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. 2016 Apr 5;6:23947. doi: 10.1038/srep23947

Figure 2. Characterization of CsR-ASIC2a by two-electrode voltage clamp (TEVC) recordings in oocytes.

Figure 2

(a) Current-voltage dependency of normalized photocurrents in 100 mM NaCl, 100 mM KCl or 100 mM CholineCl extracellular medium (all media contained additionally 1mM NaCl/KCl, 1 mM MgCl2, 0.1 mM CaCl2 and 0.1 mM MOPS, pH 7.5, normalized to ASIC2a current activated by pH 4, mean +/− SD, n = 5). (b) ASIC2a currents measured during pH titration in darkness and comparison with photocurrents measured at pH 7.5 (mean +/− SD, n = 6). The green shaded region highlights the percent activation of ASIC2a by illumination with green light at 0.1 mM MOPS at −40 mV (data shown in Fig. 5d). Inset: representative pH activated current trace of ASIC2a at −40 mV. (c) Macroscopic currents of CsRT46N-ASIC2a activated by pH 4 or green light at different buffer concentrations (5 mM MOPS, 1 mM MOPS and 0.1 mM MOPS, −40 mV, constant perfusion). (d) Percent activation of ASIC2a by the light driven proton pump CsRT46N in different buffer concentrations (5 mM MOPS, 1 mM MOPS and 0.1 mM MOPS, −40 mV, n = 9, 100% activation taken as the peak ASIC current produced by pH 4, mean +/− SD, n = 9). (e) Normalized ASIC2a (red data points) and CsRT46N (green data points) photocurrents measured at different light intensities (0.1 mM MOPS, −40 mV, normalized to ASIC2a current activated by pH 4, mean +/− SD, n = 5). Inset: representative current traces at −40 mV.