scholarly journals The Cytoplasmic Tail of Influenza A Virus Hemagglutinin and Membrane Lipid Composition Change the Mode of M1 Protein Association with the Lipid Bilayer

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 772
Author(s):  
Larisa V. Kordyukova ◽  
Petr V. Konarev ◽  
Nataliya V. Fedorova ◽  
Eleonora V. Shtykova ◽  
Alexander L. Ksenofontov ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Influenza A Virus ◽  
Influenza A ◽  
Matrix Protein ◽  
Lipid Membrane ◽  
Viral Proteins ◽  
Membrane Lipid ◽  
Viral Envelope ◽  
Virus Envelope ◽  
Complementary Techniques

Influenza A virus envelope contains lipid molecules of the host cell and three integral viral proteins: major hemagglutinin, neuraminidase, and minor M2 protein. Membrane-associated M1 matrix protein is thought to interact with the lipid bilayer and cytoplasmic domains of integral viral proteins to form infectious virus progeny. We used small-angle X-ray scattering (SAXS) and complementary techniques to analyze the interactions of different components of the viral envelope with M1 matrix protein. Small unilamellar liposomes composed of various mixtures of synthetic or “native” lipids extracted from Influenza A/Puerto Rico/8/34 (H1N1) virions as well as proteoliposomes built from the viral lipids and anchored peptides of integral viral proteins (mainly, hemagglutinin) were incubated with isolated M1 and measured using SAXS. The results imply that M1 interaction with phosphatidylserine leads to condensation of the lipid in the protein-contacting monolayer, thus resulting in formation of lipid tubules. This effect vanishes in the presence of the liquid-ordered (raft-forming) constituents (sphingomyelin and cholesterol) regardless of their proportion in the lipid bilayer. We also detected a specific role of the hemagglutinin anchoring peptides in ordering of viral lipid membrane into the raft-like one. These peptides stimulate the oligomerization of M1 on the membrane to form a viral scaffold for subsequent budding of the virion from the plasma membrane of the infected cell.

scholarly journals Multivesicular Bodies as a Platform for Formation of the Marburg Virus Envelope

2004 ◽  
Vol 78 (22) ◽  
pp. 12277-12287 ◽  
Author(s):  
Larissa Kolesnikova ◽  
Beate Berghöfer ◽  
Sandra Bamberg ◽  
Stephan Becker
Keyword(s):  
Intracellular Transport ◽  
Matrix Protein ◽  
Lipid Membrane ◽  
Marburg Virus ◽  
Viral Envelope ◽  
Multivesicular Bodies ◽  
Virus Envelope ◽  
Transport Pathways ◽  
Virus Like Particles

ABSTRACT The Marburg virus (MARV) envelope consists of a lipid membrane and two major proteins, the matrix protein VP40 and the glycoprotein GP. Both proteins use different intracellular transport pathways: GP utilizes the exocytotic pathway, while VP40 is transported through the retrograde late endosomal pathway. It is currently unknown where the proteins combine to form the viral envelope. In the present study, we identified the intracellular site where the two major envelope proteins of MARV come together as peripheral multivesicular bodies (MVBs). Upon coexpression with VP40, GP is redistributed from the trans-Golgi network into the VP40-containing MVBs. Ultrastructural analysis of MVBs suggested that they provide the platform for the formation of membrane structures that bud as virus-like particles from the cell surface. The virus-like particles contain both VP40 and GP. Single expression of GP also resulted in the release of particles, which are round or pleomorphic. Single expression of VP40 led to the release of filamentous structures that closely resemble viral particles and contain traces of endosomal marker proteins. This finding indicated a central role of VP40 in the formation of the filamentous structure of MARV particles, which is similar to the role of the related Ebola virusVP40. In MARV-infected cells, VP40 and GP are colocalized in peripheral MVBs as well. Moreover, intracellular budding of progeny virions into MVBs was frequently detected. Taken together, these results demonstrate an intracellular intersection between GP and VP40 pathways and suggest a crucial role of the late endosomal compartment for the formation of the viral envelope.

scholarly journals Crystal structure of an orthomyxovirus matrix protein reveals mechanisms for self-polymerization and membrane association

2017 ◽  
Vol 114 (32) ◽  
pp. 8550-8555 ◽  
Author(s):  
Wenting Zhang ◽  
Wenjie Zheng ◽  
Yukimatsu Toh ◽  
Miguel A. Betancourt-Solis ◽  
Jiagang Tu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Lattice ◽  
Influenza A Virus ◽  
Nuclear Export ◽  
Influenza A ◽  
Electrostatic Interactions ◽  
Matrix Protein ◽  
Structural Integrity ◽  
Viral Envelope ◽  
Protein Layer

