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Series GSE44206 Query DataSets for GSE44206
Status Public on Mar 14, 2013
Title DNA topoisomerase III localizes to centromeres and affects centromeric CENP-A levels in fission yeast
Organism Schizosaccharomyces pombe
Experiment type Expression profiling by genome tiling array
Genome binding/occupancy profiling by genome tiling array
Summary Centromeres are specialized chromatin regions marked by the presence of nucleosomes containing the centromere-specific histone H3 variant CENP-A, which is essential for chromosome segregation. Assembly and disassembly of nucleosomes is intimately linked to DNA topology and DNA topoisomerases have previously been implicated in the dynamics of canonical H3 nucleosomes. Here we show that Schizosaccharomyces pombe Top3 and its partner Rqh1 are involved in controlling the levels of CENP-ACnp1 at centromeres. Both top3 and rqh1 mutants display defects in chromosome segregation. Using chromatin immunoprecipitation and tiling microarrays we show that Top3 unlike Top1 and Top2 is highly enriched at centromeric central domains, demonstrating that Top3 is the major topoisomerase in this region. Moreover, centromeric Top3 occupancy positively correlates with CENP-ACnp1 occupancy. Intriguingly, both top3 and rqh1 mutants display increased relative enrichment of CENP-ACnp1 at centromeric central domains. Thus, Top3 and Rqh1 normally limit the levels of CENP-ACnp1 in this region. This new role is independent of the established function of Top3 and Rqh1 in homologous recombination downstream of Rad51. Therefore, we hypothesize that the Top3-Rqh1 complex has an important role in controlling centromere DNA topology which in turn affects the dynamics of CENP-ACnp1 nucleosomes.
Overall design For transcription: Total RNA from top3-105 mutant and WT control cells after 8 hours at 36C in biological duplicates.
For Top3-myc chromatin immunoprecipitation: DNA immunoprecipitated with mouse anti-Myc using chromatin extracts from cells expressing Top3-Myc from the endogenous locus at 30C in biological duplicates normalized to input DNA from wild type cells at 30C in biological duplicates.
For CENP-A/Cnp1 chromatin immunoprecipitation: DNA immunoprecipitated with anti-Cnp1 serum using chromatin extracts from top3-105 mutant and wild type control cells after 8 hours at 36C in in biological duplicates normalized to input DNA from each strain.
Contributor(s) Norman-Axelsson U, Durand-Dubief M, Prasad P, Ekwall K
Citation(s) 23516381
Submission date Feb 08, 2013
Last update date May 27, 2014
Contact name Karl Ekwall
Phone +46 8 6089133
Organization name Karolinska Inst
Street address Alfred Nobels Alle 7
City Stockholm
ZIP/Postal code S-141 89
Country Sweden
Platforms (1)
GPL7715 [Sp20b_M] Affymetrix S. pombe Tiling 1.0FR Array
Samples (5)
GSM1080762 RNA_WT_36C
GSM1080763 RNA_top3-105_36C
GSM1080764 ChIP_Top3-Myc_30C
BioProject PRJNA189154

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE44206_RAW.tar 263.5 Mb (http)(custom) TAR (of BAR, CEL, TXT)
Processed data provided as supplementary file

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