# Characterizing the role of Elevated dNTP pools in sensitizing the replisome

> **NIH NIH R01** · STATE UNIVERSITY OF NEW YORK AT BUFFALO · 2024 · $478,399

## Abstract

PROJECT SUMMARY
The fidelity of DNA replication is critical in ensuring the stability of the genome from cell division to the next.
Accurate DNA synthesis by replicative DNA requires appropriate levels and ratios of deoxyribonucleotide
triphosphates (dNTPs), the building blocks of DNA, and is enhanced by the polymerase proofreading
exonuclease function. The mismatch repair (MMR) system functions as a spell-check for DNA replication,
detecting and directing repair of replication errors that evade proofreading. When dNTP pools are dysregulated,
it interferes with the normal functioning of the replisome. Elevated dNTP pools lead to an increased rate of
nucleotide misincorporation, increase the rate of DNA replication and alter the number of replication origins that
are activated. Altering the dNTP pools in different ways (elevated, skewed) leads to distinct mutation profiles.
These misincorporation events are substrates for MMR, but as the mutation rates increase, MMR can become
saturated. Thus, altered dNTPs can promote mutagenesis that can lead to cancer. At the same time, cancer
cells have elevated dNTP pools to maintain rapid proliferation. This can, in turn, lead to further mutagenesis and
promote the molecular evolution of the cancer, providing a selective advantage. In this proposal, we hypothesize
that elevated dNTP pools fundamentally change the activity of the replisome, both in terms of its function
inaccurately synthesizing DNA and its ability to respond to DNA lesions and blocks that it encounters during DNA
replication. In parallel, we are committed to the development of a diverse biomedical workforce, able to conduct
this type of research. We hypothesize that a supportive network of researchers will support the inclusion of
underrepresented groups in the biomedical sciences. In AIM 1, we will take advantage of the altered mutation
profiles in rnr1 backgrounds to define the relative contributions of MLH complexes to MMR, which remains
unknown. This will reveal important mechanistic details of the MMR pathway, including potential interactions
among the MLH complexes. We will also define the mechanisms underlying the synthetic lethality between
rnr1Y295A and mmr∆, potentially revealing a role for MMR in cell cycle checkpoint activation in the context of
altered dNTP pools. In AIM 2, we will determine the mechanisms underlying the different ways in which elevated
and/or skewed dNTP pools compromise the stability and normal progression of the replisome. We will
characterize differences in how DSBs at the fork are processed when dNTP pools are elevated. We will assess
Okazaki fragment processing in different rnr1 backgrounds. And we will use unbiased chemicogenomic screens
to reveal pathways that are important in supporting cell viability when rnr1 strains are exposed to different DNA
damaging agents that compromise replication fork progression. In AIM 3, we will establish a set of supportive
programs that will provide research opportunitie...

## Key facts

- **NIH application ID:** 10858899
- **Project number:** 1R01GM154101-01
- **Recipient organization:** STATE UNIVERSITY OF NEW YORK AT BUFFALO
- **Principal Investigator:** JENNIFER ANNE SURTEES
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $478,399
- **Award type:** 1
- **Project period:** 2024-09-16 → 2029-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10858899

## Citation

> US National Institutes of Health, RePORTER application 10858899, Characterizing the role of Elevated dNTP pools in sensitizing the replisome (1R01GM154101-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10858899. Licensed CC0.

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