Human cytomegalovirus IE1 protein disrupts interleukin-6 signaling by sequestering STAT3 in the nucleus. J Virol 2013 Oct;87(19):10763-76
Date
08/02/2013Pubmed ID
23903834Pubmed Central ID
PMC3807375DOI
10.1128/JVI.01197-13Scopus ID
2-s2.0-84886016486 (requires institutional sign-in at Scopus site) 51 CitationsAbstract
In the canonical STAT3 signaling pathway, binding of agonist to receptors activates Janus kinases that phosphorylate cytoplasmic STAT3 at tyrosine 705 (Y705). Phosphorylated STAT3 dimers accumulate in the nucleus and drive the expression of genes involved in inflammation, angiogenesis, invasion, and proliferation. Here, we demonstrate that human cytomegalovirus (HCMV) infection rapidly promotes nuclear localization of STAT3 in the absence of robust phosphorylation at Y705. Furthermore, infection disrupts interleukin-6 (IL-6)-induced phosphorylation of STAT3 and expression of a subset of IL-6-induced STAT3-regulated genes, including SOCS3. We show that the HCMV 72-kDa immediate-early 1 (IE1) protein associates with STAT3 and is necessary to localize STAT3 to the nucleus during infection. Furthermore, expression of IE1 is sufficient to disrupt IL-6-induced phosphorylation of STAT3, binding of STAT3 to the SOCS3 promoter, and SOCS3 gene expression. Finally, inhibition of STAT3 nuclear localization or STAT3 expression during infection is linked to diminished HCMV genome replication. Viral gene expression is also disrupted, with the greatest impact seen following viral DNA synthesis. Our study identifies IE1 as a new regulator of STAT3 intracellular localization and IL-6 signaling and points to an unanticipated role of STAT3 in HCMV infection.
Author List
Reitsma JM, Sato H, Nevels M, Terhune SS, Paulus CAuthor
Scott Terhune PhD Professor in the Microbiology and Immunology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsAstrocytoma
Blotting, Western
Cell Nucleus
Cells, Cultured
Cytomegalovirus
Cytomegalovirus Infections
Fibroblasts
Fluorescent Antibody Technique
Humans
Immediate-Early Proteins
Interleukin-6
Mice
Phosphorylation
RNA, Messenger
Real-Time Polymerase Chain Reaction
Reverse Transcriptase Polymerase Chain Reaction
STAT3 Transcription Factor
Signal Transduction
Trans-Activators
Virus Replication