RESEARCH ARTICLE The Fun30 Chromatin Remodeler Fft3 Controls Nuclear Organization and Chromatin Structure of Insulators and Subtelomeres in Fission Yeast

In eukaryotic cells, local chromatin structure and chromatin organization in the nucleus both influence transcriptional regulation. At the local level, the Fun30 chromatin remodeler Fft3 is essential for maintaining proper chromatin structure at centromeres and subtelomeres in fis-sion yeast. Using genome-wide mapping and live cell imaging, we show that this role is linked to controlling nuclear organization of its targets. In fft3Δ cells, subtelomeres lose their association with the LEM domain protein Man1 at the nuclear periphery and move to the in-terior of the nucleus. Furthermore, genes in these domains are upregulated and active chro-matin marks increase. Fft3 is also enriched at retrotransposon-derived long terminal repeat (LTR) elements and at tRNA genes. In cells lacking Fft3, these sites lose their peripheral po-sitioning and show reduced nucleosome occupancy. We propose that Fft3 has a global role in mediating association between specific chromatin domains and the nuclear envelope. Author Summary In the genome of eukaryotic cells, domains of active and repressive chromatin alternate along the chromosome arms. Insulator elements are necessary to shield these different en