Figure 2.

Effect of Pak on activation of JNK and ERK. Schwann cells were cotransfected with either HA-JNK or HA-ERK and plasmids encoding the proteins shown. Fold indicates the fold increase in substrate phosphorylation over that occurring in the pcmv6 lanes, as determined through phosphorimager analysis. At the bottom of each panel is a Western blot showing expression of HA-JNK or HA-ERK, as indicated. MBP, myelin basic protein. Data shown are representative gels of three independent experiments. (a) Ras activation of JNK. (b) Ras activation of ERK. (c) Rac/Raf^D340 and Pak/Raf^D340 cooperative activation of ERK. (d) v-Raf activation of ERK.