Emerging Roles for PKC Isoforms in Immune Cell Function

Positive roles for PKC isoforms in lymphocyte signaling. Engagement of the BCR (A) or the T cell antigen receptor (TCR) (B) activates a set of similarly acting signaling molecules. Specific Src (Lyn and Lck), Syk-Zap70, and Tec (Btk and Itk/Rlk) family kinases are activated. These events mediate increased activity of PLC-γ, leading to the generation of the second messengers DAG and calcium, which are required for the activation of most PKCs. Both PKCβ and PKCθ, respectively, function in controlling BCR and TCR dependent NF–κB activation. SLP-76, src homology (SH)2 domain–containing leukocyte protein of 76-kD.