RRC ID 69942
Author Mine A, Hyodo K, Tajima Y, Kusumanegara K, Taniguchi T, Kaido M, Mise K, Taniguchi H, Okuno T.
Title Differential roles of Hsp70 and Hsp90 in the assembly of the replicase complex of a positive-strand RNA plant virus.
Journal J Virol
Abstract Assembly of viral replicase complexes of eukaryotic positive-strand RNA viruses is a regulated process: multiple viral and host components must be assembled on intracellular membranes and ordered into quaternary complexes capable of synthesizing viral RNAs. However, the molecular mechanisms underlying this process are poorly understood. In this study, we used a model virus, Red clover necrotic mosaic virus (RCNMV), whose replicase complex can be detected readily as the 480-kDa functional protein complex. We found that host heat shock proteins Hsp70 and Hsp90 are required for RCNMV RNA replication and that they interact with p27, a virus-encoded component of the 480-kDa replicase complex, on the endoplasmic reticulum membrane. Using a cell-free viral translation/replication system in combination with specific inhibitors of Hsp70 and Hsp90, we found that inhibition of p27-Hsp70 interaction inhibits the formation of the 480-kDa complex but instead induces the accumulation of large complexes that are nonfunctional in viral RNA synthesis. In contrast, inhibition of p27-Hsp90 interaction did not induce such large complexes but rendered p27 incapable of binding to a specific viral RNA element, which is a critical step for the assembly of the 480-kDa replicase complex and viral RNA replication. Together, our results suggest that Hsp70 and Hsp90 regulate different steps in the assembly of the RCNMV replicase complex.
Volume 86(22)
Pages 12091-104
Published 2012-11-1
DOI 10.1128/JVI.01659-12
PII JVI.01659-12
PMID 22933272
PMC PMC3486462
MeSH Cloning, Molecular Endoplasmic Reticulum / metabolism Gene Silencing HSP70 Heat-Shock Proteins / metabolism* HSP90 Heat-Shock Proteins / metabolism* Microscopy, Confocal / methods Plants / virology* Protein Binding Protein Biosynthesis RNA Viruses / metabolism* RNA, Viral / metabolism RNA-Dependent RNA Polymerase / chemistry* RNA-Dependent RNA Polymerase / genetics Tobacco / virology Tombusviridae / genetics Tombusviridae / metabolism* Virus Replication
IF 4.501
Arabidopsis / Cultured plant cells, genes rpc00001