Figure 1.

Tyrosine phosphorylation of p62^dok by p210^bcr-abl. (a) Time course, in vitro abl kinase reaction utilizing purified recombinant p62^dok as substrate. p62^dok is phosphorylated in a time-dependent manner by Abl. (b) In vitro p210^bcr-abl kinase reaction, utilizing in vitro-translated p62^dok as substrate. Monoclonal anti-bcr antibody was used to isolate p210^bcr-abl. Immune complex was incubated with in vitro-translated p62^dok in the presence of γ-³²P-ATP. Arrow indicates phosphorylated p62^dok. (c) p210^bcr-abl-dependent tyrosine phosphorylation of p62^dok, in vivo. Hemagglutinin-tagged Dok-1 and p210^bcr-abl were expressed in COS cells. Tyrosine phosphorylation of p62^dok was analyzed by precipitating the molecule from lysates derived from transfected cells, resolving the immune complexes by SDS/PAGE and transfer to nitrocellulose, and immunoblotting with anti-pTyr antibody (Top) or antihemagglutinin antibody (Bottom). Arrow indicates p62^dok.