Thesis
Biochemical characterisation of PARP14 activity and specificity
- Abstract:
-
PARP14 is a mono-ADP-ribosyl transferase implicated in transcriptional regulation, DNA repair, carcinogenesis, and immunity, and has recently been identified as an antiviral effector against coronaviruses. Despite its biological significance, the cellular prevalence, targets, acceptor-residue specificity, and regulation of its ADP-ribosylation activity remain poorly defined. In addition to its catalytic domain, PARP14 harbours three tandem macrodomains, the functions of which have not been extensively studied. Therefore, this thesis aimed to characterise the biochemical and cellular properties of PARP14, define its roles in cellular signalling, and elucidate its regulation by cellular and viral factors.
In this work, I demonstrated that PARP14 is a dual-function enzyme, exhibiting both ADP-ribosyl transferase and ADP-ribosyl hydrolase activities. I showed that PARP14 catalyses mono-ADP-ribosylation of numerous cellular proteins, predominantly at aspartate and glutamate residues. This modification is reversed by its hydrolytic macrodomain 1, whereas the ADP-ribose–binding macrodomains 2 and 3 promote its catalytic function. I further found that automodification provides an additional layer of self-regulation, controlling both catalytic activity and protein stability. Moreover, I identified PARP14 as the primary writer of interferon-induced ADP-ribosylation, while PARP9 and the E3 ubiquitin ligase DTX3L act as key regulators that preserve PARP14 protein levels and fine-tune its catalytic output. Finally, I showed that the SARS-CoV-2 macrodomain Mac1, which is closely related to PARP14 macrodomain 1, reverses PARP14-mediated ADP-ribosylation, providing a plausible mechanism by which Mac1 counteracts the antiviral activity of PARP14.
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Authors
Contributors
+ Ahel, I
- Institution:
- University of Oxford
- Division:
- MSD
- Department:
- Pathology Dunn School
- Role:
- Supervisor
+ Sanyal, S
- Institution:
- University of Oxford
- Division:
- MSD
- Department:
- Pathology Dunn School
- Role:
- Supervisor
- ORCID:
- 0000-0002-6230-5366
+ University of Oxford
More from this funder
- Funder identifier:
- https://ror.org/052gg0110
- Funding agency for:
- Dukic, N
- Programme:
- Oxford–E P Abraham Research Fund Graduate Scholarship
- DOI:
- Type of award:
- DPhil
- Level of award:
- Doctoral
- Awarding institution:
- University of Oxford
- Language:
-
English
- Keywords:
- Subjects:
- Deposit date:
-
2026-10-22
- ARK identifier:
Terms of use
- Copyright holder:
- Nina Dukic
- Copyright date:
- 2025
- Notes:
- PARP14 and PARP9/DTX3L regulate interferon-induced ADP-ribosylation is derived from this thesis.
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