title: Possible role of p38 MAPK-MNK1-EMI2 cascade in metaphase-II arrest of mouse oocytes.
abstract: The Mos-MAPK signaling pathway involving the Mos-MEK1/2-ERK1/2-RSK1/2/3 or MSK1-EMI2 cascade is directly linked to metaphase-II arrest of vertebrate oocytes. In this study, we examined whether p38, a member of the MAPK subfamily, is regulated under the control of Mos and contributes to metaphase-II arrest in the mouse oocyte. Morpholino oligonucleotide-mediated depletion of Mos revealed a remarkable decrease in phosphorylation of p38. Simultaneous treatment of oocytes with two chemical inhibitors of p38 and MEK1/2 induced both release from metaphase II and degradation of cyclin B1, whereas the treatment with each of these two inhibitors had little effect. Moreover, phosphorylation of EMI2 was dramatically abolished by addition of the two inhibitors. Indeed, MNK1, a kinase downstream of p38, exhibited the ability to phosphorylate EMI2. These results suggest that in addition to the Mos-MEK1/2 pathway, the Mos-mediated p38 pathway may be implicated in metaphase-II arrest.
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Miyagaki
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kanemori
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan.
authors.forename: Fumi
authors.initials: F
authors.lastname: Tanaka
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan Life Science Center of Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba Science City, Ibaraki, Japan baba.tadashi.gf@u.tsukuba.ac.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Baba
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D059447:Cell Cycle Checkpoints / Q000502:physiology*; D044783:F-Box Proteins / Q000235:genetics / Q000378:metabolism*; D008677:Metaphase / Q000502:physiology*; D051379:Mice; D009865:Oocytes / Q000166:cytology* / Q000502:physiology; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: C509434:Emi2 protein, mouse; D044783:F-Box Proteins; C106281:Mknk1 protein, mouse; D017346:Protein Serine-Threonine Kinases; D048051:p38 Mitogen-Activated Protein Kinases
keywords: EMI2; ERK1/2 MAPK; Mos; meiosis; oocyte; p38 MAPK