Figure 4.
Induction of inward currents of variants p.Ile607Thr and p.Thr570Ile at acidic pHo
(A) Typical currents of an oocyte expressing WT ClC-3 in the presence of different pH values and in a low Cl− solution at pH 5.3.
(B) Typical currents of an oocyte expressing variant p.Ile607Thr. For display reasons, capacitance (but not leak) was partially subtracted using the capacitive transients upon return to the holding potential.
(C and D) Typical current traces of WT (C) or variant p.Ile607Thr (D) expressed in Tmem206−/− HEK cells.
(E) Difference of reversal potential measured for p.Ile607Thr in oocytes in the indicated conditions and that measured at pH 6.3 (bars) (a liquid junction potential of 8 mV was added to the values measured in the low Cl− condition). Expected values were calculated assuming a 2 Cl−:1 H+ transport stoichiometry.33 For variant p.Ile607Thr, reversal potentials could be obtained at pH 6.3 and lower.
(F) Average current-density voltage relationship of WT and variant p.Ile607Thr measured in Tmem206−/− HEK cells at pH 7.5 and pH 5.0. For V ≤ 0 mV values of variant p.Ile607Thr are significantly different from those of WT (p < 10−4, Student’s t test). All error bars indicate SEM.