Structural Bioinformatics of Influenza Virus RNA Genomes

2021 ◽  
pp. 101-120
Author(s):  
Alexander P. Gultyaev ◽  
René C.L. Olsthoorn ◽  
Monique I. Spronken ◽  
Mathilde Richard
2001 ◽  
Vol 276 (33) ◽  
pp. 31179-31185 ◽  
Author(s):  
Ayae Honda ◽  
Atsushi Endo ◽  
Kiyohisa Mizumoto ◽  
Akira Ishihama

2015 ◽  
Vol 89 (12) ◽  
pp. 6376-6390 ◽  
Author(s):  
Bruno Da Costa ◽  
Alix Sausset ◽  
Sandie Munier ◽  
Alexandre Ghounaris ◽  
Nadia Naffakh ◽  
...  

ABSTRACTThe influenza virus RNA-dependent RNA polymerase catalyzes genome replication and transcription within the cell nucleus. Efficient nuclear import and assembly of the polymerase subunits PB1, PB2, and PA are critical steps in the virus life cycle. We investigated the structure and function of the PA linker (residues 197 to 256), located between its N-terminal endonuclease domain and its C-terminal structured domain that binds PB1, the polymerase core. Circular dichroism experiments revealed that the PA linker by itself is structurally disordered. A large series of PA linker mutants exhibited a temperature-sensitive (ts) phenotype (reduced viral growth at 39.5°C versus 37°C/33°C), suggesting an alteration of folding kinetic parameters. Thetsphenotype was associated with a reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using a fluorescent-tagged PB1, we observed thattsand lethal PA mutants did not efficiently recruit PB1 to reach the nucleus at 39.5°C. A protein complementation assay using PA mutants, PB1, and β-importin IPO5 tagged with fragments of theGaussia princepsluciferase showed that increasing the temperature negatively modulated the PA-PB1 and the PA-PB1-IPO5 interactions or complex stability. The selection of revertant viruses allowed the identification of different types of compensatory mutations located in one or the other of the three polymerase subunits. Twotsmutants were shown to be attenuated and able to induce antibodies in mice. Taken together, our results identify a PA domain critical for PB1-PA nuclear import and that is a “hot spot” to engineertsmutants that could be used to design novel attenuated vaccines.IMPORTANCEBy targeting a discrete domain of the PA polymerase subunit of influenza virus, we were able to identify a series of 9 amino acid positions that are appropriate to engineer temperature-sensitive (ts) mutants. This is the first time that a large number oftsmutations were engineered in such a short domain, demonstrating that rational design oftsmutants can be achieved. We were able to associate this phenotype with a defect of transport of the PA-PB1 complex into the nucleus. Reversion substitutions restored the ability of the complex to move to the nucleus. Two of thesetsmutants were shown to be attenuated and able to produce antibodies in mice. These results are of high interest for the design of novel attenuated vaccines and to develop new antiviral drugs.


2019 ◽  
Vol 1 (1A) ◽  
Author(s):  
Alexander Walker ◽  
Haitian Fan ◽  
Loic Carrique ◽  
Jeremy Keown ◽  
David Bauer ◽  
...  

2006 ◽  
Vol 81 (3) ◽  
pp. 1339-1349 ◽  
Author(s):  
Tadasuke Naito ◽  
Fumitaka Momose ◽  
Atsushi Kawaguchi ◽  
Kyosuke Nagata

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.


2009 ◽  
Vol 106 (37) ◽  
pp. 15891-15896 ◽  
Author(s):  
Qinshan Gao ◽  
Peter Palese

Influenza viruses contain segmented, negative-strand RNA genomes. Genome segmentation facilitates reassortment between different influenza virus strains infecting the same cell. This phenomenon results in the rapid exchange of RNA segments. In this study, we have developed a method to prevent the free reassortment of influenza A virus RNAs by rewiring their packaging signals. Specific packaging signals for individual influenza virus RNA segments are located in the 5′ and 3′ noncoding regions as well as in the terminal regions of the ORF of an RNA segment. By putting the nonstructural protein (NS)-specific packaging sequences onto the ORF of the hemagglutinin (HA) gene and mutating the packaging regions in the ORF of the HA, we created a chimeric HA segment with the packaging identity of an NS gene. By the same strategy, we made an NS gene with the packaging identity of an HA segment. This rewired virus had the packaging signals for all eight influenza virus RNAs, but it lost the ability to independently reassort its HA or NS gene. A similar approach can be applied to the other influenza A virus segments to diminish their ability to form reassortant viruses.


2020 ◽  
Vol 8 (10) ◽  
pp. 1610 ◽  
Author(s):  
Mitsuru Sada ◽  
Takeshi Saraya ◽  
Haruyuki Ishii ◽  
Kaori Okayama ◽  
Yuriko Hayashi ◽  
...  

Favipiravir was initially developed as an antiviral drug against influenza and is currently used in clinical trials against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection (COVID-19). This agent is presumably involved in RNA chain termination during influenza virus replication, although the molecular interactions underlying its potential impact on the coronaviruses including SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV) remain unclear. We performed in silico studies to elucidate detailed molecular interactions between favipiravir and the SARS-CoV-2, SARS-CoV, MERS-CoV, and influenza virus RNA-dependent RNA polymerases (RdRp). As a result, no interactions between favipiravir ribofuranosyl-5′-triphosphate (F-RTP), the active form of favipiravir, and the active sites of RdRps (PB1 proteins) from influenza A (H1N1)pdm09 virus were found, yet the agent bound to the tunnel of the replication genome of PB1 protein leading to the inhibition of replicated RNA passage. In contrast, F-RTP bound to the active sites of coronavirus RdRp in the presence of the agent and RdRp. Further, the agent bound to the replicated RNA terminus in the presence of agent, magnesium ions, nucleotide triphosphate, and RdRp proteins. These results suggest that favipiravir exhibits distinct mechanisms of action against influenza virus and various coronaviruses.


Sign in / Sign up

Export Citation Format

Share Document