Heat Shock Protein 70 Modulates Influenza A Virus Polymerase Activity

• Manzoor, Rashid

• Kuroda, Kazumichi

• Yoshida, Reiko

• Tsuda, Yoshimi

• Fujikura, Daisuke

• Miyamoto, Hiroko

• Kajihara, Masahiro

• Kida, Hiroshi

• Takada, Ayato

Abstract

Background: It has been shown that heat shock protein 70 (Hsp70) plays a role in influenza A virus replication. Results: A correlation between viral replication/transcription activities and nuclear/cytoplasmic shuttling of Hsp70 was observed. Conclusion: Hsp70 modulates the influenza A virus polymerase activity. Significance: This study, for the first time, suggests that Hsp70 may actually assist in influenza A virus replication. The role of heat shock protein 70 (Hsp70) in virus replication has been discussed for many viruses. The known suppressive role of Hsp70 in influenza virus replication is based on studies conducted in cells with various Hsp70 expression levels. In this study, we determined the role of Hsp70 in influenza virus replication in HeLa and HEK293T cells, which express Hsp70 constitutively. Co-immunoprecipitation and immunofluorescence studies revealed that Hsp70 interacted with PB2 or PB1 monomers and PB2/PB1 heterodimer but not with the PB1/PA heterodimer or PB2/PB1/PA heterotrimer and translocated into the nucleus with PB2 monomers or PB2/PB1 heterodimers. Knocking down Hsp70 resulted in reduced virus transcription and replication activities. Reporter gene assay, immunofluorescence assay, and Western blot analysis of nuclear and cytoplasmic fractions from infected cells demonstrated that the increase in viral polymerase activity during the heat shock phase was accompanied with an increase in Hsp70 and viral polymerases levels in the nuclei, where influenza virus replication takes place, whereas a reduction in viral polymerase activity was accompanied with an increase in cytoplasmic relocation of Hsp70 along with viral polymerases. Moreover, significantly higher levels of viral genomic RNA (vRNA) were observed during the heat shock phase than during the recovery phase. Overall, for the first time, these findings suggest that Hsp70 may act as a chaperone for influenza virus polymerase, and the modulatory effect of Hsp70 appears to be a sequel of shuttling of Hsp70 between nuclear and cytoplasmic compartments.

Journal

• Journal of Biological Chemistry

  Journal of Biological Chemistry 289 (11), 7599-7614, 2014-03-14

  American Society for Biochemistry and Molecular Biology

Keywords

• RNA Viruses
• Influenza Virus
• viral Polymerase
• cell fractionation
• NF-kappa B (NF-KB)
• viral replication
• heat shock protein 70
• heat shock

Details

• CRID: 1050001339016814976
• NII Article ID: 120005460233
• NII Book ID: AA00251083
• HANDLE: 2115/56577
• ISSN: 00219258
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles