Fig. 5.

Recombinant KSR1 phosphorylates Myelin basic protein (MBP). A) Recombinant rKSR1, rD683A/D700A, rKSR1ΔN521, rRaf-1, rRaf-1 K375M, or lysate from EGF-treated cells (EGF tx lysate) were incubated with MBP in an in vitro kinase assay. Solid bars are the average relative MBP phosphorylation compared to MBP alone and error bars represent the SEM from 3 independent experiments. B) In vitro MBP kinase assay performed as before with rKSR1 or rD683A/D700A incubated with vehicle, C2-, C8-, or C16-ceramide (3 μM). MBP phosphorylation was determined as before. Solid bars are the average relative MBP phosphorylation compared to MBP alone and error bars represent the SEM from 3 independent experiments. Statistical analysis was performed using a one-way ANOVA with Dunnett’s post-test. *** = P < 0.001