TY - JOUR
T1 - The C. elegans DYRK kinase MBK-2 marks oocyte proteins for degradation in response to meiotic maturation
AU - Stitzel, Michael L.
AU - Pellettieri, Jason
AU - Seydoux, Geraldine
N1 - Funding Information:
We are grateful to Jason Holder, Andy Golden, Rueyling Lin, Paul Mains, Frank McNally, and Bruce Bowerman for sharing reagents, unpublished results, and helpful suggestions throughout this study. We also thank the Caenorhabditis Genetics Center for strains. This work was supported by a grant from the National Institutes of Health (R01 GMG64537). G.S. is an investigator of the Howard Hughes Medical Institute.
PY - 2006/1/10
Y1 - 2006/1/10
N2 - The oocyte-to-embryo transition transforms a differentiated germ cell into a totipotent zygote capable of somatic development. In C. elegans, several oocyte proteins, including the meiotic katanin subunit MEI-1 and the oocyte maturation protein OMA-1, must be degraded during this transition [1]. Degradation of MEI-1 and OMA-1 requires the dual-specificity YAK-1-related (DYRK) kinase MBK-2 [2-4]. Here, we demonstrate that MBK-2 directly phosphorylates MEI-1 and OMA-1 in vitro and that this activity is essential for degradation in vivo. Phosphorylation of MEI-1 by MBK-2 reaches maximal levels after the meiotic divisions, immediately preceding MEI-1 degradation. MEI-1 phosphorylation and degradation still occur in spe-9 eggs, which undergo meiotic maturation and exit in the absence of fertilization [5]. In contrast, MEI-1 phosphorylation and degradation are blocked in cell-cycle mutants that arrest during the meiotic divisions, and are accelerated in wee-1.3(RNAi) oocytes, which prematurely enter meiotic M phase (A. Golden, personal communication). A GFP:MBK-2 fusion relocalizes from the cortex to the cytoplasm during the meiotic divisions, and this relocalization also depends on cell-cycle progression. Our findings suggest that regulators of meiotic M phase activate a remodeling program, independently of fertilization, to prepare eggs for embryogenesis.
AB - The oocyte-to-embryo transition transforms a differentiated germ cell into a totipotent zygote capable of somatic development. In C. elegans, several oocyte proteins, including the meiotic katanin subunit MEI-1 and the oocyte maturation protein OMA-1, must be degraded during this transition [1]. Degradation of MEI-1 and OMA-1 requires the dual-specificity YAK-1-related (DYRK) kinase MBK-2 [2-4]. Here, we demonstrate that MBK-2 directly phosphorylates MEI-1 and OMA-1 in vitro and that this activity is essential for degradation in vivo. Phosphorylation of MEI-1 by MBK-2 reaches maximal levels after the meiotic divisions, immediately preceding MEI-1 degradation. MEI-1 phosphorylation and degradation still occur in spe-9 eggs, which undergo meiotic maturation and exit in the absence of fertilization [5]. In contrast, MEI-1 phosphorylation and degradation are blocked in cell-cycle mutants that arrest during the meiotic divisions, and are accelerated in wee-1.3(RNAi) oocytes, which prematurely enter meiotic M phase (A. Golden, personal communication). A GFP:MBK-2 fusion relocalizes from the cortex to the cytoplasm during the meiotic divisions, and this relocalization also depends on cell-cycle progression. Our findings suggest that regulators of meiotic M phase activate a remodeling program, independently of fertilization, to prepare eggs for embryogenesis.
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U2 - 10.1016/j.cub.2005.11.063
DO - 10.1016/j.cub.2005.11.063
M3 - Article
C2 - 16338136
AN - SCOPUS:30044443400
SN - 0960-9822
VL - 16
SP - 56
EP - 62
JO - Current Biology
JF - Current Biology
IS - 1
ER -