BD Phosflow™ Alexa Fluor® 647 Mouse Anti-ZAP70 (PY319)/Syk (PY352)

ZAP70 is a protein tyrosine kinase (PTK) that associates with the z subunit of the T cell antigen receptor (TCR) and undergoes tyrosine phosphorylation following TCR stimulation. ZAP70 contains two SH2-like domains with the PTK domain located at the C-terminus. It appears that both ZAP70 and Syk are recruited to the phosphorylated CD3 and z subunits after TCR stimulation. TCR stimulation leads to autophosphorylation of ZAP70 at Tyr-315 amd Tyr-319, and mutation of the Tyr-319 site dramatically impairs TCR signaling. In addition, TCR-mediated Lck activity leads to phosphorylation of ZAP70 on Tyr-493 in the regulatory loop of the kinase domain leading to upregulation of ZAP70 kinase activity. The significance of ZAP70 activation in mediating TCR signal transduction has been confirmed by showing that ZAP70 activity is absent in an autosomal recessive form of severe combined immunodeficiency (SCID). This is due to mutations affecting the ZAP70 kinase domain which affect the stability of the protein and TCR signaling.

Clone 17A/P-ZAP70 recognizes the phosphorylated form of ZAP70 (Y319). It also cross-reacts with SYK (Y352) due to homology of the phosphorylation site with ZAP70 (Y319). The PE-conjugated format has been evaluated using human and mouse model systems. The unconjugated form of the antibody (Cat. No. 612574) has also been shown to work in western blot analysis on human, mouse,  and rat cells.