Proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. They promote cell membrane fusion and thereby may function in the uptake of the virus by cells.
The adherence and merging of cell membranes, intracellular membranes, or artificial membranes to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes.
The entering of cells by viruses following VIRUS ATTACHMENT. This is achieved by ENDOCYTOSIS, by direct MEMBRANE FUSION of the viral membrane with the CELL MEMBRANE, or by translocation of the whole virus across the cell membrane.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Fusion of somatic cells in vitro or in vivo, which results in somatic cell hybridization.
Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.
A subgroup of the genus FLAVIVIRUS that causes encephalitis and hemorrhagic fevers and is found in eastern and western Europe and the former Soviet Union. It is transmitted by TICKS and there is an associated milk-borne transmission from viremic cattle, goats, and sheep.
A class I viral fusion protein that forms the characteristic spikes, or peplomers, found on the viral surface that mediate virus attachment, fusion, and entry into the host cell. During virus maturation, it is cleaved into two subunits: S1, which binds to receptors in the host cell, and S2, which mediates membrane fusion.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Multinucleated masses produced by the fusion of many cells; often associated with viral infections. In AIDS, they are induced when the envelope glycoprotein of the HIV virus binds to the CD4 antigen of uninfected neighboring T4 cells. The resulting syncytium leads to cell death and thus may account for the cytopathic effect of the virus.
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.
A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Established cell cultures that have the potential to propagate indefinitely.
A species of CORONAVIRUS causing atypical respiratory disease (SEVERE ACUTE RESPIRATORY SYNDROME) in humans. The organism is believed to have first emerged in Guangdong Province, China, in 2002. The natural host is the Chinese horseshoe bat, RHINOLOPHUS sinicus.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
Glycoproteins found on the membrane or surface of cells.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Transmembrane envelope protein of the HUMAN IMMUNODEFICIENCY VIRUS which is encoded by the HIV env gene. It has a molecular weight of 41,000 and is glycosylated. The N-terminal part of gp41 is thought to be involved in CELL FUSION with the CD4 ANTIGENS of T4 LYMPHOCYTES, leading to syncytial formation. Gp41 is one of the most common HIV antigens detected by IMMUNOBLOTTING.
A subfamily of PARAMYXOVIRIDAE. Genera include RUBULAVIRUS; RESPIROVIRUS; MORBILLIVIRUS; HENIPAVIRUS; and AVULAVIRUS.
The GENETIC TRANSLATION products of the fusion between an ONCOGENE and another gene. The latter may be of viral or cellular origin.
The GENETIC RECOMBINATION of the parts of two or more GENES resulting in a gene with different or additional regulatory regions, or a new chimeric gene product. ONCOGENE FUSION includes an ONCOGENE as at least one of the fusion partners and such gene fusions are often detected in neoplastic cells and are transcribed into ONCOGENE FUSION PROTEINS. ARTIFICIAL GENE FUSION is carried out in vitro by RECOMBINANT DNA technology.
Operative immobilization or ankylosis of two or more vertebrae by fusion of the vertebral bodies with a short bone graft or often with diskectomy or laminectomy. (From Blauvelt & Nelson, A Manual of Orthopaedic Terminology, 5th ed, p236; Dorland, 28th ed)
Specific hemagglutinin subtypes encoded by VIRUSES.
Glycoprotein from Sendai, para-influenza, Newcastle Disease, and other viruses that participates in binding the virus to cell-surface receptors. The HN protein possesses both hemagglutinin and neuraminidase activity.
Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.
A genus of the family PARAMYXOVIRIDAE (subfamily PARAMYXOVIRINAE) where all the virions have both HEMAGGLUTININ and NEURAMINIDASE activities and encode a non-structural C protein. SENDAI VIRUS is the type species.
Inhibitors of the fusion of HIV to host cells, preventing viral entry. This includes compounds that block attachment of HIV ENVELOPE PROTEIN GP120 to CD4 RECEPTORS.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.
Proteins that catalyze MEMBRANE FUSION.
A species of RESPIROVIRUS also called hemadsorption virus 2 (HA2), which causes laryngotracheitis in humans, especially children.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
A sequential pattern of amino acids occurring more than once in the same protein sequence.
The infective system of a virus, composed of the viral genome, a protein core, and a protein coat called a capsid, which may be naked or enclosed in a lipoprotein envelope called the peplos.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
A family of RNA viruses causing INFLUENZA and other diseases. There are five recognized genera: INFLUENZAVIRUS A; INFLUENZAVIRUS B; INFLUENZAVIRUS C; ISAVIRUS; and THOGOTOVIRUS.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A species of ALPHAVIRUS isolated in central, eastern, and southern Africa.
Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.
The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.
Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.
Proteins found in any species of virus.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
The type species of the genus INFLUENZAVIRUS A that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The rate dynamics in chemical or physical systems.
Cytoplasmic vesicles formed when COATED VESICLES shed their CLATHRIN coat. Endosomes internalize macromolecules bound by receptors on the cell surface.
Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.
Periplasmic proteins that bind MALTOSE and maltodextrin. They take part in the maltose transport system of BACTERIA.
A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
The GENETIC RECOMBINATION of the parts of two or more GENES, including an ONCOGENE as at least one of the fusion partners. Such gene fusions are often detected in neoplastic cells and are transcribed into ONCOGENE FUSION PROTEINS.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
A transferase that catalyzes the addition of aliphatic, aromatic, or heterocyclic FREE RADICALS as well as EPOXIDES and arene oxides to GLUTATHIONE. Addition takes place at the SULFUR. It also catalyzes the reduction of polyol nitrate by glutathione to polyol and nitrite.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Proteins prepared by recombinant DNA technology.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
Proteins found in any species of bacterium.
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.
Transport proteins that carry specific substances in the blood or across cell membranes.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Crystallizable fragments composed of the carboxy-terminal halves of both IMMUNOGLOBULIN HEAVY CHAINS linked to each other by disulfide bonds. Fc fragments contain the carboxy-terminal parts of the heavy chain constant regions that are responsible for the effector functions of an immunoglobulin (COMPLEMENT fixation, binding to the cell membrane via FC RECEPTORS, and placental transport). This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.

Definition of a major p53 binding site on Ad2E1B58K protein and a possible nuclear localization signal on the Ad12E1B54K protein. (1/1579)

Previous studies have established that adenovirus 2/5 early region 1B (Ad E1B) 58K protein binds p53 strongly and co-localizes with it to cytoplasmic dense bodies whilst the homologous Ad12E1B54K protein binds only weakly and co-localizes primarily to the nucleus in Ad12E1 transformed cells. We have used these properties of the E1B proteins from different viral serotypes to map the p53 binding site on the Ad2/5 protein. A set of chimaeric genes was constructed containing different proportions of the Ad12 and Ad2E1B DNA. These, together with Ad12E1A and E1B19K DNA, were transfected into baby rat kidney cells and transformed lines isolated. From an examination of the properties of these Ad12/Ad2E1B fusion proteins in co-immunoprecipitation and subcellular localization experiments it has been concluded that the p53 binding site on Ad2E1B58K protein lies between amino acids 216 and 235 and that the homologous region on Ad12E1B54K protein also binds p53. In addition, a unique nuclear localization signal is located on Ad12E1B54K between residues 228 and 239. We suggest that primary structure differences in these regions of the Ad2 and Ad12E1B proteins are responsible for the different subcellular localizations in AdE1 transformants.  (+info)

The cytoplasmic tail of the influenza C virus glycoprotein HEF negatively affects transport to the cell surface. (2/1579)

The surface glycoprotein, HEF, of influenza C virus (C/Johannesburg/1/66) has been shown to undergo a post-translation conformational change that is evident in a dramatic change of electrophoretic mobility. If the corresponding gene is expressed in the absence of other viral proteins, this folding process does not occur at all or only very inefficiently. A chimaeric protein, HEF-HA(Tail), in which the short cytoplasmic tail (Arg-Thr-Lys) of HEF was replaced by the cytoplasmic tail of the haemagglutinin of an influenza A virus (fowl plague virus) was constructed. In contrast to the wild-type protein, the chimaeric protein was detected on the cell surface. No further improvement of the surface expression was observed when both the transmembrane domain and the cytoplasmic tail were replaced by the corresponding domains of either the influenza A haemagglutinin or gp40, an endogenous protein of MDCK cells. For the HEF-HA(Tail) construct this study shows that a substantial amount of the protein is converted to the 100 kDa mature form that is observed in virus-infected cells. The HEF-HA expressed on the cell surface reacted positively in esterase and haemadsorption assays, indicating that it was present in a biologically active form. The results show that the short cytoplasmic tail of HEF has a negative effect on the folding and surface transport of this protein. How this effect may be prevented during a virus infection is discussed.  (+info)

Glycoprotein gL-independent infectivity of pseudorabies virus is mediated by a gD-gH fusion protein. (3/1579)

Envelope glycoproteins gH and gL, which form a complex, are conserved throughout the family Herpesviridae. The gH-gL complex is essential for the fusion between the virion envelope and the cellular cytoplasmic membrane during penetration and is also required for direct viral cell-to-cell spread from infected to adjacent noninfected cells. It has been proposed for several herpesviruses that gL is required for proper folding, intracellular transport, and virion localization of gH. In pseudorabies virus (PrV), glycoprotein gL is necessary for infectivity but is dispensable for virion localization of gH. A virus mutant lacking gL, PrV-DeltagLbeta, is defective in entry into target cells, and direct cell-to-cell spread is drastically reduced, resulting in only single or small foci of infected cells (B. G. Klupp, W. Fuchs, E. Weiland, and T. C. Mettenleiter, J. Virol. 71:7687-7695, 1997). We used this limited cell-to-cell spreading ability of PrV-DeltagLbeta for serial passaging of cells infected with transcomplemented virus by coseeding with noninfected cells. After repeated passaging, plaque formation was restored and infectivity in the supernatant was observed. One single-plaque isolate, designated PrV-DeltagLPass, was further characterized. To identify the mutation leading to this gL-independent infectious phenotype, Southern and Western blot analyses, radioimmunoprecipitations, and DNA sequencing were performed. The results showed that rearrangement of a genomic region comprising part of the gH gene into a duplicated copy of part of the unique short region resulted in a fusion fragment predicted to encode a protein consisting of the N-terminal 271 amino acids of gD fused to the C-terminal 590 residues of gH. Western blotting and radioimmunoprecipitation with gD- and gH-specific antibodies verified the presence of a gDH fusion protein. To prove that this fusion protein mediates infectivity of PrV-DeltagLPass, cotransfection of PrV-DeltagLbeta DNA with the cloned fusion fragment was performed, and a cell line, Nde-67, carrying the fusion gene was established. After cotransfection, infectious gL-negative PrV was recovered, and propagation of PrV-DeltagLbeta on Nde-67 cells produced infectious virions. Thus, a gDH fusion polypeptide can compensate for function of the essential gL in entry and cell-to-cell spread of PrV.  (+info)

Gene transfer to mammalian cells using genetically targeted filamentous bacteriophage. (4/1579)

We have genetically modified filamentous bacteriophage to deliver genes to mammalian cells. In previous studies we showed that noncovalently attached fibroblast growth factor (FGF2) can target bacteriophage to COS-1 cells, resulting in receptor-mediated transduction with a reporter gene. Thus, bacteriophage, which normally lack tropism for mammalian cells, can be adapted for mammalian cell gene transfer. To determine the potential of using phage-mediated gene transfer as a novel display phage screening strategy, we transfected COS-1 cells with phage that were engineered to display FGF2 on their surface coat as a fusion to the minor coat protein, pIII. Immunoblot and ELISA analysis confirmed the presence of FGF2 on the phage coat. Significant transduction was obtained in COS-1 cells with the targeted FGF2-phage compared with the nontargeted parent phage. Specificity was demonstrated by successful inhibition of transduction in the presence of excess free FGF2. Having demonstrated mammalian cell transduction by phage displaying a known gene targeting ligand, it is now feasible to apply phage-mediated transduction as a screen for discovering novel ligands.  (+info)

Identification of a coronavirus hemagglutinin-esterase with a substrate specificity different from those of influenza C virus and bovine coronavirus. (5/1579)

We have characterized the hemagglutinin-esterase (HE) of puffinosis virus (PV), a coronavirus closely related to mouse hepatitis virus (MHV). Analysis of the cloned gene revealed approximately 85% sequence identity to HE proteins of MHV and approximately 60% identity to the corresponding esterase of bovine coronavirus. The HE protein exhibited acetylesterase activity with synthetic substrates p-nitrophenyl acetate, alpha-naphthyl acetate, and 4-methylumbelliferyl acetate. In contrast to other viral esterases, no activity was detectable with natural substrates containing 9-O-acetylated sialic acids. Furthermore, PV esterase was unable to remove influenza C virus receptors from human erythrocytes, indicating a substrate specificity different from HEs of influenza C virus and bovine coronavirus. Solid-phase binding assays revealed that purified PV was unable to bind to sialic acid-containing glycoconjugates like bovine submaxillary mucin, mouse alpha1 macroglobulin or bovine brain extract. Because of the close relationship to MHV, possible implications on the substrate specificity of MHV esterases are suggested.  (+info)

Highly diverse intergenic regions of the paramyxovirus simian virus 5 cooperate with the gene end U tract in viral transcription termination and can influence reinitiation at a downstream gene. (6/1579)

A dicistronic minigenome containing the M-F gene junction was used to determine the role of the simian virus 5 (SV5) intergenic regions in transcription. The M-F junction differs from the other SV5 junctions by having a short M gene end U tract of only four residues (U4 tract) and a 22-base M-F intergenic sequence between the M gene end and F gene start site. Replacing the 22-base M-F intergenic region with nonviral sequences resulted in a minigenome template (Rep 22) that was defective in termination at the end of the M gene. Efficient M gene termination could be restored to the mutant Rep 22 template in either of two ways: by increasing the U tract length from four to six residues or by restoring a G residue immediately downstream of the wild-type (WT) U4 tract. In a dicistronic SH-HN minigenome, a U4-G combination was functionally equivalent to the naturally occurring SH U6-A gene end in directing SH transcription termination. In addition to affecting termination, the M-F intergenic region also influenced polymerase reinitiation. In the context of the WT U4-G M gene end, substituting nonviral sequences into the M-F intergenic region had a differential effect on F gene reinitiation, where some but not all nonviral sequences inhibited reinitiation. The inhibition of F gene reinitiation correlated with foreign sequences having a high C content. Deleting 6 bases or inserting 18 additional nucleotides into the middle of the 22-base M-F intergenic segment did not influence M gene termination or F gene reinitiation, indicating that M-F intergenic length per se is not a important factor modulating the SV5 polymerase activity. Our results suggest that the sequence diversity at an SV5 gene junction reflects specific combinations which may differentially affect SV5 gene expression and provide an additional level of transcriptional control beyond that which results from the distance of a gene from the 3' end promoter.  (+info)

Structural basis for paramyxovirus-mediated membrane fusion. (7/1579)

Paramyxoviruses are responsible for significant human mortality and disease worldwide, but the molecular mechanisms underlying their entry into host cells remain poorly understood. We have solved the crystal structure of a fragment of the simian parainfluenza virus 5 fusion protein (SV5 F), revealing a 96 A long coiled coil surrounded by three antiparallel helices. This structure places the fusion and transmembrane anchor of SV5 F in close proximity with a large intervening domain at the opposite end of the coiled coil. Six amino acids, potentially part of the fusion peptide, form a segment of the central coiled coil, suggesting that this structure extends into the membrane. Deletion mutants of SV5 F indicate that putative flexible tethers between the coiled coil and the viral membrane are dispensable for fusion. The lack of flexible tethers may couple a final conformational change in the F protein directly to the fusion of two bilayers.  (+info)

The hemagglutinin-esterase of mouse hepatitis virus strain S is a sialate-4-O-acetylesterase. (8/1579)

By comparative analysis of the hemagglutinin-esterase (HE) protein of mouse hepatitis virus strain S (MHV-S) and the HE protein of influenza C virus, we found major differences in substrate specificities. In striking contrast to the influenza C virus enzyme, the MHV-S esterase was unable to release acetate from bovine submandibulary gland mucin. Furthermore, MHV-S could not remove influenza C virus receptors from erythrocytes. Analysis with free sialic acid derivatives revealed that the MHV-S HE protein specifically de-O-acetylates 5-N-acetyl-4-O-acetyl sialic acid (Neu4, 5Ac2) but not 5-N-acetyl-9-O-acetyl sialic acid (Neu5,9Ac2), which is the major substrate for esterases of influenza C virus and bovine coronaviruses. In addition, the MHV-S esterase converted glycosidically bound Neu4,5Ac2 of guinea pig serum glycoproteins to Neu5Ac. By expression of the MHV esterase with recombinant vaccinia virus and incubation with guinea pig serum, we demonstrated that the viral HE possesses sialate-4-O-acetylesterase activity. In addition to observed enzymatic activity, MHV-S exhibited affinity to guinea pig and horse serum glycoproteins. Binding required sialate-4-O-acetyl groups and was abolished by chemical de-O-acetylation. Since Neu4,5Ac2 has not been identified in mice, the nature of potential substrates and/or secondary receptors for MHV-S in the natural host remains to be determined. The esterase of MHV-S is the first example of a viral enzyme with high specificity and affinity toward 4-O-acetylated sialic acids.  (+info)

