ABCMdb

ABCC7 p.Met265Val

None has been submitted yet.

Publications

PMID: 9813087 [PubMed] Jiang Q et al: "Cystic fibrosis transmembrane conductance regulator-associated ATP release is controlled by a chloride sensor."

No. Sentence Comment

93 The NH2-terminal truncation mutant ⌬259-M265V CFTR was constructed as previously described (Piazza Carroll et al., 1995). Login to comment
157 Dissociation of Cl-Conductance and ATP Efflux Functions Associated with CFTR Because the results indicated that CFTR was necessary but not sufficient for ATP permeability, we attempted to identify the important domains in CFTR by comparing wild-type CFTR with two deletion mutants, TMD1 and ⌬259-M265V. Login to comment
158 The TMD1 mutant encompassing the NH2-terminal portion of CFTR encoded the first 369 amino acids (first six transmembrane helices), while in the ⌬259-M265V mutant the first 259 amino acids were deleted and the methionine 265 was mutated to a valine. Login to comment
161 In contrast, expression of the ⌬259-M265V mutant was associated with near wild-type rates of ATP efflux in the absence of detectable Cl-conductances (Fig. 3). Login to comment
195 Comparison of CFTR-modulated ATP release between wild-type, TMD1, and ⌬259-M265V CFTR cRNA-injected Xenopus oocytes. Login to comment
200 An equal number (N) of wt CFTR, TMD1, and ⌬259-M265V cRNA-injected oocytes were assessed for ATP efflux within each of two batches of oocytes. Login to comment
274 However, the CFTR mutant ⌬259-M265V, which failed to conduct Cl- , also conferred near wild-type rates of ATP release. Login to comment
277 First, the CFTR mutant ⌬259-M265V demonstrated near wild-type rates of CFTR-modulated ATP release despite its inability to conduct Cl- . Login to comment

PMID: 9922379 [PubMed] Schwiebert EM et al: "CFTR is a conductance regulator as well as a chloride channel."

No. Sentence Comment

92 In sharp contrast, a similar truncation to amino acid 259 Taken together, these preliminary results utilizing truncations of the CFTR cDNA from the NH2 and COOHbut with methionine-265 altered to a valine (M265V) failed to function as a cAMP-stimulated Cl0 channel in termini suggest that the domains critical for Cl0 channel function and ORCC regulatory coupling are distinct. Login to comment
94 However, despite this lack of Cl0 channel activity, M265V conferred cAMP regulation function could be eliminated with the other intact, and vice versa. Login to comment
101 Similar to the results with M265V, insertion of ''dual`` NBD1 in bilayers (7) and mammalian cells (34) (see also below). Login to comment
219 Wild-type and D259- M265V-CFTR promote cAMP-stimulated ATP release from oocytes, whereas TMD-1 CFTR fails to promote cAMP-stimulated ATP release. Login to comment

PMID: 9482946 [PubMed] Schwiebert EM et al: "Chloride channel and chloride conductance regulator domains of CFTR, the cystic fibrosis transmembrane conductance regulator."

