Coordinate activation of maternal protein degradation during the egg-to-embryo transition in C. elegans

Dev Cell. 2003 Sep;5(3):451-62. doi: 10.1016/s1534-5807(03)00231-4.


The transition from egg to embryo occurs in the absence of transcription yet requires significant changes in gene activity. Here, we show that the C. elegans DYRK family kinase MBK-2 coordinates the degradation of several maternal proteins, and is essential for zygotes to complete cytokinesis and pattern the first embryonic axis. In mbk-2 mutants, the meiosis-specific katanin subunits MEI-1 and MEI-2 persist during mitosis and the first mitotic division fails. mbk-2 is also required for posterior enrichment of the germ plasm before the first cleavage, and degradation of germ plasm components in anterior cells after cleavage. MBK-2 distribution changes dramatically after fertilization during the meiotic divisions, and this change correlates with activation of mbk-2-dependent processes. We propose that MBK-2 functions as a temporal regulator of protein stability, and that coordinate activation of maternal protein degradation is one of the mechanisms that drives the transition from symmetric egg to patterned embryo.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / isolation & purification
  • Caenorhabditis elegans Proteins / metabolism*
  • Caenorhabditis elegans Proteins / physiology*
  • Carrier Proteins / metabolism
  • Chromatin / metabolism
  • Cloning, Molecular / methods
  • Fluorescent Antibody Technique / instrumentation
  • Fluorescent Antibody Technique / methods
  • Meiosis / genetics
  • Microtubules / metabolism
  • Mitosis / genetics
  • Nuclear Proteins / metabolism
  • Ovum / physiology*
  • Plasma / metabolism
  • Protein-Serine-Threonine Kinases / classification
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Protein-Serine-Threonine Kinases / physiology*
  • Protein-Tyrosine Kinases / classification
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / isolation & purification
  • Protein-Tyrosine Kinases / physiology*
  • RNA, Small Interfering / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Time Factors


  • Caenorhabditis elegans Proteins
  • Carrier Proteins
  • Chromatin
  • Nuclear Proteins
  • OMA-1 protein, C elegans
  • RNA, Small Interfering
  • pie-1 protein, C elegans
  • Dyrk kinase
  • MBK-2 protein, C elegans
  • PAR-1 protein, C elegans
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases
  • Adenosine Triphosphatases
  • MEI-1 protein, C elegans
  • MEI-2 protein, C elegans