The CREB Regulated Transcription Coactivator 2 Suppresses HIV-1 Transcription by Preventing RNA Pol II from Binding to HIV-1 LTR

Virol Sin. 2021 Aug;36(4):796-809. doi: 10.1007/s12250-021-00363-1. Epub 2021 Mar 15.

Abstract

The CREB-regulated transcriptional co-activators (CRTCs), including CRTC1, CRTC2 and CRTC3, enhance transcription of CREB-targeted genes. In addition to regulating host gene expression in response to cAMP, CRTCs also increase the infection of several viruses. While human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) promoter harbors a cAMP response element and activation of the cAMP pathway promotes HIV-1 transcription, it remains unknown whether CRTCs have any effect on HIV-1 transcription and HIV-1 infection. Here, we reported that CRTC2 expression was induced by HIV-1 infection, but CRTC2 suppressed HIV-1 infection and diminished viral RNA expression. Mechanistic studies revealed that CRTC2 inhibited transcription from HIV-1 LTR and diminished RNA Pol II occupancy at the LTR independent of its association with CREB. Importantly, CRTC2 inhibits the activation of latent HIV-1. Together, these data suggest that in response to HIV-1 infection, cells increase the expression of CRTC2 which inhibits HIV-1 gene expression and may play a role in driving HIV-1 into latency.

Keywords: CREB regulated transcription coactivator 2 (CRTC2); Human immunodeficiency virus (HIV); Infection; Latency; Long terminal repeat (LTR); RNA polymerase II (RNA Pol II); Viral transcription; Virology.

MeSH terms

  • HIV Infections*
  • HIV Long Terminal Repeat / genetics
  • HIV-1* / genetics
  • HIV-1* / metabolism
  • Humans
  • RNA Polymerase II / genetics
  • RNA Polymerase II / metabolism
  • Transcription Factors* / genetics
  • Virus Latency

Substances

  • CRTC1 protein, human
  • CRTC2 protein, human
  • CRTC3 protein, human
  • Transcription Factors
  • RNA Polymerase II