RT Journal Article
SR Electronic
T1 Cohesin dependent compaction of mitotic chromosomes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 094946
DO 10.1101/094946
A1 Stephanie A. Schalbetter
A1 Anton Goloborodko
A1 Geoffrey Fudenberg
A1 Jon M. Belton
A1 Catrina Miles
A1 Miao Yu
A1 Job Dekker
A1 Leonid Mirny
A1 Jon Baxter
YR 2016
UL http://biorxiv.org/content/early/2016/12/17/094946.abstract
AB Structural Maintenance of Chromosomes (SMC) protein complexes are key determinants of chromosome conformation. Using Hi-C and polymer modelling, we study how cohesin and condensin, two deeply-conserved SMC complexes, organize chromosomes in budding yeast. The canonical role of cohesins is to co-align sister chromatids whilst condensins generally compact mitotic chromosomes. We find strikingly different roles in budding yeast mitosis. First, cohesin is responsible for compacting mitotic chromosomes arms, independent of and in addition to its role in sister-chromatid cohesion. Cohesin dependent mitotic chromosome compaction can be fully accounted for through cis-looping of chromatin by loop extrusion. Second, condensin is dispensable for compaction along chromosomal arms and instead plays a specialized role, structuring rDNA and peri-centromeric regions. Our results argue that the conserved mechanism of SMC complexes is to form chromatin loops and that SMC-dependent looping is readily deployed in a range of contexts to functionally organize chromosomes.Cohesin compacts mitotic chromosomes independently of sister chromatid cohesion.Formation of cis-loops by loop extrusion fully accounts for cohesin-mediated compaction.Condensin is not required for mitotic chromosome compaction of yeast chromosome armsCondensin has a focused pre-anaphase role at centromeres and rDNA in yeastHighlights