Identification and characterisation of the ubiquitin ligases that regulate CIZ1 proteostasis and evaluation of their role in cell cycle regulation
Supervisors:
Dr Nikki Copeland, Faculty of Health and Medicine, (Lancaster University)
Prof Helen Walden, School of Molecular Biosciences (University of Glasgow)
Dr Panagiotis Kotsantis, Faculty of Health and Medicine (Lancaster University)
Summary:
Precise regulation of cell division is required for accurate duplication and segregation of the genome. Recently, CIZ1 has been shown to regulate G1 length and CDK thresholds that are required to initiate DNA replication. Deletion of CIZ1 reduces G1 length, increases cyclin expression and increases DNA replication stress, suggesting that regulation of CIZ1 expression levels are important for genome maintenance. We have identified 3 putative ubiquitin ligases that may control CIZ1 protein levels. This project will evaluate their role in regulation of CIZ1 proteostasis and determine their role in cell cycle control.
This project will use live cell imaging using FuCCI cell cycle indicators and cell-free DNA replication systems to monitor cell cycle length and determine the effects of modulated CIZ1 on DNA replication initiation. In addition, the key regulators of the UPS will be determined using in vitro ubiquitylation assays, and biophysical characterisation of the E3:CIZ1 interactions in collaboration with Prof. Helen Walden. Finally, to determine the role of the UPS in DNA replication stress, DNA fibre analysis with Dr Panagiotis Kotsantis. This highly skilled supervisory team will support and develop the successful candidate in biochemical, biophysical and cell biology approaches.