title: Regulation of MBK-2/Dyrk kinase by dynamic cortical anchoring during the oocyte-to-zygote transition.
abstract: BACKGROUND
  Successful transition from oocyte to zygote depends on the timely degradation of oocyte proteins to prepare for embryonic development. In C. elegans, degradation of the oocyte protein MEI-1 depends on MBK-2, a kinase that phosphorylates MEI-1 shortly after fertilization during the second meiotic division.
  
  
  RESULTS
  Here we report that precise timing of MEI-1 phosphorylation depends on the cell cycle-regulated release of MBK-2 from the cortex. Prior to the meiotic divisions, MBK-2 is tethered at the cortex by EGG-3, an oocyte protein required for egg activation (see [1], accompanying paper in this issue). During the meiotic divisions, EGG-3 is internalized and degraded in an APC/C (anaphase-promoting complex/cyclosome)-dependent manner. EGG-3 internalization and degradation correlate with MBK-2 release from the cortex and MEI-1 phosphorylation in the cytoplasm. In an egg-3 mutant, MEI-1 is phosphorylated and degraded prematurely.
  
  
  CONCLUSIONS
  We suggest that successful transition from an oocyte to a zygote depends on the cell cycle-regulated relocalization of key regulators from the cortex to the cytoplasm of the egg.
authors.affiliation: Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Center for Cell Dynamics, Johns Hopkins School of Medicine, 725 North Wolfe Street, PCTB 706, Baltimore, Maryland 21205, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Stitzel
authors.forename: Ken Chih-Chien
authors.initials: KC
authors.lastname: Cheng
authors.forename: Geraldine
authors.initials: G
authors.lastname: Seydoux
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000201:enzymology* / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000032:analysis; D008540:Meiosis; D008969:Molecular Sequence Data; D009865:Oocytes / Q000201:enzymology* / Q000254:growth & development; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000032:analysis / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000032:analysis; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D015053:Zygote / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D044767:Ubiquitin-Protein Ligases; C478059:MBK-2 protein, C elegans; D011505:Protein-Tyrosine Kinases; C525138:EGG-3 protein, C elegans; D017027:Protein Tyrosine Phosphatases; D000251:Adenosine Triphosphatases; C086678:MEI-1 protein, C elegans