Regulation of RNA:DNA hybrid metabolism for genome stability

Proper regulation of RNA:DNA hybrids such as misincorporated ribonucleotides and R-loops is important for genome stability and healthy development. Excessive RNA:DNA hybrids can cause DNA damage and block DNA replication, causing replication stress, genome instability and inflammation. This project will investigate the regulation of RNA:DNA hybrids in human cells, employing a wide range of molecular and chemical biology techniques including cell-based assays, mass spectrometry and structural modelling.

RNaseH2 is a heterotrimeric enzyme that removes genomic RNA:DNA hybrids. RNaseH2A has the active site while RNaseH2B and RNaseH2C are regulatory subunits. RNaseH2 is essential for genome stability in animals, fungi and plants and defects in RNaseH2 activity are associated with neurodevelopmental autoinflammatory disorders. We have shown that RNaseH2 protein levels are upregulated in response to cellular growth signalling and replication stress induced by pharmaceutic drugs. High RNaseH2 levels promote replication stress resistance. The regulation of the RNaseH2 proteins remains unexplored but might provide opportunities for therapeutic targeting.

We have generated human cell lines for inducible overexpression of each RNaseH2 subunit, and showed that we can stabilise the protein levels of the endogenous subunits and increase cellular RNaseH2 activity. Increased RnaseH2 activity prevents replication fork stalling and protects genome stability. This project will utilise our cell models to investigate RNaseH2 protein-protein interactions and protein regulation, and how these impinge on RNA:DNA hybrids and replication stress in cells. It will provide training in a range of state-of-the-art molecular and cellular techniques relevant for understanding healthy development and how cells protects themselves from genomic instability and inflammation.

This is a collaborative project between two dynamic research groups and will provide ample opportunities for networking and career development within a vibrant research centre and a wider doctoral training partnership. We encourage an inclusive, supportive lab culture and mentor team members for their career progression.

https://www.evapetermann.org/

https://www.birmingham.ac.uk/staff/profiles/cancer-genomic/petermann-eva

https://www.birmingham.ac.uk/staff/profiles/cancer-genomic/turnell-andrew

Funding notes:

This project is funded by the Midlands Integrative Biosciences Training Partnership. For more information and how to apply, please visit https://warwick.ac.uk/fac/cross_fac/mibtp/ where applications will open shortly.

References:

Petermann, E., Lan, L. & Zou, L. Sources, resolution and physiological relevance of R-loops and RNA-DNA hybrids. Nat Rev Mol Cell Biol 23, 521-540 (2022).

Nazeer, R., Qashqari, F.S.I., Albalawi, A.S., Piberger, A.L., Tilotta, M.T., Read, M.L., Hu, S.Y., Davis, S., McCabe, C.J., Petermann, E. & Turnell, A.S. Adenovirus E1B 55-Kilodalton Protein Targets SMARCAL1 for Degradation during Infection and Modulates Cellular DNA Replication. Journal of virology 93 (2019).

Kotsantis, P., Silva, L.M., Irmscher, S., Jones, R.M., Folkes, L., Gromak, N. & Petermann, E. Increased global transcription activity as a mechanism of replication stress in cancer. Nat Commun 7, 13087 (2016).