The aurora kinase AIR-2 functions in the release of chromosome cohesion in Caenorhabditis elegans meiosis.
Accurate chromosome segregation during cell division requires not only the establishment, but also the precise, regulated release of chromosome cohesion. Chromosome dynamics during meiosis are more complicated, because homologues separate at anaphase I whereas sister chromatids remain attached until anaphase II. How the selective release of chromosome cohesion is regulated during meiosis remains unclear. We show that the aurora-B kinase AIR-2 regulates the selective release of chromosome cohesion during Caenorhabditis elegans meiosis. AIR-2 localizes to subchromosomal regions corresponding to last points of contact between homologues in metaphase I and between sister chromatids in metaphase II. Depletion of AIR-2 by RNA interference (RNAi) prevents chromosome separation at both anaphases, with concomitant prevention of meiotic cohesin REC-8 release from meiotic chromosomes. We show that AIR-2 phosphorylates REC-8 at a major amino acid in vitro. Interestingly, depletion of two PP1 phosphatases, CeGLC-7alpha and CeGLC-7beta, abolishes the restricted localization pattern of AIR-2. In Ceglc-7alpha/beta(RNAi) embryos, AIR-2 is detected on the entire bivalent. Concurrently, chromosomal REC-8 is dramatically reduced and sister chromatids are separated precociously at anaphase I in Ceglc-7alpha/beta(RNAi) embryos. We propose that AIR-2 promotes the release of chromosome cohesion via phosphorylation of REC-8 at specific chromosomal locations and that CeGLC-7alpha/beta, directly or indirectly, antagonize AIR-2 activity.
Rogers
Eric
E
Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Bishop
John D
JD
Waddle
James A
JA
Schumacher
Jill M
JM
Lin
Rueyling
R
D000705:Anaphase; D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000201:enzymology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D023902:Chromosome Pairing; D020090:Chromosome Segregation; D002875:Chromosomes / Q000235:genetics / Q000378:metabolism*; D015801:Helminth Proteins / Q000378:metabolism; D008540:Meiosis; D008677:Metaphase; D008856:Microscopy, Fluorescence; D009154:Mutation; D009865:Oocytes; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012330:RNA, Double-Stranded / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D013997:Time Factors
D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D012330:RNA, Double-Stranded; C118999:bir-1 protein, C elegans; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; C491506:air-2 protein, C elegans; D010749:Phosphoprotein Phosphatases