Figure 6.

Met expression (A) and Met tyrosine phosphorylation (B) in parental pools (lanes 2 and 5), s.c. tumors (lanes 3 and 6), and tumor-derived metastatic cell lines (lanes 4 and 7) expressing V12G37 Ras (lanes 2–4) and V12C40 Ras (lanes 5–7), along with that in control cells (lane 1). After Met immunoprecipitation, Western blots were probed sequentially for phospho-tyrosine (P-Tyr) and Met. The positions of the p170^Met precursor and the p140^Met β-chain that contains the tyrosine kinase domain and becomes phosphorylated on activation (33) are shown.