ABCMdb

ABCC7 p.Thr1246Asn

None has been submitted yet.

Publications

PMID: 15729345 [PubMed] Vergani P et al: "CFTR channel opening by ATP-driven tight dimerization of its nucleotide-binding domains."

No. Sentence Comment

90 b, Representative records from WT, single mutants R555K and T1246N, and double mutant R555K T1246N. Login to comment
100 To quantify this suspected interaction between Arg 555 and Thr 1246 side chains (Fig. 2a), we applied double mutant-cycle analysis6,21 (see Supplementary Information), after mutating Arg 555 to Lys and Thr 1246 to Asn, both individually and jointly. Login to comment
102 If the two residues do not interact, the effects of mutating Arg 555 to Lys should be the same in a Thr 1246 background as in a T1246N background (and vice versa); that is, the effects of the single mutations should be independent and hence additive, and mutation-linked changes on parallel sides of the cycles should thus be equal. Login to comment
112 Current levels of the triple mutant R555K T1246N K1250R did not change when [ATP] was increased to 10 mM, indicating that 5 mM [ATP] was saturating. Login to comment
117 The apparent affinity for ATP was little influenced by the mutation R555K (R555K K0.5 ¼ 71 ^ 14 mM versus WT K0.5 ¼ 55 ^ 5 mM), but was reduced by the mutation T1246N (T1246N K0.5 ¼ 261 ^ 49 mM) by the same extent in the WT background as in the R555K background (R555K T1246N K0.5 ¼ 257 ^ 51 mM). Login to comment
125 The T1246N mutation also greatly slowed channel opening, increasing the energy barrier by 2.5 ^ 0.4kT. Login to comment
133 Introducing the T1246N mutation into the K1250R background decreased Po, corresponding to destabilization of the open burst state by 2.5 ^ 1.0kT with respect to the closed state. However, adding the R555K mutation to T1246N-K1250R channels restored high stability of the open state (Fig. 4e, f). Login to comment
157 For constructs with very low Po (R555K and T1246N), we could not exclude the presence of unseen channels in the patch (even though the records lasted on average 6-7 min). Login to comment
158 The prolonged tib values we extract for R555K and T1246N channels are therefore most probably underestimates, and the real effects of the mutations are more severe (and, hence, jDDG‡ int(opening)j is actually larger) than the values we report. Login to comment

PMID: 16246032 [PubMed] Vergani P et al: "Control of the CFTR channel's gates."

No. Sentence Comment

62 The WT, the two single mutants (in our case R555K and T1246N) and the double mutant (R555K/T1246N) form the corners of a thermodynamic cycle (Figure 3, inset). Login to comment
68 The R555K mutation did not significantly affect the apparent affinity, while the T1246N mutation reduced it to the same degree whether the residue at position 555 was Arg or Lys. Login to comment
78 Introducing the T1246N mutation in a non-hydrolytic background (mutated at a crucial lysine, K1250R [39]) strongly destabilized the open state with respect to the 3 Mutant cycle analysis using activation free energies for the opening reaction Coupling between Arg555 and Thr1246 increases as the channel approaches the open state. Login to comment
79 (A) Representative records from WT, single mutants R555K and T1246N, and double mutant R555K/T1246N, activated with 300 nM cAMP-dependent protein kinase and 5 mM ATP. Login to comment

PMID: 18957373 [PubMed] Muallem D et al: "Review. ATP hydrolysis-driven gating in cystic fibrosis transmembrane conductance regulator."

No. Sentence Comment

99 The WT, the two single mutants (R555K and T1246N) and the double mutant (R555K T1246N) form the corners of a thermodynamic cycle (figure 4a). Login to comment
115 Introducing the T1246N mutation in a non-hydrolytic background (mutated at a crucial lysine, K1250R; Lerner-Marmarosh et al. 1999) strongly destabilized the open state with respect to the closed one. Login to comment
119 The apparent dissociation constant obtained from [ATP] dependence of opening rate is, for CFTR (Vergani et al. 2005), a reasonable estimate for the real dissociation constant for the ATP binding reaction WT CFTR R555K R555K T1246N T1246N 0.4 pA 20 s ∆∆int = ∆3-∆1 = ∆4-∆2 WT ∆1 ∆3 ∆2 ∆4 T1246N R555K R555K T1246N (a) (c) OH T H2N H2NNH2 + COOH NH R H2NCOOH WT CFTR H2NCOOH NH3 + K NH2 H2NCOOH O N R555K T1246N (b) Figure 4. Login to comment
139 The R555K mutation did not significantly affect apparent affinity, while the T1246N mutation reduced it to the same degree whether the residue at position 555 was WT R or mutant K. The effects of the T to N mutation in WT and mutant background are thus similar, yielding a negligible energetic coupling between the two target residues (DDGint(unbound-bound)Z0.3G0.5 kT). Login to comment
97 The WT, the two single mutants (R555K and T1246N) and the double mutant (R555K T1246N) form the corners of a thermodynamic cycle (figure 4a). Login to comment
113 Introducing the T1246N mutation in a non-hydrolytic background (mutated at a crucial lysine, K1250R; Lerner-Marmarosh et al. 1999) strongly destabilized the open state with respect to the closed one. Login to comment
117 The apparent dissociation constant obtained from [ATP] dependence of opening rate is, for CFTR (Vergani et al. 2005), a reasonable estimate for the real dissociation constant for the ATP binding reaction WT CFTR R555K R555K T1246N T1246N 0.4 pA 20 s ∆∆int = ∆3-∆1 = ∆4-∆2 WT ∆1 ∆3 ∆2 ∆4 T1246N R555K R555K T1246N (a) (c) OH T H2N H2NNH2 + COOH NH R H2NCOOH WT CFTR H2NCOOH NH3 + K NH2 H2NCOOH O N R555K T1246N (b) Figure 4. Login to comment
137 The R555K mutation did not significantly affect apparent affinity, while the T1246N mutation reduced it to the same degree whether the residue at position 555 was WT R or mutant K. The effects of the T to N mutation in WT and mutant background are thus similar, yielding a negligible energetic coupling between the two target residues (DDGint(unbound- bound)Z0.3G0.5 kT). Login to comment