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This entry includes information about the spike protein such as its function, structure, and interaction with different ACE2 receptors. The function of spike protein S1 is to initiate infection by attaching the virion to the host cell receptor. Spike protein S2 acts as a class I viral fusion protein and mediates fusion of the virion and hots cell membrane. Spike protein S2 is a viral fusion peptide that is unmasked following S2 cleavage, which occurs during the viruss endocytic entry into the host cell ...
The fusion (F) and hemagglutinin-neuraminidase (HN) glycoproteins of the paramyxovirus simian virus 5 (SV5) were expressed individually or coexpressed in CV-1 cells by using SV40-based vectors and recombinant vaccinia viruses. The extent of detectable fusion in a syncytium formation assay was found to be affected by the expression system used. In addition, when HN was coexpressed with F, it was found that the expression vector system influenced the contribution of HN in forming syncytia. The abilities of the SV5, human parainfluenza virus type 3, and Newcastle disease virus F glycoproteins to cause fusion, when expressed alone or coexpressed with HN, were directly compared by using the SV40-based vector system in CV-1 cells. The F proteins exhibited various degrees of fusion activity independent of HN expression, but the formation of syncytia could be enhanced to different extents by the coexpression of the homotypic HN protein. ...
Coronaviruses are enveloped positive-stranded RNA viruses that replicate in the cytoplasm. To deliver their nucleocapsid into the host cell, they rely on the fusion of their envelope with the host cell membrane. The spike glycoprotein (S) mediates virus entry and is a primary determinant of cell tropism and pathogenesis. It is classified as a class I fusion protein, and is responsible for binding to the receptor on the host cell as well as mediating the fusion of host and viral membranes-A process driven by major conformational changes of the S protein. This review discusses coronavirus entry mechanisms focusing on the different triggers used by coronaviruses to initiate the conformational change of the S protein: receptor binding, low pH exposure and proteolytic activation. We also highlight commonalities between coronavirus S proteins and other class I viral fusion proteins, as well as distinctive features that confer distinct tropism, pathogenicity and host interspecies transmission characteristics
UniProt ITasser SWISS Models alphafold D3Targets-2019-nCoV Spike protein S1 (residue 14-685): attaches the virion to the cell membrane by interacting with host receptor, initiating the infection. Binding to human ACE2 and CLEC4M/DC-SIGNR receptors and internalization of the virus into the endosomes of the host cell induces conformational changes in the S glycoprotein. Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes.Spike protein S2 (residue 686-1273): mediates fusion of the virion and cellular membranes by acting as a class I viral fusion protein. Under the current model, the protein has at least three conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The ...
3RRT: Structure of respiratory syncytial virus fusion glycoprotein in the postfusion conformation reveals preservation of neutralizing epitopes.
Lysolipids added between fusing membranes inhibit and cis-unsaturated fatty acids promote not only diverse biological fusion reactions (this paper and Creutz, 1981; Glick and Rothman, 1987; Chernomordik et al., 1993; Paiement et al., 1994; Yeagle et al., 1994; Chernomordik et al., 1995c; Gunther-Ausborn et al., 1995; but see Nagao et al., 1995; Coorssen, 1996), but also fusion of purely lipid bilayers (for review see Chernomordik et al., 1995b). Importantly, LPC inhibits HA-mediated fusion at membrane concentrations similar to those found to inhibit syncytia formation mediated by the Sendai virus F protein (Yeagle et al., 1994) and baculovirus gp64 (Chernomordik et al., 1995c), as well as for microsome-microsome fusion (Chernomordik et al., 1993) and vesicle-planar bilayer fusion (Chernomordik et al., 1995a). We suggest that fusion mediated by HA and other proteins and fusion of purely lipid bilayers proceed via a common lipid-involving intermediate-a stalk structure, producing local and ...
casSAR Dugability of P17003 | HE | Hemagglutinin-esterase-fusion glycoprotein - Also known as HEMA_INCHY, HE. Binds to the N-acetyl-9-O-acetylneuraminic acid residues on the cell surface, bringing about the attachment of the virus particle to the cell. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induce an irreversible conformational change in HEF2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore. Displays a receptor-destroying activity which is a neuraminidate-O-acetyl esterase. This activity cleaves off any receptor on the cell surface, which would otherwise prevent virions release. These cleavages prevent self-aggregation and ensure the efficient spread of the progeny virus from cell to cell (By
The long-term goal of the proposed research is to understand the basis for viral fusion protein-induced membrane fusion with atomic-resolution detail. Fusion of...
DI-fusion, le Dépôt institutionnel numérique de lULB, est loutil de référencementde la production scientifique de lULB.Linterface de recherche DI-fusion permet de consulter les publications des chercheurs de lULB et les thèses qui y ont été défendues.
3O45: Structure of a Major Antigenic Site on the Respiratory Syncytial Virus Fusion Glycoprotein in Complex with Neutralizing Antibody 101F.
The gH/gL heterodimer represents two from the four herpes virus glycoproteins sufficient and essential for membrane fusion. the HSV fusion glycoproteins is normally gL GSK2118436A which includes 224 proteins with no apparent transmembrane domains. The essential membrane proteins gH binds gL most GSK2118436A likely in the endoplasmic reticulum (ER) as well as the matching gH/gL heterodimer after that transits to sites of viral envelopment as well as the plasma membrane (4 5 An unchanged HSV type 1 (HSV-1) gH wont leave the ER unless it really is destined to gL (4 -7). The gH/gL heterodimer continues to be postulated to really have the hallmarks of the viral fusion proteins and to enjoy a direct function in membrane fusion (8 -13). Nevertheless the HSV-2 gH/gL framework will not resemble any known viral fusion proteins and there is certainly recent proof that HSV gH/gL has even more of a regulatory and/or structural function in membrane fusion performed by the course III fusion proteins gB (14 ...
To infect host cells, most enveloped viruses must insert a hydrophobic fusion peptide into the host cell membrane. Thus, fusion peptides may be valuable targets for developing drugs that block virus entry. We have shown previously that a natural 20-residue fragment of α1-antitrypsin, designated VIRus-Inhibitory Peptide (VIRIP), that binds to the gp41 fusion peptide of HIV-1 prevents the virus from entering target cells in vitro. Here, we examine the efficacy of 10-day monotherapy with the optimized VIR-576 derivative of VIRIP in treatment-naïve, HIV-1-infected individuals with viral RNA loads of ≥10,000 copies per ml. We report that at the highest dose (5.0 grams per day), intravenous infusion of VIR-576 reduced the mean plasma viral load by 1.23 log10 copies per ml without causing severe adverse effects. Our results are proof of concept that fusion peptide inhibitors suppress viral replication in human patients, and offer prospects for the development of a new class of drugs that prevent ...
Our present study has shown that the epitopes for MAbs 6-7 and 21-1 are cryptic in the cell surface-localized native WR F protein. By contrast, they are exposed on the surface-localized native L22P. Importantly, both the epitopes are also exposed on the Se-L22P mutant, an uncleaved form of L22P, which does not induce cell fusion unless it is cleaved by acetylated trypsin. Therefore, the epitopes for MAbs 6-7 and 21-1 seem readily exposed on the surface-localized L22P before undergoing conformational changes that lead to cell fusion. We have therefore concluded that there is a striking difference in the native (prefusion) conformation between nonfusogenic WR F protein and its fusogenic mutant, L22P. It should be stressed, however, that our present data do not exclude the possibility that the MAb epitopes may also be present in the postfusion conformation of L22P.. The epitopes for MAbs 6-7 and 21-1 in the WR F protein could be exposed by heating at 47°C as efficiently as could those in L22P ...
Enveloped viruses enter cells by using their fusion proteins to merge the virus lipid envelope and the cell membrane. While crystal structures of the water-soluble ectodomains of many viral fusion proteins have been determined, the structure and assembly of the C-terminal transmembrane domain (TMD) remains poorly understood. Here we use solid-state NMR to determine the backbone conformation and oligomeric structure of the TMD of the parainfluenza virus 5 (PIV5) fusion protein. 13C chemical shifts indicate that the central leucine-rich segment of the TMD is α-helical in POPC/cholesterol membranes and POPE membranes, while the Ile- and Val-rich termini shift to the β-strand conformation in the POPE membrane ...
Enveloped viruses enter cells by using their fusion proteins to merge the virus lipid envelope and the cell membrane. While crystal structures of the water-soluble ectodomains of many viral fusion proteins have been determined, the structure and assembly of the C-terminal transmembrane domain (TMD) remains poorly understood. Here we use solid-state NMR to determine the backbone conformation and oligomeric structure of the TMD of the parainfluenza virus 5 (PIV5) fusion protein. 13C chemical shifts indicate that the central leucine-rich segment of the TMD is α-helical in POPC/cholesterol membranes and POPE membranes, while the Ile- and Val-rich termini shift to the β-strand conformation in the POPE membrane ...
article{1942045, abstract = {Despite the medical importance of respiratory syncytial virus (RSV) infections, there is no vaccine or therapeutic agent available. Prophylactic administration of palivizumab, a humanized monoclonal RSV fusion (F) protein-specific antibody, can protect high-risk children. Previously, we have demonstrated that RSV can be neutralized by picomolar concentrations of a camelid immunoglobulin single-variable domain that binds the RSV protein F (F-VHHb nanobodies). Here, we investigated the mechanism by which these nanobodies neutralize RSV and tested their antiviral activity in vivo. We demonstrate that bivalent RSV F-specific nanobodies neutralize RSV infection by inhibiting fusion without affecting viral attachment. The ability of RSV F-specific nanobodies to protect against RSV infection was investigated in vivo. Intranasal administration of bivalent RSV F-specific nanobodies protected BALB/c mice from RSV infection, and associated pulmonary inflammation. Moreover, ...
Binds to the N-acetyl-9-O-acetylneuraminic acid residues on the cell surface, bringing about the attachment of the virus particle to the cell. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induce an irreversible conformational change in HEF2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore. Displays a receptor-destroying activity which is a neuraminidate-O-acetyl esterase. This activity cleaves off any receptor on the cell surface, which would otherwise prevent virions release. These cleavages prevent self-aggregation and ensure the efficient spread of the progeny virus from cell to cell (By similarity).
Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. This attachment induces virion internalization either through clathrin-dependent endocytosis or through clathrin- and caveolin-independent pathway. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore.
Common themes are emerging from the study of viral, cell-cell, intracellular, and liposome fusion. Viral and cellular membrane fusion events are mediated by fusion proteins or fusion machines. Viral fusion proteins share important characteristics, notably a fusion peptide within a transmembrane-anchored polypeptide chain. At least one protein involved in a cell-cell fusion reaction resembles viral fusion proteins. Components of intracellular fusion machines are utilized in multiple membrane trafficking events and are conserved through evolution. Fusion pores develop during and intracellular fusion events suggesting similar mechanisms for many, if not all, fusion events. ...
Experimental evidence points towards a remarkably conserved mechanism by which virally encoded envelope glycoproteins catalyse membrane fusion and facilitate delivery of the viral core into the target cell [13, 14]. The structures of several class 1 fusion proteins reveal a characteristic trimer-of-hairpins motif believed to represent a late or post-fusion conformation [16-19, 35-37]. Investigating the way in which envelope proteins fold from a rod-like, pre-hairpin intermediate into the trimer-of-hairpins to pull the viral and cellular membranes together is important not only for our understanding of viral entry but also for the development of therapeutically relevant inhibitors of this process.. The protein sequences of the TM ectodomains of BLV and HTLV-1 display a striking level of conservation. By scrutinizing the position of conserved residues in the context of the HTLV-1 six-helix-bundle structure, we have found that the majority of the conserved residues map to the interacting surfaces ...
Single-particle studies of dengue-virus membrane fusion and the effect of small-molecule inhibitors of infection clarify the viral fusion mechanism.
In this study, we demonstrate that cytokines induce 1) dephosphorylation of Bad on Ser136 in INS-1 and rat islet cells, 2) Bax-dependent release of cytochrome c and inhibition of mitochondrial metabolic activity in human islets, 3) cleavage/activation of caspase-9 in INS-1 cells and rat islets and cleavage/activation of caspase-3 in INS-1 cells and rat and human islets, and finally 4) β-cell apoptosis in INS-1 cells and rat and human islets. Taken together, our findings strongly suggest that cytokines induce β-cell apoptosis through the canonical intrinsic mitochondrial pathway.. It has been suggested that cytokine-induced β-cell death is independent of Bax or Bak since siRNA-mediated knockdown of Bax or Bak failed to affect cytokine-induced cell death (39). In that study, the combination of IL-1β and IFN-γ was found to induce cell death in INS-1-derived cell lines and rat islets via nonapoptotic killing, which is in contrast to our present observations. However, the INS-1-derived cells ...
E1 is a class II viral fusion protein. This trimeric (low-pH-iduced) form is fusion active, and promotes release of viral nucleocapsid in cytoplasm after cell and viral membrane fusion. Efficient fusion requires the presence of cholesterol and sphingolipid in the target membrane. N-terminal domain of this protein: 1dyl(NMR), 1vcp, 1vcq ...
Buy our Recombinant Human POLR2F protein. Ab81845 is a full length protein produced in Escherichia coli and has been validated in SDS-PAGE. Abcam provides free…
IL 17F His Human Recombinant produced in E.coli is a single, non-glycosylated polypeptide chain containing 158 amino acids (31-163).
Newcastle disease virus (NDV) causes severe diseases in avian species. Its fusion protein cleavage site (Fcs) is a major contributor to virulence and membrane fusion. Previous studies showed that a change from phenylalanine (F) to lysine (L) at position 117 of the virulent strain fusion protein, which has the polybasic amino acid Fcs motif
The G2 fusion subunit of the Junin virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that {alpha}-helical coiled-coil structures are likely critical in ...
Detection of Mouse Hepatitis Virus Nonstructural Proteins Using Antisera Directed Against Bacterial Viral Fusion Proteins - Texas A&M University (TAMU) Scholar profile, educations, publications, research, recent courses, and student works
Protein-mediated membrane fusion is essential for maintaining eukaryotic cell organization and propagation of major human viruses. Many clinically relevant memb...
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Expression-ready RSV RSV Fusion cDNA ORF clone (VG40037-CY) with enhanced promotor in expression vector (pCMV3-C-HA) is confirmed by full-length sequence and validated in expression capability for gene expression studies or other applications. Quote for bulk production.
Antiviral blocking peptides targeting the viral fusion core can inhibit viral membrane fusion, thereby inhibiting the viruss entry into the host cell.
The retroviral envelope-derived proteins syncytin-1 and syncytin-2 (syn1 and syn2) drive placentation in humans by forming a syncytiotophoblast, a structure
Fooling the Virus: The Fusion protein as Virus-Specific Therapeutic An ACE2 A fusion protein of ACE2 with an Immunogenic Component Project ID : 47-2020-10877
IFITM-mediated restriction of virus-endosome fusion in different cell types.(A) IFITM3-mediated inhibition of viral fusion with different cell types. BlaM-Vpr c
Complete information for CACNA1F gene (Protein Coding), Calcium Voltage-Gated Channel Subunit Alpha1 F, including: function, proteins, disorders, pathways, orthologs, and expression. GeneCards - The Human Gene Compendium
C9orf125 human Fusion Protein GST from Proteintech. Produced in E.coli-derived, PET28a, with high quality purity. Cat.No. Ag14695
CRABP1 human Fusion Protein 6*His from Proteintech. Produced in E.coli-derived, PET28a, with high quality purity. Cat.No. Ag19240
Aguilar, P.S., Baylies, M.K., Fleissner, A., Helming, L., Inoue, N., Podbilewicz, B., Wang, H., and Wong, M. (2013). Genetic basis of cell-cell fusion mechanisms. Trends in genetics : TIG 29, 427-437 ...
In a previous study we demonstrated that vesicular stomatitis virus (VSV) can be used as a vector to express a soluble protein in mammalian cells. Here we have generated VSV recombinants that express four different membrane proteins: the cellular CD4 protein, a CD4-G hybrid protein containing the ectodomain of CD4 and the transmembrane and cytoplasmic tail of the VSV glycoprotein (G), the measles virus hemagglutinin, or the measles virus fusion protein. The proteins were expressed at levels ranging from 23-62% that of VSV G protein and all were transported to the cell surface. In addition we found that all four proteins were incorporated into the membrane envelope of VSV along with the VSV G protein. The levels of incorporation of these proteins varied from 6-31% of that observed for VSV G. These results suggest that many different membrane proteins may be co-incorporated quite efficiently with VSV G protein into budding VSV virus particles and that specific signals are not required for this ...
In molecular biology, haemagglutinin-esterase fusion glycoprotein (HEF) is a multi-functional protein embedded in the viral envelope of several viruses, including influenza C virus, coronaviruses and toroviruses. HEF is required for infectivity, and functions to recognise the host cell surface receptor, to fuse the viral and host cell membranes, and to destroy the receptor upon host cell infection. The haemagglutinin region of HEF is responsible for receptor recognition and membrane fusion, and bears a strong resemblance to the sialic acid-binding haemagglutinin found in influenza A and B viruses, except that it binds 9-O-acetylsialic acid. The esterase region of HEF is responsible for the destruction of the receptor, an action that is carried out by neuraminidase in influenza A and B viruses. The esterase domain is similar in structure to Streptomyces scabies esterase, and to acetylhydrolase, thioesterase I and rhamnogalacturonan acetylesterase. The haemagglutinin-esterase glycoprotein HEF must ...
Newcastle disease (ND) is regarded as a highly contagious and economically important disease in poultry and has a worldwide distribution. Viral determinants for Newcastle disease virus (NDV) virulence are not completely understood and viruses of different pathotypes can be found at live-bird markets in different geographical areas. The prevalence of Newcastle disease in village poultry in Mozambique is not well documented and strains of NDV involved in yearly outbreaks are unknown. The fusion (F) protein is an important determinant of pathogenicity of the virus and is used commonly for phylogenetic analysis. Newcastle disease viruses from various geographical regions of Mozambique were sequenced and compared genetically to published sequences obtained from GenBank. Samples were collected in three different areas of Mozambique and NDV was isolated by infection of embryonated chicken eggs. Sequence analysis of the F-protein encoding gene was used to classify 28 isolates from Mozambique into ...
The use of the insect virus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) as a gene delivery vector for mammalian cells began in 1995 with the discovery that mammalian hepatocytes could be efficiently infected by the virus (40). Since then, its use has increased steadily as a result of the number of advantages the system confers: an inability to replicate in mammalian cells or cause cellular toxicity, efficient entry in certain cell lines, inherent flexibility of use and additional benefits specific to the transient expression of drug targets. However, the system has retained the limitation of inefficient entry into some mammalian cells, limiting the usefulness of the system to particular cell lines. To improve the breadth of mammalian cell entry exhibted by AcMNPV the mechanisms of promiscuous cell entry were investigated. Initial results revealed that simple physical and chemical techniques such as using low pH diluents, optimising transduction volumes and increasing access ...
