Send to

Choose Destination
JCI Insight. 2018 Oct 18;3(20). pii: 123196. doi: 10.1172/jci.insight.123196.

Histone H2A monoubiquitylation and p38-MAPKs regulate immediate-early gene-like reactivation of latent retrovirus HTLV-1.

Author information

Division of Infectious Diseases, Department of Medicine, Imperial College, London, United Kingdom.
Laboratory of Chromatin Biology and Transcription, Department of Biochemistry, and.
Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.


It is not understood how the human T cell leukemia virus human T-lymphotropic virus-1 (HTLV-1), a retrovirus, regulates the in vivo balance between transcriptional latency and reactivation. The HTLV-1 proviral plus-strand is typically transcriptionally silent in freshly isolated peripheral blood mononuclear cells from infected individuals, but after short-term ex vivo culture, there is a strong, spontaneous burst of proviral plus-strand transcription. Here, we demonstrate that proviral reactivation in freshly isolated, naturally infected primary CD4+ T cells has 3 key attributes characteristic of an immediate-early gene. Plus-strand transcription is p38-MAPK dependent and is not inhibited by protein synthesis inhibitors. Ubiquitylation of histone H2A (H2AK119ub1), a signature of polycomb repressive complex-1 (PRC1), is enriched at the latent HTLV-1 provirus, and immediate-early proviral reactivation is associated with rapid deubiquitylation of H2A at the provirus. Inhibition of deubiquitylation by the deubiquitinase (DUB) inhibitor PR619 reverses H2AK119ub1 depletion and strongly inhibits plus-strand transcription. We conclude that the HTLV-1 proviral plus-strand is regulated with characteristics of a cellular immediate-early gene, with a PRC1-dependent bivalent promoter sensitive to p38-MAPK signaling. Finally, we compare the epigenetic signatures of p38-MAPK inhibition, DUB inhibition, and glucose deprivation at the HTLV-1 provirus, and we show that these pathways act as independent checkpoints regulating proviral reactivation from latency.


Cell stress; Epigenetics; Transcription; Virology

Supplemental Content

Full text links

Icon for American Society for Clinical Investigation Icon for PubMed Central
Loading ...
Support Center