the number of experiments listed. Login to comment
199 Half-maximal inhibition by glibenclamide, measured at -90 mV, showed a small but statistically significant increase in potency compared with that at +50 mV for wild-type CFTR and CFTR-K335E, but not CFFR-K1250M. Login to comment
248 Inhibition of CFTR-K335E and CFTR-K1250M CI- currents by glibenclamide resembled that of wild-type CFFR. Login to comment
249 This suggests that residues K335E and K1250M do not form a critical part of the glibenclamide interaction site. Login to comment

PMID: 1322048 [PubMed] Anderson MP et al: "Chloride channels in the apical membrane of normal and cystic fibrosis airway and intestinal epithelia."

No. Sentence Comment

69 Relative anion permeability of CAMP-regulated channels in apical membrane and in cells expressing wild-type and mutant CFTR PXlPCl- Gx/Gcl- Br- ClI- Br ClI- CAMP 3T3 fibroblasts CFTR 1.11 1.00 0.59 1.26 1.00 0.29 HeLa cells CFTR 1.24 1.00 0.57 1.02 1.00 0.39 K95D 1.25 1.00 1.43 1.39 1.00 0.75 K335E 1.06 1.00 1.37 1.71 1.00 1.43 R347E 1.24 1.00 0.90 1.46 1.00 0.47 Rl030E 1.46 1.00 0.81 1.50 1.00 0.28 Human airway epithelia Apical ND 1.00 0.41 ND 1.00 0.35 T84 epithelia Apical 1.21 1.00 0.56 0.92 1.00 0.47 over cations. Login to comment

PMID: 1375960 [PubMed] Cuthbert AW et al: "The biochemical defect in cystic fibrosis."

No. Sentence Comment

70 Changing lysine 95 to aspartic acid and lysine 335 to glutamic acid alters the selectivity of the chloride conductance fiom chloride>iodide to iodide>chloride When the R-domain was deleted the CFTR chloride conductance was increased in the unstimulated state (ie absence ofcAMP) suggesting that the R-domain is involved in thegatingofthe ion channeL A similar mechanism has beenproposedfor the gating ofpotassium channels. Login to comment

PMID: 1375035 [PubMed] Welsh MJ et al: "Cystic fibrosis transmembrane conductance regulator: a chloride channel with novel regulation."

No. Sentence Comment

87 Yet two mutations, K95D and K335E, each altered anion selectivity. Login to comment
91 The two mutations were not, however, equivalent: unlike the changes in permeability, only K335E changed the conductivity sequence from BrZ Cl- > Ito Br- > I- > Cl-. Login to comment

PMID: 14729151 [PubMed] Larsen EH et al: "Beta-adrenergic receptors couple to CFTR chloride channels of intercalated mitochondria-rich cells in the heterocellular toad skin epithelium."

No. Sentence Comment

245 Mutation of the basic lysine at this position of hCFTR expressed in HeLa cells to the acidic residue, glutamic acid, resulted in a sequence selectivity shift from GClfGBr>GI>GF (wild-type) to GBrfGI>GCI>GF (K335E) [38]. Login to comment