title: Cellular Transcriptional Coactivator RanBP10 and Herpes Simplex Virus 1 ICP0 Interact and Synergistically Promote Viral Gene Expression and Replication.
abstract: To investigate the molecular mechanism(s) by which herpes simplex virus 1 (HSV-1) regulatory protein ICP0 promotes viral gene expression and replication, we screened cells overexpressing ICP0 for ICP0-binding host cell proteins. Tandem affinity purification of transiently expressed ICP0 coupled with mass spectrometry-based proteomics technology and subsequent analyses showed that ICP0 interacted with cell protein RanBP10, a known transcriptional coactivator, in HSV-1-infected cells. Knockdown of RanBP10 in infected HEp-2 cells resulted in a phenotype similar to that observed with the ICP0-null mutation, including reduction in viral replication and in the accumulation of viral immediate early (ICP27), early (ICP8), and late (VP16) mRNAs and proteins. In addition, RanBP10 knockdown or the ICP0-null mutation increased the level of histone H3 association with the promoters of these viral genes, which is known to repress transcription. These effects observed in wild-type HSV-1-infected HEp-2 RanBP10 knockdown cells or those observed in ICP0-null mutant virus-infected control HEp-2 cells were remarkably increased in ICP0-null mutant virus-infected HEp-2 RanBP10 knockdown cells. Our results suggested that ICP0 and RanBP10 redundantly and synergistically promoted viral gene expression by regulating chromatin remodeling of the HSV-1 genome for efficient viral replication.
  
  
  OBJECTIVE
  Upon entry of herpesviruses into a cell, viral gene expression is restricted by heterochromatinization of the viral genome. Therefore, HSV-1 has evolved multiple mechanisms to counteract this epigenetic silencing for efficient viral gene expression and replication. HSV-1 ICP0 is one of the viral proteins involved in counteracting epigenetic silencing. Here, we identified RanBP10 as a novel cellular ICP0-binding protein and showed that RanBP10 and ICP0 appeared to act synergistically to promote viral gene expression and replication by modulating viral chromatin remodeling. Our results provide insight into the mechanisms by which HSV-1 regulates viral chromatin remodeling for efficient viral gene expression and replication.
authors.affiliation: Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Kato
authors.affiliation: Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Maruzuru
authors.affiliation: Medical Proteomics Laboratory, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Oyama
authors.affiliation: Medical Proteomics Laboratory, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kozuka-Hata
authors.affiliation: Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Arii
authors.affiliation: Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan ykawagu@ims.u-tokyo.ac.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawaguchi
mesh_terms: D002460:Cell Line; D004847:Epithelial Cells / Q000821:virology; D017353:Gene Deletion; D015967:Gene Expression Regulation, Viral; D055785:Gene Knockdown Techniques; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D020543:Proteome / Q000032:analysis; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D017874:Immediate-Early Proteins; D008869:Microtubule-Associated Proteins; D020543:Proteome; C529801:RANBP10 protein, human; D044767:Ubiquitin-Protein Ligases; C051804:Vmw110 protein, Human herpesvirus 1