RNA pol II transcript abundance controls condensin accumulation at mitotically up‐regulated and heat‐shock‐inducible genes in fission yeast

Abstract

Condensin plays fundamental roles in chromosome dynamics. In this study, we determined the binding sites of condensin on fission yeast (Schizosaccharomyces pombe) chromosomes at the level of nucleotide sequences using chromatin immunoprecipitation (ChIP) and ChIP sequencing (ChIP-seq). We found that condensin binds to RNA polymerase I-, II- and III-transcribed genes during both mitosis and interphase, and we focused on pol II constitutive and inducible genes. Accumulation sites for condensin are distinct from those of cohesin and DNA topoisomerase II. Using cell cycle stage and heat-shock-inducible genes, we show that pol II-mediated transcripts cause condensin accumulation. First, condensin's enrichment on mitotically activated genes was abolished by deleting the sep1+ gene that encodes an M-phase-specific forkhead transcription factor. Second, by raising the temperature, condensin accumulation was rapidly induced at heat-shock protein genes in interphase and even during mid-mitosis. In interphase, condensin accumulates preferentially during the postreplicative phase. Pol II-mediated transcription was neither repressed nor activated by condensin, as levels of transcripts per se did not change when mutant condensin failed to associate with chromosomal DNA. However, massive chromosome missegregation occurred, suggesting that abundant pol II transcription may require active condensin before proper chromosome segregation.

Condensin promotes the juxtaposition of DNA flanking its loading site in Bacillus subtilis

“…7D). In eukaryotes, sites of condensin enrichment have been identified in a few model organisms by ChIP (D'Ambrosio et al 2008;Kim et al 2013;Kranz et al 2013;Nakazawa et al 2015) and appear to be scattered throughout the chromosomes. If these represent loading sites that function similarly to ParB/parS, then alignment of flanking DNA could provide a mechanism to promote compaction and resolution of chromosomes into discrete bodies during the early stages of mitosis.…”

Nucleosome eviction in mitosis assists condensin loading and chromosome condensation

“…Fission yeast condensin shows a similar localization pattern as condensin I, with the bulk of the complexes binding chromosomes from prophase to telophase (Sutani et al , ). However, a fraction seems to persist on chromosomes during interphase (Aono et al , ; Nakazawa et al , ).…”

“…From yeasts to mammals, condensins are enriched at centromeres, telomeres and, along chromosome arms, nearby genes that are highly transcribed by either of the three RNA polymerases (D'Ambrosio et al , ; Schmidt et al , ; Dowen et al , ; Kim et al , ; Kranz et al , ; Nakazawa et al , ; Sutani et al , ). Several factors have been implicated in the recruitment of condensins along chromosomes.…”

Condensin I subunit Cap-G is essential for proper gene expression during the maturation of post-mitotic neurons

“…Condensins have been implicated in promoting gene expression by interacting with transcription factors and localising at promoter and enhancer regions. For example, condensin is associated with RNA pol II sites in yeast and mammalian cells [18–20]. Moreover, condensin binding is documented at RNA Pol III (TFIIIC) transcribed regions such as tRNAs in multiple organisms [20–23].…”