Leo1 is essential for dynamic regulation of heterochromatin and gene expression during cellular quiescence [ChIP microarray]

Cellular quiescence is a reversible differentiation state when cells are changing the gene expression programme to reduce metabolic functions and adapt to a new cellular environment. The epigenetic changes that accompany these alterations are not so well understood. Here we investigate the role of Leo1, a subunit of the conserved Paf1 (RNA polymerase-associated factor 1) complex, in the quiescence process using fission yeast as a model organism. Fission yeast cells enter the G0 phase of the cell cycle when exposed to nitrogen starvation and the heterochromatin regions become very dynamic. The reduction of heterochromatin in early G0 correlates with the reduced activity of target of rapamycin, TORC2, signalling. Cells lacking the Leo1 show reduced survival in G0. In these cells heterochromatin regions including subtelomeres are stabilized and many genes, including membrane transport genes, fail to be expressed. Our results suggest that Leo1 is essential for dynamic regulation of heterochromatin and gene expression during cellular quiescence. Gemone-wide mapping of H3K9me2 in wt/leo1D/clr4D during quiescence; In total 48 samples; 20 Input files (duplicates) with the corresponding 20 ChIP samples