Borochova K, Niespodziana K, Focke-Tejkl M, Hofer G, Keller W, Valenta R. Dissociation of the respiratory syncytial virus F protein-specific human IgG, IgA and IgM response (2021), Scientific Reports volume 11, 3551; https://www.nature.com/articles/s41598-021-82893-y. Kratzer B, Trapin D, Ettel P, Körmöczi U, Rottal A, Tuppy F, Feichter M, Gattinger P, Borochova K, Dorofeeva Y, Tulaeva I, Weber M, Grabmeier-Pfisterhammer K, Tauber P, Gerdov M, Mühl B, Perkmann T, Fae I, Wennda S, Führer H, Henning R, Valenta R, Pickl W. Immunological imprint of COVID-19 on human peripheral blood leukocyte populations (2020). Allergy, 2020;00:1-15; https://doi.org/10.1111/all.14647.. Gattinger P, Borochova K, Dorofeeva Y, Henning R, Kiss R, Kratzer B, Mühl B, Perkmann T, Trapin D, Trella M, Ettel P, Tulaeva I, Pickl W, Valenta R. Antibodies in serum of convalescent patients following mild COVID‐19 do not always prevent virus‐receptor binding (2020). Allergy, 2020;00:1-6; ...
Read Pathotyping isolates of Newcastle disease virus using antipeptide antibodies to pathotype-specific regions of their fusion and hemagglutinin-neuraminidase proteins, Archives of Virology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
The precise way in which the presence of NDV induces tumor cell death remains to be clarified and may show variation regarding the strains of NDV used and which type of cancer is targeted. NDV triggers apoptosis[17] in a wide range of cancer cell types via the mitochondrial/intrinsic pathway, through loss of membrane potential and thereby inducing release of cytochrome c in the tumor cell. The results[17] also indicate the extrinsic pathway is activated by TNF-related, apoptosis-inducing ligand-induced, NDV-mediated apoptosis in a late stage. Another study[20] found a hyperfusogenic NDV/F3aa(L289A) with refined abilities to fuse into somatic cells. NDV has aggregating properties causing syncytia formations of tumor cells, which, apart from amplifying immune-based cell killing, also results in necrosis of cells. This pathway was believed to lead to a considerable boost of immune activation and potentially an antitumor response, which was supported by observations of a significant accumulation of ...
Mumps is caused by a paramyxovirus with a negative-strand, nonsegmented RNA genome of 15,384 bases encoding at least 8 proteins: the nucleo- (N), phospho- (P), V, matrix (M), fusion (F), small hydrophobic (SH), hemagglutinin-neuraminidase (HN), and large (L) proteins. The N, P, and L proteins together provide the polymerase activity responsible for genome transcription and replication. The viral genome is surrounded by a host cell-derived lipid bilayer envelope containing the M, F, SH, and HN proteins. The M protein is involved in viral assembly, whereas the HN and F proteins are responsible for cell attachment and entry and are the major targets of virus-neutralizing antibody. The V and SH proteins are accessory proteins, acting as antagonists of the host antiviral response; the former interferes with the interferon response and the latter with the tumor necrosis factor α (TNF-α)-mediated apoptotic signaling pathway. Because of the hypervariability of the SH gene, its nucleotide sequence is ...
Virus-cell and cell-cell fusion.: Significant progress has been made in elucidating the mechanisms of viral membrane fusion proteins; both those that function a
multiple nucleopolyhedrovirus (AcMNPV), a known person in the sort We alphabaculoviruses, can transduce and deliver an operating gene to a variety of non-host cells, including many mammalian lines and major cells, a house mediated from the envelope fusion proteins GP64. appealing cell-targeting features. By seamlessly swapping the indigenous coding series with each of five sequences encoding different F protein, a couple of F-pseudotyped AcMNPV was produced. This report information their relative capabilities both to functionally replace GP64 in viral development also to transduce human being Saos-2 and HeLa cells. All Rabbit Polyclonal to KLRC1 five backed viable attacks in insect cell ethnicities and one, the NPV (MacoNPV) F pseudotype, could be amplified to titres close to those of native AcMNPV. In contrast, none was able to transduce the Saos-2 and HeLa cell lines. The strong support provided by MacoNPV F in computer virus production makes the corresponding pseudotype a viable scaffold to ...
1.D.138. The GALA Synthetic Peptide (GALA) Family GALA is a 30 amino acid synthetic peptide with a glutamic acid-alanine-leucine-alanine (EALA) repeat that also contains a histidine and tryptophan residue as spectroscopic probes (Li et al. 2004). It was designed to explore how viral fusion protein sequences interact with membranes. The sequences selected are long enough to span a bilayer as an α-helix, the glutamic acids (Glu) were selected to provide a pH-dependent negatively charged side-chain and the EALA repeat was adjusted so that the peptide would have a hydrophobic face of sufficient hydrophobicity to interact with the bilayer when the peptide was in an α-helix. GALA converts from a random coil to an amphipathic α-helix when the pH is reduced from 7.0 to 5.0. At neutral pH, GALA is water soluble while at acid pH, GALA binds to bilayer membranes. The nature of the association and the type of peptide-peptide interactions in the membrane depend upon the physico-chemical properties of the ...
TY - JOUR. T1 - Antibody mediated in vivo delivery of small interfering RNAs via cell-surface receptors. AU - Song, Erwei. AU - Zhu, Pengcheng. AU - Lee, Sang Kyung. AU - Chowdhury, Dipanjan. AU - Kussman, Steven. AU - Dykxhoorn, Derek M.. AU - Feng, Yi. AU - Palliser, Deborah. AU - Weiner, David B.. AU - Shankar, Premlata. AU - Marasco, Wayne A.. AU - Lieberman, Judy. N1 - Funding Information: This work was supported by National Institutes of Health grant AI-056900 (J.L.), a Leukemia and Lymphoma Society fellowship (D.C.), amFAR scholar award (S.-K.L.), and Harvard CFAR scholar award (D.P.). We thank Manjunath N., Dong Zhang and Lianfa Shi for useful suggestions.. PY - 2005. Y1 - 2005. N2 - Delivery of small interfering RNAs (siRNAs) into cells is a key obstacle to their therapeutic application. We designed a protamine-antibody fusion protein to deliver siRNA to HIV-infected or envelope-transfected cells. The fusion protein (F105-P) was designed with the protamine coding sequence linked to the ...
An analysis of the R18 fusion assay was made during the fusion of the Sendai virus with erythrocyte ghosts. The increase in R18 fluorescence, reflecting the interaction process, was evaluated in terms of the different processes that in principle may contribute to this increase, that is, monomeric probe transfer, hemifusion, and complete fusion. To this end, the kinetics of the R18-labeled lipid mixing were compared to those obtained with an assay in which the fusion-monitoring probe, eosin-maleimide, was attached to the viral surface proteins. The experiments relied on the use of native and fusion-inactive viruses and studies involving viral and target membranes that were modified by the incorporation of the lysophospholipid. The total dequenching signal detected in the R18 assay consists of components from probe transferred without fusion and from fusion itself. At 37 degrees C, the initial rate of dequenching (within two minutes) was predominately from the probe diluted by fusion with little
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Complete information for NUTM2F gene (Protein Coding), NUT Family Member 2F, including: function, proteins, disorders, pathways, orthologs, and expression. GeneCards - The Human Gene Compendium
HIV-1 enters its target cells by fusion at the plasma membrane. The primary cellular receptor for HIV is CD4, but this molecule is insufficient to permit viral fusion. During 1996, the necessary entry co-factors (co-receptors or second receptors) were identified as being members of the seven-transme …
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The fusion of the cells is apparently caused by viral fusion proteins from endosymbiotic endogenous retrovirus (ERV). An ... immunoevasive action was the initial normal behavior of the viral protein, in order to avail for the virus to spread to other ... Feb 2000). "Syncytin is a captive retroviral envelope protein involved in human placental morphogenesis". Nature. 403 (6771): ... also known as placental protein 14 (PP14)). Regulatory T cells also likely play a role. Also, a shift from cell-mediated ...
It is a domesticated instance of a viral class II fusion protein. Fédry J, Liu Y, Péhau-Arnaudet G, Pei J, Li W, Tortorici MA, ... HAP2 (hapless 2), also known as GCS1 (generative cell-specific protein 1), is a family of membrane fusion proteins found in the ... February 2017). "The Ancient Gamete Fusogen HAP2 Is a Eukaryotic Class II Fusion Protein". Cell. 168 (5): 904-915.e10. doi: ... This protein is essential for gamete fusion, and therefore fertilization, in these organisms. ...
HIV infects Helper CD4+ T cells and makes them produce viral proteins, including fusion proteins. Then, the cells begin to ... the fusion protein allows it to bind with the host cell. The HN and fusion proteins are then left on the host cell walls, ... During infection, viral fusion proteins used by the virus to enter the cell are transported to the cell surface, where they can ... Typically, the viral families that can cause syncytia are enveloped because viral envelope proteins on the surface of the host ...
This protein is a fusion product of a viral nucleocapsid protein and a bacterial MBP protein. The vaccine delivered via ... namely a gene encoding a viral nucleocapsid protein and a gene encoding a bacterial maltose-binding protein (MBP). The fusion ... In all of these patents, the carrier protein is referred to as a chimeric fusion protein with an amino acid sequence derived ... viral nucleocapsid protein and bacterial maltose-binding protein). In addition, the polyhistidine-tag - a short peptide that is ...
The E1 gene is a membrane fusion protein that is important in viral entry and release. Together E1 and E2 are the glycoproteins ... Cholesterol is also necessary for the Alphavirus to undergo fusion. This fusion of the endosomal membrane to the viral envelope ... The sgRNA codes for the structural proteins that will form the new virus. The assembly of the new viral capsid occurs in the ... After being taken in through endocytosis, a low pH triggers a membrane fusion, which delivers the viral RNA genomes into the ...
Envelope fusion with the plasma membrane of the host cell causes separation of the nucleocapsid from viral DNA and proteins. ... Multiple necessary viral proteins are located within the envelope. DNA and proteins enter the host cell nucleus and turn-off ... gB, gD, gH, and gL proteins allow for fusion of the cell and envelope, and are necessary for survival. Entrance to host cells ... L genes are transcribed "after the synthesis of DNA and viral protein onset". Virion DNA maturation occurs as the nucleocapids ...
She showed that the transmembrane domain of viral fusion proteins can be conformationally plastic, and the β-sheet conformation ... Yao, Hongwei; Lee, Michelle W.; Waring, Alan J.; Wong, Gerard C. L.; Hong, Mei (2015-08-17). "Viral fusion protein ... and viral fusion proteins. She determined the structure of the membrane toroidal pores formed by the antimicrobial peptide ... In 2020 she determined both the influenza B M2 protein structure and the SARS-CoV-2 envelope protein structure, the latter in ...
The H protein mediates receptor attachment and the F protein causes fusion of viral envelope and cellular membrane. ... The RNA genome of the virus codes 6 main proteins Nucleoprotein (N), Phosphoprotein (P), Matrix protein (M), Fusion protein (F ... The measles virus has two envelope glycoproteins on the viral surface - hemagglutinin (H) and membrane fusion protein (F). ... producing all viral proteins. The viruses are then assembled from their proteins and negative sense ssRNA, and the cell will ...
... is required to cleave a viral polyprotein precursor into individual mature proteins. The viral RNA and viral proteins assemble ... This fusion creates a pore through which the viral capsid enters the cell.[13] Following entry into the cell the RNA of the ... When HIV infects its target cell it requires fusion of the viral and cellular membranes.[12] The first step is the interaction ... The mRNA is then translated into viral proteins and the third virally encoded enzyme, namely HIV protease, ...
Fusion of these membranes allows the viral proteins and genome to be released into the host cell, which then causes the ... hemagglutinin-esterase fusion (HEF). These glycoproteins allow for attachment and fusion of viral and cellular membranes. ... In each of these techniques, the antibodies for the protein of interest are added and the presence of the specific protein is ... Type D has 7 RNA segments and encodes 9 proteins, while Types A and B have 8 RNA segments and encode at least 10 proteins. The ...
The fusion protein (F) is an integral membrane protein, sharing many features similar to other viral fusion proteins and is ... a matrix protein (M), a fusion protein (F), a hemagglutinin-neuraminidase (Hn) protein and a large polymerase protein (L). A ... The structure of the envelope is characterized by the spike-like projections of two viral proteins, the fusion protein (F) and ... The M protein interacts with the Hn and F proteins, helping to incorporate these proteins into viral particles for release. It ...
... on the other hand viral fusion proteins cause the formation of the placental syncytium in order to limit the exchange of ... The fusion proteins may have been a way to spread the infection to other cells by simply merging them with the infected one. It ... are very similar to those of these bacteria in their lipid and protein compositions. Accumulating biochemical data strongly ...
The alphaviral glycoprotein E1 is a class II viral fusion protein, which is structurally different from the class I fusion ... The second encodes three structural proteins: the core nucleocapsid protein C, and the envelope proteins P62 and E1, which ... Most alphaviruses lose the peripheral protein E3, but in Semliki viruses it remains associated with the viral surface. Four ... The first is non-structural and encodes proteins (nsP1-nsP4) necessary for transcription and replication of viral RNA. ...
... such as the critical roles of the membrane regions in immune receptor activation and in viral membrane fusion protein assembly ... of cell surface proteins, particularly those of immune receptors and viral membrane proteins. The membrane regions of cell ... membrane-proximal regions of proteins in immune receptor assembly and activation and in protein-mediated lipid bilayer fusion. ... some of his earlier significant discoveries include structure and mechanism of viral ion channels and dynamic nature of ...
This fusion involves conformational changes of viral fusion proteins and protein docking, but the exact molecular mechanisms ... [email protected] has also been used to study membrane fusion, an essential event for viral infection and a wide range of biological ... Protein folding is driven by the search to find the most energetically favorable conformation of the protein, i.e., its native ... Thus, understanding protein folding is critical to understanding what a protein does and how it works, and is considered a holy ...
Attachment to the receptor can induce the viral envelope protein to undergo changes that results in the fusion of viral and ... viral protein synthesis, possible assembly of viral proteins, then viral genome replication mediated by early or regulatory ... Proteins associated with nucleic acid are known as nucleoproteins, and the association of viral capsid proteins with viral ... Transport of viral proteins to the apical membranes and interaction of matrix protein with glycoproteins in the assembly of ...
The viral genome and associated viral proteins is released into the cytoplasm following fusion of the viral envelope and the ... Several of the proteins encoded by the BoDV-1 genome have been characterised. The G glycoprotein is important for viral entry ... It has been suggested that the p10, or X, protein plays a role in viral RNA synthesis or ribonucleoprotein transport. The P40 ... "A short leucine-rich sequence in the Borna disease virus p10 protein mediates association with the viral phospho- and ...
Also, viral fusion proteins cause the formation of the placental syncytium to limit exchange of migratory cells between the ... The fusion proteins were a way to spread the infection to other cells by simply merging them with the infected one (HIV does ... Most viral vaccines are based on live attenuated viruses, whereas many bacterial vaccines are based on acellular components of ... One of the pathways is siRNA in which long double stranded RNA is cut into pieces that serve as templates for protein complex ...
... as well as its structural homology to other viral fusion proteins. PDB: 3NW8​; Stampfer SD, Lou H, Cohen GH, Eisenberg RJ, ... Other viral glycoproteins involved in the process of viral cell entry include gC, gB, gD, gH, and gL, but only gC, gB, gD, and ... The herpesvirus glycoprotein B is the most highly conserved of all surface glycoproteins and acts primarily as a fusion protein ... Herpesvirus glycoprotein B is a viral glycoprotein that is involved in the viral cell entry of Herpes simplex virus (HSV). ...
v-Crk, a transforming oncoprotein from avian sarcoma viruses, is a fusion of viral "gag" protein with the SH2 and SH3 domains ... Adapter molecule crk also known as proto-oncogene c-Crk is a protein that in humans is encoded by the CRK gene. The CRK protein ... 1994). "CRK protein binds to two guanine nucleotide-releasing proteins for the Ras family and modulates nerve growth factor- ... Adapter molecule crk is a member of an adapter protein family that binds to several tyrosine-phosphorylated proteins. This ...
Sendai virus is known to have resulted in the development of reconstituted viral envelopes containing only the fusion protein ... "Dilation of the influenza hemagglutinin fusion pore revealed by the kinetics of individual cell-cell fusion events". Journal of ... Membrane Fusion Technique. Gulf Professional Publishing. July 1993. pp. 42-. ISBN 978-0-12-182122-7. Robert Blumenthal; Debi P ... He is renowned for his researches on Sendai virus and developing reconstituted viral envelopes. He is an elected fellow of ...
All of the viral fusion proteins undergo a remarkable protein refolding event and this process brings about fusion of the viral ... Studies on the fusion protein were applicable to the envelope proteins of SARS coronavirus, HIV and Ebola virus. ... Their work mainly focused on sequencing viral genes and characterizing viral proteins. During this time, Lamb characterized the ... fusion protein. Proceedings of the National Academy of Sciences (2005) Structure of the parainfluenza virus 5 F protein in its ...
IFITM proteins inhibit viral membrane and cellular endosomal or lyso¬somal vesicles membrane fusion by modify lipid components ... Furthermore, IFITM proteins reduced membrane fluidity and affected membrane curvature to restrict viral membrane fusion with ... In addition, IFITM3 interacted with the cellular cholesterol regulatory proteins Vesicle-membrane-protein-associated protein A ... human homolog of the mouse protein), IFI17 [interferon-induced protein 17], 9-27 [Interferon-inducible protein 9-27] and Leu13 ...
Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral proteins to host ... Fusion with the plasma membrane to release the core into the host cytoplasm. Early phase: early genes are transcribed in the ... "Viral Zone". ExPASy. Retrieved 15 June 2015. ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015. Viralzone: ... Late phase: Late genes are expressed from 140 min to 48 hours post-infection, producing all structural proteins. Assembly of ...
Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral proteins to host ... Fusion with the plasma membrane to release the core into the host cytoplasm. Early phase: early genes are transcribed in the ... "Viral Zone". ExPASy. Retrieved 15 June 2015. Viralzone: Parapoxvirus ICTV Virus Pathogen Database and Analysis Resource (ViPR ... Late phase: Late genes are expressed from 140 min to 48 hours post-infection, producing all structural proteins. Assembly of ...
Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral proteins to host ... Fusion with the plasma membrane to release the core into the host cytoplasm. Early phase: early genes are transcribed in the ... The virus exits the host cell by microtubular outwards viral transport, and existing in occlusion bodies after cell death and ... "Viral Zone". ExPASy. Retrieved 15 June 2015. ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015. International ...
