Figure 3From: Signal transducer and activator of transcription 5b: a new target of breast tumor kinase/protein tyrosine kinase 6In vitro Y699 phosphorylation by breast tumor kinase. In vitro Y699 phosphorylation of signal transducer and activator of transcription 5b (STAT5b) by breast tumor kinase (Brk). Purified recombinant GST, GST-STAT5b, or GST-Y699F were incubated with (+) or without (-) purified recombinant Brk in reaction buffer containing 20 nM ATP at 30°C for 30 minutes. An equal volume of 2 × Laemmli buffer was added to end the reaction and the samples were run on SDS-PAGE. Gels were analyzed via (a) silver stain and (b) by immunoblotting with an antiphospho-Y699 STAT5b-specific antibody.Back to article page