scholarly journals Molecular Evolution of the Influenza A Virus Non-structural Protein 1 in Interspecies Transmission and Adaptation

2021 ◽  
Vol 12 ◽  
Author(s):  
Danyel Evseev ◽  
Katharine E. Magor
Keyword(s):  
Viral Replication ◽  
Influenza A Virus ◽  
Host Species ◽  
Influenza A ◽  
Viral Fitness ◽  
Interferon Signaling ◽  
Structural Protein ◽  
New Host ◽  
Viral Adaptation ◽  
New Host Species

The non-structural protein 1 (NS1) of influenza A viruses plays important roles in viral fitness and in the process of interspecies adaptation. It is one of the most polymorphic and mutation-tolerant proteins of the influenza A genome, but its evolutionary patterns in different host species and the selective pressures that underlie them are hard to define. In this review, we highlight some of the species-specific molecular signatures apparent in different NS1 proteins and discuss two functions of NS1 in the process of viral adaptation to new host species. First, we consider the ability of NS1 proteins to broadly suppress host protein expression through interaction with CPSF4. This NS1 function can be spontaneously lost and regained through mutation and must be balanced against the need for host co-factors to aid efficient viral replication. Evidence suggests that this function of NS1 may be selectively lost in the initial stages of viral adaptation to some new host species. Second, we explore the ability of NS1 proteins to inhibit antiviral interferon signaling, an essential function for viral replication without which the virus is severely attenuated in any host. Innate immune suppression by NS1 not only enables viral replication in tissues, but also dampens the adaptive immune response and immunological memory. NS1 proteins suppress interferon signaling and effector functions through a variety of protein-protein interactions that may differ from host to host but must achieve similar goals. The multifunctional influenza A virus NS1 protein is highly plastic, highly versatile, and demonstrates a diversity of context-dependent solutions to the problem of interspecies adaptation.

scholarly journals Domain-Domain Interactions in the Self-Assembly of Non-Structural Protein 1 from Influenza a Virus

2021 ◽  
Vol 120 (3) ◽  
pp. 23a
Author(s):  
James E. Gonzales ◽  
Jie Shi ◽  
Jae-Hyun Cho ◽  
Wonmuk Hwang
Keyword(s):  
Influenza A Virus ◽  
Self Assembly ◽  
Influenza A ◽  
The Self ◽  
Structural Protein ◽  
Domain Interactions

scholarly journals Cyclophilin A interacts with influenza A virus M1 protein and impairs the early stage of the viral replication

2009 ◽  
Vol 11 (5) ◽  
pp. 730-741 ◽  
Author(s):  
Xiaoling Liu ◽  
Lei Sun ◽  
Maorong Yu ◽  
Zengfu Wang ◽  
Chongfeng Xu ◽  
...  
Keyword(s):  
Viral Replication ◽  
Influenza A Virus ◽  
Influenza A ◽  
Early Stage ◽  
Cyclophilin A ◽  
M1 Protein

scholarly journals Functional Analysis of PA Binding by Influenza A Virus PB1: Effects on Polymerase Activity and Viral Infectivity

2001 ◽  
Vol 75 (17) ◽  
pp. 8127-8136 ◽  
Author(s):  
Daniel R. Perez ◽  
Ruben O. Donis
Keyword(s):  
Amino Acids ◽  
Influenza Virus ◽  
Amino Acid ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Influenza A ◽  
Amino Acid Sequences ◽  
Influenza Viruses ◽  
Virus Growth ◽  
Transcription And Replication