Fusogens involved in virus-to-cell fusion mechanisms were the first of these proteins to be discovered. Viral fusion proteins ... Cell fusion also occurs in a multitude of mammalian cells including gametes and myoblasts. Proteins that allow viral or cell ... It also must construct necessary proteins to mediate fusion. Finally, it must eliminate hindrances to fusion. For example, a ... A fusion mechanism is any mechanism by which cell fusion or virus-cell fusion takes place, as well as the machinery that ...
In some cases, expression of viral fusion proteins on the surface of the host cells can cause host cell fusion to form ... A viral infection does not always cause disease. A viral infection simply involves viral replication in the host, but disease ... Viral genetics encoding viral factors will determine the degree of viral pathogenesis. This can be measured as virulence, which ... proteins, DNA and/or RNA. Namely, viral proteins of herpes simplex virus can degrade host DNA and inhibit host cell DNA ...
An example of a Class III viral fusion protein is the rabies virus glycoprotein, G. Class IV: Class IV viral fusion proteins ... The fusion of the viral envelope with the cellular membrane requires high energy to occur. Viral membrane fusion proteins act ... and groups of viral proteins include structural proteins, nonstructural proteins, regulatory proteins, and accessory proteins. ... Examples of class II viral fusion proteins include the dengue virus E protein, and the west nile virus E protein. Class III: ...
Interbilayer forces in membrane fusion Viral membrane fusion proteins Classification of viral fusion proteins in TCDB database ... Membrane fusion proteins (not to be confused with chimeric or fusion proteins) are proteins that cause fusion of biological ... VAMP These proteins originate from the env gene of endogenous retroviruses. They are domesticated viral class I fusion proteins ... Syncytin-1 Syncytin-2 ERV3 is not functional in fusion. HAP2 is a domesticated viral class II fusion protein found in diverse ...
Viral resistance[edit]. Many people were skeptical of being too hopeful with indinavir due to previous events that occurred ... As a result, structural proteins, resulting from polypeptide products of gag and gag-pol genes, that are necessary for the HIV ... Entry/fusion inhibitors (Discovery and development). *gp41 (Enfuvirtide (ENF, T-20)). *CCR5 (Maraviroc (MVC) ... Viral resistance to the drug leads to the drug becoming useless since the virus evolves to have cells that are able to resist ...
... detecting the viral RNA by polymerase chain reaction (PCR)[6][23] and detecting proteins by enzyme-linked immunosorbent assay ( ... which is followed by fusion of the viral envelope with cellular membranes.[50] The virions taken up by the cell then travel to ... which code for proteins with antiviral properties.[51] EBOV's V24 protein blocks the production of these antiviral proteins by ... meningitis and other viral haemorrhagic fevers may resemble EVD.[1] Blood samples are tested for viral RNA, viral antibodies or ...
fusion protein against VEGF (Aflibercept). *proapoptotic peptide against ANXA2 and prohibitin (Adipotide) ... Other viral infections. *Progressive multifocal leukoencephalopathy (PML). *Immune toxicity, with depletion of B cells in 70% ... The CD20 proteins are sticking out of the cell membrane, and rituximab, the Y-shaped antibody, is binding to the CD20 proteins. ... The antibody binds to the cell surface protein CD20. CD20 is widely expressed on B cells, from early pre-B cells to later in ...
Receptor binding, as well as membrane fusion, are catalyzed by the protein E, which changes its conformation at low pH, causing ... The sfRNAs are a result of incomplete degradation of the viral genome by the exonuclease and are important for viral ... and forms a complex with protein E. The immature particles are processed in the Golgi apparatus by the host protein furin, ... Other viral hemorrhagic fevers, such as Ebola virus, Lassa virus, Marburg virus, and Junin virus, must be excluded as the cause ...
Proteins related to the cytoskeleton components of other organisms exist in archaea,[89] and filaments form within their cells, ... this fusion may make their membranes more rigid and better able to resist harsh environments.[112] For example, the lipids in ... the impact of viral infection is higher on archaea than on bacteria and virus-induced lysis of archaea accounts for up to one- ... January 2002). "Introns in protein-coding genes in Archaea". FEBS Lett. 510 (1-2): 27-30. doi:10.1016/S0014-5793(01)03219-7. ...
... is an HIV integrase strand transfer inhibitor which blocks the functioning of HIV integrase which is needed for viral ... Entry/fusion inhibitors (Discovery and development). *gp41 (Enfuvirtide (ENF, T-20)). *CCR5 (Maraviroc (MVC) ... Protein binding. ≥98.9%. Metabolism. UGT1A1 and CYP3A. Elimination half-life. ~14 hours. ...
... viral burden - viral core - viral culture - viral envelope - viral load - viremia - viricide - virion - virology - virus - ... proteins - protocol - protozoa - provirus - pruritus - pseudo-Cushing's syndrome - pseudovirion - PUBMED - pulmonary - purified ... fusion inhibitor - fusion mechanism - fusion peptide ... core protein - correlates of immunity/correlates of protection ...
... pol proteins, and env proteins. *Group-specific antigen (gag) proteins are major components of the viral capsid, which are ... of the Env protein, while the ability of the retrovirus to enter the cell via membrane fusion is imparted by the membrane- ... This step will also make viral enzymes and capsid proteins (8). Viral RNA will be made in the nucleus. These pieces are then ... Next, some of these RNA molecules are translated into viral proteins. For example, the gag gene is translated into molecules of ...
"CD46 on glial cells can function as a receptor for viral glycoprotein-mediated cell-cell fusion". Glia. 52 (3): 252-8. doi: ... OECs express glial markers such as glial fibrillary acidic protein, s100, and p75, and radial glial markers such as nestin and ... OECs have properties similar to those of astrocytes,[12] both of which have been identified as being susceptible to viral ... May 2012). "Myelin-associated proteins block the migration of olfactory ensheathing cells: an in vitro study using single-cell ...
R. L. Wysong (1976). "5: Origin of Proteins". The Creation-evolution Controversy (implications, Methodology and Survey of ... He played a fundamental role in the first experimental demonstration of nuclear fusion and also the development of the atomic ... Norman Pirie FRS (1907-1997): British biochemist and virologist co-discoverer in 1936 of viral crystallization, an important ... the Oppenheimer-Phillips process in nuclear fusion, and the first prediction of quantum tunneling. With his students he made ...
DNA and proteins seemed the dominant macromolecules in the living cell, with RNA only aiding in creating proteins from the DNA ... Through the process of viral infection into hosts the three domains of life evolved.[83][84] Another interesting proposal is ... The periodic fusions permit mutual reactivation of otherwise lethally damaged protocells. If at least one damage-free copy of ... where a nucleotide-based molecule is needed to synthesize protein, and a peptide-based (protein) molecule is needed to make ...
Combinational Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor Proteins Vamp8 and Vti1b Mediate Fusion of ... these findings have not been examined in non-viral systems. ... Ubiquitinated proteins are proteins that have been tagged with ... WIPI2, a PtdIns(3)P binding protein of the WIPI (WD-repeat protein interacting with phosphoinositides) protein family, was ... This allows unneeded proteins to be degraded and the amino acids recycled for the synthesis of proteins that are essential for ...
In an effort to localize the amino acid motif responsible for granule targeting, we constructed additional fusion proteins and ... but also found in viral capsid proteins. Cell signaling[edit]. TNF can bind two receptors, TNFR1 (TNF receptor type 1; CD120a; ... protein binding. • protease binding. • tumor necrosis factor receptor binding. • cytokine activity. • identical protein binding ... positive regulation of protein complex assembly. • protein kinase B signaling. • positive regulation of cytokine production. • ...
... and internalization in viral-cell fusion and as targets for entry inhibitors". Biochim. Biophys. Acta. 1614 (1): 51-61. PMID ... CCR5 protein pripada familiji beta hemokinskih receptora, integralnih membranskih proteina.[2][3] On je G protein spregnuti ... CCR5 (C-C hemokinski receptor tip 5, CD195) je protein na površini belih krvnih zrnca. On je komponenta imunskog sistema koja ... aktivnost G-protein spregnutog receptora. • aktivnost hemokinskog receptora. • proteinsko vezivanje. • koreceptorska aktivnost ...
The central core contains the viral RNA genome and other viral proteins that package and protect this RNA. RNA tends to be ... "An open receptor-binding cavity of hemagglutinin-esterase-fusion glycoprotein from newly-identified Influenza D Virus: Basis ... which causes the core to disassemble and release the viral RNA and core proteins.[63] The viral RNA (vRNA) molecules, accessory ... or transported back into the nucleus to bind vRNA and form new viral genome particles (step 5a). Other viral proteins have ...
... viral coat protein, a variant called E1-A226V. This mutation potentially allows the virus to multiply more easily in mosquito ... E1 contains a fusion peptide which, when exposed to the acidity of the endosome in eukaryotic cells, dissociates from E2 and ... The virus consists of four nonstructural proteins and three structural proteins.[12] The structural proteins are the capsid and ... viral antigen and viral RNA were found in macrophages in the synovial joint of a person experiencing a relapse of ...
This protein may function in vesicle trafficking, membrane fusion, protein complex assembly and cell motility. Alternative ... Gao L, Aizaki H, He JW, Lai MM (2004). "Interactions between viral nonstructural proteins and host protein hVAP-33 mediate the ... Vesicle-associated membrane protein-associated protein A is a protein that in humans is encoded by the VAPA gene. Together with ... "Phosphorylation of hepatitis C virus nonstructural protein 5A modulates its protein interactions and viral RNA replication". ...
... in viral infections. The fact that all known cell fusion molecules are viral in origin suggests that they have been vitally ... Felix Rey, of the Pasteur Institute in Paris has constructed the 3D structure of the EFF1 protein[39] and shown it does the ... Two viral components have been identified. The first is syncytin, which came from a virus. The second identified in 2007 is ... About 800 million years ago,[37] a minor genetic change in a single molecule called guanylate kinase protein-interaction domain ...
The protein ZIP1 is responsible for the active transport of zinc into prostate cells. One of the zinc's important roles is to ... Viral infection. Papilloma virus has been proposed in several studies to have a potential role in prostate cancer, but as of ... In men who are candidates for active surveillance, fusion MR/US guided prostate biopsy detected 33% of cancers compared to 7% ... Prostate specific membrane antigen is a transmembrane carboxypeptidase and exhibits folate hydrolase activity.[75] This protein ...
Brüssow, H. (2012). "On Viruses, Bats and Men: A Natural History of Food-Borne Viral Infections". Viruses: Essential Agents of ... Several species have a fission-fusion social structure, where large numbers of bats congregate in one roosting area, along with ... Carnivorous and vampire bats consume large amounts of protein and can output concentrated urine; their kidneys have a thin ... Instead, more diverse groups had greater viral diversity.[187]. They seem to be highly resistant to many of the pathogens they ...
... candidate made of the P2-VP8 fusion protein, which is currently undergoing development and trials in South Africa. Rotavirus ... Four reassortant rotaviruses express one of the outer capsid, VP7, proteins (serotypes G1, G2, G3, or G4) from the human ... The fifth reassortant virus expresses the attachment protein VP4, (type P1A), from the human rotavirus parent strain and the ... outer capsid protein VP7 (serotype G6) from the bovine rotavirus parent strain. In February 2006, the U.S. Food and Drug ...
This fusion protein has enzyme activity that can be inhibited by imatinib, a small molecule drug.[119][120][121][122] ... The susceptibility of an individual to liver damage can be altered by other factors such as the cancer itself, viral hepatitis ... As different proteins are utilised by different cancer types, the targeted therapy drugs are used on a cancer type specific, or ... Now it is clear that there is often a range of protein targets that the drug can bind. An example target for targeted therapy ...
... viral nucleocapsid protein) proteins, while L RNA encodes Z and L proteins. The L protein most likely represents the viral RNA- ... which at the lower pH of the endosome binds the lysosome protein LAMP1 which results in membrane fusion and escape from the ... This ensures an adequate supply of viral proteins for subsequent steps of replication, as the NP and L proteins are translated ... for a total of four viral proteins.[15] The large segment encodes a small zinc-binding protein (Z) that regulates transcription ...
... who have evidence of viral replication and HIV-1 strains resistant to a non-nucleoside reverse transcriptase inhibitor (NNRTI) ... Entry/fusion inhibitors. (Discovery and development). *gp41 (Enfuvirtide (ENF, T-20)). *CCR5 (Maraviroc (MVC) ... Protein binding. 99.9%. Metabolism. Hepatic (CYP3A4, CYP2C9 & CYP2C19-mediated). Biological half-life. 41±20 hours. ...
... abl fusion protein, an oncogenic tyrosine kinase. Small-scale mutations include point mutations, deletions, and insertions, ... leading to the expression of viral oncogenes in the affected cell and its descendants. ... "Negative regulation of BRCA1 gene expression by HMGA1 proteins accounts for the reduced BRCA1 protein levels in sporadic breast ... miRNAs do not code for proteins, but can "target" protein-coding genes and reduce their expression. ...
In some persons, attacks of ulceration occur at the same time as asymptomatic viral shedding and elevated viral titres.[5] ... Persons with aphthous stomatitis also have circulating lymphocytes which react with peptides 91-105 of heat shock protein 65-60 ...
Also, viral fusion proteins cause the formation of the placental syncytium[23] to limit exchange of migratory cells between the ... The fusion proteins were a way to spread the infection to other cells by simply merging them with the infected one (HIV does ... Most viral vaccines are based on live attenuated viruses, whereas many bacterial vaccines are based on acellular components of ... Last one is piRNA where small RNA binds to the Piwi protein family and controls transposones and other mobile elements.[21] ...
... antibody fragments and fusion proteins are composed from these. Common advantages over antibodies are better solubility, tissue ... elevated IgM indicates viral hepatitis and primary biliary cirrhosis, while IgG is elevated in viral hepatitis, autoimmune ... Stevens FJ, Solomon A, Schiffer M (1991). "Bence Jones proteins: a powerful tool for the fundamental study of protein chemistry ... and their realization that this protein is the same as the Bence-Jones protein described in 1845 by Henry Bence Jones.[101] ...
Tat is a regulatory protein that drastically enhances the efficiency of viral transcription.[2] Tat stands for "Trans-Activator ... Fusion protein. *Gag-onc fusion protein. Retrieved from "https://en.wikipedia.org/w/index.php?title=Tat_(HIV)&oldid=963734585" ... Protein transduction domain[edit]. Tat contains a protein transduction domain, which is therefore known as a cell-penetrating ... In molecular biology, Tat is a protein that is encoded for by the tat gene in HIV-1.[1][2] ...
Diversity of viral fusion proteins. The major differences among viral fusion proteins are their structural class (left) and ... Receptor activation of viral fusion proteins. Many viral fusion proteins are activated by host cell receptors, but there are ... The depicted Class I fusion protein is one that does not require any other viral surface proteins for fusion (e.g., influenza ... Viral fusion proteins also contain different types of fusion peptides and vary in their reliance on accessory proteins. These ...
"Viral Fusion Proteins" by people in this website by year, and whether "Viral Fusion Proteins" was a major or minor topic of ... Roles of the putative integrin-binding motif of the human metapneumovirus fusion (f) protein in cell-cell fusion, viral ... Proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. They promote cell membrane fusion and ... "Viral Fusion Proteins" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical ...
Structure/Function of Membrane-Associated Viral Fusion Proteins and Structure of Recombinant Proteins in Bacterial Inclusion ... Structure/Function of Membrane-Associated Viral Fusion Proteins and Structure of Recombinant Proteins in Bacterial Inclusion ... Structure/Function of Membrane-Associated Viral Fusion Proteins and Structure of Recombinant Proteins in Bacterial Inclusion ...
of Chemistry Structure/Function of Membrane-Associated Viral Fusion Proteins and Structure of Recombinant Proteins in ... of Chemistry Structure/Function of Membrane-Associated Viral Fusion Proteins and Structure of Recombinant Proteins in ... of Chemistry Structure/Function of Membrane-Associated Viral Fusion Proteins and Structure of Recombinant Proteins in ...
Expression of an IRF-3 fusion protein and mouse estrogen receptor, inhibits hepatitis C viral replication in RIG-I-defic.... ... Expression of an IRF-3 fusion protein and mouse estrogen receptor, inhibits hepatitis C viral replication in RIG-I-deficient ... Here, we established a stable Huh7.5-IRF3ER cell line expressing a fusion protein of IRF-3 and mouse estrogen receptor (ER) to ... Homodimerization of the IRF-3ER fusion protein was detected by Western blotting after treatment with the estrogen receptor ...
None of the proteins resemble type I or type II viral fusion proteins by sequence so that determination of the 3-dimensional ... slowing or interrupting fusion with inhibitors and decreasing the surface density of viral fusion proteins [58]-[61]. In the ... The Membrane Fusion Step of Vaccinia Virus Entry Is Cooperatively Mediated by Multiple Viral Proteins and Host Cell Components ... Class II fusion protein of alphaviruses drives membrane fusion through the same pathway as class I proteins. J Cell Biol 169 ...
To understand the fusion mechanism in more detail, we use an infection free system whereby fusion can be induced by a minimal ... Here, we describe an optimized protocol of a transient transfection based fusion assay to quantify cell-cell fusion induced by ... Membrane fusion is vital for entry of enveloped viruses into host cells as well as for direct viral cell-to-cell spread. ... Transient Transfection-based Fusion Assay for Viral Proteins Edited by. Yannick Debing ...
RuV E1 is a member of the class II fusion proteins and is structurally related to the alphavirus and flavivirus fusion proteins ... Together our data indicate that RuV E1 is the first example of a Ca(2+)-dependent viral fusion protein and has a unique ... Unlike the other known class II fusion proteins, however, RuV E1 contains two fusion loops, with a metal ion complexed between ... The structure of the RuV E1 fusion protein was recently solved in its postfusion conformation. ...
... found in the viral envelopes of a variety of viruses. They promote cell membrane fusion and thereby may function in the uptake ... What is definition of viral fusion proteins?. 3 years ago by Pozzter Q&A 0 replies, read ~167926 times ... Proteins, usually glycoproteins, found in the. viral envelopes of a variety of viruses. They. promote cell membrane fusion and ...
... are class II viral fusion proteins. Comparisons of divergent viral fusion proteins can reveal features essential for virion: ... cell membrane fusion. Class II viral fusion proteins (beta-penetrenes), encoded by members of the Alphaviridae and Flaviviridae ... has a significant amino acid sequence similarity with envelope protein 1 (E1), the class II fusion protein of Sindbis virus ( ... These results suggest that Gc of Bunyaviridae, and similar proteins of Tenuiviruses and a group of Caenorhabditis elegans ...
Viral Fusion Inhibitors. Wed, 30 May 2012 , Protein Interactions Until recently, only two proteins essential for the viral life ... thus inhibiting membrane fusion and viral entry. Interestingly, the first peptides inhibiting viral fusion were designed in the ... In an effort to design more potent inhibitors of viral fusion, Dwyer et al. (2007) applied modifications to an HR2 peptide ... absence of high-resolution structural data on the fusion protein, and structural implications of the fusion process were merely ...
"Viral Fusion Protein Inhibitors" by people in this website by year, and whether "Viral Fusion Protein Inhibitors" was a major ... "Viral Fusion Protein Inhibitors" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH ( ... Drugs that are designed to block the action of VIRAL FUSION PROTEINS and prevent VIRUSES from entering the cell. ... Below are the most recent publications written about "Viral Fusion Protein Inhibitors" by people in Profiles. ...
