Constitutively active BRK phosphorylates Dok1 at Y362.

<p>(A) Schematic diagram of Dok1 showing different deletion and point mutants. (B) The Dok1 deletion mutants and BRK-YF were co-transfected in to HEK 293 cells, the cell were then subjected to immunoprecipitation with anti-GFP antibody followed by immunobloting analysis using anti-phosphotyrosine and anti-GFP antibodies (top panel). Lower panel shows the expression of different GFP-Dok1 deletion mutants, BRK (as input) and β-tubulin as a loading control. (C) Dok1 deletion mutants were transfected either alone or with BRK-YF into HEK 293 cells, the cell lysates were then subjected to immunobloting analysis using antibodies against Dok1, phosphotyrosine, BRK and β-tubulin as loading control. (D) HEK 293 cells were co-transfected with Dok1 point mutants and BRK-YF followed by immunoprecipitation with anti-Dok1 antibody and immunoblotting analysis using anti-phosphotyrosines and anti-Dok1 antibodies. Lower panel shows the expression of BRK, GFP-Dok1 mutants (as input) and β-tubulin as a loading control. (E) HEK 293 cells were cotransfected with BRK-YF and Dok1 point mutants or transfected with BRK-YF alone. Total cell lysates were analyzed by immunoblotting analysis with antibodies against phosphotyrosines, BRK, Dok1 and β-tubulin as loading control.