Description

ZAP70 is a member of the Syk protein tyrosine kinase subfamily that is expressed exclusively in T cells and NK cells that plays an essential role in T cell receptor (TCR) signaling in combination with the Src family kinases, LCK and FYN. Upon TCR stimulation, phosphorylation of CD3 by LCK leads to the recruitment of ZAP70 to the activated receptor. Upon association of ZAP70 with the activated TCR complex, the kinase is phosphorylated on several tyrosine residues, including Tyrosine 493. Phosphorylation of Tyrosine 493, which is found within the activation loop of the protein, results in increased enzymatic activity. ZAP70 subsequently phosphorylates downstream targets, including the adaptor molecules LAT and LCP2, facilitating the recruitment and activation of other signaling molecules, ultimately leading to T cell proliferation, differentiation, and activation. ZAP70 mays also serve as a scaffold for recruiting additional factors to the activated TCR, and can function to regulate TCR-CD247/CD3Z expression at the plasma membrane. ZAP70 deficiency results in severely impaired immune function, while higher levels of ZAP70 expression are associated with certain B cell malignancies. PTN22 is required for the dephosphorylation of ZAP70 Tyrosine 493.

Formulation

Recommended Usage

Each lot of this antibody is quality control tested by intracellular immunofluorescent staining with flow cytometric analysis. For flow cytometric staining, the suggested use of this reagent is 5 µl per million cells in 100 µl staining volume or 5 µl per 100 µl of whole blood.