Figure 2.

Enzymatic activity of ITK and mutants in the presence or absence of Src and inhibitor. (A) Immunoprecipitates of ITK or mutants expressed in the presence of absence or Src and/or Ly294002 were assayed for kinase activity. ▪, ITK alone; ░⃞, ITK plus Src; □, ITK plus Ly294002. Assays were corrected for expression and expressed as n-fold increase over ITK expressed in the absence of Src. (B) Enzymatic activity of ITK and mutants in the presence or absence of Ly294002. COS-7 cells transfected with the indicated mutants and either left untreated or treated with Ly294002. ITK immunoprecipitates were assayed for in vitro kinase activity, then probed with anti-HA antibody (to detect ITK) (Lower). The filter was treated with KOH and exposed to x-ray film (Upper). Arrow indicates ITK or mutants.