Chromatin immunoprecipitation (ChIP)

Schizosaccharomyces pombe cell cultures were fixed with 3% paraformaldehyde (PFA) (Sigma-Aldrich, St Louis, MO) for 30 min, then quenched with 0.2 M glycine. For non-histone targets, cells were fixed with 10 mM dimethyl adipimidate (DMA) (Thermo Scientific) for 45 min at room temperature after PFA fixation. Cells were then washed with PBS thrice. ChIP was conducted as previously described (33,39). Relative fold enrichment was calculated by the ΔΔCt method, whereby NDR or act1 was used as internal control and further titrated from the whole cell extract (WCE) or histone H3 immunoprecipitant as backgrounds.