Selective STAT Protein Degradation Induced by Paramyxoviruses Requires both STAT1 and STAT2 but Is Independent of Alpha/Beta Interferon Signal Transduction

作者：Jean-Patrick Parisien, Joe F. Lau, Jason J. Rodriguez, Christina M. Ulane, Curt M. Horvath · 发表于：Journal of Virology · 年份：2002 · DOI：10.1128/jvi.76.9.4190-4198.2002 · 被引用次数：138 · 研究领域：interferon and immune responses、Viral Infections and Vectors、Virology and Viral Diseases

The alpha/beta interferon (IFN-alpha/beta)-induced STAT signal transduction pathway leading to activation of the ISGF3 transcription complex and subsequent antiviral responses is the target of viral pathogenesis strategies. Members of the Rubulavirus genus of the Paramyxovirus family of RNA viruses have acquired the ability to specifically target either STAT1 or STAT2 for proteolytic degradation as a countermeasure for evading IFN responses. While type II human parainfluenza virus induces STAT2 degradation, simian virus 5 induces STAT1 degradation. The components of the IFN signaling system that are required for STAT protein degradation by these paramyxoviruses have been investigated in a series of human somatic cell lines deficient in IFN signaling proteins. Results indicate that neither the IFN-alpha/beta receptor, the tyrosine kinases Jak1 or Tyk2, nor the ISGF3 DNA-binding subunit, IFN regulatory factor 9 (IRF9), is required for STAT protein degradation induced by either virus. Nonetheless, both STAT1 and STAT2 are strictly required in the host cell to establish a degradation-permissive environment enabling both viruses to target their respective STAT protein. Complementation studies reveal that STAT protein-activating tyrosine phosphorylation and functional src homology 2 (SH2) domains are dispensable for creating a permissive STAT degradation environment in degradation-incompetent cells, but the N terminus of the missing STAT protein is essential. Protein-protein intera...