Biology subjects

DeLuca, N. A.

Publications and source records attributed to DeLuca, N. A..

3 recordsLinked to original sources

bioRxiv2021

Manipulation of RNA Polymerase III by Herpes Simplex Virus-1

RNA Polymerase III (Pol III) transcribes noncoding RNA, including transfer RNA (tRNA), and acts as a pathogen sensor during the innate immune response. To promote enhanced proliferation, the Pol III machinery is commonly targeted during cancer and viral infection. Herein we employ DM-RNA-Seq, 4SU-Seq, ChIP-Seq, and ATAC-Seq to characterize how Herpes Simplex Virus-1 (HSV-1) perturbs the Pol III landscape. We find that HSV-1 stimulates tRNA expression 10-fold, with mature tRNAs exhibiting a 2-fold increase within 12 hours of infection. Perturbation of host tRNA synthesis requires nuclear viral entry, but not synthesis of specific viral transcripts, nascent viral genomes, or viral progeny. Host tRNA with a specific codon bias were not targeted--rather increased transcription was observed from euchromatic, actively transcribed loci. tRNA upregulation is linked to unique crosstalk between the Pol II and III transcriptional machinery. While viral infection is known to mediate host transcriptional shut off and lead to a depletion of Pol II on host mRNA promoters, we find that Pol II binding to tRNA loci increases. Finally, we report Pol III and associated factors bind the HSV genome, which suggests a previously unrecognized role in HSV-1 gene expression. These data provide insight into novel mechanisms by which HSV-1 alters the host nuclear environment, shifting key processes in favor of the pathogen.

molecular biology↗

bioRxiv2019

Herpes Simplex nucleoprotein creates a competitive environment facilitating robust viral transcription and host shut off

Herpes simplex virus-1 (HSV-1) replicates within the nucleus coopting the hosts RNA Polymerase II (Pol II) machinery for production of viral mRNAs culminating in host transcriptional shut off. The mechanism behind this rapid reprogramming of the host transcriptional environment is largely unknown. We identified ICP4 as responsible for preferential recruitment of the Pol II machinery to the viral genome. ICP4 is a viral nucleoprotein which binds double stranded DNA. We determined ICP4 discriminately binds the viral genome due to the absence of cellular nucleosomes and high density of cognate binding sites. We posit that ICP4s ability to recruit not just Pol II, but also more limiting essential components, such as TBP and Mediator create a competitive transcriptional environment. These distinguishing characteristics ultimately result in a rapid and efficient reprogramming of the hosts transcriptional machinery, which does not occur in the absence of ICP4.\n\nHighlightsO_LIHSV-1 ICP4 coats the viral genome promoting robust recruitment of Pol II transcription machinery.\nC_LIO_LIICP4 prefers the viral genome due to the absence of nucleosomes and density of binding motifs.\nC_LIO_LIAt high concentrations ICP4 promiscuously binds DNA including euchromatic host promoters.\nC_LIO_LIICP4 is required for host transcriptional shut off, independent of genome replication.\nC_LI

genomics↗

bioRxiv2018

Temporal Viral Genome-Protein Interactions Define Distinct Stages of Productive Herpesviral Infection

Herpesviruses utilize multiple mechanisms to redirect host proteins for use in viral processes and to avoid recognition and repression by the host. To investigate the dynamic interactions between HSV-1 DNA and viral and host proteins, we developed an approach to identify proteins that associate with the infecting viral genome from nuclear entry through packaging. We found that input viral DNA progressed within six hours through four temporal stages where the genomes: 1. interacted with intrinsic and DNA damage response proteins, 2. underwent a robust transcriptional switch mediated largely by ICP4, 3. engaged in replication, repair, and continued transcription, and then 4. transitioned to a more transcriptionally inert state engaging de novo synthesized viral structural components while maintaining interactions with replication proteins. Using a combination of genetic, imaging, and proteomic approaches, we provide a new and temporally compressed view of the HSV-1 life cycle based on genome-proteome dynamics.

microbiology↗