# Integrative single molecule studies: DNA repair and technology development

> **NIH NIH R35** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2022 · $463,759

## Abstract

Project Summary
The overall objective of this proposal is to develop and apply single-molecule techniques to gain mechanistic
insights into the critical processes occurring during DNA repair. DNA repair processes, which are the guardian
of the genome, involve multiple sequential enzymatic steps that require the coordinated assembly and action of
many proteins on the DNA. The transient nature of these interactions presents significant challenges in
elucidating the molecular mechanisms of DNA repair using traditional biochemical methods. Single molecule
approaches are well suited to overcome these difficulties; however, they present their own challenges, requiring
innovative solutions. Research in my laboratory focuses on elucidating the molecular mechanisms of DNA
mismatch repair (MMR) and on the development of single-molecule tools that will give us access to previously
unattainable information and/or greatly facilitate throughput of implementation or analysis. MMR plays a
major role in mutation avoidance, including correcting DNA replication errors, modulating cellular responses
to DNA damaging agents, and preventing recombination between diverged sequences. Mutations that
inactivate MMR proteins cause Lynch syndrome, the most common hereditary cancer. In addition, they cause
resistance to the cytotoxic effects of several DNA damaging agents that are often used in the treatment of
cancer. As such, understanding the molecular mechanisms that underlie these different processes is essential
for developing effective treatments for the associated cancers. MutSα initiates repair by binding to a mismatch
and undergoing ATP-dependent conformational changes that promotes its interaction with one or more MutLα
proteins. Subsequently, PCNA activates MutLα to incise the daughter strand in an ATP-dependent manner.
Once MutLα nicks the DNA 5' to the mismatch, MutSα can activate the 5'-3' exonuclease EXO1 to processively
excise the DNA containing the error or promote POLδ/ε to initiate strand-displacement synthesis. Finally,
DNA polymerase δ or ε catalyzes resynthesis, and DNA ligase seals the nick. Single-molecule, structural, and
biochemical studies, including several from our laboratory, indicate that the conformational dynamics and
assembly states of the proteins and protein-DNA complexes are central to the regulation of MMR. We will
extend our ongoing studies to decipher the molecular mechanisms critical to MMR. We are taking an
integrative approach in which we utilize an array of single-molecule techniques to examine MMR in multiple
organisms in vitro and in vivo. We will focus on examining the temporal and spatial assembly of MMR
proteins on the DNA during MMR initiation. To further our (and others) ability probe these mechanisms, we
will continue to develop new single-molecule tools, focusing on: 1) development of a high-throughput platform
for preparation and imaging of AFM samples and 2) optimization of our newly invented electrostatic force
imaging ...

## Key facts

- **NIH application ID:** 10428623
- **Project number:** 5R35GM127151-05
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** DOROTHY A ERIE
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $463,759
- **Award type:** 5
- **Project period:** 2018-06-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10428623

## Citation

> US National Institutes of Health, RePORTER application 10428623, Integrative single molecule studies: DNA repair and technology development (5R35GM127151-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10428623. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*