REPLICATION OF INFLUENZA VIRUS

Summary

Principal Investigator: ROBERT KRUG
Affiliation: University of Texas
Country: USA
Abstract: The biological activities of the NS1 protein of influenza A virus (NS1A protein) differ markedly from those of the NS1 protein of influenza B virus (NS1B protein). The NS1 proteins of these two genera of influenza viruses, which cause widespread human disease, likely mediate many of the viral countermeasures that combat cellular antiviral responses. Our overall aim is to identify all the activities of the NS1A and NS1B proteins and to elucidate how these different activities counter the cellular antiviral response and/or have other functions during virus replication. At early times after infection with either influenza A or B virus the transcription of cellular genes controlled by IFN (interferon)-stimulated response elements (ISREs) is activated without the involvement of IFNalpha/beta. Mature cellular mRNAs are produced in influenza B-, but not in influenza A-, infected cells. Our aims are to determine: (1) whether the absence of mature cellular mRNAs in influenza A virus-infected cells is caused by the block in 3' end processing of cellular pre-mRNA that is mediated by the NS1A protein, a function lacked by the NS1B protein; and (2) the mechanism by which ISREs of these cellular genes are activated in influenza A and B virus-infected cells. The NS1A protein contains a nuclear export signal (NES) which is activated between 2 and 4 hours post-infection. Our aim is to determine the mechanism of activation of this NES and its role during influenza A virus infection. The NS1B protein, but not the NS1A protein, binds ISG15, a human ubiquitin-like protein that is induced by either IFNalpha/beta or virus infection, and inhibits the conjugation of ISG15 to its target proteins. Because these protein targets have not yet been identified, it is not known why ISG15 conjugation would be detrimental to influenza B virus infection. Our goals are: (i) to establish how the conjugation of ISG15 to its target protein affects influenza B virus replication; and (ii) to identify the protein targets of ISG15 conjugation and to determine how this conjugation affects the activities of these target proteins. Other cellular proteins also likely bind to the NS1A and/or NS1B protein, e.g., the SRp54 protein that binds to NS1A, but not to NS1B, and our aim is to determine whether the binding of these other proteins has a functional role in influenza virus-infected cells. These functional analyzes of the NS1A and NS1B proteins will be complemented by structural studies using both nuclear magnetic resonance and X-ray crystallography.
Funding Period: 1977-07-01 - 2007-12-14
more information: NIH RePORT

Top Publications

  1. pmc Human ISG15 conjugation targets both IFN-induced and constitutively expressed proteins functioning in diverse cellular pathways
    Chen Zhao
    Institute for Cellular and Molecular Biology, University of Texas, 2500 Speedway, Austin, TX 78712, USA
    Proc Natl Acad Sci U S A 102:10200-5. 2005
  2. pmc Interferon-induced ISG15 conjugation inhibits influenza A virus gene expression and replication in human cells
    Tien Ying Hsiang
    Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
    J Virol 83:5971-7. 2009
  3. pmc Influenza a virus polymerase is an integral component of the CPSF30-NS1A protein complex in infected cells
    Rei Lin Kuo
    Institute for Cellular and Molecular Biology, University of Texas at Austin, 78712, USA
    J Virol 83:1611-6. 2009
  4. pmc Interaction of the influenza a virus nucleocapsid protein with the viral RNA polymerase potentiates unprimed viral RNA replication
    Laura L Newcomb
    Institute for Cellular and Molecular Biology, University of Texas at Austin, 2500 Speedway, Austin, TX 78712, USA
    J Virol 83:29-36. 2009
  5. pmc Structural basis for suppression of a host antiviral response by influenza A virus
    Kalyan Das
    Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ 08854, USA
    Proc Natl Acad Sci U S A 105:13093-8. 2008
  6. pmc The H5N1 influenza virus NS genes selected after 1998 enhance virus replication in mammalian cells
    Karen Y Twu
    Institute for Cellular and Molecular Biology, University of Texas at Austin, 2500 Speedway, Austin, TX 78712, USA
    J Virol 81:8112-21. 2007
  7. ncbi Conserved surface features form the double-stranded RNA binding site of non-structural protein 1 (NS1) from influenza A and B viruses
    Cuifeng Yin
    Center for Advanced Biotechnology and Medicine, Northeast Structural Genomics Consortium, Department of Molecular Biology and Biochemistry, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
    J Biol Chem 282:20584-92. 2007
  8. pmc Nuclear and nucleolar targeting of influenza A virus NS1 protein: striking differences between different virus subtypes
    Krister Melen
    Department of Viral Diseases and Immunology, National Public Health Institute, Mannerheimintie 166, FIN 00300, Helsinki, Finland
    J Virol 81:5995-6006. 2007
  9. ncbi A site on the influenza A virus NS1 protein mediates both inhibition of PKR activation and temporal regulation of viral RNA synthesis
    Ji Young Min
    Institute for Cellular and Molecular Biology, Section of Molecular Genetics and Microbiology, room 2 122, 2500 Speedway, University of Texas at Austin, Austin, TX 78712, USA
    Virology 363:236-43. 2007
  10. ncbi Retinoic acid inducible gene-I and mda-5 are involved in influenza A virus-induced expression of antiviral cytokines
    Jukka Sirén
    Department of Viral Diseases and Immunology, National Public Health Institute, Helsinki, Finland
    Microbes Infect 8:2013-20. 2006

