scholarly journals Influenza A matrix protein M1 is sufficient to induce lipid membrane deformation

2019 ◽  
Author(s):  
Ismail Dahmani ◽  
Kai Ludwig ◽  
Salvatore Chiantia
Keyword(s):  
Influenza A ◽  
Matrix Protein ◽  
Lipid Membrane ◽  
Membrane Curvature ◽  
Correlation Spectroscopy ◽  
Dimensional Structure ◽  
Membrane Deformation ◽  
Induced Membrane ◽  
Cellular Models ◽  
Matrix Protein M1

AbstractThe matrix protein M1 of the Influenza A virus is considered to mediate viral assembly and budding at the plasma membrane (PM) of infected cells. In order for a new viral particle to form, the PM lipid bilayer has to bend into a vesicle towards the extracellular side. Studies in cellular models have proposed that different viral proteins might be responsible for inducing membrane curvature in this context (including M1), but a clear consensus has not been reached. In this study, we use a combination of fluorescence microscopy, cryogenic transmission electron microscopy (cryo-TEM), cryo-electron tomography (cryo-ET) and scanning fluorescence correlation spectroscopy (sFCS) to investigate M1-induced membrane deformation in biophysical models of the PM. Our results indicate that M1 is indeed capable to cause membrane curvature in lipid bilayers containing negatively-charged lipids, in the absence of other viral components. Furthermore, we prove that simple protein binding is not sufficient to induce membrane restructuring. Rather, it appears that stable M1-M1 interactions and multimer formation are required in order to alter the bilayer three-dimensional structure, through the formation of a protein scaffold. Finally, our results suggest that, in a physiological context, M1-induced membrane deformation might be modulated by the initial bilayer curvature and the lateral organization of membrane components (i.e. the presence of lipid domains).

scholarly journals Influenza A matrix protein M1 induces lipid membrane deformation via protein multimerization

2019 ◽  
Vol 39 (8) ◽  
Author(s):  
Ismail Dahmani ◽  
Kai Ludwig ◽  
Salvatore Chiantia
Keyword(s):  
Influenza A ◽  
Matrix Protein ◽  
Lipid Membrane ◽  
Membrane Curvature ◽  
Correlation Spectroscopy ◽  
Dimensional Structure ◽  
Membrane Deformation ◽  
Induced Membrane ◽  
Cellular Models ◽  
Matrix Protein M1

Abstract The matrix protein M1 of the Influenza A virus (IAV) is supposed to mediate viral assembly and budding at the plasma membrane (PM) of infected cells. In order for a new viral particle to form, the PM lipid bilayer has to bend into a vesicle toward the extracellular side. Studies in cellular models have proposed that different viral proteins might be responsible for inducing membrane curvature in this context (including M1), but a clear consensus has not been reached. In the present study, we use a combination of fluorescence microscopy, cryogenic transmission electron microscopy (cryo-TEM), cryo-electron tomography (cryo-ET) and scanning fluorescence correlation spectroscopy (sFCS) to investigate M1-induced membrane deformation in biophysical models of the PM. Our results indicate that M1 is indeed able to cause membrane curvature in lipid bilayers containing negatively charged lipids, in the absence of other viral components. Furthermore, we prove that protein binding is not sufficient to induce membrane restructuring. Rather, it appears that stable M1–M1 interactions and multimer formation are required in order to alter the bilayer three-dimensional structure, through the formation of a protein scaffold. Finally, our results suggest that, in a physiological context, M1-induced membrane deformation might be modulated by the initial bilayer curvature and the lateral organization of membrane components (i.e. the presence of lipid domains).

scholarly journals Multi-color fluorescence fluctuation spectroscopy in living cells via spectral detection

2020 ◽  
Author(s):  
Valentin Dunsing ◽  
Annett Petrich ◽  
Salvatore Chiantia
Keyword(s):  
Correlation Analysis ◽  
Influenza A ◽  
Cross Correlation ◽  
Matrix Protein ◽  
Living Cells ◽  
Correlation Spectroscopy ◽  
Image Correlation ◽  
Fluorescence Fluctuation Spectroscopy ◽  
Diffusion Dynamics ◽  
Cross Correlation Analysis

