The role of ChlR1 in DNA replication, DNA damage repair and cohesion establishment

DNA helicases;DNA-binding proteins;DNA replication--Regulation;DNA repair

Wasson, Christopher ; Parish, Joanna Louise ; Parish, Joanna Louise

University:University of St Andrews

Department:Medicine (School of)

关键词: DNA helicases;    DNA-binding proteins;    DNA replication--Regulation;    DNA repair;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/3134/ChristopherWassonPhDThesis.pdf?sequence=3&isAllowed=y

来源: DR-NTU

【 摘 要 】

Sister chromatid cohesion is essential for the equal distribution of genetic material inmitosis. The cohesin complex plays a central role in the establishment of sister chromatidcohesion. The cohesin complex is a ring shaped structure that encircles sister chromatidsprior to the onset of anaphase ensuring equal distribution of genetic material. TheDEAD/H DNA helicase ChlR1 is important in the establishment of sister chromatidcohesion. ChlR1 interacts with the cohesin complex and is required for the loading ofcohesin onto DNA. Cohesin is loaded onto the DNA during DNA replication.Here I identified a novel interacting partner of ChlR1. The multifunctional DNA bindingprotein FHL2 was shown to interact with ChlR1, and FHL2 was shown to have a role insister chromatid cohesion since depletion of FHL2 resulted in abnormal metaphase spreadsand reduced centromeric cohesion. These sister chromatid cohesion defects also result in aG₂/M delay.Here I show an additional function of ChlR1 in the repair of DNA damage. ChlR1 wasrequired for the repair of DNA double strand breaks and ChlR1 was recruited to DNAdouble strand breaks. Furthermore the function of ChlR1 in DNA double strand breakrepair is S phase specific. This suggests that ChlR1 is important in the homologyrecombination repair pathway. I also show that ChlR1 is important in DNA replication. Depletion of ChlR1 results ininefficient DNA replication. In addition depletion of ChlR1 results in defects in DNAreplication after hydroxyurea treatment.The results in this thesis shed light on novel functions of the DNA helicase ChlR1 in DNAreplication and DNA damage repair and the multifunctional DNA binding protein FHL2 incohesion establishment.