# Cis- and Trans-Acting Requirements for HSV-1 Late Gene Transcription

> **NIH NIH F31** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2020 · $18,239

## Abstract

PROJECT SUMMARY
 Herpes Simplex Virus Type 1 (HSV-1) is a common pathogen of the oral and genital mucosa with a
seroprevalence last estimated at 54% in the United States. In cases of immune compromise, infection can
have serious consequences including pneumonia, encephalitis, and keratitis. The large DNA virus employs a
coordinated cascade of transcriptional events to efficiently generate progeny. The gene groups are temporally
classified as immediate early (𝛼), early (𝛽), and late (𝛾). DNA replication is required for efficient transcription of
𝛾 genes—this transcriptional strategy occurs in other virus families including adenoviridae, papillomaviridae,
polyomaviridae, and baculoviridae. A better understanding of this essential transcriptional switch may aid in
identification of novel drug targets and development of therapeutics.
 Recent work from our laboratory has demonstrated that initial rounds of DNA replication are sufficient
for robust transcription of true late (𝛾2) genes. Furthermore, viral DNA replication forks recruit numerous
cellular factors including Mediator complex, Integrator complex, SUPT5H, SUPT6H, and RNA Polymerase II.
We intend to expand on this observation and determine if DNA replication activates 𝛾2 transcription at the level
of initiation or elongation. We hypothesize that the act of DNA replication alters genome conformation
facilitating recruitment of transcription factors, and that DNA synthesis components, in addition to the key viral
regulatory proteins ICP4, and ICP27, recruit transcription factors that are important for late transcription.
 To assess the role of DNA replication in 𝛾2 transcription we propose three aims. First, we will determine
the extent of genome replication sufficient for activation of 𝛾2 transcription and whether DNA replication
promotes initiation or elongation. We will inhibit viral DNA replication at various time points and use RNA-Seq
to assess the minimal amount of DNA replication sufficient for robust 𝛾2 transcription. We will then determine
the transcription defect for 𝛾2 genes in the absence of DNA synthesis by performing ChIP-Seq. Transcription
initiation will be assessed by analyzing the presence of initiation factors on 𝛾2 promoters. Transcription
elongation will be assessed by analyzing the occupancy of RNA polymerase II on 𝛾2 transcription start sites
and message bodies. Next, we will investigate whether DNA synthesis components play an additional role in
𝛾2 transcription beyond the act of DNA replication. We will use temperature sensitive mutants in temperature
shift experiments to determine if the component is required after initial rounds of DNA replication. Finally, we
will elucidate the repertoire of cellular and viral factors required for robust 𝛾2 transcription. Using aniPOND on
prelabeled genomes we can determine what factors are bound to viral genomes immediately before and after
DNA replication. Using HSV-1 mutants uniquely defective for 𝛾2 transcription we can perform a...

## Key facts

- **NIH application ID:** 9947871
- **Project number:** 5F31AI136251-03
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** Sarah Dremel
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $18,239
- **Award type:** 5
- **Project period:** 2018-06-19 → 2020-06-20

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9947871

## Citation

> US National Institutes of Health, RePORTER application 9947871, Cis- and Trans-Acting Requirements for HSV-1 Late Gene Transcription (5F31AI136251-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9947871. Licensed CC0.

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