# Regulation of stalled fork repair in mammalian cells

> **NIH NIH R01** · BETH ISRAEL DEACONESS MEDICAL CENTER · 2022 · $350,000

## Abstract

PROJECT SUMMARY
Error-free DNA repair initiated at the sites of replication fork stalling is critical to the prevention of genomic
instability in cycling cells. Defects in stalled fork repair have been directly implicated in cancer and other human
diseases. Fanconi Anemia (FA) is a rare, autosomal recessive (or X-linked) disease caused by inactivation of
any one of several FA genes. The clinical manifestations of FA include childhood anemia and progressive
bone marrow failure, together with short stature and congenital defects affecting a wide variety of organs. The
risk of cancer, including solid tumors, is elevated, with particularly high incidence of acute myelogenous
leukemia. The gene encoding a nuclease-coordinating scaffolding protein, SLX4/FANCP, is found mutated in
some individuals with Fanconi anemia and has been implicated in stalled fork repair through interactions with
the nucleases MUS81, XPF and SLX1. We adapted the Escherichia coli Tus/Ter replication fork arrest
complex for use in mammalian cells and have used it to provoke site-specific replication fork stalling and
homologous recombination (HR) at defined loci of a mammalian chromosome. We find that SLX4 plays a
crucial role in mediating error-free HR induced by Tus/Ter. This function is restricted to stalled fork repair and
is not a feature of HR induced by a conventional chromosomal double strand break. In work proposed here, we
will use novel tools developed by the Scully lab, to analyze how SLX4 regulates homologous recombination at
stalled replication forks. We will use physical and genomic assays to measure specific DNA structures that
form at the Tus/Ter-stalled fork and will determine whether SLX4 regulates the formation or metabolism of
these DNA structures. This project will identify the mechanisms by which SLX4 coordinates stalled fork
processing to preserve genome stability in the face of replication stress. Success in this work will lead to the
identification of new targets for therapy in cancer and other human diseases.

## Key facts

- **NIH application ID:** 10434669
- **Project number:** 5R01GM134425-04
- **Recipient organization:** BETH ISRAEL DEACONESS MEDICAL CENTER
- **Principal Investigator:** Ralph Scully
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $350,000
- **Award type:** 5
- **Project period:** 2019-09-03 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10434669

## Citation

> US National Institutes of Health, RePORTER application 10434669, Regulation of stalled fork repair in mammalian cells (5R01GM134425-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10434669. Licensed CC0.

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