Scientific Experts

  • ROBERT KRUG
  • Krister Melen
  • Rei Lin Kuo
  • Chen Zhao
  • Karen Y Twu
  • Ji Young Min
  • Diana L Noah
  • Tien Ying Hsiang
  • Shoudong Li
  • Laura L Newcomb
  • Kalyan Das
  • Jesper Marklund
  • Gaetano T Montelione
  • Cuifeng Yin
  • Ganes C Sen
  • Anahita Dastur
  • Jukka Sirén
  • Jon M Huibregtse
  • Yizhi Jane Tao
  • Qiaozhen Ye
  • Yunyun Jiang
  • Rong Xiao
  • Li Chung Ma
  • Brian Radvansky
  • Li Zhao
  • Eddy Arnold
  • James Aramini
  • Asli Ertekin
  • Javed A Khan
  • G V T Swapna
  • Liang Tong
  • Sylvie Beaudenon
  • Tadaatsu Imaizumi
  • Devanand Sarkar
  • Ping Rao
  • Melissa Kelley
  • Paul B Fisher
  • John Hiscott
  • Ilkka Julkunen
  • Taija Pietilä
  • Sampsa Matikainen
  • Rongtuan Lin
  • Steven Gygi
  • Carilee Denison

Detail Information

Publications16

  1. pmc Human ISG15 conjugation targets both IFN-induced and constitutively expressed proteins functioning in diverse cellular pathways
    Chen Zhao
    Institute for Cellular and Molecular Biology, University of Texas, 2500 Speedway, Austin, TX 78712, USA
    Proc Natl Acad Sci U S A 102:10200-5. 2005
    ..By targeting a wide array of constitutively expressed proteins, ISG15 conjugation greatly extends the repertoire of cellular functions that are affected by IFN-alpha/beta...
  2. pmc Interferon-induced ISG15 conjugation inhibits influenza A virus gene expression and replication in human cells
    Tien Ying Hsiang
    Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
    J Virol 83:5971-7. 2009
    ..In contrast, we show that in mouse embryo fibroblasts ISG15 conjugation not only does not affect influenza A virus replication but also does not contribute to the IFN-induced antiviral activity against influenza A virus gene expression...
  3. pmc Influenza a virus polymerase is an integral component of the CPSF30-NS1A protein complex in infected cells
    Rei Lin Kuo
    Institute for Cellular and Molecular Biology, University of Texas at Austin, 78712, USA
    J Virol 83:1611-6. 2009
    ....
  4. pmc Interaction of the influenza a virus nucleocapsid protein with the viral RNA polymerase potentiates unprimed viral RNA replication
    Laura L Newcomb
    Institute for Cellular and Molecular Biology, University of Texas at Austin, 2500 Speedway, Austin, TX 78712, USA
    J Virol 83:29-36. 2009
    ....
  5. pmc Structural basis for suppression of a host antiviral response by influenza A virus
    Kalyan Das
    Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ 08854, USA
    Proc Natl Acad Sci U S A 105:13093-8. 2008
    ....
  6. pmc The H5N1 influenza virus NS genes selected after 1998 enhance virus replication in mammalian cells
    Karen Y Twu
    Institute for Cellular and Molecular Biology, University of Texas at Austin, 2500 Speedway, Austin, TX 78712, USA
    J Virol 81:8112-21. 2007
    ..Consequently, these internal HK97 proteins largely compensate for the absence of F103 and M106, presumably by stabilizing the NS1A-CPSF30 complex...
  7. ncbi Conserved surface features form the double-stranded RNA binding site of non-structural protein 1 (NS1) from influenza A and B viruses
    Cuifeng Yin
    Center for Advanced Biotechnology and Medicine, Northeast Structural Genomics Consortium, Department of Molecular Biology and Biochemistry, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
    J Biol Chem 282:20584-92. 2007
    ..This pocket provides a target on the surface of the NS1 protein that is potentially suitable for the development of antiviral drugs targeting both influenza A and B viruses...
