FIG. 3.

Binding of Src kinases to K15 mutants. HEK 293-T cells were transiently transfected with expression vectors for myc-tagged PTKs Lyn, Src, and Hck. Cell lysates were incubated overnight at 4°C with the GST-K15-P and GST-K15-M exon 8 (ex8) wild-type (WT) proteins, and their respective mutants (YEEV, PPLP, YEEV PPLP, and YASI), immobilized to glutathione-Sepharose beads. Precipitated Lyn, Src, and Hck proteins were analyzed by immunoblotting with an anti-c-myc antibody. Purified GST or GST-K15 fusion proteins separated on an SDS-PAGE gel were visualized by Coomassie blue staining to show that equal amounts of fusion protein were used for GST pulldown experiments (bottom). α, anti.