Viral fusion proteins undergo dramatic conformational transitions during membrane fusion. For viruses that enter through the ... N2 - Viral fusion proteins undergo dramatic conformational transitions during membrane fusion. For viruses that enter through ... AB - Viral fusion proteins undergo dramatic conformational transitions during membrane fusion. For viruses that enter through ... abstract = "Viral fusion proteins undergo dramatic conformational transitions during membrane fusion. For viruses that enter ...
Recent structural studies revealed a stunning diversity of viral fusion proteins in their native state. In spite of this ... The converging hairpin motif, along with biochemical and functional data, implies that disparate viral proteins promote ... the post-fusion structures of these proteins share a common trimeric hairpin motif in which the amino- and carboxy-terminal ... permitting the cytosolic release of the viral cores. Understanding the molecular details of this process is essential for ...
The long-term goal of the proposed research is to understand the basis for viral fusion protein-induced membrane fusion with ... The long-term goal of the proposed research is to understand the basis for viral fusion protein-induced membrane fusion with ... Fusion proteins are also a target of viral vaccine development. The proposed research focuses on the gp41 and the hemagglutinin ... Solid-State NMR of Viral Fusion Peptides and Proteins Weliky, David Paul Michigan State University, East Lansing, MI, United ...
Detection of viral titers in mouse lung. Mice (n = 5/group) immunized with fusion proteins Flg-HA2-2-4M2ehs and FlgSh-HA2-2- ... Design and characterization of fusion proteins. Fusion protein Flg-HА2-2-4M2ehs was designed containing full-length flagellin ... HA2-M2e fusion proteins immunization significantly reduced influenza viral load in lungs. Two weeks after completion of the ... Immunization with HA2-M2e fusion proteins protected mice from lethal H3N2 and H7N9 viral challenge. In order to evaluate the ...
The viral fusion proteins (E1 and E, respectively) from these two genera have been grouped as "class II" viral fusion proteins ... Stem antibodies and peptides failed to inhibit viral fusion. Sequence comparisons of alphavirus fusion proteins showed several ... Studies on domain III and the stem region of class II viral fusion proteins. ... refolded and purified domain III proteins from SFV and DV2. These proteins potently inhibited SFV and dengue virus fusion, and ...
In the past year we have been exploring different approaches to expressing F protein trimers at the surface of yeast and have ... developed two novel strategies that utilize self-cleaving 2A peptides and reporter fluorescent proteins as our foundational ... Yeast Surface Display Approaches for Engineering Stabilized Viral Fusion Protein Subunit Vaccines. ... In the past year we have been exploring different approaches to expressing F protein trimers at the surface of yeast and have ...
We determine the crystal structure of the Gn glycoprotein and fit it with the Gc fusion protein into cryo-electron microscopy ... Our analysis reveals how the Gn shields the hydrophobic fusion loops of the Gc, preventing premature fusion. Electron ... However, the intermediate conformations during fusion remain unknown. Here, we address the fusion mechanism of Rift Valley ... Repositioning of the Gn allows extension of Gc and insertion of fusion loops in the outer leaflet of the target membrane. These ...
LearnCoil-VMF: Computational evidence for coiled-coil-like motifs in many viral membrane-fusion proteins. Journal of Molecular ... LearnCoil-VMF : Computational evidence for coiled-coil-like motifs in many viral membrane-fusion proteins. / Singh, Mona; ... Crystallographic studies have shown that the coiled-coil motif occurs in several viral membrane-fusion proteins, including HIV- ... N2 - Crystallographic studies have shown that the coiled-coil motif occurs in several viral membrane-fusion proteins, including ...
Detailed mechanisms of membrane fusion and the protein structures involved have been mainly studied in eukaryotic systems, ... This sheds light on protein structures involved in prokaryotic membrane fusion. ... and we establish the orientation of the molecules with respect to the viral membrane. We also show that the viral membrane ... Here we determine atomic structures of the ectodomains of the 57-kDa spike protein VP5 from two related HRPVs revealing a ...
LearnCoil-VMF: computational evidence for coiled-coil-like motifs in many viral membrane-fusion proteins.. Singh M, Berger B, ... Viral Membrane-Fusion Proteins. Protein Sequence Analysis ... Viral Membrane-Fusion Protein 98 views. Sorry, the comment form ... LearnCoil-VMF program uses an iterative learning algorithm to detect coiled-coil-like regions in viral membrane-fusion proteins ... Motif Network Next Generation Sequencing Phylogenetic Tree Population Predict Prediction Protein Protein Sequence Protein ...
Although cell fusion is an omnipresent process in life, to date considerably less is still known about the mechanisms and the ... Class III Viral Membrane Fusion Proteins Marija Backovic, Theodore S. Jardetzky. Pages 91-101 ... In Cell Fusion in Health and Disease Vol 1 & Vol 2 leading experts will present up-to-date overviews about cell fusion in ... Volume 2 focuses on Cell Fusion in Disease with a particular emphasis on the role of cell fusion in cancer development and ...
... membrane barrier including the use of molecular ferries such as cell penetrating peptides or viral membrane fusion proteins, ... been developed in the last decades to overcome endosomal accumulation and subsequent lysosomal degradation of targeted protein- ... To date, three different classes of viral fusion proteins (Class I-III) [62] based on post-fusion structural motifs have been ... which then induces the necessary conformational changes in the fusion protein to mediate membrane fusion between viral and host ...
The Transmembrane Domain and Acidic Lipid Flip-Flop Regulates Voltage-Dependent Fusion Mediated by Class II and III Viral ... Proteins. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material ... Voltage dependence of fusion induced by class II and class III viral fusion proteins was investigated. Class II proteins from ... Fusion induced by class I viral proteins is independent of voltage; chimeras expressing the ectodomain of a class I fusion ...
Fusion phenomenon occurs at the host cell surface or in the cytoplasmic compounds and in cytoplasmic components. The fusion ... Viral fusion protein through protected areas called fusion peptide are essential for entry of the virus into the host cell by ... proteins are divided into three categories according to ... ... Viral fusion protein through protected areas called fusion ... The changes in fusion protein in the levels before and after fusion, description of fusion proteins in viruses such as ...
Detection of Mouse Hepatitis Virus Nonstructural Proteins Using Antisera Directed Against Bacterial Viral Fusion Proteins - ... Antisera were raised in rabbits against these fusion proteins. Viral nonstructural proteins were detected in infected murine ... Detection of Mouse Hepatitis Virus Nonstructural Proteins Using Antisera Directed Against Bacterial Viral Fusion Proteins ... RecA/viral/LacZ tripartite fusion proteins were synthesized from these plasmids and purified from E. coli. ...
3.6 Membrane fusion mediated by viral proteins. Until now, we have focused on the transport of material between different ... This type of fusion is endoplasmic fusion. Another type of membrane fusion, called ectoplasmic fusion, is used by enveloped ... This feature of proteins is crucial for a variety of biological processes from protein degradation to protein sorting for ... The biophysical and structural studies of viral proteins involved in the processes of membrane fusion provide a foundation for ...
3.6 Membrane fusion mediated by viral proteins. This unit explains the function of the cytoskeleton and its role in controlling ... 5.2 Motor proteins. This unit explains the function of the cytoskeleton and its role in controlling transport of vesicles ... 3.5 Cycling and re-use of membranes and traffic proteins. This unit explains the function of the cytoskeleton and its role in ... 3.4 The function of Rab proteins in directing traffic. This unit explains the function of the cytoskeleton and its role in ...
2004) Class I, class II viral fusion protein structures reveal similar principles in membrane fusion. Mol Membr Biol 21:361-371 ... 1995) Structural characterization of viral fusion proteins. Curr Biol 5:265-274.. ... The GP2 subunit is a transmembrane protein that mediates fusion of the viral and cellular membranes after internalization of ... 2006) Virus membrane-fusion proteins: More than one way to make a hairpin. Nat Rev Microbiol 4:67-76.. ...
  • Yet despite this staggering diversity, all characterized viral fusion proteins convert from a fusion-competent state (dimers or trimers, depending on the class) to a membrane-embedded homotrimeric prehairpin, and then to a trimer-of-hairpins that brings the fusion peptide, attached to the target membrane, and the transmembrane domain, attached to the viral membrane, into close proximity thereby facilitating the union of viral and target membranes. (nih.gov)
  • During these conformational conversions, the fusion proteins induce membranes to progress through stages of close apposition, hemifusion, and then the formation of small, and finally large, fusion pores. (nih.gov)
  • The target and viral membranes are, respectively, at the top and bottom of the images. (nih.gov)
  • The aim of the present study was to determine the roles of cellular and viral proteins in initial stages of entry, specifically fusion of the membranes of the mature virion and cell. (prolekare.cz)
  • Entry of enveloped viruses into cells can be divided into three steps: (i) close apposition of viral and cellular membranes, (ii) lipid mixing of the outer membrane leaflets leading to formation of a hemifusion intermediate, and (iii) formation and expansion of a fusion pore allowing entry of the viral nucleoprotein or core into the cytoplasm [1] . (prolekare.cz)
  • The mechanism leading to fusion of herpesvirus envelopes with cellular membranes is only incompletely understood. (bio-protocol.org)
  • Panel E: As previously proposed [11,33,54] the formation of more extensive Gc contacts in the trimers and stem regions may release of energy for distortion of the endosomal and viral membranes resulting in formation of "nipple-like" projections. (biomedcentral.com)
  • Panel E': Alternatively, aa sequences of Gc that form a track with the ability to interface with bilayer membranes (Fig. 2, black), may facilitate mixing of the endosomal and viral membranes. (biomedcentral.com)
  • Enveloped viruses encode specialized fusion proteins which promote the merger of viral and cell membranes, permitting the cytosolic release of the viral cores. (biomedcentral.com)
  • According to this model, fusion proteins first anchor themselves to the target membrane through their hydrophobic segments and then fold back, bringing the viral and cellular membranes together and forcing their merger. (biomedcentral.com)
  • Whereas viral proteins regulate and promote the merger of biological membranes, complete fusion occurs when lipids from two distinct bilayers rearrange to form a continuous membrane. (biomedcentral.com)
  • Fusion of viral and target cell membranes is a key step in infection for many viruses important in disease and a detailed understanding of fusion mechanisms will aid development of anti-viral therapeutics whose mode of action is fusion inhibition. (grantome.com)
  • Although the domains essentially maintain their original folds during fusion, domain III and the stem (the region connecting domain III to the transmembrane domain) fold back to form a hairpin structure, bringing together the viral and target membranes. (yu.edu)
  • Until now, we have focused on the transport of material between different intracellular membrane-bound compartments and fusion of cytoplasmic membranes. (nottingham.ac.uk)
  • The GP2 subunit is a transmembrane protein that mediates fusion of the viral and cellular membranes after internalization of the virus into acidified endosomes ( 21 - 24 ). (pnas.org)
  • It is classified as a class I fusion protein, and is responsible for binding to the receptor on the host cell as well as mediating the fusion of host and viral membranes-A process driven by major conformational changes of the S protein. (nih.gov)
  • One focus of the Dutch lab is to study the specific proteins in these viruses that promote fusion between the viral membranes and the host cell membranes. (murraystate.edu)
  • Rigid amphipathic fusion inhibitors (RAFIs) are a family of nucleoside derivatives that inhibit the infectivity of several enveloped viruses by interacting with virion envelope lipids and inhibiting fusion between viral and cellular membranes. (bireme.br)
  • The Membrane Structure and Function Subgroup (MSAF) promotes and advances knowledge about the biophysical properties of lipids, membranes, and membrane-associated molecules, including membrane proteins. (biophysics.org)
  • to foster the advance of knowledge pertaining to the biophysical properties of lipids, lipid assemblies, membrane proteins and lipid-protein interactions generally relevant to biological membranes and their assembly. (biophysics.org)
  • Fusion in Cell Membranes. (booktopia.com.au)
  • Role of Metalloendoprotease in the Fusion of Biological Membranes. (booktopia.com.au)
  • Fusion in Model Membranes. (booktopia.com.au)
  • The Mechanism of Polyethylene Glycol-Induced Fusion in Model Membranes. (booktopia.com.au)
  • The pre-fusion complexes then undergo a series of conformational changes by specific cellular triggers to achieve fusion of host-to-viral membranes, mediating entry ( 1 , 2 ). (frontiersin.org)
  • However, the mechanism by which viral genomes pass endosomal membranes has not been elucidated. (asm.org)
  • Fusions between green fluorescent protein and the L2 peptide integrated into cellular membranes like the wild type but not like C-terminal mutants of L2. (asm.org)
  • Cellular membranes, composed of proteins and lipids, are the first line of defense against infection. (cancer.gov)
  • G then triggers F to flip up and down, triggering fusion between the cellular and viral membranes-the first moment of infection. (genengnews.com)
  • Proteins that allow viral or cell membranes to overcome barriers to fusion are called fusogens. (wikipedia.org)
  • They form polymeric structures to induce fusion of membranes. (wikipedia.org)
  • Reoviruses do not have membranes themselves, so class IV fusogens are not usually involved in traditional virus-cell fusion. (wikipedia.org)
  • A 20 amino acid peptide from the N-terminus of the influenza HA fusion peptide (WT20) assumed the oblique orientation at the interface between water and the membrane made up of dipalmitoylphosphatidylcholine (DPPC)/palmitic acid (PA), as reported previously for different membranes. (scirp.org)
  • Taken together, these results imply that the influenza HA fusion peptide can have substantial effects on the membrane curvature and can assume a wide range of orientation/position in membranes depending on the local environment of the lipid/water system. (scirp.org)
  • Membrane fusion proteins (not to be confused with chimeric or fusion proteins) are proteins that cause fusion of biological membranes. (wikipedia.org)
  • Enveloped viruses readily overcome the thermodynamic barrier of merging two plasma membranes by storing kinetic energy in fusion (F) proteins. (wikipedia.org)
  • This topology may be required to coordinate the behavior of the two mitochondrial membranes during the fusion reaction. (rupress.org)
  • T he homotypic, or self-fusion, of mitochondrial membranes plays an important role in controlling the copy number and cellular distribution of these essential organelles ( Bereiter-Hahn and Voth, 1994 ). (rupress.org)
  • Molecules that regulate the heterotypic and homotypic fusion of membranes in the secretory and endocytic pathways have been studied in some detail. (rupress.org)
  • Thus, in some cases, the recognition of "like" membranes in homotypic fusion reactions may be mediated by homomeric interactions between compartment-specific t-SNAREs. (rupress.org)
  • Viral fusion protein causes neighboring cell's membranes to fuse. (armoredpenguin.com)
  • The F-protein is responsible for fusion of the virus and host cell membranes, viral penetration, and hemolysis. (cdc.gov)
  • Proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. (umassmed.edu)
  • For many viruses, one or two proteins allow cell attachment and entry, which occurs through the plasma membrane or following endocytosis at low pH. (prolekare.cz)
  • One or two glycoproteins that provide cell binding and membrane fusion are sufficient to mediate entry of many enveloped viruses [2] . (prolekare.cz)
  • Membrane fusion is vital for entry of enveloped viruses into host cells as well as for direct viral cell-to-cell spread. (bio-protocol.org)
  • Membrane fusion is essential for entry and spread of enveloped viruses. (bio-protocol.org)
  • Many enveloped viruses require only one or two viral proteins to mediate attachment to host cells and membrane fusion, and the molecular mechanisms are well understood (Harrison, 2015). (bio-protocol.org)
  • Different model systems, whereby fusion is induced with a minimal set of the core fusion machinery represented by glycoproteins gB and gH/gL and receptor-binding gD, in the absence of infection, have been developed, for example, for herpes simplex viruses type 1 and 2 (HSV-1 and 2 [Turner et al . (bio-protocol.org)
  • While the mutant viruses were efficiently assembled and endocytosed by host cells, E1-membrane insertion and fusion were specifically blocked. (pasteur.fr)
  • Drugs that are designed to block the action of VIRAL FUSION PROTEINS and prevent VIRUSES from entering the cell. (ctsicn.org)
  • These proteins are chosen because the viruses cause major human diseases and because the proteins serve as prototypes for other class I viral fusion proteins. (grantome.com)
  • Entry of enveloped viruses relies on insertion of hydrophobic residues of the viral fusion protein into the host cell membrane. (ox.ac.uk)
  • Haloarchaeal pleomorphic viruses (HRPVs) have a membrane envelope decorated with spikes that are presumed to be responsible for host attachment and membrane fusion. (ox.ac.uk)
  • Kianfar R, Soleimanjahi H. Investigation of the Viral Fusion Proteins Mechanism and Their Analysis in Different Viruses. (ac.ir)
  • In the first category, which includes viruses such as orthomixo, paramyxo, filo, corona, and retroviruses, definite domains of fusion proteins are cleaved and removed and they become mature and functional. (ac.ir)
  • The changes in fusion protein in the levels before and after fusion, description of fusion proteins in viruses such as influenza, filo, and reoviruses as a prototype of fusion protein viruses and their therapeutic applications of fusion protein as potential drugs such as Lactoferrin and Enfuvertide in preventing the occurrence of fusion phenomenon is an important issue for consideration about multiplication and virus entry. (ac.ir)
  • Another type of membrane fusion, called ectoplasmic fusion , is used by enveloped viruses to infect cells (enveloped viruses have an outer phospholipid bilayer). (nottingham.ac.uk)
  • Isolation of revertant viruses revealed that second site mutations caused frame shifts and premature termination of A26 protein such that reverent viruses regained cell entry through plasma membrane fusion. (elsevier.com)
  • In most viruses, these fusion (F) proteins have a positively charged plasmid DNA residue that interacts with the negatively charged membrane of the host cell. (murraystate.edu)
  • NNS viruses have limited encoding capacity compared to many DNA viruses, and as a likely consequence, most open reading frames encode multifunctional viral proteins that interact with host factors in order to evade host cell defenses while promoting viral replication. (bireme.br)
  • Determined viral proteins are able to change the host's ubiquitin machinery and some viruses even encode their own ubiquitinating or deubiquitinating enzymes. (bireme.br)
  • These classical scenarios give different timelines for the origin(s) of viruses and do not explain the provenance of the two key functional modules that are responsible, respectively, for viral genome replication and virion morphogenesis. (nature.com)
  • Here, we outline a 'chimeric' scenario under which different types of primordial, selfish replicons gave rise to viruses by recruiting host proteins for virion formation. (nature.com)
  • This morning I watched an online lecture by Scientists at the University of Southampton, on the subject of glycosylation in the 'Spike Protein' SARS-CoV2 viruses. (democraticunderground.com)
  • These viruses are not likely to share immunodominant cytotoxic T-cell (CTL) epitopes, and the structural differences in Env protein may lead to qualitative differences in the antibody responses. (frontiersin.org)
  • A(H3N2) influenza viruses have circulated in humans since 1968, and antigenic drift of the hemagglutinin (HA) protein continues to be a driving force that allows the virus to escape the human immune response. (proteopedia.org)
  • The access of enveloped viruses to the cytosol requires the fusion of the viral envelope with a target cell membrane ( 13 ). (asm.org)