PMID: 21576373 [PubMed] Szollosi A et al: "Mutant cycles at CFTR's non-canonical ATP-binding site support little interface separation during gating."

No. Sentence Comment

239 Site-1 mutations affect channel closing, likely by affecting the relative stability of open states In contrast to composite site-2 mutations R555K and T1246N (Vergani et al., 2005, but compare Teem et al., 1996), in positions equivalent to T460 and L1353, all site-1 mutations studied here had relatively small effects on channel gating, consistent with the notion that the gating cycle is driven by the catalytic cycle at composite site 2. Login to comment

PMID: 22966014 [PubMed] Jih KY et al: "Nonintegral stoichiometry in CFTR gating revealed by a pore-lining mutation."

No. Sentence Comment

254 Indeed, mutations of the amino acid residue that directly interacts with ATP have been reported to decrease the opening rate in an ATP-dependent manner (Zhou et al., 2006); further, mutations located at the NBD dimer interface have also been shown to lower the opening rate (e.g., T1246N in Vergani et al., 2005). Login to comment
256 Figure 7. R352C shorten the locked-open time of hydrolytic-deficient CFTR mutant. Login to comment
257 Macroscopic current traces of E1371S-CFTR (A), R352C/E1371S-CFTR (B), T1246N/E1371S-CFTR (C), and R352C/T1246N/E1371S-CFTR (D). Login to comment
259 The current relaxation was fitted with a single-exponential function resulting in the relaxation time constant for each mutant: 65.6 ± 10.1 s (n = 8) for E1371S-CFTR, 4.9 ± 0.8 s (n = 12) for R352C/ E1371S-CFTR, 7.8 ± 1.6 s (n = 7) for T1246N/E1371S-CFTR, and 2.27 ± 0.27 s (n = 6) for R352C/T1246N/E1371S-CFTR. Login to comment
261 *, P < 0.05 compared with E1371S; #, P < 0.05 between two designated data. Login to comment
292 It follows that mutations that decrease the rate of NBD dimerization (CATP→CAD), e.g., T1246N in Vergani et al. (2005), or those that reduce the rate for CAD→O1 (presumably the R352C mutation), will accelerate the decay rate of macroscopic currents in hydrolysis-deficient mutants upon ATP washout. Login to comment
293 Here, in Fig. 7, we show that both R352C and T1246N mutations significantly shorten the locked-open time of the hydrolytic-deficient E1371S-CFTR (Fig. 7). Login to comment
294 Notably, this result is somewhat different from that shown in Vergani et al. (2005) in which the current relaxation is prolonged in T1246N/K1250R- CFTR. Login to comment
296 Nonetheless, the locked-open time is further shortened when combining R352C and T1246N mutations together (Fig. 7, D and E), suggesting that the two mutations affects two different kinetic steps as described above. Login to comment
295 Here, in Fig. 7, we show that both R352C and T1246N mutations significantly shorten the locked-open time of the hydrolytic-deficient E1371S-CFTR (Fig. 7). Login to comment
298 Nonetheless, the locked-open time is further shortened when combining R352C and T1246N mutations together (Fig. 7, D and E), suggesting that the two mutations affects two different kinetic steps as described above. Login to comment

PMID: 19766125 [PubMed] Moran O et al: "Model of the cAMP activation of chloride transport by CFTR channel and the mechanism of potentiators."

No. Sentence Comment

57 Disruption of the binding site on NBD1 and NBD2 by mutations R555K and T1246N, respectively, yield an approximation of the independent equilibrium constants, KATP1 ¼ 71 mM and KATP2 ¼ 261 mM (Vergani et al., 2005). Login to comment
59 Disruption of the binding site on NBD1 and NBD2 by mutations R555K and T1246N, respectively, yield an approximation of the independent equilibrium constants, KATP1 &#bc; 71 mM and KATP2 &#bc; 261 mM (Vergani et al., 2005). Login to comment

PMID: 26496611 [PubMed] Sorum B et al: "Timing of CFTR Pore Opening and Structure of Its Transition State."

No. Sentence Comment

56 Timing of Motion at Position 1246 of the NBD1-NBD2 Interface (A) Inward single-channel currents of the cut-DR(D1370N) CFTR background construct (top trace) and of channels bearing mutations T1246V, T1246P, T1246C, T1246N, and T1246A, respectively, in the same background. Login to comment