FIG. 10.

Catalytic activities of ZAP-70–Syk chimeric proteins. K562 cells were transfected with the indicated expression plasmids. Cellular extracts were immunoprecipitated with the tag-specific 9E10 MAb. Immune complex kinase reactions were done with [γ-³²P]ATP and 2 μg of His-tagged cdb3 as the substrate. Radiolabeled proteins were detected by autoradiography (middle panel), and the incorporation of ³²P into His-cdb3 was quantitated with an AMBIS phosphorimager (bottom panel). The immunoprecipitated protein tyrosine kinases were detected by immunoblotting with 9E10 MAb (upper panel).