Figure 5. VPA triggers Ca²⁺ influx via the Cch1-Yam8 channel complex.

(A) The increase in the cytoplasmic Ca²⁺ level is derived from the extracellular medium. The experiment was performed as described in Figure 4, expect that prior to the addition of 6 mM VPA, various concentrations of BAPTA (0.5, 1 and 2 mM) were added to chelate Ca²⁺ in EMM medium. The data are representative of six independent experiments. (B) The cch1 deletion abolished VPA-induced Ca²⁺ influx. The Δcch1 cells harboring pKB6892 were cultured and assayed as described in the legend of Figure 4A. The data are representative of six independent experiments. (C) The yam8 deletion abolished VPA-induced Ca²⁺ influx. The Δyam8 cells harboring pKB6892 were cultured and assayed as described in the legend of Figure 4A. The data are representative of six independent experiments. (D) The VPA-induced Ca²⁺ influx was observed in Δpmk1. The Δpmk1 cells harboring pKB6892 were cultured and assayed as described in Figure 4A. The data are representative of six independent experiments.