Project No. 2404
Dr Robert Baldock – University of Portsmouth
Prof Sarah Newbury- University of Sussex
Dr Garry Scarlett – University of Portsmouth
Maintaining the integrity of the mitochondrial genome (mtDNA) is essential for normal cellular function and tolerating cellular stress.
Maintaining the integrity of the mitochondrial genome (mtDNA) is essential for normal cellular function and tolerating cellular stress. An evolving picture of mtDNA repair mechanisms is revealing how cells repair and tolerate mtDNA damage. Importantly, repair of DNA in the nucleus has revealed that RNA is a central player in this process. Furthermore, the balance between mtDNA repair and targeted degradation is likely to be an important mechanistic step in the pathogenesis mitochondrial-associated diseases. Despite this, the mechanism of degradation and factors involved remain largely enigmatic.
This project aims to uncover the role of nucleases in mitochondrial DNA degradation and repair. Using a targeted informatics screen to identify candidate nucleases, we will combine mammalian cell culture with the versatility of Drosophila genetics to selectively downregulate candidate nucleases and study their impact on mtDNA integrity, stability, and overall mitochondrial function.
This project will involve studying the localisation and interactions of specific nucleases with DNA/RNA using cellular fractionation, immunoblotting and nucleic acid-protein proximity ligation assays. In nuclease-depleted cells, mtDNA copy number variation will be determined by qPCR in response to different mitotoxic stresses. Finally, mitochondrial function will be evaluated for oxygen consumption, reactive oxygen species (ROS) production, and mitochondrial membrane potential will be characterised using high-throughput analysers. This project will lead to a new understanding of the mitochondrial-associated pathogenesis by investigating the quality control mechanism(s) that degrade damaged mtDNA