# Mechanism of Eukaryotic Environmental Mutagenesis

> **NIH NIH R35** · MASSACHUSETTS INSTITUTE OF TECHNOLOGY · 2021 · $507,216

## Abstract

Project Summary/Abstract
A fundamental molecular mechanism by which virtually all organisms respond to environmental damage to
their genetic material is by carrying out translesion synthesis (TLS) over DNA lesions. The eukaryotic
Rev1/3/7-dependent pathway of mutagenic TLS is critically important to human health, not only because it can
help cells to survive by tolerating environmental DNA damage, including the repair of DNA crosslinks, but also
because this molecular process is responsible for the vast majority of the mutagenesis that occurs as a result
of damage to DNA. Mutations from environmental exposure contribute to cancer, other human diseases, and
aging. Rev1 is member of the Y family of TLS DNA polymerases, while Rev3 and Rev7 respectively are the
catalytic and non-catalytic subunits of TLS DNA pol ζ. The overall goal of this research is to build on exciting
progress funded by NIEHS grant R01-ES015818 by taking advantage of new developments in human and
mammalian biology to gain detailed new insights into the mechanism, regulation, and physiological
consequences of this Rev1/3/7-dependent process at a level of resolution that has historically only been
attainable using organisms with sophisticated genetic systems such as Escherichia coli and Saccharomyces
cerevisiae. A particularly innovative component of this research is to develop a suite of novel inhibitors and
other strategies to interfere with Rev1/3/7-dependent TLS, DNA crosslink repair, and other Rev1/3/7-related
processes. These will not only be powerful probes to advance basic research into how organisms respond to
DNA from environmental chemicals, but also have the potential to improve chemotherapy and possibly other
aspects of human health. One major strategy is to identify small molecules that inhibit Rev1/3/7-dependent
mutagenic TLS by interfering with critical interactions required for operation of the pathway, such as the
interaction of the Rev1 100 amino acid C-terminal domain (CTD) with the Rev7 component of DNA pol ζ
through one interface and the RIR (Rev1-interacting region) of other TLS DNA polymerases through a second
interface. Exemplar compounds have already been identified that bind to each Rev1 Interface and have the
expected biological effects. These will be evaluated in syngeic mouse models of human lung cancer and
lymphoma as possible chemotherapy adjuvants that increase killing while also reducing the mutagenesis that
gives rise to resistance. Other innovative approaches to inhibiting Rev1/3/7-dependent mutagenic TLS include
using stapled RIR peptides, using the Anthrax Protective Antigen to deliver the Rev1 CTD into mammalian
cells by fusing it to the N-terminus of Lethal Factor, and testing whether Rev7-interacting sequences can serve
as dominant negative inhibitors by trapping Rev7 in nonproductive complexes. In a complementary approach,
a series of partial-loss-of-function mutants affecting proteins in the Rev1/3/7-dependent-pathway will yield
detailed f...

## Key facts

- **NIH application ID:** 10179392
- **Project number:** 5R35ES028303-05
- **Recipient organization:** MASSACHUSETTS INSTITUTE OF TECHNOLOGY
- **Principal Investigator:** GRAHAM C WALKER
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $507,216
- **Award type:** 5
- **Project period:** 2017-09-15 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10179392

## Citation

> US National Institutes of Health, RePORTER application 10179392, Mechanism of Eukaryotic Environmental Mutagenesis (5R35ES028303-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10179392. Licensed CC0.

---

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