ABCMdb

ABCC7 p.Tyr1219Ile

[switch to full view]
Comments [show]

None has been submitted yet.

Publications

PMID: 16966475 [PubMed] Zhou Z et al: "The two ATP binding sites of cystic fibrosis transmembrane conductance regulator (CFTR) play distinct roles in gating kinetics and energetics."

No. Sentence Comment

106 The ATP dose-response relationships of Y1219F and Y1219I mutants lie between those of WT and Y1219G. Login to comment
113 Since the opening rate of Y1219G is not saturated at 20 mM ATP, we also studied single-channel kinetics of Y1219I, which shows a smaller shift in the ATP dose-response relationship (Fig. 2 A). Login to comment
115 The opening rate of Y1219I at 10 or 20 mM ATP is very similar to that of WT at 2.75 mM ATP (Fig. 2, B and C), indicating that mutations at the Y1219 residue likely affect the ATP binding step with minimal effect on the post-binding events. Login to comment
116 Fig. 2 C shows the relationship between the opening rate and [ATP] for WT, W401G, Y1219I, and Y1219G. Login to comment
122 (A) Normalized ATP dose-response relationships of WT (black line, Michaelis-Menten fit from Fig. 1 D), Y1219W (brown), Y1219F (pink), Y1219I (blue), and Y1219G (green line, Michaelis-Menten fit from Fig. 1 D). Login to comment
124 K1/2 values are 0.13 ± 0.02 mM (Y1219W), 0.46 ± 0.06 mM (Y1219F), and 0.94 ± 0.20 mM (Y1219I), respectively. Login to comment
125 (B) Representative single-channel current traces of WT, W401G, Y1219G, and Y1219I in response to [ATP] as marked. Login to comment
126 (C) Relationships between channel opening rates and [ATP] for WT (black), W401G (red), Y1219I (blue), and Y1219G (green). Login to comment
127 Solid lines are Michaelis-Menten fits to the data of WT (black) and Y1219I (blue). Login to comment
128 The maximal opening rate and K1/2 values are 2.42 ± 0.11 s-1 and 0.11 ± 0.02 mM for WT, and 2.60 ± 0.11 s-1 and 1.73 ± 0.26 mM for Y1219I, respectively. Login to comment
129 (D) Relationships between channel opening rates and [ATP] for ∆R-CFTR (black), ∆R-Y1219I (blue), and ∆R-Y1219G (green). Login to comment
130 K1/2 from Michaelis-Menten fits (solid lines) are 0.16 ± 0.04 mM and 1.27 ± 0.16 mM for ∆R-CFTR and ∆R-Y1219I, respectively. Login to comment
134 Fig. 2 D shows a similar rightward shift of the ATP dose-response relationships for Y1219I and Y1219G mutants under the ∆R-CFTR background. Login to comment
205 The Y1219I mutation lowers the sensitivity of the opening rate to [ATP] without altering the maximal opening rate (Fig. 2), indicating that this mutation indeed decreases the binding affinity for ATP at the NBD2 site. Login to comment

PMID: 17700963 [PubMed] Bompadre SG et al: "Cystic fibrosis transmembrane conductance regulator: a chloride channel gated by ATP binding and hydrolysis."

No. Sentence Comment

180 The mutation Y1219G shows an ATP dose-response relationship shifted more than 50-fold towards higher [ATP], however more conservative mutations (Y1219I, Y1219F) show smaller shifts, indicating the importance of the nature of the side chain in the interaction with the ATP molecule. Login to comment

PMID: 18391167 [PubMed] Chen TY et al: "CLC-0 and CFTR: chloride channels evolved from transporters."

No. Sentence Comment

787 The ATP dose-response relationships of Y1219F and Y1219I mutants lie between those of wild type and Y1219G, suggesting a correlation between changes of the ATP sensitivity and the chemical natures of the side chain at this position. Login to comment
788 Single-channel kinetic analysis indicates that the shifts of the ATP dose-response relationships in Y1219G and Y1219I mutants are mainly due to changes of the opening rate (360). Login to comment

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

No. Sentence Comment

65 The dose-response curve of channel opening rate as a function of [ATP] was seen to shift dramatically to the right when the consensus site 2 was mutated ( Y1219G or Y1219I) but not when the degenerate site 1 was altered (W401G). Login to comment
63 The dose-response curve of channel opening rate as a function of [ATP] was seen to shift dramatically to the right when the consensus site 2 was mutated ( Y1219G or Y1219I) but not when the degenerate site 1 was altered (W401G). Login to comment

PMID: 20628841 [PubMed] Shimizu H et al: "A stable ATP binding to the nucleotide binding domain is important for reliable gating cycle in an ABC transporter CFTR."

