The gammaherpesviral TATA-box-binding protein directly interacts with the CTD of host RNA Pol II to direct late gene transcription

PLoS Pathog. 2020 Sep 4;16(9):e1008843. doi: 10.1371/journal.ppat.1008843. eCollection 2020 Sep.

Abstract

β- and γ-herpesviruses include the oncogenic human viruses Kaposi's sarcoma-associated virus (KSHV) and Epstein-Barr virus (EBV), and human cytomegalovirus (HCMV), which is a significant cause of congenital disease. Near the end of their replication cycle, these viruses transcribe their late genes in a manner distinct from host transcription. Late gene transcription requires six virally encoded proteins, one of which is a functional mimic of host TATA-box-binding protein (TBP) that is also involved in recruitment of RNA polymerase II (Pol II) via unknown mechanisms. Here, we applied biochemical protein interaction studies together with electron microscopy-based imaging of a reconstituted human preinitiation complex to define the mechanism underlying Pol II recruitment. These data revealed that the herpesviral TBP, encoded by ORF24 in KSHV, makes a direct protein-protein contact with the C-terminal domain of host RNA polymerase II (Pol II), which is a unique feature that functionally distinguishes viral from cellular TBP. The interaction is mediated by the N-terminal domain (NTD) of ORF24 through a conserved motif that is shared in its β- and γ-herpesvirus homologs. Thus, these herpesviruses employ an unprecedented strategy in eukaryotic transcription, wherein promoter recognition and polymerase recruitment are facilitated by a single transcriptional activator with functionally distinct domains.

Publication types

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

MeSH terms

  • Amino Acid Motifs
  • HEK293 Cells
  • Herpesvirus 8, Human / genetics
  • Herpesvirus 8, Human / metabolism*
  • Humans
  • Protein Binding
  • Protein Domains
  • RNA Polymerase II / genetics
  • RNA Polymerase II / metabolism*
  • TATA-Box Binding Protein / genetics
  • TATA-Box Binding Protein / metabolism*
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*

Substances

  • TATA-Box Binding Protein
  • Viral Proteins
  • RNA Polymerase II