FIGURE 4.

Non-oncogenic tyrosine kinases phosphorylate Tyr¹⁶⁰ on Grb2. A, HEK-293T cells were transiently co-transfected with the human WT ALK receptor tyrosine kinase or its activating mutant (ALK^F1174L) combined with Grb2^WT or Grb2^Y160F. Anti-ALK-immunoprecipitated proteins (IP) and total cell lysates were analyzed by Western blot with p-Tyr, ALK, and Grb2 antibodies. FL, full length; nt, not transfected; m, mobility. B, HEK-293T cells were transiently co-transfected with human MET (hMET) receptor tyrosine kinase and Grb2^WT or Grb2^Y160F. Cell lysates were analyzed by Western blot. p-Tyr and Grb2 antibodies show that the Y160F mutation abolishes Grb2 phosphorylation in the lower mobility band.