# Molecular mechanisms of DNA damage signaling and repair

> **NIH NIH R01** · WASHINGTON UNIVERSITY · 2022 · $333,899

## Abstract

PROJECT ABSTRACT
 The overall goal of this proposal is to decipher a novel Ca2+-dependent signaling pathway that protects
the genome in human cells in the presence of DNA replication stress. Replication stress, which can cause DNA
damage and chromosomal instability, is frequently induced by both environmental agents and endogenous
factors (e.g., reactive oxygen species, aldehyde, and oncogene activation). In order to maintain genome stability
cells must protect the replication fork structure upon replication stress to avoid fork collapse and DNA damage.
Defects in fork protection can result in cell death or transformation, which can give rise to cancer, premature
ageing and other diseases. The fork protection mechanisms can also be exploited to sensitize cancer cells to
replication stress-inducing agents during cancer treatment. Despite its critical importance, exactly how
replication forks are protected after replication stress remain an outstanding question. In our effort to address
this fundamental question, we recently discovered a novel Ca2+-dependent signaling pathway that protects
stressed replication fork structure. In addition, we have established multiple components in the pathway,
including CaMKK2, AMPK and Exo1, that act downstream of intracellular Ca2+, which is elevated after replication
stress. Disruption of the pathway causes excessive fork degradation, chromosomal aberrations and
compromised cell viability. Building on this exciting finding and our extensive preliminary results, in this proposal
we describe a series of studies to further delineate this novel fork protection pathway, focusing on the key players
and molecular mechanisms that mediate Ca2+ induction and pathway activation. In Aim 1, we will define a key
ion channel responsible for Ca2+ induction in the replication stress response. Our preliminary results suggest
that TRPV2 is a major ion channel for Ca2+ induction upon replication stress. We will characterize the molecular
functions of TRPV2 in this fork protection pathway and its regulation by a novel interacting protein in the
replication stress response. Aim 2 seeks to define the direct signal for Ca2+ induction after replication stress.
Our preliminary results suggest that cytosolic self-DNA generated after replication stress has a previously
unrecognized role in triggering Ca2+ induction for fork protection. We plan to explore the sources of cytosolic
self-DNA in cells after replication stress. In addition, we will determine whether other cytosolic DNA-inducing
genetic conditions also activate the Ca2+-dependent signaling cascade. In Aim 3, we will elucidate the molecular
mechanisms of TRPV2 activation for Ca2+ induction after replication stress, focusing on the role of cytosolic DNA
sensing and signal transduction. These studies will further establish a novel fork protection signaling pathway
and provide critical insights into the interplay between replication stress, cytosolic DNA sensing and Ca2+
signaling. T...

## Key facts

- **NIH application ID:** 10444707
- **Project number:** 2R01GM098535-10
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Zhongsheng You
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $333,899
- **Award type:** 2
- **Project period:** 2012-04-05 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10444707

## Citation

> US National Institutes of Health, RePORTER application 10444707, Molecular mechanisms of DNA damage signaling and repair (2R01GM098535-10). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10444707. Licensed CC0.

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