Unreplicated DNA in mitosis precludes condensin binding and chromosome condensation in S. cerevisiae.
Condensin is the core activity responsible for chromosome condensation in mitosis. In the yeast S. cerevisiae, condensin binding is enriched at the regions where DNA replication terminates. Therefore, we investigated whether DNA replication completion determines the condensin-binding proficiency of chromatin. In order to fulfill putative mitotic requirements for condensin activity we analyzed chromosome condensation and condensin binding to unreplicated chromosomes in mitosis. For this purpose we used pGAL:CDC6 cdc15-ts cells that are known to enter mitosis without DNA replication if CDC6 transcription is repressed prior to S-phase. Both the condensation of nucleolar chromatin and proper condensin targeting to rDNA sites failed when unreplicated chromosomes were driven in mitosis. We propose that the DNA replication results in structural and/or biochemical changes to replicated chromatin, which are required for two-phase condensin binding and proper chromosome condensation.
Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, Bethesda, MD 20892, USA.
Stanimir
S
Dulev
Luis
L
Aragon
Alexander
A
Strunnikov
D000251:Adenosine Triphosphatases / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000235:genetics / Q000502:physiology*; D004261:DNA Replication; D004271:DNA, Fungal / Q000235:genetics* / Q000378:metabolism; D004275:DNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D008938:Mitosis / Q000502:physiology*; D046912:Multiprotein Complexes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
D004271:DNA, Fungal; D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; D029701:Saccharomyces cerevisiae Proteins; C108312:condensin complexes; D000251:Adenosine Triphosphatases