Fig. 8

Fig. 8 PP2 inhibition of Yes kinase activity, effect on development. The effectiveness of PP2 on Yes kinase was tested by immune complex assay (upper panel). Yes immunoprecipitates from 5-h zebrafish embryos were incubated for 5 min with different concentrations of PP2 or PP3 (control). Protein tyrosine kinase activity in the immunoprecipitates was then measured by an autophosphorylation reaction in the presence of [γ-³²P]ATP, and the phosphorylated proteins were resolved by SDS-PAGE and detected by autoradiography. The position of the 62-kDa band representing Yes kinase is indicated by the arrow. The effect of PP2 on development (lower panel) was tested by culturing zebrafish zygotes in different concentrations of PP2 and PP3. After 5 h incubation, the embryos were washed free of the inhibitors. At 5.5 h of development, groups of 25–30 embryos were examined and those scored as having successfully undergone 50% epiboly were classified as having developed normally. Values represent the average of three experiments ± S.E.M.