# Replication resolved in the living cell: Replisome dynamics, stability and structure.

> **NIH NIH R01** · VANDERBILT UNIVERSITY · 2020 · $345,660

## Abstract

Summary. Timely and faithful replication is essential to cellular proliferation in all living systems. Replication
malfunction leads to mutations, breaks in the DNA, and cell death, all of which play central roles in human
diseases including cancer and the development of antibiotic-resistant bacterial pathogens. Very recently, our
laboratories have discovered that conflicts between the replication and transcription machineries increase
mutation rates as well as cause significant instability of the replisome complex during the replication process.
Our long-term goal is to dissect the mechanisms, cellular responses and biological and medical
consequences of transcription-replication conflicts. The objective of this grant is to characterize the structure
and stability of the replisome in general, and in particular, in response to transcription-induced conflicts with
single-molecule sensitivity. Motivated by our recent observations, the central hypothesis of this proposal is
that replisome structure is a critical regulator of replication and a mechanism of conflict avoidance.
Our rationale is that we will gain fundamental insight into both the replication process as well as replication
conflicts by studying the replisome structure in living cells one conflict at a time with single-molecule sensitivity.
Our specific aims combine structural and functional analyses: Aim 1 describes a program to characterize the
dynamic organization of the replisome at high-resolution. Aim 2 describes a functional analysis of the
mechanisms for exchange, restart and recovery after replisome collapse. Aim 3 describes the test of the
hypothesis that cellular organization is key mechanism for reducing replication conflicts. Our preliminary work
has already changed the fundamental understanding of the replication process by demonstrating that it is
discontinuous. The proposed work is significant since it will continue this program by probing fundamental,
but untested assumptions about the structure of the replisome and the cellular mechanisms of conflict
resolution and avoidance. The proposed research is innovative because we apply an interdisciplinary
approach to study the replisome with single-molecule sensitivity in living cells. No other experiments have yet
probed the replisome structure with this resolution in vivo and therefore the work has great potential to reveal
both novel and fundamental insights into replisome structure and function.

## Key facts

- **NIH application ID:** 9933010
- **Project number:** 5R01GM128191-04
- **Recipient organization:** VANDERBILT UNIVERSITY
- **Principal Investigator:** Houra Merrikh
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $345,660
- **Award type:** 5
- **Project period:** 2018-09-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9933010

## Citation

> US National Institutes of Health, RePORTER application 9933010, Replication resolved in the living cell: Replisome dynamics, stability and structure. (5R01GM128191-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9933010. Licensed CC0.

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