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J Virol. 2009 Jun 3. [Epub ahead of print]
Nuclear factor 90, NF90, negatively regulates influenza virus replication by interacting with viral nucleoprotein.
Wang P, Song W, Mok BW, Zhao P, Qin K, Lai A, Smith GJ, Zhang J, Lin T, Guan Y, Chen H. State Key Laboratory for Emerging Infectious Diseases, Department of Microbiology and the Research Centre of Infection and Immunology, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong SAR, P.R. China; International Institute of Infection and Immunity, Shantou University, Shantou, P.R. China; School of Life Sciences, Xiamen University, Xiamen, P.R. China.
Interactions between host factors and the viral replication complex play important roles in host adaptation and regulation of influenza virus replication. A cellular protein, nuclear factor 90 (NF90) was co-purified with H5N1 viral NP from human cells in which NP was transiently expressed, and identified using Mass Spectrometry (MALDI-TOF MS) analysis. In vitro co-immunoprecipitation (co-IP) of NF90 and NP proteins co-expressed in HEK 293T cells, or individually expressed in bacterial and HEK 293T cells, respectively, confirmed a direct interaction between NF90 and NP, independent of other subunits of the RNP complex. This interaction was prevented by a mutation, F412A, in the C-terminal region of the NP protein, indicating that the C-terminal of NP is required for NF90 binding. RNase V treatment did not prevent co-precipitation of NP and NF90, which demonstrates that the interaction is RNA binding independent. Following siRNA knockdown of NF90 expression in A549 and HeLa cells, viral polymerase complex activity and virus replication were significantly increased, suggesting that NF90 negatively affects viral replication. Both NP and NF90 co-localized in the nucleus of virus infected cells during the early phase of infection, suggesting that the interaction between NF90 and NP is an early event in virus replication. Quantitative RT-PCR showed that NF90 down regulates both viral genome replication and mRNA transcription in infected cells. These results suggest that NF90 inhibits influenza virus replication during the early phase of infection through direct interaction with viral nucleoprotein.
PMID: 19494010 [PubMed - as supplied by publisher]
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Nuclear factor 90, NF90, negatively regulates influenza virus replication by interacting with viral nucleoprotein.
Wang P, Song W, Mok BW, Zhao P, Qin K, Lai A, Smith GJ, Zhang J, Lin T, Guan Y, Chen H. State Key Laboratory for Emerging Infectious Diseases, Department of Microbiology and the Research Centre of Infection and Immunology, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong SAR, P.R. China; International Institute of Infection and Immunity, Shantou University, Shantou, P.R. China; School of Life Sciences, Xiamen University, Xiamen, P.R. China.
Interactions between host factors and the viral replication complex play important roles in host adaptation and regulation of influenza virus replication. A cellular protein, nuclear factor 90 (NF90) was co-purified with H5N1 viral NP from human cells in which NP was transiently expressed, and identified using Mass Spectrometry (MALDI-TOF MS) analysis. In vitro co-immunoprecipitation (co-IP) of NF90 and NP proteins co-expressed in HEK 293T cells, or individually expressed in bacterial and HEK 293T cells, respectively, confirmed a direct interaction between NF90 and NP, independent of other subunits of the RNP complex. This interaction was prevented by a mutation, F412A, in the C-terminal region of the NP protein, indicating that the C-terminal of NP is required for NF90 binding. RNase V treatment did not prevent co-precipitation of NP and NF90, which demonstrates that the interaction is RNA binding independent. Following siRNA knockdown of NF90 expression in A549 and HeLa cells, viral polymerase complex activity and virus replication were significantly increased, suggesting that NF90 negatively affects viral replication. Both NP and NF90 co-localized in the nucleus of virus infected cells during the early phase of infection, suggesting that the interaction between NF90 and NP is an early event in virus replication. Quantitative RT-PCR showed that NF90 down regulates both viral genome replication and mRNA transcription in infected cells. These results suggest that NF90 inhibits influenza virus replication during the early phase of infection through direct interaction with viral nucleoprotein.
PMID: 19494010 [PubMed - as supplied by publisher]
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