# Complex Mechanisms of Mutation and Mutation Avoidance in Living Cells

> **NIH NIH R35** · UNIVERSITY OF NORTH CAROLINA GREENSBORO · 2022 · $345,348

## Abstract

All organisms strive to maintain genomic fidelity in the face of agents that can damage their genetic material
and the possibility that errors that can occur whenever their DNA is replicated. The ultimate goals of my
research are to understand (i) how the mechanism and high-level coordination of DNA repair processes are
governed by molecular, genetic, and epigenetic factors in vivo; (ii) how these factors affect diverse repair
processes in different contexts to affect human health; and (iii) how clinically-important modulators of DNA
repair activities and of repair-related toxicity can be leveraged as novel therapeutics. I have focused primarily
on DNA mismatch repair (MMR) pathways, the pathways responsible for correcting errors that occur during
DNA replication. As a primary mechanism of mutation avoidance in nearly all organisms, MMR plays a central
role in many diverse processes that affect human health, from the emergence of drug resistance in infectious
pathogens and cancers to the onset and treatment of somatic genetic diseases. We developed a novel assay
to deconstruct the biomolecular mechanisms of MMR that uses chemically-modified oligonucleotide probes to
insert targeted DNA `mismatches' directly into the genome of living cells. This assay, which we call by the
acronym `SPORE,' can thus be used to directly interrogate replication-coupled repair processes like MMR
quantitatively in a strand-, orientation-, and lesion-specific manner in vivo—something nearly impossible to
achieve otherwise. Using the SPORE assay as a uniquely powerful baseline of approach, and in combination
with next-generation biotechnologies like CRISPR and innovative experimental design, my laboratory will seek
to answer the following broad-spectrum and transdisciplinary questions: · How do different molecular, genetic,
and epigenetic factors affect the higher-order architecture (components and interactions), coordination,
dynamics of different MMR mechanisms? How do these factors affect repair-associated toxicities? Are different
molecular lesions recognized by MMR repaired according to different mechanisms and toxicities? · Do the
unique repair mechanisms in pathogenic organisms represent a novel source of antimicrobial targets? · How
do viral factors and environmental mutagens modulate MMR and MMR-related toxicities and by what
mechanism? What is their role in hypermutation and emergence of drug resistance? · What governs the
tradeoff between mutagenic and anti-mutagenic roles of MMR in microsatellite instability (MSI) diseases? ·
What occurs during collisions between DNA repair or other processes on DNA, and what is the nature and
origin of related catastrophic mutational events? These questions are each complex in their own right and have
remained difficult to answer using traditional techniques, but our unique hybrid approach provides a direct way
to address each of them. The likely outcomes during the R35 award will be numerous breakthroughs in our
understandi...

## Key facts

- **NIH application ID:** 10455496
- **Project number:** 5R35GM133483-04
- **Recipient organization:** UNIVERSITY OF NORTH CAROLINA GREENSBORO
- **Principal Investigator:** Eric Alan Josephs
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $345,348
- **Award type:** 5
- **Project period:** 2019-09-17 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10455496

## Citation

> US National Institutes of Health, RePORTER application 10455496, Complex Mechanisms of Mutation and Mutation Avoidance in Living Cells (5R35GM133483-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10455496. Licensed CC0.

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