ABCMdb

ABCC7 p.Arg104Gln

None has been submitted yet.

Publications

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

62 To investigate the role of charge on these residues in controlling I-V shape, neutral substitutions (R104Q, R117Q, K335A, R1128Q) were also investigated. 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
116 All mutants depicted (R104Q, R117Q, K335A, R104E, R117E, K335E) significantly different from wild type (asterisk P<0.05). Login to comment
120 As shown in Fig. 8a, while Pt(NO2)4 2-induced strong inward rectification in wild type (as a result of strongly voltage-dependent current inhibition) [26], this effect was less marked in R104Q, K335A, and R1128Q. Login to comment
122 Considering the data at +80 mV, where the inhibitory effects of Pt(NO2)4 2- are strongest, suggests that Pt(NO2)4 2- inhibition is significantly weakened in R104Q, K335A, and (to a lesser extent) R1128Q but not significantly altered in K114C, R117Q, K329A, K829Q, or R899Q (Fig. 8c). Login to comment
126 In contrast, unitary current amplitude in both R104Q and K335A appeared relatively resistant to the inhibitory effects of external Pt(NO2)4 2- ions (Fig. 9a-c), again consistent with effects on macroscopic currents (Fig. 8), suggesting that positive charge at positions 104 and 335 is necessary for the full inhibitory effects of extracellular Pt(NO2)4 2- ions. 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
147 b Mean fraction of control normalized current remaining in the presence of 10 mM extracellular Pt(NO2)4 2at different membrane potentials in wild type (closed circles), R104Q (closed squares), K335A (open circles), and R1128Q (open squares), quantified as the IREL in the presence of 10 mM Pt(NO2)4 2- [IREL(block)] as a fraction of that in the absence of Pt(NO2)4 2- [IREL(control)]. Login to comment
162 These inhibitory effects are weakened in R104Q and K335Q (Figs. 8 and 9), consistent with the idea that Pt(NO2)4 2- ions may interact with these positive charges to interfere with Cl- permeation. Login to comment
170 c Mean fractional unitary current amplitude remaining in the presence of this concentration of Pt (NO2)4 2- ions as a function of voltage, in wild type (open circles), R104Q (closed circles, left panel), and K335A (closed circles, right panel). Login to comment

PMID: 19448737 [PubMed] Zhou JJ et al: "Evidence that extracellular anions interact with a site outside the CFTR chloride channel pore to modify channel properties."

No. Sentence Comment

68 In contrast, external Pt(NO2)4 2- ions did not significantly affect the apparent affinity of block by internal Pt(NO2)4 2- in R104Q, R117Q, or R899Q (Fig. 2). Login to comment
89 (C) Mean fraction of control current remaining (I / I0) at different voltages after the addition of Pt(NO2)4 2- in wild type (*), R104Q (*), and R117Q (!). Login to comment
90 Curves were fitted to mean data by eq. 1, giving Kd(0) = 89.5 mmol/L and -zd = -0.270 for wild type, Kd(0) = 131.1 mmol/L and -zd = -0.261 for R104Q, and Kd(0) = 44.8 mmol/L and -zd = -0.222 for R117Q. Login to comment
104 Curves were fitted to mean data by eq. 1, giving the following values: for wild type, (*) Kd(0) = 89.5 mmol/L and -zd = -0.270, (*) Kd(0) = 274.1 mmol/L and -zd = -0.262; for R104Q, (*) Kd(0) = 131.1 mmol/L and -zd = -0.261, (*) Kd(0) = 200.41 mmol/L and -zd = -0.326; for R117Q, (*) Kd(0) = 44.8 mmol/L and -zd = -0.222, (*) Kd(0) = 65.0 mmol/L and -zd = -0.304; for K892Q, (*) Kd(0) = 58.4 mmol/L and -zd = -0.275, (*) Kd(0) = 21.1 mmol/L and -zd = -0.250; and for R899Q, (*) Kd(0) = 102.8 mmol/L and -zd = -0.312, (*) Kd(0) = 92.8 mmol/L and -zd = -0.334. Login to comment
136 For 154 mmol/L Cl- (*), fitted curves gave the following values: Kd(0) = 308.8 mmol/L and -zd = -0.441 for wild type; Kd(0) = 356.4 mmol/L and -zd = -0.378 for R104Q; Kd(0) = 234.9 mmol/L and -zd = -0.376 for R117Q; Kd(0) = 204.2 mmol/L and -zd = -0.395 for K892Q; and Kd(0) = 169.4 mmol/L and -zd = -0.462 for R899Q. Login to comment
154 Thus, whereas direct pore block by externally applied Pt(NO2)4 2- ions is weakened in R104Q but not in R117Q (Zhou et al. 2008), loss of the interactions with external Pt(NO2)4 2- that influence the blocking effects of internal Pt(NO2)4 2- appears similar in both R104Q and R117Q (Fig. 2). Login to comment

PMID: 25277268 [PubMed] Broadbent SD et al: "The cystic fibrosis transmembrane conductance regulator is an extracellular chloride sensor."