  • Nonenveloped viruses either lyse the limiting vesicular membrane ( 26 ) or generate a pore through it to allow escape of the viral genome into the cytosol ( 20 ). (asm.org)
  • New research from investigators at Cornell University not only uncovered how two highly lethal viruses have greater pathogenic potential when their proteins are combined but may have also stumbled upon potential novel targets to combat these diseases. (genengnews.com)
  • Co-infections with these two viruses can occur in the same host, but we didn't know what would happen if their proteins combined," noted senior study investigator Hector Aguilar-Carreno, PhD, associate professor in the department of microbiology and immunology at Cornell. (genengnews.com)
  • Since both Nipah and Hendra viruses can potentially co-infect fruit bats, a protein partner switch is likely to occur in the wild. (genengnews.com)
  • Virus-cell fusions occur during infections of several viruses that are health concerns relevant today. (wikipedia.org)
  • The research, published in the journal Nature Structural and Molecular Biology , describes the structure of the viral fusion protein gp64, which is involved in the mechanism which viruses use to invade host cells. (phys.org)
  • Professor Ian Jones from the School of Biological Sciences at the University of Reading said "this research has greatly increased our understanding about viral fusion proteins and how viruses get into cells. (phys.org)
  • Fusion proteins can originate from genes encoded by infectious enveloped viruses, ancient retroviruses integrated into the host genome, or solely by the host genome. (wikipedia.org)
  • The TWiVites discuss Zika virus seroprevalence in wild monkeys, Zika virus mRNA vaccines, and a gamete fusion protein inherited from viruses. (asm.org)
  • Filoviruses, members of the family Filoviridae of nonsegmented negative-strand RNA viruses, cause sporadic viral hemorrhagic fever outbreaks that primarily affect areas of equatorial Africa ( 1 ). (asm.org)
  • The reovirus Fusion-Associated Small Transmembrane (FAST) proteins are the smallest known membrane fusion proteins, and are the only identified fusion proteins from nonenveloped viruses. (dal.ca)
  • Studies to date indicate the FAST proteins do not function according to the paradigm established from investigations of the fusion proteins encoded by enveloped viruses such as HIV and influenza virus. (dal.ca)
  • Current models of protein-mediated membrane fusion are based extensively on the complex, multimeric fusion proteins encoded by enveloped viruses that mediate virus-cell fusion. (dal.ca)
  • Phage display is a laboratory technique for the study of protein-protein, protein-peptide, and protein-DNA interactions that uses bacteriophages (viruses that infect bacteria) to connect proteins with the genetic information that encodes them. (wikipedia.org)
  • Phage display was first described by George P. Smith in 1985, when he demonstrated the display of peptides on filamentous phage (long, thin viruses that infect bacteria) by fusing the virus's capsid protein to one peptide out of a collection of peptide sequences. (wikipedia.org)
  • The availability of specific inhibitors targeting distinct steps of HIV-1 entry permitted the identification of key conformational states of its envelope glycoprotein en route to fusion. (biomedcentral.com)
  • These studies provided functional evidence for the direct engagement of the target membrane by HIV-1 envelope glycoprotein prior to fusion and revealed the role of partially folded pre-hairpin conformations in promoting the pore formation. (biomedcentral.com)
  • We determine the crystal structure of the Gn glycoprotein and fit it with the Gc fusion protein into cryo-electron microscopy reconstructions of the virion. (ox.ac.uk)
  • Both proteins are synthesized in infected cells as a single glycoprotein precursor (GPC), which is proteolytically processed to these two mature subunits ( 13 - 16 ). (pnas.org)
  • The structure of motavizumab in complex with a 24-residue peptide corresponding to its epitope on the RSV fusion (F) glycoprotein reveals the structural basis for this greater potency. (nih.gov)
  • Major glycoprotein, comprises over 80% of the envelope proteins present in virus particle. (uniprot.org)
  • A structural basis for antibody-mediated neutralization of Nipah virus reveals a site of vulnerability at the fusion glycoprotein apex. (nih.gov)
  • Herpes simplex virus (HSV) fusion with cells requires the gD, gB, and gH/gL glycoprotein quartet. (pubmedcentralcanada.ca)
  • Importantly, to accurately measure their fusogenic capacities, as these depend on glycoprotein cell surface expression (CSE) levels, we inserted identical extracellular tags to both fusion (FLAG tags) or both attachment (hemagglutinin [HA] tags) glycoproteins. (genengnews.com)
  • 2021). Ebola virus glycoprotein interacts with cholesterol to enhance membrane fusion and cell entry. (tcdb.org)
  • It derives from gPr72 of 341 aas which is an Env protein fragment that is further degraded to the envelope glycoprotein, Env-GP of 127 aas (acc# L0R354) and then to the fusion peptide. (tcdb.org)
  • Researchers at FDA developed an efficacious Filovirus subunit vaccine based on a recombinant protein consisting of the extracellular domain of the Filovirus glycoprotein fused to an Fc Fragment of human immunoglobulin (FiloGP-Fc). (fda.gov)
  • The FiloGP-Fc fusion protein resembles the native glycoprotein expressed at the surface of cells and viral particles. (fda.gov)
  • Ebola virus glycoprotein Fc fusion protein confers protection against lethal challenge in vaccinated mice" Vaccine 2011 Apr. (fda.gov)
  • B) The key features of a class I fusion protein from N- to C-terminus: a fusion peptide (FP) at or near the N-terminus, an N-heptad repeat (N-HR aka HR1 or HRA), a C-heptad repeat (C-HR aka HR2 or HRB), a transmembrane domain (TMD), and a cytoplasmic tail ( squiggle ). (nih.gov)
  • Certain Bunyaviruses may encode other membrane-associated proteins that interact with the fusion peptide or other regions of Gc. (biomedcentral.com)
  • Panel D: bending at the flexible "hinge" region beween domains I and II permits Gc trimer formation and insertion of the fusion peptide into the endosomal vesicle membrane. (biomedcentral.com)
  • Enfuvirtide is a peptide consisting of residues 643-678 of the HIV-1 gp160 protein. (pharmacologicalsciences.us)
  • Indeed, several peptide sequences modified accordingly have been shown to be more active in inhibiting viral entry, with IC50 values in the upper femtomolar to lower nanomolar range (Otaka et al. (pharmacologicalsciences.us)
  • 2007). A peptide termed T-1249 appeared to be the most promising candidate for development of second-generation fusion inhibitors because it possesses greater in vitro potency than Enfuvirtide and is active on most Enfuvirtide-resistant strains, too (Eron et al. (pharmacologicalsciences.us)
  • The yellow triangle and arrow represent the position and orientation of the membrane spanning domain and the fusion peptide, respectively. (biomedcentral.com)
  • There is particular emphasis on the N-terminal """"""""fusion peptide"""""""" (FP) domains of the fusion proteins, which represent ~20-residue apolar regions at the N-termini of the proteins. (grantome.com)
  • Viral fusion protein through protected areas called fusion peptide are essential for entry of the virus into the host cell by membrane integration. (ac.ir)
  • Cathepsin L functionally cleaves the severe acute respiratory syndrome coronavirus class I fusion protein upstream of rather than adjacent to the fusion peptide. (ac.ir)
  • Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. (rcsb.org)
  • Here we show the crystal structures of the prefusion MeV-F alone and in complex with the small compound AS-48 or a fusion inhibitor peptide. (pnas.org)
  • LL-37 is the cleaved antimicrobial 37-residue C-terminal peptide of hCAP18, the only identified member in humans of a family of proteins called cathelicidins. (federalregister.gov)
  • In this report we show that the minor capsid protein L2 is required for egress of viral genomes from endosomes but not for initial uptake and uncoating and that a 23-amino-acid peptide at the C terminus of L2 is necessary for this function. (asm.org)
  • Pseudogenomes encapsidated by L1 and L2 lacking this peptide accumulated in vesicular compartments similar to that observed with L1-only viral particles, and these mutant pseudoviruses were noninfectious. (asm.org)
  • 1992 ). A potential fusion peptide and an integrin ligand domain in a protein active in sperm-egg fusion. (biologists.org)
  • He was the first to identify and publish the entry peptide sequence of HIV-1 in 1987, and he and his colleagues, including Dr. Garry, were first to model the structure of the HIV-1 entry protein in 1989. (medicalnewstoday.com)
  • He was also the first to identify and model the entry peptide loop and entry protein of Ebola virus in 1996. (medicalnewstoday.com)
  • Viral fusion proteins share important characteristics, notably a fusion peptide within a transmembrane-anchored polypeptide chain. (sciencemag.org)
  • Gallaher, W.R. (1987) Detection of a fusion peptide se-quence in the transmembrane protein of human immu-nodeficiency virus. (scirp.org)
  • The peptide regions required to drive fusion are formed from the turns between the β-sheets. (wikipedia.org)
  • The E1 protein of Hepatitis C Virus (HCV) can be dissected into two distinct hydrophobic regions: a central domain containing an hypothetical fusion peptide (FP), and a C-terminal domain (CT) comprising two segments, a pre-anchor and a trans-membrane (TM) region. (uni-potsdam.de)
  • Protein & Peptide Letters (2009) 16: 743. (eurekaselect.com)
  • Using CD and NMR spectroscopy coupled with liposome-cell, cell-cell, and peptide-induced liposome-liposome fusion assays, we are pursuing a mechanistic analysis of how dynamic changes in FAST protein fusion motifs allow the FAST proteins to function as modular cell-cell fusogens. (dal.ca)
  • In the case of M13 filamentous phage display, the DNA encoding the protein or peptide of interest is ligated into the pIII or pVIII gene, encoding either the minor or major coat protein, respectively. (wikipedia.org)
  • A current trend in the design of universal flu vaccines is the construction of recombinant proteins based on combinations of various conserved epitopes of viral proteins (M1, M2, HA2, NP). (springer.com)
  • In this study, we compared the immunogenicity and protective action of two recombinant proteins which feature different designs and which target different antigens. (springer.com)
  • A mutation in the stalk of the newcastle disease virus hemagglutinin-neuraminidase (HN) protein prevents triggering of the F protein despite allowing efficient HN-F complex formation. (umassmed.edu)
  • The proposed research focuses on the gp41 and the hemagglutinin HA2 fusion proteins of the respective human immunodeficiency virus and influenza virus. (grantome.com)
  • Crystallographic studies have shown that the coiled-coil motif occurs in several viral membrane-fusion proteins, including HIV-1 gp41 and influenza virus hemagglutinin. (princeton.edu)
  • Gething, M.J., Doms, R.W., York, D. and White, J. (1986) Studies on the mechanism of membrane fusion: Site- specific mutagenesis of the hemagglutinin of influenza virus. (scirp.org)
  • Chen, J., Skehel, J.J. and Wiley, D.C. (1999) N- and C-terminal residues combine in the fusion-pH influenza hemagglutinin HA(2) subunit to form an N cap that ter-minates the triple-stranded coiled coil. (scirp.org)
  • Those tubercular studs colorized maroon, are known as H-proteins (hemagglutinin), while those colorized gray, represented what are referred to as F-proteins (fusion). (cdc.gov)
  • To understand the fusion mechanism in more detail, we use an infection free system whereby fusion can be induced by a minimal set of the alphaherpesvirus pseudorabies virus (PrV) glycoproteins gB, gH and gL. (bio-protocol.org)
  • Here, we describe an optimized protocol of a transient transfection based fusion assay to quantify cell-cell fusion induced by the PrV glycoproteins. (bio-protocol.org)
  • Here, we describe an optimized protocol for an in vitro transient transfection based cell-cell fusion assay to quantify membrane fusion induced by the PrV glycoproteins gB and gH/gL (Schröter et al . (bio-protocol.org)
  • 2015). However, we know that this assay also is functional with other fusion-active glycoproteins, not just those of pseudorabies virus. (bio-protocol.org)
  • This review will discuss the general principles by which viral proteins promote fusion, focusing on the retroviral envelope (Env) glycoproteins exemplified by HIV-1 Env. (biomedcentral.com)
  • Oligomannose abundances of viral glycoproteins were ascertained by HILIC UPLC analysis of PNGase F released N-linked glycans that were fluorescently labelled with procainamide29,46,55 (SI Fig. 5). (democraticunderground.com)
  • All viral glycoproteins analysed were expressed as trimers in HEK 293F cells apart from LASV GPC, which was derived from virus-like particles from Madin-Darby canine kidney II cells. (democraticunderground.com)
  • These viral surface glycoproteins are also candidates as subunit vaccines. (frontiersin.org)
  • Neutralizing antibodies against functional and conserved epitopes present on several viral glycoproteins protect against acquisition of infection in numerous challenge studies ( 3 - 9 ). (frontiersin.org)
  • i.e., it senses that virions have reached a receptor-positive cell and signals to the downstream glycoproteins gB and gH/gL that fusion between the virion envelope and the cell membrane needs to be executed ( 19 ). (pubmedcentralcanada.ca)
  • Those studies defined a superfamily of viral entry proteins subsequently named by others as "Class I fusion/entry glycoproteins. (medicalnewstoday.com)
  • Findings from the new study were published recently in the Journal of Virology " Nipah and Hendra Virus Glycoproteins Induce Comparable Homologous but Distinct Heterologous Fusion Phenotypes . (genengnews.com)
  • NiV and HeV glycoproteins induced comparable levels of homologous HEK293T cell-cell fusion. (genengnews.com)
  • This is an enveloped, positive-sense RNA virus with four main structural proteins, including spike (S) and membrane (M) glycoproteins, as well as envelope (E) and nucleocapsid (N) proteins. (nature.com)
  • Additionally, HCV viral replication declined in time-dependent fashion. (ufl.edu)
  • Under proteasome inhibition, ASF viral genome replication, late gene expression and viral production were severely reduced. (bireme.br)
  • Core-associated and/or viral proteins involved in DNA replication may be targets for the ubiquitin-proteasome pathway that could possibly assist virus uncoating at final core breakdown and viral DNA release. (bireme.br)
  • Fig. 2: Evolution of viral and cellular replication modules from the ancestral RNA recognition motif. (nature.com)
  • All of the observed effects were seen in the absence of both other papillomaviral proteins and papillomaviral DNA replication. (biomedsearch.com)
  • Several innate retroviral restriction factors, such as APOBEC3 family of proteins, TRIM5α, BST2, and SAMHD1, that prevent HIV-1 replication have been identified in macaque cells. (frontiersin.org)
  • Thus, these studies suggest that additional blocks to HIV-1 replication exist in macaques that prevent high-level viral replication. (frontiersin.org)
  • The "cell-intrinsic" arm of innate immunity prevents virus replication in host cells by detecting virus invasion and interfering with the viral life cycle. (cancer.gov)
  • Several of these strategies rely on an array of virally encoded accessory proteins, including Vif, Vpr, Vpu, and Nef, which collectively appear to manipulate host cell biology as a means to ensure a favorable cellular state for viral replication, transmission, dissemination, and immune evasion. (bloodjournal.org)
  • In contrast, loss of endogenous Mfn2 enhanced virus-induced production of IFN-β and thereby decreased viral replication. (sciencemag.org)
  • Targeting tumor-associated vascular endothelium by replication-competent viral vectors is a promising strategy for cancer gene therapy. (aacrjournals.org)
  • We displayed a disintegrin, M28L echistatin that binds with a high affinity to integrin αvβ3 on the COOH terminus of the viral attachment (H) protein and rescued the replication-competent recombinant virus by reverse genetics. (aacrjournals.org)
  • We found that, whereas wild-type mice had high viral loads and succumbed to EBOV infection, Npc1 −/− mice were entirely free of viral replication and completely protected from EBOV disease. (asm.org)
  • Recent work has identified three distinct classes of viral membrane fusion proteins based on structural criteria. (nih.gov)
  • Interestingly, the first peptides inhibiting viral fusion were designed in the absence of high-resolution structural data on the fusion protein, and structural implications of the fusion process were merely based on secondary-structure prediction from the primary sequence of gp160 (Wild et al. (pharmacologicalsciences.us)
  • Recent structural studies revealed a stunning diversity of viral fusion proteins in their native state. (biomedcentral.com)
  • Additionally, sequence analyses of these proteins outside their putative coiled-coil domains illustrate some structural differences between them. (princeton.edu)
  • The abundance and structural conservation of this motif, even in the absence of sequence homology, suggests that it is critical for viral-cellular membrane fusion. (princeton.edu)
  • Fig. 3: Major viral structural proteins and their cellular homologues. (nature.com)
  • Tamm, L.K., Crane, J. and Kiessling, V. (2003) Mem-brane fusion: A structural perspective on the interplay of lipids and proteins. (scirp.org)
  • Structural studies are revealing the mechanisms by which SNARES form complexes and interact with other proteins. (biologists.org)
  • A defined structural unit enables de novo design of small-molecule-binding proteins. (ucsf.edu)
  • This entire process, called x-ray crystallography, is a technique often used to determine structural information about large biological molecules, like proteins. (bnl.gov)
  • Rather than inducing virus-cell fusion, these non-structural viral proteins are expressed inside virus-infected cells where they traffic to the plasma membrane and induce cell-cell fusion resulting in multinucleated syncytium formation. (dal.ca)
  • Experiments in which cells were enriched with acidic lipids led to the conclusion that it is the flip-flop of acidic lipids that carries the charge responsible for the observed voltage dependence of fusion. (duhnnae.com)
  • For cellular and molecular biologists like Nathan Roy, Ph.D., a University of Vermont postdoctoral fellow in microbiology and molecular genetics, effective visualization is essential to analyzing proteins - as well as the behavior of lipids, nucleic acids and organelles - within cells. (uvm.edu)
  • Exchange of lipids, metabolites or proteins across the lipid bilayer can occur through integral membrane proteins - as demonstrated for peroxisomes, mitochondria or chloroplasts. (biologists.org)
  • The outer layer, made of HCV proteins and lipids derived from the membrane of the host cell, helps the virus enter the host cell and evade its immune system. (bnl.gov)
  • Steps in the entry process of Bunyaviruses can be extrapolated from current models of class II viral fusion protein-mediated virion cell fusion. (biomedcentral.com)
  • F proteins can be independently expressed on host cell surfaces which can either (1) drive the infected cell to fuse with neighboring cells, forming a syncytium, or (2) be incorporated into a budding virion from the infected cell which leads to the full emancipation of plasma membrane from the host cell. (wikipedia.org)
  • In contrast, herpesviruses use a more complex mechanism requiring a receptor-binding protein and the core fusion machinery composed of gB and the heterodimeric gH/gL complex for infectious entry. (bio-protocol.org)
  • Together our data indicate that RuV E1 is the first example of a Ca(2+)-dependent viral fusion protein and has a unique membrane interaction mechanism. (pasteur.fr)
  • The mechanism of action is thought to involve competitive binding of Enfuvirtide to HR1 while gp41 is still in the pre-fusion state, thus inhibiting membrane fusion and viral entry. (pharmacologicalsciences.us)
  • HR1 region also inhibit viral entry, indicating that the believed mechanism of action is essentially correct (Wild et al. (pharmacologicalsciences.us)
  • The converging hairpin motif, along with biochemical and functional data, implies that disparate viral proteins promote membrane merger via a universal "cast-and-fold" mechanism. (biomedcentral.com)
  • However, the pathways of protein refolding and the mechanism by which this refolding is coupled to membrane rearrangements are still not understood. (biomedcentral.com)
  • Thus, to elucidate the principles of protein-mediated fusion, it is essential to understand the mechanism of lipid bilayer fusion. (biomedcentral.com)
  • The data from domain III proteins, stem antibodies and stem mutagenesis have significantly advanced the understanding of the class II fusion mechanism. (yu.edu)
  • Here, we address the fusion mechanism of Rift Valley fever virus. (ox.ac.uk)
  • Author Correction: A dynamic three-step mechanism drives the HIV-1 pre-fusion reaction. (nih.gov)
