Figure 5.

GRASP55 is directly phosphorylated by active MAPKs. MPM2 reactivity of equivalent amounts of wild-type (wt) or the alanine-substituted (T222A T225A) GST-GRASP55 was determined after in vitro incubation, 30 min at 37°C, with an ATP containing buffer and purified active ERK2, JNK, p38, or MKK1 (G7B, ΔN4/S218D/S222D). An equivalent amount of each active kinase was used in each assay.