Figure 1.

The nuclear translocation of ERK is blocked by the EPE peptide. Active ERK translocates to the nucleus via its interaction with importin7. Cytosolic ERK is activated initially by phosphorylation on its regulatory Tyr and Thr residues (TEY) followed by phosphorylation on its Ser residues (SPS) located within the nuclear translocation sequence (NTS). This facilitates the binding of the beta-like importin, Imp7, to ERK escorting it to the nucleus via the nuclear pores, where it modulates a large number of targets such as transcription factors (Upper panel). A myristoylated NTS-derived phosphomimetic peptide (EPE peptide) specifically blocks the interaction of Imp7 with ERK thereby inhibits nuclear translocation of ERK (Lower panel).