ABSTRACT Influenza A virus expresses three viral polymerase (P) subunits—PB1, PB2, and PA—all of which are essential for RNA and viral replication. The functions of P proteins in transcription and replication have been partially elucidated, yet some of these functions seem to be dependent on the formation of a heterotrimer for optimal viral RNA transcription and replication. Although it is conceivable that heterotrimer subunit interactions may allow a more efficient catalysis, direct evidence of their essentiality for viral replication is lacking. Biochemical studies addressing the molecular anatomy of the P complexes have revealed direct interactions between PB1 and PB2 as well as between PB1 and PA. Previous studies have shown that the N-terminal 48 amino acids of PB1, termed domain α, contain the residues required for binding PA. We report here the refined mapping of the amino acid sequences within this small region of PB1 that are indispensable for binding PA by deletion mutagenesis of PB1 in a two-hybrid assay. Subsequently, we used site-directed mutagenesis to identify the critical amino acid residues of PB1 for interaction with PA in vivo. The first 12 amino acids of PB1 were found to constitute the core of the interaction interface, thus narrowing the previous boundaries of domain α. The role of the minimal PB1 domain α in influenza virus gene expression and genome replication was subsequently analyzed by evaluating the activity of a set of PB1 mutants in a model reporter minigenome system. A strong correlation was observed between a functional PA binding site on PB1 and P activity. Influenza viruses bearing mutant PB1 genes were recovered using a plasmid-based influenza virus reverse genetics system. Interestingly, mutations that rendered PB1 unable to bind PA were either nonviable or severely growth impaired. These data are consistent with an essential role for the N terminus of PB1 in binding PA, P activity, and virus growth.

Regressive evolution of an effector following a host jump in the Irish Potato Famine Pathogen Lineage

2021 ◽  
Author(s):  
Erin K. Zess ◽  
Yasin F. Dagdas ◽  
Esme Peers ◽  
Abbas Maqbool ◽  
Mark J. Banfield ◽  
...  
Keyword(s):  
Host Species ◽  
Irish Potato ◽  
Sequence Motif ◽  
New Host ◽  
Regressive Evolution ◽  
Host Environment ◽  
Host Jump ◽  
Potato Famine ◽  
Irish Potato Famine ◽  
New Host Species

AbstractIn order to infect a new host species, the pathogen must evolve to enhance infection and transmission in the novel environment. Although we often think of evolution as a process of accumulation, it is also a process of loss. Here, we document an example of regressive evolution in the Irish potato famine pathogen (Phytophthora infestans) lineage, providing evidence that a key sequence motif in the effector PexRD54 has degenerated following a host jump. We began by looking at PexRD54 and PexRD54-like sequences from across Phytophthora species. We found that PexRD54 emerged in the common ancestor of Phytophthora clade 1b and 1c species, and further sequence analysis showed that a key functional motif, the C-terminal ATG8-interacting motif (AIM), was also acquired at this point in the lineage. A closer analysis showed that the P. mirabilis PexRD54 (PmPexRD54) AIM appeared unusual, the otherwise-conserved central residue mutated from a glutamate to a lysine. We aimed to determine whether this PmPexRD54 AIM polymorphism represented an adaptation to the Mirabilis jalapa host environment. We began by characterizing the M. jalapa ATG8 family, finding that they have a unique evolutionary history compared to previously characterized ATG8s. Then, using co-immunoprecipitation and isothermal titration calorimetry assays, we showed that both full-length PmPexRD54 and the PmPexRD54 AIM peptide bind very weakly to the M. jalapa ATG8s. Through a combination of binding assays and structural modelling, we showed that the identity of the residue at the position of the PmPexRD54 AIM polymorphism can underpin high-affinity binding to plant ATG8s. Finally, we conclude that the functionality of the PexRD54 AIM was lost in the P. mirabilis lineage, perhaps owing to as-yet-unknown pressure on this effector in the new host environment.Author SummaryPathogens evolve in concert with their hosts. When a pathogen begins to infect a new host species, known as a “host jump,” the pathogen must evolve to enhance infection and transmission. These evolutionary processes can involve both the gain and loss of genes, as well as dynamic changes in protein function. Here, we describe an example of a pathogen protein that lost a key functional domain following a host jump, a salient example of “regressive evolution.” Specifically, we show that an effector protein from the plant pathogen Phytopthora mirabilis, a host-specific lineage closely related to the Irish potato famine pathogen Phytopthora infestans, has a derived amino acid polymorphism that results in a loss of interaction with certain host machinery.

scholarly journals The AntCardiocondyla elegansas Host of the Enigmatic Endoparasitic FungusMyrmicinosporidium durum