Many enveloped viruses encode a matrix protein. In the influenza A virus, the matrix protein M1 polymerizes into a rigid protein layer underneath the viral envelope to help enforce the shape and structural integrity of intact viruses. The influenza virus M1 is also known to mediate virus budding as well as the nuclear export of the viral nucleocapsids and their subsequent packaging into nascent viral particles. Despite extensive studies on the influenza A virus M1 (FLUA-M1), only crystal structures of its N-terminal domain are available. Here we report the crystal structure of the full-length M1 from another orthomyxovirus that infects fish, the infectious salmon anemia virus (ISAV). The structure of ISAV-M1 assumes the shape of an elbow, with its N domain closely resembling that of the FLUA-M1. The C domain, which is connected to the N domain through a flexible linker, is made of four α-helices packed as a tight bundle. In the crystal, ISAV-M1 monomers form infinite 2D arrays with a network of interactions involving both the N and C domains. Results from liposome flotation assays indicated that ISAV-M1 binds membrane via electrostatic interactions that are primarily mediated by a positively charged surface loop from the N domain. Cryoelectron tomography reconstruction of intact ISA virions identified a matrix protein layer adjacent to the inner leaflet of the viral membrane. The physical dimensions of the virion-associated matrix layer are consistent with the 2D ISAV-M1 crystal lattice, suggesting that the crystal lattice is a valid model for studying M1–M1, M1–membrane, and M1–RNP interactions in the virion.

Co-evolution analysis to predict protein–protein interactions within influenza virus envelope

2014 ◽  
Vol 12 (02) ◽  
pp. 1441008 ◽  
Author(s):  
Ramil R. Mintaev ◽  
Andrei V. Alexeevski ◽  
Larisa V. Kordyukova
Keyword(s):  
Amino Acid ◽  
Protein Interactions ◽  
Influenza A ◽  
Matrix Protein ◽  
Amino Acid Sequences ◽  
Viral Envelope ◽  
Research Database ◽  
Virus Envelope ◽  
Physical Constraints ◽  
Matrix Protein M1

Interactions between integral membrane proteins hemagglutinin (HA), neuraminidase (NA), M2 and membrane-associated matrix protein M1 of influenza A virus are thought to be crucial for assembly of functionally competent virions. We hypothesized that the amino acid residues located at the interface of two different proteins are under physical constraints and thus probably co-evolve. To predict co-evolving residue pairs, the EvFold ( http://evfold.org ) program searching the (nontransitive) Direct Information scores was applied for large samplings of amino acid sequences from Influenza Research Database ( http://www.fludb.org/ ). Having focused on the HA, NA, and M2 cytoplasmic tails as well as C-terminal domain of M1 (being the less conserved among the protein domains) we captured six pairs of correlated positions. Among them, there were one, two, and three position pairs for HA–M2, HA–M1, and M2–M1 protein pairs, respectively. As expected, no co-varying positions were found for NA–HA, NA–M1, and NA–M2 pairs obviously due to high conservation of the NA cytoplasmic tail. The sum of frequencies calculated for two major amino acid patterns observed in pairs of correlated positions was up to 0.99 meaning their high to extreme evolutionary sustainability. Based on the predictions a hypothetical model of pair-wise protein interactions within the viral envelope was proposed.

scholarly journals Human Cytotoxic T-Lymphocyte Repertoire to Influenza A Viruses

1998 ◽  
Vol 72 (11) ◽  
pp. 8682-8689 ◽  
Author(s):  
Julie Jameson ◽  
John Cruz ◽  
Francis A. Ennis
Keyword(s):  
Cell Line ◽  
Influenza A Virus ◽  
Cell Lines ◽  
T Lymphocyte ◽  
Influenza A ◽  
Matrix Protein ◽  
Cytotoxic T Lymphocyte ◽  
Viral Proteins ◽  
Influenza A Viruses ◽  
Nonstructural Protein 1

