DNA topological stress during DNA replication in Saccharomyces cerevisiae

Minchell, Nicola E (2019) DNA topological stress during DNA replication in Saccharomyces cerevisiae. Doctoral thesis (PhD), University of Sussex.

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Abstract

DNA topological stress impedes normal DNA replication. If topological stress is allowed to build up in front of the replication fork, the fork rotates to overcome the stress, leading to formation of DNA pre-catenanes. The formation of DNA pre-catenanes is therefore a marker of DNA topological stress. In this study, I have examined how transcription linked DNA topological stress impacts on fork rotation and on endogenous DNA damage. Transcription, similar to replication, affects the topology of the DNA; and collision between the two machineries is likely to lead to high levels of DNA topological stress. I found that the frequency of fork rotation during DNA replication, increases with the number of genes present on a plasmid. Interestingly, I also found that this increase in pre-catenation is dependent on the cohesin complex. Cohesin and transcription are known to be linked, as transcription leads to the translocation of cohesin along budding yeast DNA away from its loading sites. Cohesin plays a major role in establishing chromosomal structure, influencing gene expression and genetic inheritance. In this work, I have analysed the relationship between cohesin and the generation of topological stress and found that topological stress associated with cohesin can lead to DNA replication stress and DNA damage.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Life Sciences > Sussex Centre for Genome Damage and Stability
Subjects: Q Science > QH Natural history > QH0301 Biology > QH0426 Genetics > QH0447 Genes. Alleles. Genome
Depositing User: Library Cataloguing
Date Deposited: 10 Jan 2019 15:52
Last Modified: 10 Jan 2019 15:52
URI: http://srodev.sussex.ac.uk/id/eprint/81222

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