Figure 4.

MAP4K4 is phosphorylated by Pyk2. (a) Cells were transfected with MAP4K4 or cotransfected with MAP4K4 and either wild type Pyk2 or a kinase-deficient Pyk2 variant (Pyk2KD). Cell lysates immunoprecipitated for Pyk2 were immunoblotted with anti-Pyk2 and the anti-phosphotyrosine antibody pY20. Cell lysates immunoprecipitated with anti-MAP4K4 antibody were immunoblotted for MAP4K4, anti pY20, and anti-Pyk2. Whole cell lysates (WCL) were immunoblotted with the indicated antibodies. (b) Cells were cotransfected with Pyk2 and wild type MAP4K4 or a kinase-deficient MAP4K4 variant (K54R). Anti-MAP4K4 immunoprecipitates or whole cell lysates were immunoblotted with the indicated antibodies.