Biomaterial Database

The role of stearate attachment to the hemagglutinin-esterase-fusion glycoprotein HEF of influenza C virus. 2016

Mingyang Wang, and Kai Ludwig, and Christoph Böttcher, and Michael Veit

Institute of Virology, Department of Veterinary Medicine, Free University Berlin, Berlin, Germany.

The only spike of influenza C virus, the hemagglutinin-esterase-fusion glycoprotein (HEF) combines receptor binding, receptor hydrolysis and membrane fusion activities. Like other hemagglutinating glycoproteins of influenza viruses HEF is S-acylated, but only with stearic acid at a single cysteine located at the cytosol-facing end of the transmembrane region. Previous studies established the essential role of S-acylation of hemagglutinin for replication of influenza A and B virus by affecting budding and/or membrane fusion, but the function of acylation of HEF was hitherto not investigated. Using reverse genetics we rescued a virus containing non-stearoylated HEF, which was stable during serial passage and showed no competitive fitness defect, but the growth rate of the mutant virus was reduced by one log. Deacylation of HEF does neither affect the kinetics of its plasma membrane transport nor the protein composition of virus particles. Cryo-electron microscopy showed that the shape of viral particles and the hexagonal array of spikes typical for influenza C virus were not influenced by this mutation indicating that virus budding was not disturbed. However, the extent and kinetics of haemolysis were reduced in mutant virus at 37°C, but not at 33°C, the optimal temperature for virus growth, suggesting that non-acylated HEF has a defect in membrane fusion under suboptimal conditions.

UI	MeSH Term	Description	Entries
D007251	Influenza, Human	An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.	Grippe,Human Flu,Human Influenza,Influenza in Humans,Influenza,Flu, Human,Human Influenzas,Influenza in Human,Influenzas,Influenzas, Human
D009982	Gammainfluenzavirus	A genus of the family ORTHOMYXOVIRIDAE comprising viruses similar to types A and B but less common, more stable, more homogeneous, and lacking the neuraminidase protein. They have not been associated with epidemics but may cause mild influenza. Influenza C virus is the type species.	FLUCV,Gammainfluenzavirus influenzae,Influenza C Virus,Influenza Viruses Type C,Influenza virus type C,Influenzavirus C,Orthomyxoviruses Type C,Gammainfluenzaviruses,Influenza C Viruses,Virus, Influenza C
D006389	Hemagglutinins, Viral	Specific hemagglutinin subtypes encoded by VIRUSES.	Viral Hemagglutinin,Viral Hemagglutinins,Hemagglutinin, Viral
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000215	Acylation	The addition of an organic acid radical into a molecule.
D000595	Amino Acid Sequence	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.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D013228	Stearates	Salts and esters of the 18-carbon saturated, monocarboxylic acid--stearic acid.	Octadecanoate,Octadecanoates,Stearate
D014760	Viral Fusion Proteins	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.	Fusion Proteins, Viral,Viral Fusion Glycoproteins,F Protein (Sendai Virus),F Protein Measles Virus,F Protein Newcastle Disease Virus,F Protein SV,F-Glycoprotein SV,F1 Polypeptide (Paramyxovirus),Fusion Glycoprotein, Viral,Fusion VP1 Protein,Glycoprotein, Viral Fusion,Measles Fusion Protein,Mumps Virus Fusion Protein,Paramyxovirus Fusion Protein,Sendai Virus Fusion Protein,Viral Fusion-GP,Virus Fusion Proteins,Fusion Glycoproteins, Viral,Fusion Protein, Measles,Fusion Protein, Paramyxovirus,Fusion Proteins, Virus,Fusion-GP, Viral,Glycoproteins, Viral Fusion,Proteins, Virus Fusion,VP1 Protein, Fusion,Viral Fusion GP,Viral Fusion Glycoprotein
D019267	Hemagglutinin Glycoproteins, Influenza Virus	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.
D020285	Cryoelectron Microscopy	Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.	Electron Cryomicroscopy,Cryo-electron Microscopy,Cryo electron Microscopy,Cryo-electron Microscopies,Cryoelectron Microscopies,Cryomicroscopies, Electron,Cryomicroscopy, Electron,Electron Cryomicroscopies,Microscopies, Cryo-electron,Microscopies, Cryoelectron,Microscopy, Cryo-electron,Microscopy, Cryoelectron