title: The vaccinia virus K7 protein promotes histone methylation associated with heterochromatin formation.
abstract: It has been well established that many vaccinia virus proteins suppress host antiviral pathways by targeting the transcription of antiviral proteins, thus evading the host innate immune system. However, whether viral proteins have an effect on the host's overall cellular transcription is less understood. In this study we investigated the regulation of heterochromatin during vaccinia virus infection. Heterochromatin is a highly condensed form of chromatin that is less transcriptionally active and characterized by methylation of histone proteins. We examined the change in methylation of two histone proteins, H3 and H4, which are major markers of heterochromatin, during the course of viral infection. Using immunofluorescence microscopy and flow cytometry we were able to track the overall change in the methylated levels of H3K9 and H4K20. Our results suggest that there is significant increase in methylation of H3K9 and H4K20 during Orthopoxviruses infection compared to mock-infected cells. However, this effect was not seen when we infected cells with Leporipoxviruses. We further screened several vaccinia virus single and multi-gene deletion mutant and identified the vaccinia virus gene K7R as a contributor to the increase in cellular histone methylation during infection.
authors.affiliation: Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Wondimagegnehu M
authors.initials: WM
authors.lastname: Teferi
authors.affiliation: Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Megan A
authors.initials: MA
authors.lastname: Desaulniers
authors.affiliation: Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Noyce
authors.affiliation: Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Mira
authors.initials: M
authors.lastname: Shenouda
authors.affiliation: Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Brittany
authors.initials: B
authors.lastname: Umer
authors.affiliation: Department of Medical Microbiology & Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: David H
authors.identifier: http://orcid.org/0000-0001-5871-299X
authors.initials: DH
authors.lastname: Evans
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D042002:Chromatin Assembly and Disassembly; D004622:Embryo, Mammalian; D044127:Epigenesis, Genetic; D005347:Fibroblasts / Q000378:metabolism / Q000821:virology*; D006570:Heterochromatin / Q000378:metabolism / Q000648:ultrastructure; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D006801:Humans; D018152:Leporipoxvirus / Q000235:genetics / Q000378:metabolism; D008745:Methylation; D008856:Microscopy, Fluorescence; D009154:Mutation; D061251:Primary Cell Culture; D014616:Vaccinia virus / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D006570:Heterochromatin; D006657:Histones; D014764:Viral Proteins