ABSTRACT The murine CD8+ cytotoxic-T-lymphocyte (CTL) repertoire appears to be quite limited in response to influenza A viruses. The CTL responses to influenza A virus in humans were examined to determine if the CTL repertoire is also very limited. Bulk cultures revealed that a number of virus proteins were recognized in CTL assays. CTL lines were isolated from three donors for detailed study and found to be specific for epitopes on numerous influenza A viral proteins. Eight distinct CD8+ CTL lines were isolated from donor 1. The proteins recognized by these cell lines included the nucleoprotein (NP), matrix protein (M1), nonstructural protein 1 (NS1), polymerases (PB1 and PB2), and hemagglutinin (HA). Two CD4+ cell lines, one specific for neuraminidase (NA) and the other specific for M1, were also characterized. These CTL results were confirmed by precursor frequency analysis of peptide-specific gamma interferon-producing cells detected by ELISPOT. The epitopes recognized by 6 of these 10 cell lines have not been previously described; 8 of the 10 cell lines were cross-reactive to subtype H1N1, H2N2, and H3N2 viruses, 1 cell line was cross-reactive to subtypes H1N1 and H2N2, and 1 cell line was subtype H1N1 specific. A broad CTL repertoire was detected in the two other donors, and cell lines specific for the NP, NA, HA, M1, NS1, and M2 viral proteins were isolated. These findings indicate that the human memory CTL response to influenza A virus is broadly directed to epitopes on a wide variety of proteins, unlike the limited response observed following infection of mice.

scholarly journals Influenza A M2 recruits M1 to the plasma membrane: a fluorescence fluctuation microscopy study

2021 ◽  
Author(s):  
Annett Petrich ◽  
Valentin Dunsing ◽  
Sara Bobone ◽  
Salvatore Chiantia
Keyword(s):  
Plasma Membrane ◽  
Influenza A ◽  
Cross Correlation ◽  
Matrix Protein ◽  
Viral Proteins ◽  
Correlation Spectroscopy ◽  
Viral Envelope ◽  
Respiratory Pathogen ◽  
Oligomeric State ◽  
Fluctuation Microscopy

Influenza A virus (IAV) is a respiratory pathogen that causes seasonal epidemics and occasional pandemics of severe illnesses with significant mortality. One of the most abundant proteins in IAV particles is the matrix protein 1 (M1), which is essential for the structural stability of the virus. M1 organizes virion assembly and budding at the plasma membrane (PM), where it can interact with other viral components and cellular membrane factors (i.e. lipids and host proteins). Of interest, the recruitment of M1 to the PM as well as its interaction with the other viral envelope proteins (hemagglutinin (HA), neuraminidase, matrix protein 2 (M2)) is controversially discussed in previous studies. Therefore, we used fluorescence fluctuation microscopy techniques (i.e. (cross-correlation) number and brightness, and scanning fluorescence cross-correlation spectroscopy) to quantify the oligomeric state of M1 and its interaction with other viral proteins in co-transfected as well as infected cells. Our results indicate that M1 is recruited to the PM by M2, as a consequence of the strong interaction between the two proteins. In contrast, only a weak interaction between M1 and HA was observed. M1-HA interaction occurred only in the case that M1 was already bound to the PM. We therefore conclude that M2 initiates the assembly of IAV by recruiting M1 to the PM, possibly allowing its further interaction with other viral proteins.

scholarly journals Identification of the domains of the influenza A virus M1 matrix protein required for NP binding, oligomerization and incorporation into virions

2007 ◽  
Vol 88 (8) ◽  
pp. 2280-2290 ◽  
Author(s):  
Sarah L. Noton ◽  
Elizabeth Medcalf ◽  
Dawn Fisher ◽  
Anne E. Mullin ◽  
Debra Elton ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Protein Interactions ◽  
Influenza A ◽  
Matrix Protein ◽  
Fluorescent Protein ◽  
Viral Envelope ◽  
Major Protein ◽  
Middle Domain ◽  
Self Association

The matrix (M1) protein of influenza A virus is a multifunctional protein that plays essential structural and functional roles in the virus life cycle. It drives virus budding and is the major protein component of the virion, where it forms an intermediate layer between the viral envelope and integral membrane proteins and the genomic ribonucleoproteins (RNPs). It also helps to control the intracellular trafficking of RNPs. These roles are mediated primarily via protein–protein interactions with viral and possibly cellular proteins. Here, the regions of M1 involved in binding the viral RNPs and in mediating homo-oligomerization are identified. In vitro, by using recombinant proteins, it was found that the middle domain of M1 was responsible for binding NP and that this interaction did not require RNA. Similarly, only M1 polypeptides containing the middle domain were able to bind to RNP–M1 complexes isolated from purified virus. When M1 self-association was examined, all three domains of the protein participated in homo-oligomerization although, again, the middle domain was dominant and self-associated efficiently in the absence of the N- and C-terminal domains. However, when the individual fragments of M1 were tagged with green fluorescent protein and expressed in virus-infected cells, microscopy of filamentous particles showed that only full-length M1 was incorporated into budding virions. It is concluded that the middle domain of M1 is primarily responsible for binding NP and self-association, but that additional interactions are required for efficient incorporation of M1 into virus particles.

