Transcription factors mediate condensin recruitment and global chromosomal organization in fission yeast

Abstract

It is becoming clear that Structural Maintenance of Chromosomes (SMC) complexes, such as condensin and cohesin, are involved in the three-dimensional genome organization, yet the exact roles of these complexes in the functional organization remain unclear. This study employs the ChIA-PET approach to comprehensively identify genome-wide associations mediated by condensin and cohesin in fission yeast. We find that although cohesin and condensin often bind to the same loci, they direct different association networks and generate small and larger chromatin domains, respectively. Cohesin mediates local associations between loci positioned within 100 kb; condensin can drive longer-range associations. Moreover, condensin, but not cohesin, connects cell cycle-regulated genes bound by mitotic transcription factors. This study describes the different functions of condensin and cohesin in genome organization and how specific transcription factors function in condensin loading, cell cycle-dependent genome organization, and mitotic chromosome organization to support faithful chromosome segregation.

Architectural alterations of the fission yeast genome during the cell cycle

“…It has been shown that the fission yeast genome is organized into ~50-kb domains, hereby referred to as small domains 21,27 . The in situ Hi-C approach detected the presence of these small domains consistently during the cell cycle (Fig.…”

“…It has previously been suggested that cohesin is required for the formation of ~50-kb domains 21,27 . We posited that these domains are identical to the stable small domains detected by the in situ Hi-C study (Fig.…”

Cohesins and condensins orchestrate the 4D dynamics of yeast chromosomes during the cell cycle

“…At the same time, condensins such as Smc2 are loaded onto SCs to facilitate their segregation (Renshaw et al , 2010; Stephens et al , 2011; Hirano, 2012). In fission yeast, the binding of SMCs modifies the level of chromosome compaction defined as the ratio between long (> 10 kb)‐ and short‐range (< 10 kb) contacts at specific loci (Mizuguchi et al , 2014; Kim et al , 2016). …”

Shelterin components mediate genome reorganization in response to replication stress

“…Indeed, computational analyses indicate spatial segregation of replication origins based on their timing of firing during S-phase (4), suggesting that besides local chromatin structure, the 3D organization of chromosomes is an important contributing factor in the spatiotemporal control of replication (5, 6). Despite important advances, understanding the connections between diverse chromosomal events and genome organization remains an important challenge.The complexities of genome organization have been studied in several model organisms, including the fission yeast Schizosaccharomyces pombe, for which the 3D organization has been explored at high resolution (7,8). This simple eukaryote contains the basic chromosomal elements of more complex systems, including partitioning of the genome into euchromatin and heterochromatin domains.…”

“…The complexities of genome organization have been studied in several model organisms, including the fission yeast Schizosaccharomyces pombe, for which the 3D organization has been explored at high resolution (7,8). This simple eukaryote contains the basic chromosomal elements of more complex systems, including partitioning of the genome into euchromatin and heterochromatin domains.…”