  8. pmc Nuclear and nucleolar targeting of influenza A virus NS1 protein: striking differences between different virus subtypes
    Krister Melen
    Department of Viral Diseases and Immunology, National Public Health Institute, Mannerheimintie 166, FIN 00300, Helsinki, Finland
    J Virol 81:5995-6006. 2007
    ..It is likely that the evolutionarily well-conserved nucleolar targeting function of NS1A protein plays a role in the pathogenesis of influenza A virus...
  9. ncbi A site on the influenza A virus NS1 protein mediates both inhibition of PKR activation and temporal regulation of viral RNA synthesis
    Ji Young Min
    Institute for Cellular and Molecular Biology, Section of Molecular Genetics and Microbiology, room 2 122, 2500 Speedway, University of Texas at Austin, Austin, TX 78712, USA
    Virology 363:236-43. 2007
    ..This interaction would occur in the nucleus, whereas PKR would bind to NS1A proteins in the cytoplasm prior to their import into the nucleus...
  10. ncbi Retinoic acid inducible gene-I and mda-5 are involved in influenza A virus-induced expression of antiviral cytokines
    Jukka Sirén
    Department of Viral Diseases and Immunology, National Public Health Institute, Helsinki, Finland
    Microbes Infect 8:2013-20. 2006
    ..In conclusion, our results show that in epithelial cells influenza A virus-induced antiviral cytokine gene expression is triggered by RIG-I and mda-5, whose expression is positively regulated by IFN-alpha...
  11. pmc The primary function of RNA binding by the influenza A virus NS1 protein in infected cells: Inhibiting the 2'-5' oligo (A) synthetase/RNase L pathway
    Ji Young Min
    Section of Molecular Genetics and Microbiology, Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA
    Proc Natl Acad Sci U S A 103:7100-5. 2006
    ....
  12. pmc The CPSF30 binding site on the NS1A protein of influenza A virus is a potential antiviral target
    Karen Y Twu
    Institute for Cellular and Molecular Biology, Section of Molecular Genetics and Microbiology, University of Texas at Austin, 2500 Speedway, Austin, Texas 78712, USA
    J Virol 80:3957-65. 2006
    ....
  13. ncbi Binding of the influenza A virus NS1 protein to PKR mediates the inhibition of its activation by either PACT or double-stranded RNA
    Shoudong Li
    Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
    Virology 349:13-21. 2006
    ..In addition, we demonstrated that PKR activation is inhibited in cells infected with a recombinant influenza A virus expressing NS1A mutant protein that cannot bind RNA, as is the case in cells infected with wild-type influenza A virus...
  14. ncbi Herc5, an interferon-induced HECT E3 enzyme, is required for conjugation of ISG15 in human cells
    Anahita Dastur
    Institute for Cellular and Molecular Biology, Section of Molecular Genetics and Microbiology, The University of Texas at Austin, 78712, USA
    J Biol Chem 281:4334-8. 2006
    ..These results demonstrate that Herc5 is required for conjugation of ISG15 to a broad spectrum of target proteins in human cells...
  15. ncbi Influenza virus virulence and its molecular determinants
    Diana L Noah
    Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, USA
    Adv Virus Res 65:121-45. 2005
  16. pmc ISG15 conjugation system targets the viral NS1 protein in influenza A virus-infected cells
    Chen Zhao
    Institute for Cellular and Molecular Biology, Section of Molecular Genetics and Microbiology, University of Texas at Austin, TX 78712, USA
    Proc Natl Acad Sci U S A 107:2253-8. 2010
    ....