Affiliations 

  • 1 School of Science, Monash University, Subang Jaya, Selangor, 47500, Malaysia
  • 2 Virology Group, International Centre for Genetic Engineering &Biotechnology, New Delhi, 110067, India
  • 3 Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta GA, 30333, USA
Sci Rep, 2016;6:19063.
PMID: 26750153 DOI: 10.1038/srep19063

Abstract

A unique feature of influenza A virus (IAV) life cycle is replication of the viral genome in the host cell nucleus. The nuclear import of IAV genome is an indispensable step in establishing virus infection. IAV nucleoprotein (NP) is known to mediate the nuclear import of viral genome via its nuclear localization signals. Here, we demonstrate that cellular heat shock protein 40 (Hsp40/DnaJB1) facilitates the nuclear import of incoming IAV viral ribonucleoproteins (vRNPs) and is important for efficient IAV replication. Hsp40 was found to interact with NP component of IAV RNPs during early stages of infection. This interaction is mediated by the J domain of Hsp40 and N-terminal region of NP. Drug or RNAi mediated inhibition of Hsp40 resulted in reduced nuclear import of IAV RNPs, diminished viral polymerase function and attenuates overall viral replication. Hsp40 was also found to be required for efficient association between NP and importin alpha, which is crucial for IAV RNP nuclear translocation. These studies demonstrate an important role for cellular chaperone Hsp40/DnaJB1 in influenza A virus life cycle by assisting nuclear trafficking of viral ribonucleoproteins.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.