Direct interaction with the BRD4 carboxyl-terminal motif (CTM) and TopBP1 is required for human papillomavirus 16 E2 association with mitotic chromatin and plasmid segregation function

J Virol. 2023 Oct 31;97(10):e0078223. doi: 10.1128/jvi.00782-23. Epub 2023 Sep 15.

Abstract

Human papillomavirus 16 (HPV16) is a causative agent in around 3%-4% of all human cancers, and currently, there are no anti-viral therapeutics available for combating this disease burden. In order to identify new therapeutic targets, we must increase our understanding of the HPV16 life cycle. Previously, we demonstrated that an interaction between E2 and the cellular protein TopBP1 mediates the plasmid segregation function of E2, allowing distribution of viral genomes into daughter nuclei following cell division. Here, we demonstrate that E2 interaction with an additional host protein, BRD4, is also essential for E2 segregation function, and that BRD4 exists in a complex with TopBP1. Overall, these results enhance our understanding of a critical part of the HPV16 life cycle and presents several therapeutic targets for disruption of the viral life cycle.

Keywords: BRD4; E2; TopBP1; cervical cancer; head and neck cancer; human papillomavirus; mitotic interaction; plasmid segregation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Bromodomain Containing Proteins
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Chromatin* / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Human papillomavirus 16 / genetics
  • Human papillomavirus 16 / metabolism
  • Humans
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Oncogene Proteins, Viral* / genetics
  • Oncogene Proteins, Viral* / metabolism
  • Plasmids / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • BRD4 protein, human
  • Bromodomain Containing Proteins
  • Cell Cycle Proteins
  • Chromatin
  • DNA-Binding Proteins
  • Nuclear Proteins
  • Oncogene Proteins, Viral
  • Transcription Factors
  • E2 protein, Human papillomavirus type 16
  • TOPBP1 protein, human