No. Sentence Comment

28 For N-terminal truncation mutations, the M265V missense mutation and a silent mutation to create a unique SpeI site were introduced into the CFTR cDNA with a mutagenic oligonucleotide, 5Ј-GAC TAG TGA TTA CCT CAG AAG TGA TTG-3Ј. Login to comment
30 This created the #2c;259-M265V construct. Login to comment
98 ⌬259-M265V is identical to ⌬259-M265 but with methionine-265 changed to a valine, shifting the translation initiation codon downstream within the coding sequence. Login to comment
100 In sharp contrast, ⌬259-M265V does not produce any currents (Table 1.). Login to comment
103 No single channel events were observed from oocytes injected with the ⌬259-M265V construct, suggesting that this mutant either does not conduct Cl- or is not processed normally in oocytes. Login to comment
123 Cl- currents in CFTR cRNA-injected Xenopus oocytes cRNA injected Current, nA n P valueBasal cAMP-stimulated None -89.3 Ϯ 13.7 -82.7 Ϯ 13.5 9 NS Wild-type CFTR -117.2 Ϯ 27.7 -828.1 Ϯ 295.7 16 Ͻ0.001 ⌬259-M265 -133.4 Ϯ 27.6 -509.9 Ϯ 159.9 8 Ͻ0.01 ⌬259-M265V -106.2 Ϯ 32.1 -103.7 Ϯ 29. Login to comment
139 Importantly, ⌬259-M265V-transfected IB3-1 cell cultures and R334W͞R347P-transfected cultures also responded to cAMP in 36 Cl- efflux assays, despite the lack of intrinsic Cl- channel function in oocyte recordings (Table 2). Login to comment
158 In contrast, in IB3-1 cells transfected with ⌬259-M265V, currents were more strongly outwardly rectified and were completely inhibited by DIDS, with no underlying linear CFTR currents (Fig. 3). Login to comment
159 Consistent with oocyte expression and the Cl- efflux studies, these results showed that elimination of the first four ␣-helices of CFTR and mutation of methionine-265 to a valine eliminated CFTR`s ability to generate Cl- currents in both oocytes and IB3-1 cells. Login to comment
172 More importantly, results with T-N-R CFTR suggest that the region of CFTR important for regulatory interaction with ORCCs lies Table 2. cAMP-stimulated Cl- efflux in CFTR cDNA-transfected IB3-1 CF cells cDNA transfected n Cl- efflux, % lost per min Paired P valueBefore agonists After agonists Mock 42 33.01 Ϯ 3.12 29.53 Ϯ 2.22 NS Wild-type 37 22.99 Ϯ 1.47 46.51 Ϯ 6.53* Ͻ0.005 ⌬259-M265 30 21.85 Ϯ 1.43 47.67 Ϯ 5.95* Ͻ0.005 ⌬259-M265V 18 24.55 Ϯ 1.17 29.25 Ϯ 2.23** Ͻ0.05 TMD-1 (K370X) 24 16.63 Ϯ 1.80 53.51 Ϯ 9.50* Ͻ0.005 TMD-1 (K370EcoRV) 24 19.54 Ϯ 1.67 41.27 Ϯ 5.22* Ͻ0.005 T-N-R 18 19.21 Ϯ 1.89 28.05 Ϯ 3.35** Ͻ0.05 R334W-R347P 18 19.85 Ϯ 3.20 31.16 Ϯ 6.79** Ͻ0.05 R334W-R347P-TMD-1 18 23.12 Ϯ 2.60 26.26 Ϯ 3.42 NS The Before agonists value is the rate of 36Cl- efflux immediately prior to stimulation with cAMP agonists (2.5 ␮M forskolin, 250 ␮M CPT-cAMP, and 250 ␮M 8-bromo-cAMP). Login to comment
174 For mutants ⌬259-M265V, T-N-R, and R334W-R347P, the magnitude of cAMP stimulation is significantly less (P Ͻ 0.05, versus paired control value as denoted by two asterisks) than that for the wild type and other responding mutants [⌬259-M265, TMD-1 (K370X), TMD-1 (K370EcoRV), P Ͻ 0.005 as denoted by one asterisk], as determined by ANOVA followed by the Bonferroni ad hoc test. Login to comment
200 (B) ⌬259-M265V CFTR: Typical whole cell patch-clamp recordings of basal, cAMP-stimulated, and DIDS-inhibited cAMP-stimulated Cl- currents from a ⌬259-M265V-transfected cell. DIDS (500 ␮M) inhibited all of the current that was significantly outward rectified; no underlying linear current (CFTR current) was observed. Login to comment
283 Summarized total whole cell currents (in nA) are presented as ICl- at -100 mV͞ICl- at -100 mV with n in parentheses: parental IB3-1, -101.9 Ϯ 12.1͞66.3 Ϯ 24.1 (8); nonresponders, -82.4 Ϯ 15.9͞57.2 Ϯ 14.7 (71); wild-type, -676.2 Ϯ 75.8͞878.9 Ϯ 76.0 (7); ⌬259-M265, -316.8 Ϯ 111.4͞653.7 Ϯ 63.3 (11); ⌬259-M265V, -206.9 Ϯ 52.3͞371.1 Ϯ 54.8 (8); TMD-1, -587.1 Ϯ 83.0͞582.5 Ϯ 84.8 (8); T-N-R, -289.3 Ϯ 27.3͞435.4 Ϯ 28.6 (6); dual arginine (Dual R), -177.5 Ϯ 39.8͞389.6 Ϯ 57.7 (8); and Dual R-TMD-1, -150.3 Ϯ 18.1͞147.3 Ϯ 15.3 (10). Login to comment
