# Chromatin-mediated mechanisms of genome integrity

> **NIH NIH R35** · DUKE UNIVERSITY · 2024 · $434,700

## Abstract

Abstract
Our research is focused on understanding how the local chromatin environment regulates DNA-templated pro-
cesses like transcription and DNA replication. We have developed and pioneered the use of factor-agnostic
approaches to map chromatin occupancy at nucleotide resolution across the S. cerevisiae genome. We have
used this approach to provide mechanistic insights into how the local chromatin environment mediates origin se-
lection and activation. In order to identify the chromatin changes that occur with helicase activation at the onset of
S-phase, we depleted cells of functional DNA polymerase alpha (Pol a) to prevent the priming of DNA synthesis.
Activation of the helicase in the absence of priming not only resulted in the local disruption of chromatin, but
also resulted in the uncoupling of the helicase from DNA synthesis and the unwinding of approximately 1 kb of
DNA surrounding each activated origin. We will identify the mechanism(s) which regulate helicase progression
in the absence of DNA replication with a focus on sequence, topological and rad53-mediated signaling. A conse-
quence of the helicase traveling away from the origin in each direction and stalling is that upon restoration of Pol a
priming, the helicase is oriented to travel away from the origin and thus will leave an unreplicated gap. These un-
replicated gaps are a unique molecular intermediate that are analogous to intermediates predicted to occur from
termination defects and provide a unique opportunity to identify factors involved in their resolution. We will also
examine the role of speciﬁc histone chaperones in the spatiotemporal deposition of nucleosomes behind the DNA
replication fork and how speciﬁc genomic features like active transcription may impact the maturation process in
a locus speciﬁc manner. Finally, we have generated chromatin occupancy proﬁles for 201 yeast deletion mutants
representing non-essential transcription factors and chromatin remodelers. Combining the chromatin occupancy
proﬁles with gene expression data, we will be able to generate gene regulatory networks that are more accurately
able to deﬁne direct and indirect targets.

## Key facts

- **NIH application ID:** 10837012
- **Project number:** 5R35GM127062-07
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** David M MacAlpine
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $434,700
- **Award type:** 5
- **Project period:** 2018-04-01 → 2028-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10837012

## Citation

> US National Institutes of Health, RePORTER application 10837012, Chromatin-mediated mechanisms of genome integrity (5R35GM127062-07). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10837012. Licensed CC0.

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