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Mechanics of membrane fusion

Abstract

Diverse membrane fusion reactions in biology involve close contact between two lipid bilayers, followed by the local distortion of the individual bilayers and reformation into a single, merged membrane. We consider the structures and energies of the fusion intermediates identified in experimental and theoretical work on protein-free lipid bilayers. On the basis of this analysis, we then discuss the conserved fusion-through-hemifusion pathway of merger between biological membranes and propose that the entire progression, from the close juxtaposition of membrane bilayers to the expansion of a fusion pore, is controlled by protein-generated membrane stresses.

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Figure 1: Fusion-through hemifusion pathway of lipid bilayer fusion.
Figure 2: The stalk is the key intermediate in most of the theoretical models developed with the continuous and the simulation approaches.
Figure 3: Hypothetical pathway of biological fusion powered by protein-generated membrane stresses.

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Acknowledgements

We apologize for not citing many important papers because of space limitations. Figure 2b,c were kindly provided by M. Schick and S.J. Marrink, respectively. The work of L.V.C. is supported by the Intramural Research Program of the US National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development. The work of M.M.K. is supported by the Israel Science Foundation and Marie Curie Network 'Flippases'.

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Correspondence to Leonid V Chernomordik or Michael M Kozlov.

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Chernomordik, L., Kozlov, M. Mechanics of membrane fusion. Nat Struct Mol Biol 15, 675–683 (2008). https://doi.org/10.1038/nsmb.1455

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