Defense Date

4-4-2025

Graduation Date

Summer 8-2025

Availability

Immediate Access

Submission Type

dissertation

Degree Name

PhD

Department

Biological Sciences

School

School of Science and Engineering

Committee Chair

Jill Dembowski

Committee Member

Sarah Hainer

Committee Member

Michael Jensen-Seamen

Committee Member

Sarah Woodley

Keywords

HSV-1, Topoisomerase 1, Integrator Complex, Virus-Host Interactions, Transcription, DNA Replication

Abstract

Herpes simplex virus type 1 (HSV-1) is a ubiquitous human pathogen that infects the majority of the human population. To facilitate infection, this virus relies on a combination of host and viral factors. Previous studies have revealed a number of host proteins that associate with the HSV-1 genome throughout infection but their putative role(s) in this process remain undefined. This study aims to examine two such proteins to determine their contributions to HSV-1 gene expression and DNA replication. The first of these factors is Ints3, a subunit of the Integrator complex. This protein complex functions in transcription regulation, and Ints3 can also act outside of the complex to facilitate the repair of damaged DNA. We disrupted Ints3 function by generating Ints3 short hairpin RNA (shRNA) knockdown cells. We observed minimal reduction in viral yield at a low multiplicity of infection (MOI) and no reduction in viral DNA replication or gene expression. These findings indicate that Ints3 disruption does not substantially hinder HSV-1 infection but positions other Integrator complex subunits as topics of interest for future investigation. Next, we examined topoisomerase 1 (TOP1), a host protein that functions to relieve topological stress on DNA. We disrupted TOP1 activity using a commercially available inhibitor, as well as by knockdown. We found that inhibition of TOP1 results in defects in viral yield, gene expression, and DNA replication. Finally, we characterized TOP1 protein-protein interactions during infection and found that TOP1 coprecipitates with HSV-1 ribonucleotide reductase. Together, these data position TOP1 as a potential new HSV-1 antiviral target. These studies provide insight into the role that host proteins play during HSV-1 infection and highlight the importance of further exploring virus-host interactions.

Language

English

Additional Citations

Heath JR, Fromuth DP, Dembowski JA. 2024. Integrator Complex Subunit 3 Knockdown Has Minimal Effect on Lytic Herpes Simplex Virus Type-1 Infection in Fibroblast Cells. microPublication Biology.

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