Fig. 5.

PIP₂ depletion renders TRPC5 channels DAG sensitive. (A–F) Whole-cell measurements of HEK293 cells expressing TRPC5 alone (A–D and E) or together with Lyn11–FRB–mCherry and pseudojanin–FKBP–pmRFP-C1, which is fused to the phosphatases Sac1 and INPP5E leading to rapamycin-induced degradation of PIP₂ to PI(4)P and to PI (E). Representative CD voltage curves, CD time courses, and summaries of CDs at holding potentials of ±60 mV are shown. CD analysis shows summary of CDs before and during application of 100 µM OAG in the presence of 20 µM wortmannin (A), 100 nM wortmannin (B), 100 µM LY294002 (C), 3 µg/mL poly-l-lysine (PLL) (D), 5 µM rapamycin (E), 100 µM carbachol (CCh) (F), and during application of 300 µM LaCl₃. Numbers over bars indicate the number of measured cells and independent experiments measured at different experimental days. Bath applications of OAG, LaCl₃, and of wortmannin (A and B), LY294002 (C), rapamycin (E), and CCh (F) are indicated. PLL was applied through the patch pipette (D). Stippled line indicates zero current. Significant differences are compared with basal CDs (mean ± SEM, two-tailed, paired t test; **P < 0.01, *P < 0.05, ***P < 0.001). Significant differences between CDs induced by PIP₂ depletions with wortmannin, LY294002, PLL, rapamycin, or CCh compared with additional application of OAG (mean ± SEM, two-tailed, paired t test; *P < 0.05, **P < 0.01, ***P < 0.001).