FIGURE 2.

C1093A mutant channels do not respond to H₂O₂. A, representative time course of TRPM4 whole cell currents from HEK 293 cells overexpressing the C1093A mutant exposed to 200 μm H₂O₂ (indicated by the bar) recorded at 100 mV with 600 nm Ca²⁺ in the pipette solution (n = 12). B and C, representative time course of inside-out recordings from membrane patches from HEK 293 cells overexpressing wild type TRPM4 channels (B) or C1093A mutants (C) recorded at 100 mV and activated by 10 μm Ca²⁺ in the bath solution. Bars indicate exposure to the water-soluble form of PI(4,5)P₂ (dioctanoyl-phosphatidylinositol-4,5-bisphosphate (diC₈-PIP₂), Echelon Biosciences Inc., Salt Lake City, UT) or 200 μm H₂O₂ (n = 10 for wild type TRPM4 channels and n = 12 for C1093A mutants).