Presentation Information
[SS17-03]Modeling mitotic chromosomes organization
*Yuji Sakai1 (1. Yokohama City University (Japan))
Keywords:
chromosome,modeling,simulation
For accurate mitotic cell division, replicated chromatin must be assembled into chromosomes and faithfully segregated into daughter cells. While protein factors like condensin play key roles in this process, it remain largely unknown how condensins act on nucleosomes to organize chromosomes.
To approach these questions, we modeled condensin function and chromatin, then simulated the dynamics of chromosome formation and the nucleosome behavior during mitosis. We show that two molecular activities of condensins, the chromatin loop formation and the inter-condensin attraction, are essential for efficient mitotic chromosome formation and segregation. Furthermore, we show that condensins acts as molecular crossinkers to create chromatin loops, locally constraining nucleosome movements to organize chromosomes. Nucleosome-nucleosome interactions via histone tails additionally constrain and compact whole chromosomes. Our findings elucidate the physical nature of the chromosome assembly process during mitosis.
To approach these questions, we modeled condensin function and chromatin, then simulated the dynamics of chromosome formation and the nucleosome behavior during mitosis. We show that two molecular activities of condensins, the chromatin loop formation and the inter-condensin attraction, are essential for efficient mitotic chromosome formation and segregation. Furthermore, we show that condensins acts as molecular crossinkers to create chromatin loops, locally constraining nucleosome movements to organize chromosomes. Nucleosome-nucleosome interactions via histone tails additionally constrain and compact whole chromosomes. Our findings elucidate the physical nature of the chromosome assembly process during mitosis.