Figure 1.

Phosphorylation of Erk1/2 in 64 CRC cell lines on its key regulatory epitope. Equal amounts of total cell RIPA protein extracts were analyzed by western blotting with anti-pT202/pY204 (for human Erk1; corresponds to pT183/pY185 in Erk2), which is well established to reflect the activation state of Erk1/2. C10 extract from the same batch is included on each blot for standardization. Note that numerous proteins from CoCM-1 cells display aberrant gel migration for reasons unknown to us (T.K. and S.F., unpublished data).