Figure 2. Kinetics and specificity of the tyrosine phosphorylation responses to CD32A cross-linking on neutrophil membranes.

(A) Neutrophil membranes were incubated with IV.3 alone, GAM alone or both for the time periods indicated, as indicated in the Materials and methods section. Samples were probed with an anti-pY. (B) CD32A was cross-linked on neutrophil membranes for 10 min in the absence (−) or presence (+) of ATP and MnCl₂ (kinase mix) and orthovanadate (VO₄). Samples were probed with an anti-pY. The two major substrates whose tyrosine phosphorylations are enhanced are indicated by arrows.