96 D259-M265V is identical to D259-M265 but with methionine-265 changed to a valine, shifting the translation initiation codon downstream within the coding sequence. Login to comment
102 No single channel events were observed from oocytes injected with the D259-M265V construct, suggesting that this mutant either does not conduct Cl2 or is not processed normally in oocytes. Login to comment
122 Cl2 currents in CFTR cRNA-injected Xenopus oocytes cRNA injected Current, nA n P value Basal cAMP-stimulated None 289.3 6 13.7 282.7 6 13.5 9 NS Wild-type CFTR 2117.2 6 27.7 2828.1 6 295.7 16 ,0.001 D259-M265 2133.4 6 27.6 2509.9 6 159.9 8 ,0.01 D259-M265V 2106.2 6 32.1 2103.7 6 29. Login to comment
138 Importantly, D259-M265V-transfected IB3-1 cell cultures and R334WyR347P-transfected cultures also responded to cAMP in 36 Cl2 efflux assays, despite the lack of intrinsic Cl2 channel function in oocyte recordings (Table 2). Login to comment
156 In contrast, in IB3-1 cells transfected with D259-M265V, currents were more strongly outwardly rectified and were completely inhibited by DIDS, with no underlying linear CFTR currents (Fig. 3). Login to comment
157 Consistent with oocyte expression and the Cl2 efflux studies, these results showed that elimination of the first four a-helices of CFTR and mutation of methionine-265 to a valine eliminated CFTR`s ability to generate Cl2 currents in both oocytes and IB3-1 cells. Login to comment
171 More importantly, results with T-N-R CFTR suggest that the region of CFTR important for regulatory interaction with ORCCs lies Table 2. cAMP-stimulated Cl2 efflux in CFTR cDNA-transfected IB3-1 CF cells cDNA transfected n Cl2 efflux, % lost per min Paired P value Before agonists After agonists Mock 42 33.01 6 3.12 29.53 6 2.22 NS Wild-type 37 22.99 6 1.47 46.51 6 6.53* ,0.005 D259-M265 30 21.85 6 1.43 47.67 6 5.95* ,0.005 D259-M265V 18 24.55 6 1.17 29.25 6 2.23** ,0.05 TMD-1 (K370X) 24 16.63 6 1.80 53.51 6 9.50* ,0.005 TMD-1 (K370EcoRV) 24 19.54 6 1.67 41.27 6 5.22* ,0.005 T-N-R 18 19.21 6 1.89 28.05 6 3.35** ,0.05 R334W-R347P 18 19.85 6 3.20 31.16 6 6.79** ,0.05 R334W-R347P-TMD-1 18 23.12 6 2.60 26.26 6 3.42 NS The Before agonists value is the rate of 36Cl2 efflux immediately prior to stimulation with cAMP agonists (2.5 mM forskolin, 250 mM CPT-cAMP, and 250 mM 8-bromo-cAMP). Login to comment
173 For mutants D259-M265V, T-N-R, and R334W-R347P, the magnitude of cAMP stimulation is significantly less (P , 0.05, versus paired control value as denoted by two asterisks) than that for the wild type and other responding mutants [D259-M265, TMD-1 (K370X), TMD-1 (K370EcoRV), P , 0.005 as denoted by one asterisk], as determined by ANOVA followed by the Bonferroni ad hoc test. Login to comment
199 (B) D259-M265V CFTR: Typical whole cell patch-clamp recordings of basal, cAMP-stimulated, and DIDS-inhibited cAMP-stimulated Cl2 currents from a D259-M265V-transfected cell. DIDS (500 mM) inhibited all of the current that was significantly outward rectified; no underlying linear current (CFTR current) was observed. Login to comment
281 Summarized total whole cell currents (in nA) are presented as ICl- at 2100 mVyICl- at 2100 mV with n in parentheses: parental IB3-1, 2101.9 6 12.1y66.3 6 24.1 (8); nonresponders, 282.4 6 15.9y57.2 6 14.7 (71); wild-type, 2676.2 6 75.8y878.9 6 76.0 (7); D259-M265, 2316.8 6 111.4y653.7 6 63.3 (11); D259-M265V, 2206.9 6 52.3y371.1 6 54.8 (8); TMD-1, 2587.1 6 83.0y582.5 6 84.8 (8); T-N-R, 2289.3 6 27.3y435.4 6 28.6 (6); dual arginine (Dual R), 2177.5 6 39.8y389.6 6 57.7 (8); and Dual R-TMD-1, 2150.3 6 18.1y147.3 6 15.3 (10). Login to comment

PMID: 9511929 [PubMed] Devidas S et al: "CFTR: domains, structure, and function."

No. Sentence Comment

72 These include A259CFTR and A259-M265V CFTR. Login to comment
76 The A259-M265V CFTR mutanthas its next initiation methionine at amino acid M281. Login to comment