FIG. 8.

Pyk2 adhesion-dependent tyrosine phosphorylation is impaired by FAK expression. (A) Relative Pyk2 levels were determined by immunoblot (IB) analysis of total cell lysates (30 μg of total protein) from FAK-null cells (parental population to Tet-FAK clones) versus normal mouse embryo fibroblasts. (B) Induced or noninduced Tet-FAK(F397)-21 cells were serum starved for 2 h and then lysed when either attached (Att.), trypsinized and held in suspension for 30 min (Susp.), or replated onto fibronectin for either 30 min (Fn-30′) or 60 min (Fn-60′). Either FAK or Pyk2 was immunoprecipitated (IP) from 300 μg of total protein lysates and then divided equally for immunoblot (IB) detection of either FAK, Pyk2, or phosphotyrosine (pTyr).