Fig. 5
Effect of ASIC4 mutations on ASIC1a channel activity. Co‐expression of ASIC4 and ASIC1a reduced acid-induced currents. a A representative image of Chinese hamster ovary (CHO) cells co-transfected with both pCMV-mCherry-P2A-ASIC1a and pCMV-ASIC4-IRES-hrGFP. b Representative current traces of acid (pH 5.0)-induced currents in CHO cells transfected with ASIC1a, ASIC1a + ASIC4WT, ASIC1a + ASIC4N191A, N243A, N341A, N376A, ASIC1a + ASIC4N191A, ASIC1a + ASIC4N243A, ASIC1a + ASIC4N341A or ASIC1a + ASIC4N376A (n = 10 cells each). Co-expression of ASIC1a with ASIC4WT or its mutants reduced ASIC1a-mediated acid-induced current (IASIC1a). c Acid (pH 5.0) did not induce a current in CHO cells transfected with ASIC4WT, ASIC4N191A, N243A, N341A, N376A, ASIC4N191A, ASIC4N243A, ASIC4N341A, or ASIC4N376A (n = 5 cells each). d Quantification of acid-induced peak current density in transfected CHO cells. e pH dependence of the IASIC1a in transfected CHO cells. f Desensitization time constant (τ) of IASIC1a at pH 5.0 in transfected CHO cells. g Activation time constant (τ) of IASIC1a at pH 5.0 in transfected CHO cells. h Western blot analysis of surface ASIC1a expression in transfected groups (n = 2). *p < 0.05, ***p < 0.001 vs. ASIC1a + ASIC4WT. Data are mean ± SEM