The mbk-2 kinase is required for inactivation of MEI-1/katanin in the one-cell Caenorhabditis elegans embryo.
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.
Quintin
Sophie
S
Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany.
Mains
Paul E
PE
Zinke
Andrea
A
Hyman
Anthony A
AA
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D003594:Cytoplasmic Granules / Q000378:metabolism; D005838:Genotype; D009154:Mutation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
D029742:Caenorhabditis elegans Proteins; C478059:MBK-2 protein, C elegans; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D000251:Adenosine Triphosphatases; C086678:MEI-1 protein, C elegans