Involvement of Hsp90 in Assembly and Nuclear Import of Influenza Virus RNA Polymerase Subunits
- 1 February 2007
- journal article
- Published by American Society for Microbiology in Journal of Virology
- Vol. 81 (3) , 1339-1349
- https://doi.org/10.1128/jvi.01917-06
Abstract
Transcription and replication of the influenza virus RNA genome occur in the nuclei of infected cells through the viral RNA-dependent RNA polymerase consisting of PB1, PB2, and PA. We previously identified a host factor designated RAF-1 (RNA polymerase activating factor 1) that stimulates viral RNA synthesis. RAF-1 is found to be identical to Hsp90. Here, we examined the intracellular localization of Hsp90 and viral RNA polymerase subunits and their molecular interaction. Hsp90 was found to interact with PB2 and PB1, and it was relocalized to the nucleus upon viral infection. We found that the nuclear transport of Hsp90 occurs in cells expressing PB2 alone. The nuclear transport of Hsp90 was in parallel with that of the viral RNA polymerase binary complexes, either PB1 and PB2 or PB1 and PA, as well as with that of PB2 alone. Hsp90 also interacted with the binary RNA polymerase complex PB1-PB2, and it was dissociated from the PB1-PB2 complex upon its association with PA. Furthermore, Hsp90 could form a stable PB1-PB2-Hsp90 complex prior to the formation of a ternary polymerase complex by the assembly of PA in the infected cells. These results suggest that Hsp90 is involved in the assembly and nuclear transport of viral RNA polymerase subunits, possibly as a molecular chaperone for the polymerase subunits prior to the formation of a mature ternary polymerase complex.Keywords
This publication has 54 references indexed in Scilit:
- Role of Ran Binding Protein 5 in Nuclear Import and Assembly of the Influenza Virus RNA Polymerase ComplexJournal of Virology, 2006
- In Vitro Assembly of PB2 with a PB1-PA Dimer Supports a New Model of Assembly of Influenza A Virus Polymerase Subunits into a Functional Trimeric ComplexJournal of Virology, 2005
- The PA Subunit Is Required for Efficient Nuclear Accumulation of the PB1 Subunit of the Influenza A Virus RNA Polymerase ComplexJournal of Virology, 2004
- Crystal Structure of UAP56, a DExD/H-Box Protein Involved in Pre-mRNA Splicing and mRNA ExportStructure, 2004
- Two Aromatic Residues in the PB2 Subunit of Influenza A RNA Polymerase Are Crucial for Cap BindingJournal of Biological Chemistry, 2003
- PA Subunit from Influenza Virus Polymerase Complex Interacts with a Cellular Protein with Homology to a Family of Transcriptional ActivatorsJournal of Virology, 2001
- The Highly Inducible Member of the 70 kDa Family of Heat Shock Proteins Increases Canine Distemper Virus Polymerase ActivityJournal of General Virology, 1996
- Nuclear transport of influenza virus polymerase PA proteinVirus Research, 1992
- Efficient selection for high-expression transfectants with a novel eukaryotic vectorGene, 1991
- Host cell proteins required for measles virus reproductionJournal of General Virology, 1990