The influenza haemagglutinin-induced fusion cascade: effects of target membrane permeability changes.
To define the stages in influenza haemagglutinin (HA)-mediated fusion the kinetics of fusion between cell pairs consisting of single influenza HA-expressing cells and single erythrocytes (RBC) which had been labelled with both a fluorescent lipid (Dil) in the membrane and a fluorescent solute (calcein) in the aqueous space have been monitored. It is shown that release of solute from the target cell occurs, following the formation of the hemi-fusion diaphragm. These results are discussed in terms of a model in which fusion peptide insertion into the target membrane induces lipid stalks, which results in the formation of a hemifusion diaphragm and a fusion pore. Bilayer expansion due to overproduction of these stalks can give rise to collateral damage of target membranes.
Blumenthal
R
R
Laboratory of Experimental and Computational Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Morris
S J
SJ
D016475:3T3 Cells; D000818:Animals; D002463:Cell Membrane Permeability; D004912:Erythrocytes / Q000821:virology; D006389:Hemagglutinins, Viral / Q000502:physiology*; D006801:Humans; D008561:Membrane Fusion; D051379:Mice; D008954:Models, Biological; D009975:Orthomyxoviridae / Q000502:physiology*; D013997:Time Factors; D014760:Viral Fusion Proteins / Q000502:physiology*; D014763:Viral Matrix Proteins / Q000502:physiology*
D006389:Hemagglutinins, Viral; D014760:Viral Fusion Proteins; D014763:Viral Matrix Proteins