The mbk-2 kinase is required for inactivation of MEI-1/katanin in the one-cell Caenorhabditis elegans embryo

EMBO Rep. 2003 Dec;4(12):1175-81. doi: 10.1038/sj.embor.7400029. Epub 2003 Nov 21.


The Caenorhabditis elegans early embryo is widely used to study the regulation of microtubule-related processes. In a screen for mutants affecting the first cell division, we isolated a temperature-sensitive mutation affecting pronuclear migration and spindle positioning, phenotypes typically linked to microtubule or centrosome defects. In the mutant, microtubules are shorter and chromosome segregation is impaired, while centrosome organization appears normal. The mutation corresponds to a strong loss of function in mbk-2, a conserved serine/threonine kinase. The microtubule-related defects are due to the postmeiotic persistence of MEI-1, a homologue of the microtubule-severing protein katanin. In addition, P-granule distribution is abnormal in mbk-2 mutants, consistent with genetic evidence that mbk-2 has other functions and with the requirement of mbk-2 activity at the one-cell stage. We propose that mbk-2 potentiates the degradation of MEI-1 and other proteins, possibly via direct phosphorylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism*
  • Animals
  • Caenorhabditis elegans / embryology
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Division
  • Cytoplasmic Granules / metabolism
  • Genotype
  • Mutation
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism
  • Protein-Tyrosine Kinases / chemistry
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Temperature
  • Time Factors


  • Caenorhabditis elegans Proteins
  • MBK-2 protein, C elegans
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases
  • Adenosine Triphosphatases
  • MEI-1 protein, C elegans