Fig. 4

WUS is an MPK3 substrate in vitro. Kinase assay with in vitro translated, affinity purified wild-type GST-WUS (WUS) and T108A, S112A mutant GST-WUS (WUS-AA) variants. C: control, MPK3: WUS variants incubated with in vitro translated, affinity purified, eluted MKK4/MPK3. SDS-PAGE separated WUS protein on the autoradiograph is indicated by arrowhead. Phosphorylation of myelin basic protein (MBP) by MPK3 is shown in the right panel