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Julia Giehr ◽  
Jürgen Heinze ◽  
Alexandra Schrempf
Keyword(s):  
Host Species ◽  
Sampling Methods ◽  
Infection Rates ◽  
New Host ◽  
High Infection ◽  
New Host Species

Data on host species and the distribution of the endoparasitic fungusMyrmicinosporidium durumincreased continuously in recent decades. Here, we add the antCardiocondyla elegansas new host species. Colonies of the monogynous species were found infested in the region of Languedoc-Roussillon (South France). Samples from the nest indicate high infection rates. All castes and sexes were infected by the spores. Variations of infection rates between sampling methods and species are discussed.

scholarly journals NLRP3 Inflammasome Activation Enhanced by TRIM25 is Targeted by the NS1 Protein of 2009 Pandemic Influenza A Virus

2021 ◽  
Vol 12 ◽  
Author(s):  
Hong-Su Park ◽  
Yao Lu ◽  
Kannupriya Pandey ◽  
GuanQun Liu ◽  
Yan Zhou
Keyword(s):  
Influenza A Virus ◽  
Nlrp3 Inflammasome ◽  
Influenza A ◽  
Inflammatory Responses ◽  
Interleukin 1 ◽  
Inflammasome Activation ◽  
Ns1 Protein ◽  
Structural Protein ◽  
Caspase 1 ◽  
C Terminus

Nucleotide-binding domain and leucine-rich repeat-containing protein 3 (NLRP3) inflammasome-mediated interleukin-1 beta (IL-1β) production is one of the crucial responses in innate immunity upon infection with viruses including influenza A virus (IAV) and is modulated by both viral and host cellular proteins. Among host proteins involved, we identified tripartite motif-containing protein 25 (TRIM25) as a positive regulator of porcine NLRP3 inflammasome-mediated IL-1β production. TRIM25 achieved this function by enhancing the pro-caspase-1 interaction with apoptosis-associated speck-like protein containing caspase recruitment domain (ASC). The N-terminal RING domain, particularly residues predicted to be critical for the E3 ligase activity of TRIM25, was responsible for this enhancement. However, non-structural protein 1 (NS1) C-terminus of 2009 pandemic IAV interfered with this action by interacting with TRIM25, leading to diminished association between pro-caspase-1 and ASC. These findings demonstrate that TRIM25 promotes the IL-1β signaling, while it is repressed by IAV NS1 protein, revealing additional antagonism of the NS1 against host pro-inflammatory responses.

scholarly journals Organization of the Influenza A Virus Genomic RNA in the Viral Replication Cycle—Structure, Interactions, and Implications for the Emergence of New Strains

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 951
Author(s):  
Julita Piasecka ◽  
Aleksandra Jarmolowicz ◽  
Elzbieta Kierzek
Keyword(s):  
Viral Replication ◽  
Influenza A Virus ◽  
Rna Structure ◽  
Influenza A ◽  
Respiratory Infections ◽  
Specific Interaction ◽  
Replication Cycle ◽  
Genome Packaging ◽  
Functional Roles ◽  
Interaction Sites

The influenza A virus is a human pathogen causing respiratory infections. The ability of this virus to trigger seasonal epidemics and sporadic pandemics is a result of its high genetic variability, leading to the ineffectiveness of vaccinations and current therapies. The source of this variability is the accumulation of mutations in viral genes and reassortment enabled by its segmented genome. The latter process can induce major changes and the production of new strains with pandemic potential. However, not all genetic combinations are tolerated and lead to the assembly of complete infectious virions. Reports have shown that viral RNA segments co-segregate in particular circumstances. This tendency is a consequence of the complex and selective genome packaging process, which takes place in the final stages of the viral replication cycle. It has been shown that genome packaging is governed by RNA–RNA interactions. Intersegment contacts create a network, characterized by the presence of common and strain-specific interaction sites. Recent studies have revealed certain RNA regions, and conserved secondary structure motifs within them, which may play functional roles in virion assembly. Growing knowledge on RNA structure and interactions facilitates our understanding of the appearance of new genome variants, and may allow for the prediction of potential reassortment outcomes and the emergence of new strains in the future.

