An integrative approach identifies direct targets of the late viral transcription complex and an expanded promoter recognition motif in Kaposi's sarcoma-associated herpesvirus

PLoS Pathog. 2019 May 16;15(5):e1007774. doi: 10.1371/journal.ppat.1007774. eCollection 2019 May.

Abstract

The structural proteins of DNA viruses are generally encoded by late genes, whose expression relies on recruitment of the host transcriptional machinery only after the onset of viral genome replication. β and γ-herpesviruses encode a unique six-member viral pre-initiation complex (vPIC) for this purpose, although how the vPIC directs specific activation of late genes remains largely unknown. The specificity underlying late transcription is particularly notable given that late gene promoters are unusually small, with a modified TATA-box being the only recognizable element. Here, we explored the basis for this specificity using an integrative approach to evaluate vPIC-dependent gene expression combined with promoter occupancy during Kaposi's sarcoma-associated herpesvirus (KSHV) infection. This approach distinguished the direct and indirect targets of the vPIC, ultimately revealing a novel promoter motif critical for KSHV vPIC binding. Additionally, we found that the KSHV vPIC component ORF24 is required for efficient viral DNA replication and identified a ORF24 binding element in the origin of replication that is necessary for late gene promoter activation. Together, these results identify an elusive element that contributes to vPIC specificity and suggest novel links between KSHV DNA replication and late transcription.

Publication types

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

MeSH terms

  • DNA, Viral / genetics
  • Gene Expression Regulation, Viral*
  • Genome, Viral
  • HEK293 Cells
  • Herpesvirus 8, Human / physiology*
  • Host-Pathogen Interactions
  • Humans
  • Promoter Regions, Genetic*
  • Protein Binding
  • RNA Polymerase II / metabolism
  • Sarcoma, Kaposi / genetics
  • Sarcoma, Kaposi / metabolism
  • Sarcoma, Kaposi / virology
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*
  • Transcription Initiation, Genetic*
  • Viral Proteins / genetics*
  • Viral Proteins / metabolism
  • Virus Latency
  • Virus Replication*

Substances

  • DNA, Viral
  • Trans-Activators
  • Viral Proteins
  • RNA Polymerase II