Journal article
Visualizing the coordination of apurinic/apyrimidinic endonuclease (APE1) and DNA Polymerase β during Base Excision Repair
The Journal of biological chemistry, Vol.299(5), 104636
05/2023
DOI: 10.1016/j.jbc.2023.104636
PMCID: PMC10148159
PMID: 36963489
Abstract
Base Excision Repair (BER) is carried out by a series of proteins that function in a step-by-step process to identify, remove, and replace DNA damage. During BER, the DNA transitions through various intermediate states as it is processed by each DNA repair enzyme. Left unrepaired, these BER intermediates can transition into double-stranded DNA breaks and promote genome instability. Previous studies have proposed a short-lived complex consisting of the BER intermediate, the incoming enzyme, and the outgoing enzyme at each step of the BER pathway to protect the BER intermediate. The transfer of BER intermediates between enzymes, known as BER coordination or substrate channeling, remains poorly understood. Here, we utilize single-molecule total internal reflection fluorescence (TIRF) microscopy to investigate the mechanism of BER coordination between apurinic/apyrimidinic endonuclease 1 (APE1) and DNA polymerase β (Pol β). When preformed complexes of APE1 and the incised abasic site product (APE1 product and Pol β substrate) were subsequently bound by Pol β, the Pol β enzyme dissociated shortly after binding in most of the observations. In the events where Pol β binding was followed by APE1 dissociation during substrate channeling, Pol β remained bound for a longer period of time to allow disassociation of APE1. Our results indicate that transfer of the BER intermediate from APE1 to Pol β during BER is dependent on the dissociation kinetics of APE1 and the duration of the ternary complex on the incised abasic site.
Details
- Title: Subtitle
- Visualizing the coordination of apurinic/apyrimidinic endonuclease (APE1) and DNA Polymerase β during Base Excision Repair
- Creators
- Max S Fairlamb - University of Kansas Medical CenterMaria Spies - University of IowaTodd M Washington - University of IowaBret D Freudenthal
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.299(5), 104636
- DOI
- 10.1016/j.jbc.2023.104636
- PMID
- 36963489
- PMCID
- PMC10148159
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Language
- English
- Electronic publication date
- 03/22/2023
- Date published
- 05/2023
- Academic Unit
- Radiation Oncology; Biochemistry and Molecular Biology
- Record Identifier
- 9984380460702771
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