Figure 10.

Effects by pretreatment with 300 µM zinc on currents recorded from ASIC1a histidine mutant co-expressed with ASIC3 WT on CHO cells. (A) Representative traces show that pretreatment with zinc at a concentration of 300 µM inhibited the currents recorded from heteromeric ASIC1a-H110A/3, ASIC1a-H163A/3, ASIC1a-H173A/3, ASIC1a-H250A/3, and ASIC1a-H327A/3, but not ASIC1a-H72A/3 and ASIC1a-H73A/3. The dashed blue line represents pretreatment with 300 µM zinc in the pH 7.4 solution with a duration of 2 min; (B) Statistical bar graphs show relative peak amplitude of the currents from ASIC1a/3 WTs and its histidine mutant/3 as mentioned above by pretreatment with 300 µM zinc (n = 7 to 15). Pretreatment with or without 300 µM zinc did not affect the peak amplitude of the currents recorded from ASIC1a-H72A/3 and ASIC1a-H73A/3 (p > 0.05, t-test). There was no significant difference for zinc inhibition among ASIC1a/3 WTs, ASIC1a-H110A/3, ASIC1a-H163A/3, ASIC1a-H173A/3, ASIC1a-H250A/3, and ASIC1a-H327A/3 (p > 0.05, ANOVA). Whole-cell patch-clap recording was performed and currents from heteromeric ASIC1a/3 WTs and ASIC1a histidine mutant co-expressed with ASIC3 on CHO cells were triggered by a drop in pH from 7.4 to 6.8. Data are presented as mean ± SEM. CTRL, control; I_CTRL, ASIC current without any treatment; I_Zinc, ASIC current by zinc treatment. * p < 0.05 (t-test).