Award details

Elucidating how the PrimPol DNA damage tolerance pathway is regulated and where it operates in human cells

Reference	BB/X000834/1
Principal Investigator / Supervisor	Professor Aidan Doherty
Co-Investigators / Co-Supervisors
Institution	University of Sussex
Department	Sch of Life Sciences
Funding type	Research
Value (£)	868,582
Status	Current
Type	Research Grant
Start date	01/01/2023
End date	31/12/2025
Duration	36 months

Abstract

Complete and accurate chromosomal replication is essential to maintain genetic stability and prevent the accumulation of disease-promoting mutations. Replication forks are susceptible to stalling or collapse as they encounter obstacles on DNA, including damage. Failure to reactivate stalled or arrested forks is a major source of replicative stress, directly linked to chromosomal instability, particularly in cancer cells. Fortunately, cells possess a variety of DNA damage tolerance (DDT) pathways whose role it is restart stalled replication forks in order to complete DNA duplication and maintain genome stability. Our goal is to understand how stalled genome replication is restarted by a specific DDT pathway that reprimes DNA synthesis downstream of lesions in human cells. We previously demonstrated that a DNA replicase called Primase-Polymerase (PrimPol) is responsible for repriming replication restart in vertebrate cells and. We recently identified that the PrimPol pathway is tightly regulated by the PLK1 kinase during the cell cycle and in response to damage. Deregulation of this mechanism, leading to uncontrolled repriming, induces significant genome instability and cell death. We aim to establish how this mechanism is regulated and deployed during fork stalling, what happens when it is deregulated, its functional intersection with other DDT pathways and, finally, identify where PrimPol preferentially operates on the human genome. Together, this research programme will provide significant mechanistic insights into the operation and regulation of this important DDT pathway. This proposal will push the boundaries of our current knowledge about this and related damage tolerance mechanisms, providing critical insights into how this important biological pathway functions to overcome replication stalling barriers to ensure the maintenance of genome stability

Summary

Cells produce enzymes called DNA polymerases responsible for "photocopying" the genome, which encodes the cell's biological blueprint. Polymerases are frequently stalled by genetic obstacles caused by DNA damage or structures on the template being replicated, leading to defective DNA copying or the formation of mutations that can lead to diseases, such as cancer. We have identified a damage tolerance protein called PrimPol, whose role it is to restart stalled replication by repriming DNA synthesis downstream of obstacles encountered on the genome. We are proposing to identify how and when PrimPol, and its partners, localise to sites of stalled replication, how this process is regulated and deregulated, where on the genome this repriming mechanism performs its roles and, finally, how PrimPol co-operates with other restart mechanisms in the cell to ensure that replication proceeds in an efficient way. Understanding how the replication machinery tolerates such genetic obstacles in human cells will advance the development of more efficiency inhibitors that block genome duplication in cancer cells.

Committee	Research Committee D (Molecules, cells and industrial biotechnology)
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

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