A D543E mutant of TRPM2 shows the loss-of-function activity. A, Current traces of HEK cells transfected with mock (empty vector), WT TRPM2, or D543E, R755C, and A890V mutants of TRPM2, activated by the pipette application of 500 μm ADPR. B, Summary of the current densities activated by the ADPR of cells expressing WT TRPM2 or D543E, R755C, and A890V mutants of TRPM2. Numbers in parentheses represent the number of experiments. *p < 0.05 (N.S., not significant), one-way ANOVA, Tukey's post hoc test. C, Ca2+-imaging traces of HEK cells transfected with mock, WT TRPM2, or D543E, R755C, and A890V mutants of TRPM2 after the application of 200 μm H2O2. D, Summary of the current densities of cells expressing WT TRPM2 or D543E, R755C, and A890V mutants of TRPM2. *p < 0.05 (N.S., not significant), one-way ANOVA, Tukey's post hoc test.