New state and host records for Agromyzidae (Diptera) in the United States, with the description of thirty new species

Zootaxa ◽  
2018 ◽  
Vol 4479 (1) ◽  
pp. 1 ◽  
Author(s):  
CHARLES S. EISEMAN ◽  
OWEN LONSDALE
Keyword(s):  
United States ◽  
New Species ◽  
North America ◽  
Host Species ◽  
The United States ◽  
Distribution Data ◽  
New Host ◽  
The Usa ◽  
New Host Species ◽  
State Records

We present rearing records of Agromyzidae (Diptera) from five years of collecting throughout the United States. We review host and distribution data, and describe leaf mines, for 93 species, plus 28 others that could not be confidently identified in the absence of male specimens. We report 147 new host species records, including the first rearing records for Agromyza bispinata Spencer, A. diversa Johnson, A. parca Spencer, A. pudica Spencer, A. vockerothi Spencer, Calycomyza michiganensis Steyskal, Ophiomyia congregata (Malloch), and Phytomyza aldrichi Spencer. Phytomyza anemones Hering and (tentatively identified) Cerodontha (Dizygomyza) iraeos (Robineau-Desvoidy) are new to North America; Agromyza albitarsis Meigen, Amauromyza shepherdiae Sehgal, Aulagromyza populicola (Walker), Liriomyza orilliensis Spencer, Phytomyza linnaeae (Griffiths), P. solidaginivora Spencer, and P. solidaginophaga Sehgal are new to the USA. We also present confirmed USA records for Calycomyza menthae Spencer (previous records were based only on leaf mines), Ophiomyia maura (Meigen) (reported from the USA in older literature but deleted from the fauna in the most recent revision (Spencer & Steyskal 1986)), and Phytomyza astotinensis Griffiths and P. thalictrivora Spencer (previously only tentatively recorded from the USA). We provide 111 additional new state records. We describe the following 30 new species: Agromyza fission, A. soka, Melanagromyza palmeri, Ophiomyia euthamiae, O. mimuli, O. parda, Calycomyza artemisivora, C. avira, C. eupatoriphaga, C. vogelmanni, Cerodontha (Dizygomyza) edithae, Cer. (D.) feldmani, Liriomyza ivorcutleri, L. valerianivora, Phytomyza actaeivora, P. aesculi, P. confusa, P. doellingeriae, P. erigeronis, P. hatfieldae, P. hydrophyllivora, P. palmeri, P. palustris, P. sempervirentis, P. tarnwoodensis, P. tigris, P. triangularidis, P. vancouveriella, P. verbenae, and P. ziziae. 

scholarly journals Host Shutoff in Influenza A Virus: Many Means to an End

Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 475 ◽  
Author(s):  
Rachel Levene ◽  
Marta Gaglia
Keyword(s):  
Immune Responses ◽  
Influenza A Virus ◽  
Influenza A ◽  
Rna Synthesis ◽  
Viral Proteins ◽  
Host Gene Expression ◽  
Structural Protein ◽  
Infected Cells ◽  
Host Shutoff ◽  
Virus Replication Cycle

Influenza A virus carries few of its own proteins, but uses them effectively to take control of the infected cells and avoid immune responses. Over the years, host shutoff, the widespread down-regulation of host gene expression, has emerged as a key process that contributes to cellular takeover in infected cells. Interestingly, multiple mechanisms of host shutoff have been described in influenza A virus, involving changes in translation, RNA synthesis and stability. Several viral proteins, notably the non-structural protein NS1, the RNA-dependent RNA polymerase and the endoribonuclease PA-X have been implicated in host shutoff. This multitude of host shutoff mechanisms indicates that host shutoff is an important component of the influenza A virus replication cycle. Here we review the various mechanisms of host shutoff in influenza A virus and the evidence that they contribute to immune evasion and/or viral replication. We also discuss what the purpose of having multiple mechanisms may be.

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