Condensin targets and reduces unwound DNA structures associated with transcription in mitotic chromosome condensation

Nat Commun. 2015 Jul 23;6:7815. doi: 10.1038/ncomms8815.


Chromosome condensation is a hallmark of mitosis in eukaryotes and is a prerequisite for faithful segregation of genetic material to daughter cells. Here we show that condensin, which is essential for assembling condensed chromosomes, helps to preclude the detrimental effects of gene transcription on mitotic condensation. ChIP-seq profiling reveals that the fission yeast condensin preferentially binds to active protein-coding genes in a transcription-dependent manner during mitosis. Pharmacological and genetic attenuation of transcription largely rescue bulk chromosome segregation defects observed in condensin mutants. We also demonstrate that condensin is associated with and reduces unwound DNA segments generated by transcription, providing a direct link between an in vitro activity of condensin and its in vivo function. The human condensin isoform condensin I also binds to unwound DNA regions at the transcription start sites of active genes, implying that our findings uncover a fundamental feature of condensin complexes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Chromosomes / metabolism*
  • DNA-Binding Proteins / metabolism*
  • Genome
  • HeLa Cells
  • Humans
  • Mitosis
  • Multiprotein Complexes / metabolism*
  • RNA Polymerase II / metabolism
  • Schizosaccharomyces / metabolism*
  • Transcription, Genetic*


  • DNA-Binding Proteins
  • Multiprotein Complexes
  • condensin complexes
  • RNA Polymerase II
  • Adenosine Triphosphatases