Figure 4.

PLCγ1 expression enhances Ca²⁺ signaling to the same level as dominant-active Cdc42, whereas o-Dbl exhibits partial rescue in B6A4C1 cells. B6A4C1 cells were infected with 20 pfu/cell of vector and Cdc42^V12 (a and d); o-Dbl (b and e); and PLCγ1 (c and f) for 6 h at 37°C and loaded with indo-1. Overall Ca²⁺ responses were measured in response to stimulation with 100 ng/ml DNP/BSA (➩). To measure release of Ca²⁺ from ER stores (d–f), loaded cells were treated with 4 mM EDTA (➞) and then stimulated with 100 ng/ml DNP/BSA. Measurements of the Ca²⁺ responses in the absence and presence of EGTA were performed concurrently. Traces shown are representative of at least three independent experiments.