  • The structures and accompanying cell-based fusion assays with inhibitors provide insight into the molecular mechanism for the inhibition of MeV-mediated fusion, which would help us conquer MeV-induced neurodegenerative diseases. (pnas.org)
  • The Roles of Ca2+Dependent Membrane-Binding Proteins in the Regulation and Mechanism of Exocytosis. (booktopia.com.au)
  • A fusion mechanism is any mechanism by which cell fusion or virus-cell fusion takes place, as well as the machinery that facilitates these processes. (wikipedia.org)
  • There are four groups of F proteins categorized by their mechanism of fusion. (wikipedia.org)
  • Thus, the molecular machinery that mediates mitochondrial fusion is likely to be unique, even though the general mechanism of membrane fusion may be conserved. (rupress.org)
  • Applications of phage display technology include determination of interaction partners of a protein (which would be used as the immobilised phage "bait" with a DNA library consisting of all coding sequences of a cell, tissue or organism) so that the function or the mechanism of the function of that protein may be determined. (wikipedia.org)
  • In this review we summarize the various efforts made to establish efficient techniques to disrupt the endosomal membrane barrier including the use of molecular ferries such as cell penetrating peptides or viral membrane fusion proteins, endosomal leakage inducing molecules such as saponins or monensin and physicochemical methods as represented by photochemical internalization. (mdpi.com)
  • This fusion event may occur at the cell surface or after internalization of the virus. (asm.org)
  • Sera raised against proteins encoded in cDNAs from 5' portions of gene A immunoprecipitate the 200-250K polypeptides synthesized in vitro from genome RNA. (tamu.edu)
  • Pseudovirions carrying a marker plasmid instead of the viral genome have been especially useful in the study of the infectious entry pathway ( 6 , 31 , 42 , 47 ). (asm.org)
  • The lab hopes that this approach will avoid some of the challenges of homologous recombination at double-stranded breaks (which CRISPR-based genome editing technologies rely on) and of using viral vectors to introduce transgenes. (asbmb.org)
  • The spherical viral particles, colorized blue, contain cross-section through the viral genome, seen as black dots. (cdc.gov)
  • The spherical extracellular viral particles contain cross-sections through the viral genome, seen as black dots. (cdc.gov)
  • Clearly, highly divergent proteins have converged on the same overall strategy to mediate fusion, an essential step in the life cycle of every enveloped virus. (nih.gov)
  • four proteins mediate cell attachment and twelve that are associated in a membrane complex and conserved in all poxviruses are dedicated to entry. (prolekare.cz)
  • They are distributed in specific organelles where they mediate the assembly of distinctive groups of proteins. (nottingham.ac.uk)
  • Vaccinia mature virus requires A26 envelope protein to mediate acid-dependent endocytosis into HeLa cells in which we hypothesized that A26 protein functions as an acid-sensitive membrane fusion suppressor. (elsevier.com)
  • Whereas Rab-GTPases seem to mediate the initial membrane contact, SNAREs appear to lie at the center of the fusion process. (biologists.org)
  • The chemokines mediate their effect through binding to their cognate chemokine receptors, which belong to the class of G protein-coupled receptors and are differentially expressed on diverse leukocyte subtypes ( 5 ). (jimmunol.org)
  • Since the FAST proteins mediate cell-cell, rather than virus-cell, membrane fusion, their mode of action may be more relevant to the undefined proteins responsible for biological cell-cell fusion events. (dal.ca)
  • We determined that inhibitors of tyrosine protein kinases, dynamin GTPase and actin dynamics had little effect on binding of virions to cells but impaired membrane fusion, whereas partial cholesterol depletion and inhibitors of endosomal acidification and membrane blebbing had a severe effect at the later stage of core entry. (prolekare.cz)
  • Different strategies have been developed in the last decades to overcome endosomal accumulation and subsequent lysosomal degradation of targeted protein-based drugs. (mdpi.com)
  • Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. (rcsb.org)
  • Here, we established a stable Huh7.5-IRF3ER cell line expressing a fusion protein of IRF-3 and mouse estrogen receptor (ER) to examine IFN production and anti-HCV effects of IRF-3 in retinoic acid inducible-gene-I (RIG-I) deficient Huh 7.5 cells. (ufl.edu)
  • The anti-gene B, ORF1 sera detect a 30K cytoplasmic protein while the anti-gene E, ORF2 sera detect a 9.6K protein. (tamu.edu)
  • Antisera raised against proteins encoded in both 5' and 3' portions of gene A immunoprecipitate membrane associated polypeptides of 150K and greater than 600K from MHV infected cells. (tamu.edu)
  • The herpes viral protein, VP22, has been reported to confer intercellular trafficking activity on 'cargo' proteins, potentially facilitating gene therapy with intracellular proteins. (ox.ac.uk)
  • Treatment with the isoflavone genistein, an inhibitor of protein tyrosine kinases, reduced the delivery of incoming viral particles to the nuclear periphery and virus-induced gene expression in keratinocytes but not neurons. (asm.org)
  • Eukaryotic genomes contain several gene families, of host and viral origin, which encode products involved in driving membrane fusion. (wikipedia.org)
  • VAMP These proteins originate from the env gene of endogenous retroviruses. (wikipedia.org)
  • A novel gene required for mitochondrial fusion, fuzzy onions ( fzo ), 1 was recently identified through the analysis of Drosophila mutants defective in spermatogenesis ( Hales and Fuller, 1997 ). (rupress.org)
  • Overexpression of Mfn2 resulted in the inhibition of retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5), two cytosolic sensors of viral RNA, as well as of MAVS-mediated activation of the transcription factors interferon regulatory factor 3 (IRF-3) and nuclear factor κB (NF-κB). (sciencemag.org)
  • he has researched gene regulation in eukaryotic cells and phase separation in proteins with low-complexity regions. (asbmb.org)
  • Well-known examples are viral gene functions for immune evasion from host cell defense or capsid movement within host cells ( 1 , 2 ). (sciencemag.org)
  • Here, we present evidence that a virus gene product with homology to resident INM proteins can breach this barrier by recruiting cellular kinases that act to dissolve the obstacle. (sciencemag.org)
  • To identify the viral gene(s) responsible for this phenotype, we subcloned a series of candidate open reading frames (ORFs) of murine CMV (MCMV) into a eukaryotic expression vector and then screened the ORFs for this phenotype in transient assays. (sciencemag.org)
  • In this technique, a gene encoding a protein of interest is inserted into a phage coat protein gene, causing the phage to "display" the protein on its outside while containing the gene for the protein on its inside, resulting in a connection between genotype and phenotype. (wikipedia.org)
  • Interferon Regulatory Factor-3 (IRF-3) plays a central role in the induction of interferon (IFN) production and succeeding interferon-stimulated genes (ISG) expression en route for restraining hepatitis C virus (HCV) infection. (ufl.edu)
  • When expression of ISGs such as 1-8U and hnRNP M were measured in 4-HT-treated Huh7.5-IRF3ER cells, both genes were positively regulated by activation of the IRF-3ER fusion protein. (ufl.edu)
  • Viral genes can target and abuse specific cellular functions for generating a favorable environment for virus maintenance and spread. (sciencemag.org)
  • Structures and mechanisms of viral membrane fusion proteins: multiple variations on a common theme. (nih.gov)
  • Genetic engineering of the glucocorticoid receptor by fusion with the herpes viral protein VP22 causes selective loss of transactivation. (ox.ac.uk)
  • The host restriction factor APOBEC3G and retroviral Vif protein coevolve due to ongoing genetic conflict. (cancer.gov)
  • The team tested out different Nipah-Hendra protein combinations in the lab, using genetic approaches in human cells. (genengnews.com)
  • The genetic and molecular mechanisms that control mitochondrial fusion have not been defined. (rupress.org)
  • Viral genetic material that resides in a host cell's chromosome. (armoredpenguin.com)
  • Viral enzyme that incorporates viral genetic material into a host cell's chromosome. (armoredpenguin.com)
  • One aim of the study was to determine whether E2 has the features and behavior of related viral proteins, which would mean that it functions by allowing the virus to fuse to the host cell membrane so that it can release its genetic material into the cell and initiate infection. (bnl.gov)
  • 1. Wawra S, Djamei A, Albert I, Nürnberger T, Kahmann R, Van West P. In vitro translocation experiments with RxLR-reporter fusion proteins of Avr1b from Phytophthora sojae and AVR3a from Phytophthora infestans fail to demonstrate specific autonomous uptake in plant and animal cells. (ac.ir)
  • The Anticoagulant Nafamostat Potently Inhibits SARS-CoV-2 S Protein-Mediated Fusion in a Cell Fusion Assay System and Viral Infection In Vitro in a Cell-Type-Dependent Manner. (bvsalud.org)
  • In this way, large libraries of proteins can be screened and amplified in a process called in vitro selection, which is analogous to natural selection. (wikipedia.org)
  • Phage display is also a widely used method for in vitro protein evolution (also called protein engineering). (wikipedia.org)
  • Several small molecules inhibiting HIV-1 fusion with IC50 in the lower micromolar range have been discovered by high-throughput screening of molecular libraries. (pharmacologicalsciences.us)
  • By Volta phase plate cryo-electron tomography we show that VP5 is monomeric on the viral surface, and we establish the orientation of the molecules with respect to the viral membrane. (ox.ac.uk)
  • Although cell fusion is an omnipresent process in life, to date considerably less is still known about the mechanisms and the molecules being involved in this biological phenomenon in higher organisms. (springer.com)
  • In Cell Fusion in Health and Disease Vol 1 & Vol 2 leading experts will present up-to-date overviews about cell fusion in physiological and patho-physiological processes, which further covers the current knowledge about cell fusion-mediating molecules. (springer.com)
  • The distinct chemistry of proteins at the N- and C-termini provides protein molecules with two positionally and chemically unique sites for post-translational modifications and with the means to control their spatial and temporal interactions and position. (nottingham.ac.uk)
  • 23 , 24 Human NKG2D ligands consist of 2 classes of MHC-I-like molecules: MHC-1-related chains (MIC) and human cytomegalovirus UL16 binding proteins (ULBP), which are generally poorly expressed by normal cells and up-regulated on virus-infected, tumor, and stressed cells. (bloodjournal.org)
  • Entry of a virus into a living cell is driven by molecules on the virus' envelope known as viral fusion proteins. (phys.org)
  • molecules in the NSF, SNAP, and SNARE families have not been implicated in mitochondrial fusion. (rupress.org)
  • since returning to academia in 2013 he has studied potential inhibitors of that fusion, focusing on HIV, and on finding ways to target protein surfaces that are difficult to target with traditional small molecules. (asbmb.org)
  • This approach critically tests our understanding of protein folding and function, while also laying the groundwork for the design of molecules with properties unprecedented in nature. (ucsf.edu)
  • These displaying phages can then be screened against other proteins, peptides or DNA sequences, in order to detect interaction between the displayed protein and those other molecules. (wikipedia.org)
  • Modification of the respiratory syncytial virus f protein in virus-like particles impacts generation of B cell memory. (umassmed.edu)
  • The hypothesis is that, in these environments, the SARS-CoV-2 S protein may find on a fraction of the airborne particles an alkaline pH, favorable to trigger the conformational changes, needed to induce the fusion of the viral envelope with the plasma membrane of the target cells. (mdpi.com)
  • The PV particles are composed of 360 copies of the major capsid protein, L1, organized into pentameric capsomers ( 1 , 19 , 27 ), and a less well defined number of the minor capsid protein, L2 ( 2 , 34 , 46 ). (asm.org)
  • 1 Vpr (Viral protein R), one of these accessory proteins, is a 96-amino acid protein that is expressed at the late stage of the virus life cycle but is present during the early steps of infection because it is packaged into viral particles via an interaction with the p6 domain of Gag. (bloodjournal.org)
  • Type of infection where viral particles are continually being produced. (armoredpenguin.com)
  • no new viral particles are produced. (armoredpenguin.com)
  • In this view, the protein particles E, S, and M, also located on the outer surface of the particle, have all been labeled as well. (cdc.gov)
  • If a "phagemid" vector is used (a simplified display construct vector) phage particles will not be released from the E. coli cells until they are infected with helper phage, which enables packaging of the phage DNA and assembly of the mature virions with the relevant protein fragment as part of their outer coat on either the minor (pIII) or major (pVIII) coat protein. (wikipedia.org)
  • However, Ca(2+) was required for low pH-triggered E1 liposome insertion, virus fusion and infection. (pasteur.fr)
  • 12. Yang R, Zhang G, Zhang F, Li Z, Huang C. Membrane permeabilization design of antimicrobial peptides based on chikungunya virus fusion domain scaffold and its antibacterial activity against gram-positive Streptococcus pneumoniae in respiratory infection. (ac.ir)
  • We previously found that nafamostat mesylate , an existing drug used for disseminated intravascular coagulation ( DIC ), effectively blocked Middle East respiratory syndrome coronavirus ( MERS-CoV ) S protein -mediated cell fusion by targeting transmembrane serine protease 2 (TMPRSS2), and inhibited MERS-CoV infection of human lung epithelium -derived Calu-3 cells . (bvsalud.org)
  • The viral ubiquitin-conjugating enzyme (UBCv1) is expressed throughout ASFV infection and accumulates at late times post infection. (bireme.br)
  • UBCv is also present in the viral particle suggesting that the ubiquitin-proteasome pathway could play an important role at early ASFV infection. (bireme.br)
  • The major antiviral effect was observed when aUY11 and cm1UY11 were added at early stages of infection and maintained during the complete viral cycle. (bireme.br)
  • The clinical outcome of viral infection, the difference between survival and death of the host, rests delicately on events occurring at the molecular level of individual cells. (cancer.gov)
  • William Gallaher, PhD, Emeritus Professor of Microbiology, Immunology & Parasitology at LSU Health New Orleans School of Medicine, has discovered a fragment of an Ebola virus protein that is toxic to cells and may contribute to infection and illness. (medicalnewstoday.com)
  • Interestingly, the scientists knew this "dance" between G and F was a crucial step in viral infection but was curious to know how the dance might change if the proteins got new partners. (genengnews.com)
  • There is evidence that ancestral species of mammals may have incorporated these same proteins into their own cells as a result of infection. (wikipedia.org)
  • This class of fusogens contains some of the proteins utilized by influenza, HIV, coronaviruses, and Ebola during infection. (wikipedia.org)
  • The almost identical affinities of CCL14a(7-74), CCL14a(9-74), and CCL14a(10-74) for the US28 receptor and the inhibition of US28-mediated HIV infection of 293T cells by all of the N-terminally truncated CCL14a analogs support the promiscuous nature of the viral chemokine receptor US28. (jimmunol.org)
  • Last name of the scientist that proposed that a viral infection could hijack the control center of a cell. (armoredpenguin.com)
  • The innate immune response to viral infection involves the activation of multiple signaling steps that culminate in the production of type I interferons (IFNs). (sciencemag.org)
  • On HCV, there are two envelope proteins known as E1 and E2 that have roles in the infection process. (bnl.gov)
  • From a virus perspective, the FAST proteins promote rapid dissemination of the infection and contribute to the inherent pathogenicity of the fusogenic reoviruses. (dal.ca)
  • In addition, there are at least four distinct mechanisms by which viral fusion proteins can be triggered to undergo fusion-inducing conformational changes. (nih.gov)
  • Viral fusion proteins undergo dramatic conformational transitions during membrane fusion. (elsevier.com)
  • This review discusses coronavirus entry mechanisms focusing on the different triggers used by coronaviruses to initiate the conformational change of the S protein: receptor binding, low pH exposure and proteolytic activation. (nih.gov)
  • Crystal structure of A26 protein revealed that His48 and His53 are in close contact with Lys47, Arg57, His314 and Arg312, suggesting that at low pH these His-cation pairs could initiate conformational changes through protonation of His48 and His53 and subsequent electrostatic repulsion. (elsevier.com)
  • Here, we provide a comprehensive review of the molecular interactions that govern pH-dependent rearrangements and introduce a paradigm for electrostatic residue pairings that regulate progress through the viral fusion coordinate. (elsevier.com)
  • A greater understanding of these interactions will be critical in facilitating the development of effective therapeutics and viral countermeasures. (bireme.br)
  • Furthermore, it is now apparent that the SNARE transmembrane segment not only anchors the protein but engages in SNARE-SNARE interactions and plays an active role in fusion. (biologists.org)
  • Membrane proteins must be routed to the correct cellular membrane compartment, which requires specific interactions between sorting and trafficking signals in the membrane protein with the complex, multi-protein complexes that regulate vesicular transport. (dal.ca)
  • Like the two-hybrid system, phage display is used for the high-throughput screening of protein interactions. (wikipedia.org)
  • They promote cell membrane fusion and thereby may function in the uptake of the virus by cells. (umassmed.edu)
  • Homodimerization of the IRF-3ER fusion protein was detected by Western blotting after treatment with the estrogen receptor agonist 4-hydrotamoxifen (4-HT) in Huh7.5-IRF3ER cells. (ufl.edu)
  • To determine the role of viral proteins, virions lacking individual membrane components were purified from cells infected with members of a panel of ten conditional-lethal inducible mutants. (prolekare.cz)
  • A better understanding is aided by studying the cell fusion activity of cells transiently expressing the relevant proteins. (bio-protocol.org)
  • RuV is a small enveloped RNA virus that infects target cells by receptor-mediated endocytosis and low pH-dependent membrane fusion. (pasteur.fr)
  • Viral nonstructural proteins were detected in infected murine fibroblasts and glial cells. (tamu.edu)
  • I am continuing my research to study the effects of this on the viral fusion process by transfecting the mutated plasmid DNA onto animal cells. (murraystate.edu)
  • We also found decrease in the synthesis of early and late viral proteins in Vero cells treated with cm1UY11. (bireme.br)
  • Most of the current work in the field of membrane fusion takes place within the context of intact or modified cells. (booktopia.com.au)
  • Experimental Cell Fusion with Selected Siphonocladalean Algal Cells. (booktopia.com.au)
  • Microinjection of Culture Cells via Fusion with Loaded Erythrocytes. (booktopia.com.au)
  • The fusion of the cells is apparently caused by viral fusion proteins from endosymbiotic endogenous retrovirus (ERV). (wikipedia.org)
  • An immunoevasive action was the initial normal behavior of the viral protein, in order to avail for the virus to spread to other cells by simply merging them with the infected one. (wikipedia.org)
  • One problem with studying the parasite Entamoeba histolytica is that there are very few suitable protein tags that can be used to monitor the behavior of proteins in live cells," says Roy. (uvm.edu)
  • Accessory proteins expressed by Simian Immunodeficiency virus (SIV) such as viral infectivity factor (Vif), viral protein X (Vpx), viral protein R (Vpr), and negative factor (Nef) have been shown to play key roles in overcoming these restriction factors in macaque cells. (frontiersin.org)
  • Moreover, in keratinocyte monolayer islets, HSV infected both the inner and outer cells in a genistein-sensitive manner, suggesting viral endocytosis from both basolateral and apical plasma membrane surfaces. (asm.org)
  • It also inhibited cell-cell fusion in transfected cells. (pubmedcentralcanada.ca)
  • The fragment was found within a grouping of amino acids that is made in parallel with the protein involved in attachment of the virus to cells. (medicalnewstoday.com)