No. Sentence Comment

112 To explore the role of phosphorylation further, we studied the effect of deleting the R domain from CFTR (residues 634-836) [12, 7], which removes all the major PKA/PKC Table 1 Summary of the FSK stimulation of whole cell currents and Erev shifts observed with the CFTR constructs used in this study CFTR Construct n FSK Stimulation (%&#b1;SEM) Erev shift (mV&#b1;SEM) WT (50 bc;M ATP) 5 180&#b1;96 15.0&#b1;3.6 WT (100 bc;M ATP) 6 12,000&#b1;6,000 15.2&#b1;3.0 WT (300 bc;M ATP) 8 1,200&#b1;600 17.0&#b1;3.0 WT (1 mM ATP) 24 13,000&#b1;6,000 23.7&#b1;1.8 WT (1.3 mM ATP) 9 1,400&#b1;900 16.7&#b1;2.6 WT (2 mM ATP) 24 6,100&#b1;5,300 16.7&#b1;1.6 WT (5 mM ATP) 7 1,600&#b1;1,000 20.1&#b1;4.4 WT (50 bc;M ATP + 50 bc;M P-ATP) 7 224&#b1;130 15.3&#b1;1.0 WT + Genistein 4 7,600&#b1;5,200 26.1&#b1;5.4 WT + AMP-PNP 5 2,800&#b1;2,500 21.8&#b1;5.5 WT (3 mM MgCl2) 7 28,000&#b1;17,000 18.3&#b1;3.1 R104Q 5 4,600&#b1;1,600 28.6&#b1;4.7 K114C 5 12,000&#b1;6,700 29.2&#b1;3.0 R117Q 4 33,000&#b1;20,000 30.1&#b1;3.4 K329A 5 13,000&#b1;10,000 33.7&#b1;2.1 R334Q 9 13,000&#b1;6,700 27.3&#b1;2.9 K335A 5 3,200&#b1;1,500 20.8&#b1;7.1 W401G 7 2,600&#b1;1,800 18.5&#b1;4.8 Delta-R (No Stim) 5 - 25.1&#b1;2.7 Delta-R (No FSK, Genistein) 5 140&#b1;13 22.7&#b1;3.0 Delta-R (FSK, No Genistein) 4 89&#b1;14 15.6&#b1;6.0 Delta-R (FSK + Genistein) 6 639&#b1;432 25.1&#b1;4.9 Delta-R-E1371S (No FSK) 9 - 21.4&#b1;4.8 Delta-R-E1371S (FSK) 4 2,600&#b1;1,400 15.3&#b1;4.7 K892Q 7 16,000&#b1;9,500 36.8&#b1;4.8 R899E 4 1,200&#b1;400 25.0&#b1;2.7 R899K 4 1,600&#b1;900 26.6&#b1;2.9 R899Q 7 5,400&#b1;2,800 30.0&#b1;1.3 R899Q + AMP-PNP 4 72,000&#b1;50,000 15.2&#b1;2.8 R899Q-E1371Q (No FSK) 4 - 18.4&#b1;5.9 R899Q-E1371Q (FSK) 6 107&#b1;48 15.6&#b1;3.0 R1128Q 6 14,000&#b1;6,100 41.1&#b1;4.2 Y1219G 6 3,200&#b1;2,500 19.2&#b1;3.3 E1371Q (No FSK) 6 - 25.5&#b1;3.5 E1371Q (FSK) 8 -28&#b1;9 22.3&#b1;4.0 E1371Q (FSK, No ATP, No GTP) 8 270&#b1;130 19.4&#b1;4.5 E1371Q + AMP-PNP (No FSK) 4 - 24.7&#b1;6.5 E1371Q + AMP-PNP (FSK) 8 180&#b1;170 17.4&#b1;4.0 Vector Control 4 15&#b1;38 - FSK stimulation was calculated as the percentage increase in current density at -60 mV from the Erev, after 5-min exposure to 10 bc;M FSK. Login to comment
162 In support of this conclusion, the stimulating effect of [Cl- ]o cannot be due to the ion entering the pore, since mutations that do affect CFTR Cl-conductance (R104Q, R117Q, R334Q, K335A) have no effect on [Cl- ]o stimulation (Fig. 2), and the one site that is important for sensing (R899) does not affect Cl-conductance [45, 47]. Login to comment