No. Sentence Comment

19 The degree of dose-response shift, a descending order of Y1218G, Y1219I, Y1219F and Y1219W, seemed to depend on the similarity of chemical properties, e.g., hydrophobicity and p bond by aromatic ring, of the side chains introduced by the mutations to tyrosine. Login to comment
59 Figure 2b compares macroscopic current relaxations for Y1219G, Y1219I, Y1219F and Y1219W mutants. Login to comment
60 Although a slow phase of current decay can be seen with Y1219G and Y1219I, this second phase is hardly discernable for the Y1219W mutant. Login to comment
65 b A representative current trace of WT-CFTR channel showing immediate closing upon a rapid removal of ATP somewhere between Y1219W and Y1219I. Login to comment
67 The time constants of the initial fast phase for all the Y1219 mutants are within hundreds of milliseconds (sfast: 504 &#b1; 76 ms, n = 5 for Y1219G; 450 &#b1; 44 ms, n = 7 for Y1219I; 571 &#b1; 142 ms, n = 4 for Y1219F; 513 &#b1; 66 ms, n = 5 for Y1219W) and there is not significant difference in the fast time constant among these Y1219 mutants (Fig. 2b). Login to comment
68 On the other hand, the time constants of the slow component for Y1219F and Y1219W are shorter than those of Y1219G and Y1219I (Fig. 3a). Login to comment
69 More importantly, the fraction of the slow component (Fig. 3b) shows a gradual decrease as the mutation becomes less 'preserved` (Y1219G [ Y1219I [ Y1219F [ Y1219W). Login to comment
80 b Macroscopic current relaxations upon ATP wash-out for Y1219G, Y1219I, Y1219F and Y1219W. Login to comment
82 The time constant and the fraction of the slow component are summarized in Fig. 3. c Single channel recording of Y1219G-CFTR showing a long opening even after ATP removal 35 30 25 20 15 10 5 0 Y1219G Y1219I Y1219F Y1219W 0.5 0.4 0.3 0.2 0.1 0.0 Y1219G Y1219I Y1219F Y1219W A slow / (A slow + A fast ) c4; slow (s) A B Fig. 3 Kinetic parameters of macroscopic current relaxations for Y1219G, Y1219I, Y1219F and Y1219W. Login to comment
83 a Time constants of the slow component of the current relaxation for the Y1219 mutants. Y1219G: n = 5; Y1219I: n = 7; Y1219F: n = 4; and Y1219W: n = 5. b Fraction of the slow component (Aslow/Aslow ? Login to comment
84 Afast) for the Y1219 mutants. Y1219G: n = 5; Y1219I: n = 7; Y1219F: n = 4; and Y1219W: n = 5 ATP because of their similar rate-limiting hydrolyzing rates [11]. Login to comment
85 Figure 4 shows the effects of application and removal of 5 mM ATP and 100 lM P-ATP on the macroscopic current of the Y1219I mutant. Login to comment
92 Since the slow phase of current decay in Y1219I-CFTR channels was diminished when opened by P-ATP (Fig. 4a), we next examined the accessibility of P-ATP to the binding site during the long-lasting open state by testing if P-ATP can rapidly close Y1219I channels in the long-lasting open state. Login to comment
93 We first opened Y1219I-CFTR channels with ATP. Login to comment
109 We show a correlation between the occurrence of these events and the degree of P-ATP 100 bc;M ATP 5 mM P-ATP 100 bc;M P-ATP 100 bc;M A B 50 s 20 pA 10 s 5 pA ATP 5 mM Fig. 4 Effects of P-ATP on Y1219I mutant. Login to comment
110 a A representative macroscopic current trace of Y1219I-CFTR responding to rapid application and removal of 5 mM ATP or 100 lM P-ATP. Login to comment
112 b Effects of a brief rapid application of P-ATP on Y1219I macroscopic current during the slow phase of the current relaxation after ATP wash-out. Login to comment
132 Although the results with Y1219G and Y1219I mutations are quantified accurately, this may not be the case with the data for Y1219F and Y1219W. Login to comment
135 This effect is expected to be small when the probability of the stable open state is high such as in Y1219G or Y1219I. Login to comment
139 Since P-ATP has a [50-fold higher affinity to NBD2 compared with ATP [11], P-ATP may also assume a high affinity for the Y1219 mutants. Indeed, while we need millimolar ATP to elicit significant currents from Y1219I-CFTR, 100 lM P-ATP can generate a current similar to the initial current induced by 5 mM ATP (Fig. 4a), indicating that P-ATP is more potent in opening Y1219I channels. Login to comment
140 Thus, the high-affinity ATP analog, P-ATP, can effectively abolish the stable open state of Y1219I-CFTR, corroborating the idea that weakening ATP binding at NBD2 promotes the stable open state. Login to comment
146 Although P-ATP is able to shorten the lifetime of ATP-opened Y1219I mutants (Fig. 4a), we could not conclude whether the bound ATP has dissociated so that the binding pocket is now unoccupied or the dislocated ATP is still in the binding pocket. Login to comment
151 In fact, even when ATP affinity is drastically reduced by mutations such as Y1219G and Y1219I, the probability of the stable open state remains quite low compared to the short-lived open state. Login to comment
162 If different mutations at Y1219 can affect the entry rate and the exit rate differently as shown in Table 2, this hypothesis may explain most of the results Table 1 Parameter sets (s-1 ) for the ''kiss and run`` hypothesis kCO1 kO1C kO1O2 kO2C Y1219G 3 or 0a 3 2 9 10-2 3.8 9 10-2 Y1219I : : 1.3 9 10-2 : Y1219F : : 1.1 9 10-2 : Y1219W : : 4 9 10-3 : a kCO1 was set to 3 s-1 for simulating the ''with ATP`` condition and 0 s-1 for simulating the ''after the ATP washout`` condition. Login to comment
166 b Representative reproduced macroscopic current relaxations mimicking those in Y1219G (red), Y1219I (green), Y1219F (cyan) and Y1219W (blue). Login to comment
172 In addition, the slow time constant for Y1219G is not different from that for Y1219I despite the fraction of the slow phase is different between these two mutants. Login to comment

PMID: 25225552 [PubMed] Lin WY et al: "A single amino acid substitution in CFTR converts ATP to an inhibitory ligand."

No. Sentence Comment

133 Y1219F, Y1219I, and Y1219G, mutations known to cause a graded change of the apparent affinity for Figure 3.ߓ Paradoxical [ATP] dependence of G551D-CFTR currents supports the hypothesis of two ATP-binding sites exerting opposite actions. Login to comment
168 (A-C) Real-time current traces in response to ATP removal for G551D/Y1219F (A), G551D/Y1219I (B), and G551D/Y1219G (C). Login to comment