Regulation of nuclear translocation of extracellular signal-regulated kinase 5 by active nuclear import and export mechanisms.
Extracellular signal-regulated kinase 5 (ERK5), a member of the mitogen-activated protein kinase family, plays an important role in growth factor signaling to the nucleus. However, molecular mechanisms regulating subcellular localization of ERK5 have remained unclear. Here, we show that nucleocytoplasmic shuttling of ERK5 is regulated by a bipartite nuclear localization signal-dependent nuclear import mechanism and a CRM1-dependent nuclear export mechanism. Our results show that the N-terminal half of ERK5 binds to the C-terminal half and that this binding is necessary for nuclear export of ERK5. They further show that the activating phosphorylation of ERK5 by MEK5 results in the dissociation of the binding between the N- and C-terminal halves and thus inhibits nuclear export of ERK5, causing its nuclear import. These results reveal the mechanism by which the activating phosphorylation of ERK5 induces its nuclear import and suggest a novel example of a phosphorylation-dependent control mechanism for nucleocytoplasmic shuttling of proteins.
Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Kunio
K
Kondoh
Kazuya
K
Terasawa
Hiroko
H
Morimoto
Eisuke
E
Nishida
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D028884:Karyopherins / Q000378:metabolism; D048671:MAP Kinase Kinase 5 / Q000378:metabolism; D048054:Mitogen-Activated Protein Kinase 7 / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D000097606:Exportin 1 Protein
D028884:Karyopherins; D048671:MAP Kinase Kinase 5; D048054:Mitogen-Activated Protein Kinase 7; D019913:Nuclear Localization Signals; D018160:Receptors, Cytoplasmic and Nuclear; D000097606:Exportin 1 Protein; C482563:MAP2K5 protein, human