Fig. 2.

TRPC3 regulates mitochondrial Ca²⁺ uptake. (A) Mitochondrial Ca²⁺ dynamics ([Ca²⁺]_mito) in WT or Trpc3^−/− MEF cells treated with 100 μM ATP in 0.3 mM extracellular Ca²⁺. [Ca²⁺]_mito was monitored by changes in Pericam fluorescence. (B) Similar measurements in HeLa cells or HeLa cells stably transfected with human TRPC3 (HeLa-TRPC3) treated with 1 μM histamine in 0.3 mM extracellular Ca²⁺. (C and D) Same experiments as A and B, but cells treated with 200 μM ATP or 10 μM histamine in a Ca²⁺-free extracellular solution. (E) [Ca²⁺]_mito changes in digitonin-permeabilized WT and KO MEF cells challenged with cytosolic loading of 300 μM Ca²⁺. (F) [Ca²⁺]_mito changes in digitonin-permeabilized HeLa and HeLa-TRPC3 cells challenged with cytosolic loading of 50 μM Ca²⁺. (B–F) (Left) Representative traces from single experiments. (Right) Means ± SEM of peak [Ca²⁺]_mito changes normalized to that of control (WT, MEF, or HeLa) of three independent experiments with the total number of MEF cells, n = 30, control HeLa and HeLa-TRPC3 cells, n = 186. *P < 0.05, **P < 0.01.