scholarly journals Antiviral Activity of Benzoic Acid Derivative NC-5 Against Influenza A Virus and Its Neuraminidase Inhibition

2019 ◽  
Vol 20 (24) ◽  
pp. 6261
Author(s):  
Min Guo ◽  
Jiawei Ni ◽  
Jie Yu ◽  
Jing Jin ◽  
Lingman Ma ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Benzoic Acid ◽  
Influenza A Virus ◽  
Influenza A ◽  
Matrix Protein ◽  
Influenza Viruses ◽  
Drug Candidate ◽  
Dependent Manner ◽  
Drug Resistant

The currently available drugs against influenza A virus primarily target neuraminidase (NA) or the matrix protein 2 (M2) ion channel. The emergence of drug-resistant viruses requires the development of new antiviral chemicals. Our study applied a cell-based approach to evaluate the antiviral activity of a series of newly synthesized benzoic acid derivatives, and 4-(2,2-Bis(hydroxymethyl)-5-oxopyrrolidin-l-yl)-3-(5-cyclohexyl-4H-1,2,4-triazol-3-yl)amino). benzoic acid, termed NC-5, was found to possess antiviral activity. NC-5 inhibited influenza A viruses A/FM/1/47 (H1N1), A/Beijing/32/92 (H3N2) and oseltamivir-resistant mutant A/FM/1/47-H275Y (H1N1-H275Y) in a dose-dependent manner. The 50% effective concentrations (EC50) for H1N1 and H1N1-H275Y were 33.6 μM and 32.8 μM, respectively, which showed that NC-5 had a great advantage over oseltamivir in drug-resistant virus infections. The 50% cytotoxic concentration (CC50) of NC-5 was greater than 640 μM. Orally administered NC-5 protected mice infected with H1N1 and H1N1-H275Y, conferring 80% and 60% survival at 100 mg/kg/d, reducing body weight loss, and alleviating virus-induced lung injury. NC-5 could suppress NP and M1 protein expression levels during the late stages of viral biosynthesis and inhibit NA activity, which may influence virus release. Our study proved that NC-5 has potent anti-influenza activity in vivo and in vitro, meaning that it could be regarded as a promising drug candidate to treat infection with influenza viruses, including oseltamivir-resistant viruses.

scholarly journals Cooperation between the Hemagglutinin of Avian Viruses and the Matrix Protein of Human Influenza A Viruses

2002 ◽  
Vol 76 (4) ◽  
pp. 1781-1786 ◽  
Author(s):  
Christoph Scholtissek ◽  
Jürgen Stech ◽  
Scott Krauss ◽  
Robert G. Webster
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Matrix Protein ◽  
Gene Products ◽  
Human Influenza ◽  
Influenza A Viruses ◽  
M Gene ◽  
Human Virus ◽  
Ha Gene ◽  
M Proteins

ABSTRACT To analyze the compatibility of avian influenza A virus hemagglutinins (HAs) and human influenza A virus matrix (M) proteins M1 and M2, we doubly infected Madin-Darby canine kidney cells with amantadine (1-aminoadamantane hydrochloride)-resistant human viruses and amantadine-sensitive avian strains. By using antisera against the human virus HAs and amantadine, we selected reassortants containing the human virus M gene and the avian virus HA gene. In our system, high virus yields and large, well-defined plaques indicated that the avian HAs and the human M gene products could cooperate effectively; low virus yields and small, turbid plaques indicated that cooperation was poor. The M gene products are among the primary components that determine the species specificities of influenza A viruses. Therefore, our system also indicated whether the avian HA genes effectively reassorted into the genome and replaced the HA gene of the prevailing human influenza A viruses. Most of the avian HAs that we tested efficiently cooperated with the M gene products of the early human A/PR/8/34 (H1N1) virus; however, the avian HAs did not effectively cooperate with the most recently isolated human virus that we tested, A/Nanchang/933/95 (H3N2). Cooperation between the avian HAs and the M proteins of the human A/Singapore/57 (H2N2) virus was moderate. These results suggest that the currently prevailing human influenza A viruses might have lost their ability to undergo antigenic shift and therefore are unable to form new pandemic viruses that contain an avian HA, a finding that is of great interest for pandemic planning.

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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