Faculty Opinions recommendation of A simple biophysical model emulates budding yeast chromosome condensation.

Mitotic chromosomes were one of the first cell biological structures to be described, yet their molecular architecture remains poorly understood. We have devised a simple biophysical model of a 300 kb-long nucleosome chain, the size of a budding yeast chromosome, constrained by interactions between binding sites of the chromosomal condensin complex, a key component of interphase and mitotic chromosomes. Comparisons of computational and experimental (4C) interaction maps, and other biophysical features, allow us to predict a mode of condensin action. Stochastic condensin-mediated pairwise interactions along the nucleosome chain generate native-like chromosome features and recapitulate chromosome compaction and individualization during mitotic condensation. Higher order interactions between condensin binding sites explain the data less well. Our results suggest that basic assumptions about chromatin behavior go a long way to explain chromosome architecture and are able to generate a molecular model of what the inside of a chromosome is likely to look like.

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Faculty Opinions recommendation of Mutation rates across budding yeast chromosome VI are correlated with replication timing.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13335957.14702055 ◽

2011 ◽

Author(s):

Nicolas Galtier ◽

Julien Dutheil

Keyword(s):

Budding Yeast ◽

Replication Timing ◽

Mutation Rates ◽

Yeast Chromosome

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THE SPATIAL REGULATION OF CONDENSIN ACTIVITY IN CHROMOSOME CONDENSATION

10.1101/849273 ◽

2019 ◽

Author(s):

Rebecca Lamothe ◽

Lorenzo Costantino ◽

Douglas E Koshland

Keyword(s):

Chromosome Segregation ◽

Ribosomal Dna ◽

Budding Yeast ◽

Chromosome Condensation ◽

Mitotic Chromosomes ◽

Spatial Regulation ◽

Polo Kinase ◽

Evolutionarily Conserved

AbstractCondensin mediates chromosome condensation, which is essential for proper chromosome segregation during mitosis. Prior to anaphase of budding yeast, the ribosomal DNA (RDN) condenses to a thin loop that is distinct from the rest of the chromosomes. We provide evidence that the establishment and maintenance of this RDN condensation require the regulation of condensin by Cdc5p (polo) kinase. We show that Cdc5p is recruited to the site of condensin binding in the RDN by cohesin, a complex related to condensin. Cdc5p and cohesin prevent condensin from misfolding the RDN into an irreversibly decondensed state. From these and other observations, we propose that the spatial regulation of Cdc5p by cohesin modulates condensin activity to ensure proper RDN folding into a thin loop. This mechanism may be evolutionarily conserved, promoting the thinly condensed constrictions that occur at centromeres and RDN of mitotic chromosomes in plants and animals.

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Global reorganization of budding yeast chromosome conformation in different physiological conditions

The Journal of Cell Biology ◽

10.1083/jcb.201507069 ◽

2016 ◽

Vol 212 (3) ◽

pp. 321-334 ◽

Cited By ~ 27

Author(s):

Elisa Dultz ◽

Harianto Tjong ◽

Elodie Weider ◽

Mareike Herzog ◽

Barry Young ◽

...

Keyword(s):

Nuclear Envelope ◽

Large Scale ◽

Budding Yeast ◽

Single Gene ◽

Critical Role ◽

Nuclear Periphery ◽

Systematic Analysis ◽

Chromosome Conformation ◽

A Genome ◽

Yeast Chromosome

The organization of the genome is nonrandom and important for correct function. Specifically, the nuclear envelope plays a critical role in gene regulation. It generally constitutes a repressive environment, but several genes, including the GAL locus in budding yeast, are recruited to the nuclear periphery on activation. Here, we combine imaging and computational modeling to ask how the association of a single gene locus with the nuclear envelope influences the surrounding chromosome architecture. Systematic analysis of an entire yeast chromosome establishes that peripheral recruitment of the GAL locus is part of a large-scale rearrangement that shifts many chromosomal regions closer to the nuclear envelope. This process is likely caused by the presence of several independent anchoring points. To identify novel factors required for peripheral anchoring, we performed a genome-wide screen and demonstrated that the histone acetyltransferase SAGA and the activity of histone deacetylases are needed for this extensive gene recruitment to the nuclear periphery.

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