title: Mechanisms of influenza viral membrane fusion.
abstract: Influenza viral particles are enveloped by a lipid bilayer. A major step in infection is fusion of the viral and host cellular membranes, a process with large kinetic barriers. Influenza membrane fusion is catalyzed by hemagglutinin (HA), a class I viral fusion protein activated by low pH. The exact nature of the HA conformational changes that deliver the energy required for fusion remains poorly understood. This review summarizes our current knowledge of HA structure and dynamics, describes recent single-particle experiments and modeling studies, and discusses their role in understanding how multiple HAs mediate fusion. These approaches provide a mechanistic picture in which HAs independently and stochastically insert into the target membrane, forming a cluster of HAs that is collectively able to overcome the barrier to membrane fusion. The new experimental and modeling approaches described in this review hold promise for a more complete understanding of other viral fusion systems and the protein systems responsible for cellular fusion.
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
authors.forename: Jelle S
authors.initials: JS
authors.lastname: Blijleven
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
authors.forename: Sander
authors.initials: S
authors.lastname: Boonstra
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Onck
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: van der Giessen
authors.affiliation: School of Chemistry, Faculty of Science, Medicine and Health, University of Wollongong, NSW 2522, Australia. Electronic address: vanoijen@uow.edu.au.
authors.forename: Antoine M
authors.initials: AM
authors.lastname: van Oijen
mesh_terms: D000818:Animals; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry; D006801:Humans; D008561:Membrane Fusion; D008958:Models, Molecular; D009975:Orthomyxoviridae / Q000502:physiology*; D011487:Protein Conformation; D053586:Virus Internalization
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus
keywords: Hemagglutinin; Influenza; Membrane fusion; Modeling; Single-particle; Structure