  • Phage display represents a high-throughput technique for screening billions of random fusion antibodies against virtually any target on the surface or inside cancer cells, or even soluble markers found in patient serum. (mdpi.com)
  • Cell fusion is the formation of a hybrid cell from two separate cells. (wikipedia.org)
  • There are three major actions taken in both virus-cell fusion and cell-cell fusion: the dehydration of polar head groups, the promotion of a hemifusion stalk, and the opening and expansion of pores between fusing cells. (wikipedia.org)
  • Cell fusion also occurs in a multitude of mammalian cells including gametes and myoblasts. (wikipedia.org)
  • However, when they are expressed on the surface of cells, they can induce cell-cell fusion. (wikipedia.org)
  • It is necessary for cell entry and mediates receptor binding, a decrease in pH which triggers membrane fusion and facilitates Baclovirus entry into many types of mammalian cells. (phys.org)
  • While adult somatic cells do not typically undergo membrane fusion under normal conditions, gametes and embryonic cells follow developmental pathways to non-spontaneously drive membrane fusion, such as in placental formation, syncytiotrophoblast formation, and neurodevelopment. (wikipedia.org)
  • Functionally, this viral receptor has been suggested to act as a sink by binding and sequestering chemokines from the extracellular vicinity of CMV-infected cells, thereby allowing them to escape immune surveillance ( 10 ). (jimmunol.org)
  • Proteins produced and secreted by cells infected with a virus which stimulate production of antiviral proteins in neighboring cells. (armoredpenguin.com)
  • Thus, GD2 is a convenient tumor-specific marker for targeting immune-stimulatory protein domains to tumor cells for the purpose of raising an effective immune response against the tumor cells to destroy them. (google.es)
  • While the 14.18 mouse antibody (m14.18 antibody) may assist the targeting of these protein domains to tumor cells, its mouse-derived amino acid sequences can impair the desired therapeutic effect. (google.es)
  • The H-protein is responsible for the binding of virions to cells. (cdc.gov)
  • Local duplications of the nuclear membrane and patches containing wrapped viral capsids have been observed in cells infected with cytomegalovirus (CMV), which belongs to the subgroup of β-herpesviruses ( 4 , 5 ). (sciencemag.org)
  • While FAST proteins are both necessary and sufficient to fuse lipid bilayers, they rely on and recruit cellular co-factors to assist with the more complex process of fusing cells together and generating syncytia. (dal.ca)
  • Using FAST proteins, enveloped virus fusion proteins, and differentiation-dependent fusion of muscle cells to generate multinucleated muscle myotubes, we are determining how these pathways are interconnected and how they contribute to syncytiogenesis. (dal.ca)
  • Stem antibodies and peptides failed to inhibit viral fusion. (yu.edu)
  • Neuraminidase and O-glycosidase were without effect on the proteins detected by antibodies G11 and M13. (biologists.org)
  • Robust techniques combining an antibody library displayed on the phage surface and protein microarray allowed the identification of auto antibodies recognized by patient sera. (mdpi.com)
  • Additionally, the heterologous character of those proteins turn them often immunogenic to humans eliciting HAMA response (Human Anti-Mouse Antibodies), which restrict their therapeutic use [ 5 ]. (mdpi.com)
  • Phage display technology was further developed and improved by groups at the Laboratory of Molecular Biology with Greg Winter and John McCafferty, The Scripps Research Institute with Richard Lerner and Carlos Barbas and the German Cancer Research Center with Frank Breitling and Stefan Dübel for display of proteins such as antibodies for therapeutic protein engineering. (wikipedia.org)
  • it contains both a receptor binding subunit (labeled rb in image i) and a fusion subunit (labeled f in images i to iii). (nih.gov)
  • in all cases studied, however, the rb subunit of this type of class I fusion protein must move out of the way, thus unclamping the fusion subunit in the metastable fusion competent state and allowing fusion to proceed. (nih.gov)
  • As with other class I fusion proteins, the GP1 subunit associates with a cellular receptor ( 17 - 20 ). (pnas.org)
  • Protein subunit that is used to build the capsid. (armoredpenguin.com)
  • The viral fusion proteins (E1 and E, respectively) from these two genera have been grouped as "class II" viral fusion proteins, which are distinct from "class I" proteins such as HIV-1 gp41 and influenza virus HA2. (yu.edu)
  • With the exception of a certain fold exhibited by sheet A, these features are not consistent with class II viral fusion proteins. (bnl.gov)
  • See and text for comparisons among the different classes of viral fusion proteins. (nih.gov)
  • Combined with previous studies, in all, four class II and two class III protein have now been shown to exhibit voltage-dependent fusion, demonstrating that this is probably a general phenomenon for these two classes of viral fusion proteins. (duhnnae.com)
  • These proteins potently inhibited SFV and dengue virus fusion, and showed cross-inhibition within but not between virus genera. (yu.edu)
  • The study with domain III proteins provided the first demonstration of dominant-negative fusion inhibition of class II proteins. (yu.edu)
  • These compounds are believed to inhibit viral entry by interacting with the hydrophobic cavity of gp41-HR1, thereby destabilizing the central three-helix stalk and inhibiting formation of the post-fusion six-helix bundle (Jiang et al. (pharmacologicalsciences.us)
  • Evidence against extracellular exposure of a highly immunogenic region in the C-terminal domain of the simian immunodeficiency virus gp41 transmembrane protein. (umassmed.edu)
  • Of particular relevance to viral infections are those pattern recognition receptors that activate type I interferon responses, which establish an antiviral state. (bireme.br)
  • Thus, vesicle formation requires the uptake of targeting and fusion factors, including Rab-GTPases, tethering factors and SNAREs [soluble NSF (N-ethylmaleimide-sensitive factor) attachment protein receptors]. (biologists.org)
  • Viral entry into this broad array of host cell types may be facilitated by multiple cellular pathways. (asm.org)
  • DNA stress/damage checkpoint pathways initiated by ATM (ataxia telangiectasia-mutated) or ATR protein kinases are essential to the maintenance of genomic integrity and stability, but interestingly, recent findings suggest that they are also involved in innate immune surveillance. (bloodjournal.org)
  • Fusion pathways are also involved in the development of musculoskeletal and nervous system tissues. (wikipedia.org)
  • The cellular proteins and pathways responsible for these cell-cell fusion events remain elusive. (dal.ca)
  • Using fluorescent fusion assays (FACS analysis and confocal microscopy), site-directed mutagenesis, and proteomic approaches, we are exploring both the nature of the FAST proteins and the cellular proteins and pathways involved in cell-cell fusion events. (dal.ca)
  • Using reovirus FAST proteins as our model, we are exploring the function of a novel Golgi export signal in recruiting Rab-dependent trafficking pathways. (dal.ca)
  • Each of the entry protein-deficient virions had severely reduced infectivity and except for A28, L1 and L5 greatly impaired membrane fusion. (prolekare.cz)
  • IFITM proteins incorporated into HIV-1 virions impair viral fusion and spread. (cancer.gov)
  • To gain insight into the atomistic details of membrane fusion induced by fusogenic peptides, molecular dynamic simulations of synthetic peptides, derived from viral fusion proteins, contained in lipid bilayers were performed. (scirp.org)
  • We propose that the fuzzy onions family of transmembrane GTPases act as molecular switches to regulate a key step in mitochondrial membrane docking and/or fusion. (rupress.org)
  • They determined the molecular structure of a protein that is directly involved in how the virus penetrates the host cell membrane. (bnl.gov)
  • Since there is no evidence that sperm can translocate intact membrane protein from the cytoplasmic face to the extracellular face of the plasma membrane during the acrosome reaction, the evidence suggests that there are two isolated antigen pools. (biologists.org)
  • 2 , 3 The protein also exists in an extracellular form because it can be detected in the serum and cerebrospinal fluid of HIV-1-infected persons. (bloodjournal.org)
  • In spite of this diversity, the post-fusion structures of these proteins share a common trimeric hairpin motif in which the amino- and carboxy-terminal hydrophobic domains are positioned at the same end of a rod-shaped molecule. (biomedcentral.com)
  • Our analysis reveals how the Gn shields the hydrophobic fusion loops of the Gc, preventing premature fusion. (ox.ac.uk)
  • These hydrophobic regions are known as fusion peptides or fusion loops, and they are responsible for causing localized membrane instability and fusion. (wikipedia.org)
  • They are secured in the viral membrane by hydrophobic trans-membrane regions. (wikipedia.org)
  • The binding domain is rich in α-helices and hydrophobic fusion peptides located near the N-terminus. (wikipedia.org)
  • Probing the Function of Viral Fusion Proteins with Synthetic Peptides. (booktopia.com.au)
  • and (iii) often redundant number of proteins the majority of which may undergo off-pathway refolding. (biomedcentral.com)
  • This is not entirely unexpected since mitochondrial fusion, unlike most other membrane fusion reactions in the cell, requires the sequential mixing of two distinct lipid bilayers. (rupress.org)
  • Class II proteins from Ross River and Sindbus virus and a mutant class III protein from Epstein Barr virus were found to induce cell-cell fusion that is voltage dependent. (duhnnae.com)
  • Vpr appears to induce a G 2 cell-cycle arrest by mimicking a DNA stress/damage checkpoint arrest initiated by the DNA damage-sensing protein kinase ATR (ataxia telangiectasia-mutated and Rad3-related). (bloodjournal.org)
  • These reoviral cell-cell fusogens contain fusion loops that can induce cell fusion. (wikipedia.org)
  • However, the method they utilize to induce membrane fusion is mechanistically similar. (wikipedia.org)
  • Generally, vesicle formation requires a conserved set of coat proteins that bind to cargo and induce membrane curvature. (biologists.org)
  • Wei Y, Zhang Y, Cai H, Mirza AM, Iorio RM, Peeples ME, Niewiesk S, Li J. Roles of the putative integrin-binding motif of the human metapneumovirus fusion (f) protein in cell-cell fusion, viral infectivity, and pathogenesis. (umassmed.edu)
  • Complementing previous crystallographic studies, the coiled-coil-like regions detected by LearnCoil-VMF provide further evidence that the three-stranded coiled coil is a common motif found in many diverse viral membrane-fusion proteins. (princeton.edu)
  • 31]. Based on limited similarities with Alphavirus E2 proteins (Table 3), Gn is depicted as the receptor-binding protein of Bunyaviruses. (biomedcentral.com)
  • Skehel, J.J. and Wiley, D.C. (2000) Receptor binding and membrane fusion in virus entry: The influenza hemag-glutinin. (scirp.org)
  • 2011). Imaging single retrovirus entry through alternative receptor isoforms and intermediates of virus-endosome fusion. (tcdb.org)
  • The plant receptor FLAGELLIN SENSING 2 (FLS2) recognizes the bacterial protein flagellin to initiate host defense responses contributing to immunity. (prolekare.cz)
  • Recent work demonstrated that the Niemann-Pick C1 (NPC1) protein is an essential entry receptor for filoviruses. (asm.org)
  • Detailed mechanisms of membrane fusion and the protein structures involved have been mainly studied in eukaryotic systems, whereas very little is known about membrane fusion in prokaryotes. (ox.ac.uk)
  • The ancient gamete fusogen HAP2 is a eukaryotic class II fusion protein. (ac.ir)
  • Membrane fusion is critical for many biological processes, especially in eukaryotic development and viral entry. (wikipedia.org)
  • The SNARE family include bona fide eukaryotic fusion proteins. (wikipedia.org)
  • Furthermore, although the SHIV-model allows for testing of HIV Env based vaccines, it is not possible to test vaccines or antiretroviral drugs targeting multiple HIV-1 proteins. (frontiersin.org)
  • Purified fusion protein vaccines against the most common viral causes of bronchiolitis are currently under development. (news-medical.net)
  • Using the Pioneer Award grant, Kim seeks to create "high-resolution, epitope-focused vaccines" that raise immunity against smaller regions on the target protein. (asbmb.org)
  • A) The model depicts a Class I fusion protein, but related structures ( e.g ., prehairpins and trimers-of-hairpins) form for Class II and III proteins, which also promote membrane merger through stages of close apposition (iv), hemifusion (v), small fusion pores (not shown), and large fusion pores (vi). (nih.gov)
  • Here we determine atomic structures of the ectodomains of the 57-kDa spike protein VP5 from two related HRPVs revealing a previously unreported V-shaped fold. (ox.ac.uk)
  • This sheds light on protein structures involved in prokaryotic membrane fusion. (ox.ac.uk)
  • When activated, all of these fusogens form elongated trimeric structures and bury their fusion peptides into the membrane of the target cell. (wikipedia.org)
  • We also show that the viral membrane fuses with the host cytoplasmic membrane in a process mediated by VP5. (ox.ac.uk)
  • Fusion phenomenon occurs at the host cell surface or in the cytoplasmic compounds and in cytoplasmic components. (ac.ir)
  • Residents of this critical threshold include cellular transmembrane proteins that remodel membrane vesicles or redirect their trafficking in order to inhibit the viral entry process. (cancer.gov)
  • Frank, J. A. & Feschotte, C. Co-option of endogenous viral sequences for host cell function. (nature.com)
  • Triggering of fusion requires gD sequences, named the profusion domain, located in part in the ectodomain C terminus and in part upstream. (pubmedcentralcanada.ca)
  • Panel G: Formation of the "fusion pore" and entry of the ribonucleoprotein (RNP) segments. (biomedcentral.com)
  • Several trimers are required to form a competent fusion pore. (rcsb.org)
  • These inner leaflets then fuse, forming a fusion pore. (wikipedia.org)
  • The fusion process involves a relatively stable hemifusion-like intermediate that precedes fusion pore opening. (tcdb.org)
  • Finally, at least in some instances, several VFPs co-assemble with transmembrane anchors into membrane integral helical bundles, following a locking movement hypothetically coupled to fusion-pore expansion. (tcdb.org)
  • Some F components solely drive fusion while a subset of F proteins can interact with host factors. (wikipedia.org)
  • Murine immune responses to virus-like particle-associated pre- and postfusion forms of the respiratory syncytial virus F protein. (umassmed.edu)
  • Role of the two sialic acid binding sites on the newcastle disease virus HN protein in triggering the interaction with the F protein required for the promotion of fusion. (umassmed.edu)
  • Taken together, these results suggested a 2-step entry model and implicated an unprecedented number of viral proteins and cellular components involved in signaling and actin rearrangement for initiation of virus-cell membrane fusion during poxvirus entry. (prolekare.cz)
  • The structure in B is the trimeric core of the Simian Immunodeficiency Virus gp41 in a post-fusion conformation. (biomedcentral.com)
  • Recent studies show that conserved influenza viral proteins (such as HA2, M2, NP and M1) can provide protective immune response against a range of influenza virus subtypes. (springer.com)
  • Here the alphavirus Semliki Forest virus (SFV) and the flavivirus dengue virus (DV) were used to understand the functions of domain III and the stem of class II proteins. (yu.edu)
  • Stem mutagenesis revealed important functions of the stem in virus assembly, but showed that neither specific residues nor the conserved length of the stem were required for fusion. (yu.edu)
  • Based upon the use of LearnCoil-VMF, as well as other computational tools, we report detailed sequence analyses of coiled-coil-like regions in retrovirus, paramyxovirus and filo-virus membrane-fusion proteins. (princeton.edu)
  • In the present study, monitoring fusion of pseudovirus expressing Vesicular Stomatitis virus VSV G within endosomes shows that here, too, fusion is voltage dependent. (duhnnae.com)
  • 4. Floyd DL, Ragains JR, Skehel JJ, Harrison SC, Van Oijen AM. Single-particle kinetics of influenza virus membrane fusion. (ac.ir)
  • 8. Kielian M. Mechanisms of virus membrane fusion proteins. (ac.ir)
  • Mouse hepatitis virus, strain A59 cDNAs were inserted into the procaryotic fusion vector pGE374. (tamu.edu)
  • Together, we conclude that viral A26 protein functions as an acid-sensitive fusion suppressor during vaccinia mature virus endocytosis. (elsevier.com)
  • Rigid amphipathic fusion inhibitors demonstrate antiviral activity against African swine fever virus. (bireme.br)
  • Virus-Induced Cell Fusion. (booktopia.com.au)
  • We and others have constructed macaque-tropic HIV-1 derivatives [also called simian-tropic HIV-1 (stHIV-1) or Human-Simian Immunodeficiency Virus (HSIV)] carrying SIV vif to overcome APOBEC3 family proteins. (frontiersin.org)
  • Cumulatively, the present results provide several lines of evidence that HSV gH/gL interacts with a cell surface cognate protein(s), that this protein is not necessarily an αVβ3 integrin, and that this interaction is required for the process of virus entry/fusion. (pubmedcentralcanada.ca)
  • But one hybrid-a Hendra F and Nipah G-behaved like Lindy Hoppers, allowing the F protein to perform "aerials" that heightened fusion between the virus and the cell. (genengnews.com)
  • Fusogens involved in virus-to-cell fusion mechanisms were the first of these proteins to be discovered. (wikipedia.org)
  • Scientists have found the following four classes of fusogens to be involved with virus-cell or cell-cell fusions. (wikipedia.org)
  • Class III fusogens are involved with virus-cell fusions. (wikipedia.org)
  • Protein that is on the outside of a virus that is responsible for attaching to the host cell for entry. (armoredpenguin.com)
  • To identify new viral functions that target or divert cellular functions, we addressed an important step during morphogenesis: the exit of the newly formed virus capsid from the nucleus. (sciencemag.org)
  • In the present study, we took advantage of the natural sequence variability present among HCV strains to test, by purely sequence-based computational tools, the hypothesis that in this virus the fusion process involves the physical interaction of the FP and CT regions of E1. (uni-potsdam.de)
  • Here we describe the development of a viral vector based on the Edmonston vaccine strain of measles virus targeted to integrin αvβ3, which is expressed abundantly on activated but not quiescent vascular endothelium. (aacrjournals.org)
  • The protein is a component of the outer portion of the virus particle. (bnl.gov)
  • These virus-encoded cellular fusogens provide a new model to investigate the mechanisms responsible for protein-mediated cell-cell membrane fusion. (dal.ca)
  • Lipid membrane fusion is an essential function in many biological processes. (ox.ac.uk)
  • Thus, Cell Fusion in Health and Disease Vol 1 & Vol 2 represents a state-of-the-art work for researchers, physicians or professionals being interested in the biological phenomenon of cell fusion and beyond. (springer.com)
  • This feature of proteins is crucial for a variety of biological processes from protein degradation to protein sorting for specific cellular compartments. (nottingham.ac.uk)
  • p>This section provides any useful information about the protein, mostly biological knowledge. (uniprot.org)
  • Cell-cell membrane fusion is involved in numerous biological processes, including fertilization (sperm-egg fusion), muscle (myotubes) and placenta (syncytiotrophoblast) formation, bone maintenance (osteoclasts), and possibly cancer cell metastasis (reviewed in Developmental Cell 14: 11-21, 2008). (dal.ca)
  • Mitochondrial antiviral signaling (MAVS), a mitochondrial outer membrane adaptor protein, plays an important role in this process. (sciencemag.org)
  • Here, we report that mitofusin 2 (Mfn2), a mediator of mitochondrial fusion, interacts with MAVS to modulate antiviral immunity. (sciencemag.org)
  • Unlike the other known class II fusion proteins, however, RuV E1 contains two fusion loops, with a metal ion complexed between them by the polar residues N88 and D136. (pasteur.fr)
  • Sequence comparisons of alphavirus fusion proteins showed several highly conserved residues and a totally conserved length for the stem. (yu.edu)
  • Point mutations that alter conserved residues in the GTPase domain do not affect Fzo1p localization but disrupt mitochondrial fusion. (rupress.org)
  • The researchers' focus is on the viral fusion proteins (or F proteins) and attachment proteins (G proteins). (genengnews.com)
  • They are also called fusion-associated small transmembrane (FAST) proteins and are most often associated with non-enveloped reoviruses. (wikipedia.org)
  • Viral and cellular membrane fusion events are mediated by fusion proteins or fusion machines. (sciencemag.org)