Preprint
Single-molecule analysis of PARP1-G-quadruplex interaction
bioRxiv
Cold Spring Harbor Laboratory, 1.1
01/08/2025
DOI: 10.1101/2025.01.06.631587
PMCID: PMC11741300
PMID: 39829912
Abstract
The human genome contains numerous repetitive nucleotide sequences that display a propensity to fold into non-canonical DNA structures including G-quadruplexes (G4s). G4s have both positive and negative impacts on various aspects of nucleic acid metabolism including DNA replication, DNA repair and RNA transcription. Poly (ADP-ribose) polymerase (PARP1), an important anticancer drug target, has been recently shown to bind a subset of G4s, and to undergo auto-PARylation. The mechanism of this interaction, however, is poorly understood. Utilizing Mass Photometry (MP) and single-molecule total internal reflection fluorescence microscopy (smTIRFM), we demonstrate that PARP1 dynamically interacts with G4s with a 1:1 stoichiometry. Interaction of a single PARP1 molecule with nicked DNA or DNA containing G4 and a primer-template junction is sufficient to activate robust auto-PARylation resulting in the addition of poly (ADP-ribose) chains with molecular weight of several hundred kDa. Pharmacological PARP inhibitors EB-47, Olaparib and Veliparib differently affect PARP1 retention on G4-containing DNA compared to nicked DNA.
Details
- Title: Subtitle
- Single-molecule analysis of PARP1-G-quadruplex interaction
- Creators
- Paras Gaur - University of IowaFletcher E. Bain - University of IowaRiaz Meah - University of IowaMaria Spies - University of Iowa
- Resource Type
- Preprint
- Publication Details
- bioRxiv
- Edition
- 1.1
- DOI
- 10.1101/2025.01.06.631587
- PMID
- 39829912
- PMCID
- PMC11741300
- NLM abbreviation
- bioRxiv
- ISSN
- 2692-8205
- eISSN
- 2692-8205
- Publisher
- Cold Spring Harbor Laboratory
- Number of pages
- 23
- Language
- English
- Date posted
- 01/08/2025
- Academic Unit
- Radiation Oncology; Biochemistry and Molecular Biology
- Record Identifier
- 9984775019302771
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