Figure 7.

PIP₂ sensitivity of drTRPM2 membrane interfacial cavity mutant channels. (A) ADPR (100 µM, black bar) induced currents of wild-type and mutant drTRPM2 channels. Current trace of R934A (II) (B) and R1092A (IV) (C) perfused with increasing concentrations of PIP₂ (green bars). Polylysine (15 µg/mL, PL, orange bar) was used to scavenge PIP₂ since even in the absence of external PIP₂ the channels are already saturated with natural membrane PIP₂. (D) Summary of the presented data showing a right shift in PIP₂ sensitivity of mutants R934A (II) and R1092A (IV). Data represented as mean ± SEM; n = 5–6.