Figure 4.

Preactivation of PLCγ₂ sensitizes the enzyme to further activation by catalytically-inert BTK. COS-7 cells were transfected as indicated with 50 ng/well of vector encoding WT PLCγ₂ (γ₂WT), PLCγ₂4Y→F (γ₂4F), PLCγ₂4Y→E (γ₂4E), PLCγ₂N-myr (γ₂N-myr) (left panel), or PLCγ₂S707Y (γ₂S707Y) (right panel) and 100 ng/well of vector encoding WT BTK (WT) or BTK variants K430R, E41K, or E41K/K430R. Inset, COS-7 cells were transfected as indicated with 500 ng/well of vector to examine the influence of the PLCγ₂ mutations on basal inositol phosphate formation in intact transfected cells. Analysis of inositol phosphate formation was done as in Fig. 1. The graph shows representative results from three independent experiments as mean values of three technical replicates.