title: Fission yeast Cid12 has dual functions in chromosome segregation and checkpoint control.
abstract: Fission yeast Cid12 is a member of the Cid1 family of specialized poly(A) polymerases. Like cells lacking cid1, cid12Delta mutants were shown to have checkpoint defects when DNA replication was inhibited. Here, we show that Cid12 is also required for faithful chromosome segregation and that mutation of amino acid residues predicted to be essential for poly(A) polymerase activity resulted in loss of Cid12 function in vivo. Cells lacking Cid12 had an increased chromosome segregation failure rate due to precocious loss of sister chromatid cohesion at the centromere but not along the chromosome arms. In keeping with a recently described function for Cid12 in RNA interference (RNAi)-mediated heterochromatin assembly, this was accompanied by an accumulation of polyadenylated transcripts corresponding to naturally silenced repeat elements within heterochromatic domains, with consequent defects in centromeric gene silencing. These cells also suffered increased meiotic defects, and their viability was dependent on the spindle checkpoint protein Bub1. To account for the effects of Cid12 on various aspects of DNA metabolism, including chromosome segregation and the checkpoint control, we suggest that Cid12 has dual functions in RNAi silencing and regulating mRNA stability.
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
authors.forename: Thein Z
authors.initials: TZ
authors.lastname: Win
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Stevenson
authors.forename: Shao-Win
authors.initials: SW
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation / Q000502:physiology*; D004257:DNA Polymerase II / Q000235:genetics / Q000378:metabolism; D004258:DNA Polymerase III; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D005800:Genes, Fungal; D018816:Genes, cdc; D008540:Meiosis / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D011062:Polynucleotide Adenylyltransferase / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D020871:RNA Stability; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D012331:RNA, Fungal; D012333:RNA, Messenger; D029702:Schizosaccharomyces pombe Proteins; C513024:cdc27 protein, S pombe; D011062:Polynucleotide Adenylyltransferase; D004257:DNA Polymerase II; D004258:DNA Polymerase III