New World and Old World Alphaviruses Have Evolved to Exploit Different Components of Stress Granules, FXR and G3BP Proteins, for Assembly of Viral Replication Complexes

Autor: Ilya Frolov, Aliaksandra Rasalouskaya, Dal Young Kim, Elena I. Frolova, Ivan Akhrymuk, Josephine M. Reynaud, James A. Mobley
Jazyk: angličtina
Rok vydání: 2016
Předmět:
0301 basic medicine
RNA viruses
Viral Diseases
viruses
Cell Membranes
Viral Nonstructural Proteins
Virus Replication
Pathology and Laboratory Medicine
Polymerase Chain Reaction
Biochemistry
Encephalitis Virus
Venezuelan Equine
Gene Knockout Techniques
Mice
Medicine and Health Sciences
Poly-ADP-Ribose Binding Proteins
lcsh:QH301-705.5
In Situ Hybridization
Genetics
Microscopy
Confocal
Chikungunya Virus
biology
Nucleic acids
RNA Recognition Motif Proteins
Infectious Diseases
Medical Microbiology
Viral Pathogens
Viruses
Cell lines
Pathogens
Cellular Structures and Organelles
Biological cultures
RNA Helicases
Research Article
Neglected Tropical Diseases
lcsh:Immunologic diseases. Allergy
Sindbis virus
Alphaviruses
Nucleic acid synthesis
030106 microbiology
Immunology
Alphavirus
Microbiology
Host-Parasite Interactions
Togaviruses
03 medical and health sciences
Stress granule
dsRNA viruses
NIH 3T3 cells
Virology
Animals
Chemical synthesis
RNA synthesis
Molecular Biology
Microbial Pathogens
DNA Helicases
Organisms
RNA
Biology and Life Sciences
Chikungunya Infection
Cell Biology
biology.organism_classification
Tropical Diseases
Viral Replication
Research and analysis methods
Biosynthetic techniques
030104 developmental biology
Viral replication
lcsh:Biology (General)
Viral replication complex
Parasitology
Sindbis Virus
Carrier Proteins
lcsh:RC581-607
Zdroj: PLoS Pathogens, Vol 12, Iss 8, p e1005810 (2016)
PLoS Pathogens
ISSN: 1553-7374
1553-7366
Popis: The positive-strand RNA viruses initiate their amplification in the cell from a single genome delivered by virion. This single RNA molecule needs to become involved in replication process before it is recognized and degraded by cellular machinery. In this study, we show that distantly related New World and Old World alphaviruses have independently evolved to utilize different cellular stress granule-related proteins for assembly of complexes, which recruit viral genomic RNA and facilitate formation of viral replication complexes (vRCs). Venezuelan equine encephalitis virus (VEEV) utilizes all members of the Fragile X syndrome (FXR) family, while chikungunya and Sindbis viruses exploit both members of the G3BP family. Despite being in different families, these proteins share common characteristics, which determine their role in alphavirus replication, namely, the abilities for RNA-binding and for self-assembly into large structures. Both FXR and G3BP proteins interact with virus-specific, repeating amino acid sequences located in the C-termini of hypervariable, intrinsically disordered domains (HVDs) of viral nonstructural protein nsP3. We demonstrate that these host factors orchestrate assembly of vRCs and play key roles in RNA and virus replication. Only knockout of all of the homologs results in either pronounced or complete inhibition of replication of different alphaviruses. The use of multiple homologous proteins with redundant functions mediates highly efficient recruitment of viral RNA into the replication process. This independently evolved acquisition of different families of cellular proteins by the disordered protein fragment to support alphavirus replication suggests that other RNA viruses may utilize a similar mechanism of host factor recruitment for vRC assembly. The use of different host factors by alphavirus species may be one of the important determinants of their pathogenesis.
Author Summary Many viruses encode proteins containing intrinsically disordered domains, whose functions are as yet unknown. Here we show that such a domain (HVD) in the alphavirus nsP3 protein orchestrates assembly of viral replication complexes through interaction with RNA-binding cellular factors. Surprisingly, geographically isolated viruses have evolved to utilize different cellular proteins: the nsP3 HVD of Venezuelan equine encephalitis virus (VEEV) binds all members of the FXR family, while nsP3 HVDs of Sindbis and chikungunya viruses interact with G3BP proteins. Despite being in different families, G3BPs and FXRs have similar domain organization, and assemble into higher order complexes, such as stress granules. Alphaviruses exploit their abilities for complex self-assembly and RNA binding to build RNA-containing pre-replication complexes. Using CRISPR/Cas9 mediated knockouts, we show that deletion of all homologs strongly affects virus replication, while knockout of a single FXR or G3BP homolog has no or mild effect. Our data suggest that an alphavirus HVD serves as a hub to recruit host factors for replication complex assembly and may determine virus adaptation to distinct cellular environments. Notably, the improved understanding of HVD interactions allows alphavirus replication to be switched from an FXR- to G3BP-dependent mode and opens new possibilities for development of antiviral therapeutics.
Databáze: OpenAIRE
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