Figure 6.

Histidine modifier DEPC blocked the zinc effects on heteromeric ASIC1a/3 channels. (A) Representative traces show the time course of the treatment with and without the DEPC (0.6 mM) on potentiation of heteromeric ASIC1a/3 currents by co-application of 100 µM zinc. Treatment with histidine modifying agent DEPC at a concentration of 0.6 mM inhibited the potentiation of heteromeric ASIC1a/3 currents during the incubation. This was recorded in the same cell by different treatments and the current trace was recorded every 2 min. The dashed blue line represents pretreatment with DEPC in the pH 7.4 solution, the dashed green line represents washout with normal pH 7.4 solution, and the solid red and black lines represent 100 µM zinc and pH 6.8 application, respectively (each recoding with 7 s of zinc application); (B) Statistical bar graphs show that relative peak amplitude of the ASIC1a/3 currents by zinc potentiation was blocked in the presence of 0.6 mM DEPC (n = 6); (C) Statistical bar graphs show that relative peak amplitude of the ASIC1a/3 currents by zinc inhibition was blocked in the presence of 0.6 mM DEPC (n = 5). Whole-cell patch-clap recording was performed and heteromeric ASIC1a/3 currents were activated 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 < 0.01.