AbstractFluorescence fluctuation spectroscopy provides a powerful toolbox to quantify transport dynamics and interactions between biomolecules in living cells. For example, cross-correlation analysis of spectrally separated fluctuations allows the investigation of inter-molecular interactions. This analysis is conventionally limited to two fluorophore species that are excited with a single or two different laser lines and detected in two non-overlapping spectral channels. However, signaling pathways in biological systems often involve interactions between multiple biomolecules, e.g. formation of ternary or quaternary protein complexes. Here, we present a methodology to investigate such interactions at the plasma membrane (PM) of cells, as encountered for example in viral assembly or receptor-ligand interactions. To this aim, we introduce scanning fluorescence spectral correlation spectroscopy (SFSCS), a combination of scanning fluorescence correlation spectroscopy with spectrally resolved detection and decomposition. We first demonstrate that SFSCS allows cross-talk-free cross-correlation analysis of PM-associated proteins labeled with strongly overlapping fluorescent proteins (FPs), such as mEGFP and mEYFP, excited with a single excitation line. We then verify the applicability of SFSCS for quantifying diffusion dynamics and protein oligomerization (based on molecular brightness analysis) of two protein species tagged with spectrally overlapping FPs. Adding a second laser line, we demonstrate the possibility of three- and four-species (cross-) correlation analysis using mApple and mCherry2, as examples of strongly overlapping FP tags in the red spectral region. Next, we apply this scheme to investigate the interactions of influenza A virus (IAV) matrix protein 2 (M2) with two cellular host factors simultaneously. Using the same set of fluorophores, we furthermore extend the recently presented raster spectral image correlation spectroscopy (RSICS) approach to four species analysis, successfully demonstrating multiplexed RSICS measurements of protein interactions in the cell cytoplasm. Finally, we apply RSICS to investigate the assembly of the ternary IAV polymerase complex and report a 2:2:2 stoichiometry of these protein assemblies in the nucleus of living cells.

scholarly journals Structural determinants of the interaction between influenza A virus matrix protein M1 and lipid membranes

2019 ◽  
Vol 1861 (6) ◽  
pp. 1123-1134 ◽  
Author(s):  
C.T. Höfer ◽  
S. Di Lella ◽  
I. Dahmani ◽  
N. Jungnick ◽  
N. Bordag ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Lipid Membranes ◽  
Influenza A ◽  
Matrix Protein ◽  
Structural Determinants ◽  
Matrix Protein M1

scholarly journals Endogenously expressed matrix protein M1 and nucleoprotein of influenza A are efficiently presented by class I and class II major histocompatibility complexes

2011 ◽  
Vol 92 (5) ◽  
pp. 1162-1171 ◽  
Author(s):  
Jean-Daniel Doucet ◽  
Marie-Andrée Forget ◽  
Cécile Grange ◽  
Ronan Nicolas Rouxel ◽  
Nathalie Arbour ◽  
...  
Keyword(s):  
Influenza A ◽  
Matrix Protein ◽  
Class Ii ◽  
Influenza Vaccines ◽  
Class I ◽  
Mhc I ◽  
Mhc Ii ◽  
The Matrix ◽  
Specific Effector ◽  
Matrix Protein M1

Current influenza vaccines containing primarily hypervariable haemagglutinin and neuraminidase proteins must be prepared against frequent new antigenic variants. Therefore, there is an ongoing effort to develop influenza vaccines that also elicit strong and sustained cytotoxic responses against highly conserved determinants such as the matrix (M1) protein and nucleoprotein (NP). However, their antigenic presentation properties in humans are less defined. Accordingly, we analysed MHC class I and class II presentation of endogenously processed M1 and NP in human antigen presenting cells and observed expansion of both CD8+- and CD4+-specific effector T lymphocytes secreting gamma interferon and tumour necrosis factor. Further enhancement of basal MHC-II antigenic presentation did not improve CD4+ or CD8+ T-cell quality based on cytokine production upon challenge, suggesting that endogenous M1 and NP MHC-II presentation is sufficient. These new insights about T-lymphocyte expansion following endogenous M1 and NP MHC-I and -II presentation will be important to design complementary heterosubtypic vaccination strategies.

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 Cell penetrable human ScFv specific to influenza A virus matrix protein, M1, mitigates influenza severity

2013 ◽  
Vol 4 ◽  
Author(s):  
Dong-din-on Fonthip ◽  
Srimanote Potjanee ◽  
Pissawong Tippawan ◽  
Monkong Angkasiya ◽  
Lertwatcharasarakul Preeda ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Matrix Protein ◽  
Human Scfv ◽  
Matrix Protein M1

scholarly journals Influenza Virus M2 Ion Channel Protein Is Necessary for Filamentous Virion Formation

2010 ◽  
Vol 84 (10) ◽  
pp. 5078-5088 ◽  
Author(s):  
Jeremy S. Rossman ◽  
Xianghong Jing ◽  
George P. Leser ◽  
Victoria Balannik ◽  
Lawrence H. Pinto ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Matrix Protein ◽  
Influenza Virus Infection ◽  
Cytoplasmic Tail ◽  
Integral Membrane Protein ◽  
Filament Formation ◽  
The Matrix ◽  
Matrix Protein M1 ◽  
Raft Domains

ABSTRACT Influenza A virus buds from cells as spherical (∼100-nm diameter) and filamentous (∼100 nm × 2 to 20 μm) virions. Previous work has determined that the matrix protein (M1) confers the ability of the virus to form filaments; however, additional work has suggested that the influenza virus M2 integral membrane protein also plays a role in viral filament formation. In examining the role of the M2 protein in filament formation, we observed that the cytoplasmic tail of M2 contains several sites that are essential for filament formation. Additionally, whereas M2 is a nonraft protein, expression of other viral proteins in the context of influenza virus infection leads to the colocalization of M2 with sites of virus budding and lipid raft domains. We found that an amphipathic helix located within the M2 cytoplasmic tail is able to bind cholesterol, and we speculate that M2 cholesterol binding is essential for both filament formation and the stability of existing viral filaments.

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