MEI-1/MEI-2 katanin-like microtubule severing activity is required for Caenorhabditis elegans meiosis.
The Caenorhabditis elegans meiotic spindle is morphologically distinct from the first mitotic spindle, yet both structures form in the same cytoplasm approximately 20 minutes apart. The mei-1 and mei-2 genes of C. elegans are required for the establishment of the oocyte meiotic spindle but are not required for mitotic spindle function. mei-1 encodes an AAA ATPase family member with similarity to the p60 catalytic subunit of the heterodimeric sea urchin microtubule-severing protein, katanin. We report that mei-2 encodes a 280-amino acid protein containing a region similar to the p80-targeting subunit of katanin. MEI-1 and MEI-2 antibodies decorate the polar ends of meiotic spindle microtubules and meiotic chromatin. We find that the subcellular location of MEI-2 depends on wild-type mei-1 activity and vice versa. These experiments, combined with MEI-1 and MEI-2's similarity to p60 and p80 katanin, suggest that the C. elegans proteins function as a complex. In support of this idea, MEI-1 and MEI-2 physically associate in HeLa cells. Furthermore, co-expression of MEI-1 and MEI-2 in HeLa cells results in the disassembly of microtubules. These data lead us to conclude that MEI-1/MEI-2 microtubule-severing activity is required for meiotic spindle organization in C. elegans.
Srayko
M
M
Department of Biochemistry, Development Research Group, University of Calgary, Calgary, Alberta, T2N 4N1 Canada.
Buster
D W
DW
Bazirgan
O A
OA
McNally
F J
FJ
Mains
P E
PE
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian / Q000502:physiology; D005260:Female; D006367:HeLa Cells; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D000074201:Katanin; D008540:Meiosis / Q000235:genetics*; D008969:Molecular Sequence Data; D009865:Oocytes / Q000166:cytology* / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D011994:Recombinant Proteins; D000251:Adenosine Triphosphatases; C086678:MEI-1 protein, C elegans; C409220:MEI-2 protein, C elegans; D000074201:Katanin