Lipids in biological membrane fusion

1995 ◽  
Vol 146 (1) ◽  
Author(s):  
L. Chernomordik ◽  
M.M. Kozlov ◽  
J. Zimmerberg
Keyword(s):  
Membrane Fusion ◽  
Biological Membrane

scholarly journals Membrane lysis during biological membrane fusion: collateral damage by misregulated fusion machines

2008 ◽  
Vol 183 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Alex Engel ◽  
Peter Walter
Keyword(s):  
Membrane Fusion ◽  
Biological Membrane ◽  
Membrane Integrity ◽  
Fusion Pore ◽  
Mechanistic Models ◽  
Collateral Damage ◽  
Vacuole Fusion ◽  
Membrane Lysis

In the canonical model of membrane fusion, the integrity of the fusing membranes is never compromised, preserving the identity of fusing compartments. However, recent molecular simulations provided evidence for a pathway to fusion in which holes in the membrane evolve into a fusion pore. Additionally, two biological membrane fusion models—yeast cell mating and in vitro vacuole fusion—have shown that modifying the composition or altering the relative expression levels of membrane fusion complexes can result in membrane lysis. The convergence of these findings showing membrane integrity loss during biological membrane fusion suggests new mechanistic models for membrane fusion and the role of membrane fusion complexes.

scholarly journals Expansion of the fusion stalk and its implication for biological membrane fusion

2014 ◽  
Vol 111 (30) ◽  
pp. 11043-11048 ◽  
Author(s):  
H. J. Risselada ◽  
G. Bubnis ◽  
H. Grubmuller
Keyword(s):  
Membrane Fusion ◽  
Biological Membrane

scholarly journals Application of (1)H and (31)P NMR to topological description of a model of biological membrane fusion: topological description of a model of biological membrane fusion.

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Agnieszka Janiak-Osajca ◽  
Anna Timoszyk
Keyword(s):  
Membrane Fusion ◽  
Lipid Bilayers ◽  
Nmr Spectra ◽  
Biological Membrane ◽  
Hexagonal Phase ◽  
Fusion Process ◽  
H Nmr ◽  
Small Unilamellar Vesicle ◽  
Topological Description ◽  
Nmr Study

The process of biological membrane fusion can be analysed by topological methods. Mathematical analysis of the fusion process of vesicles indicated two significant facts: the formation of an inner, transient structure (hexagonal phase - H(II)) and a translocation of some lipids within the membrane. This shift had a vector character and only occurred from the outer to the inner layer. Model membrane composed of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) was studied. (31)P- and (1)H-NMR methods were used to describe the process of fusion. (31)P-NMR spectra of multilamellar vesicles (MLV) were taken at various temperatures and concentrations of Ca(2+) ions (natural fusiogenic agent). A (31)P-NMR spectrum with the characteristic shape of the H(II) phase was obtained for the molar Ca(2+)/PS ratio of 2.0. During the study, (1)H-NMR and (31)P-NMR spectra for small unilamellar vesicle (SUV), which were dependent on time (concentration of Pr(3+) ions was constant), were also recorded. The presence of the paramagnetic Pr(3+) ions permits observation of separate signals from the hydrophilic part of the inner and outer lipid bilayers. The obtained results suggest that in the process of fusion translocation of phospholipid molecules takes place from the outer to the inner layer of the vesicle and size of the vesicles increase. The NMR study has showed that the intermediate state of the fusion process caused by Ca(2+) ions is the H(II) phase. The experimental results obtained are in agreement with the topological model as well.

What is the role of SNARE proteins in membrane fusion?

2003 ◽  
Vol 285 (2) ◽  
pp. C237-C249 ◽  
Author(s):  
Joseph G. Duman ◽  
John G. Forte
Keyword(s):  
Subcellular Localization ◽  
Membrane Fusion ◽  
Biological Membrane ◽  
Snare Complex ◽  
Model Systems ◽  
Snare Proteins ◽  
Protein Receptor ◽  
Sensitive Factor ◽  
Membrane Contact

Soluble N-ethylmaleimide-sensitive factor activating protein receptor (SNARE) proteins have been at the fore-front of research on biological membrane fusion for some time. The subcellular localization of SNAREs and their ability to form the so-called SNARE complex may be integral to determining the specificity of intracellular fusion (the SNARE hypothesis) and/or serving as the minimal fusion machinery. Both the SNARE hypothesis and the idea of the minimal fusion machinery have been challenged by a number of experimental observations in various model systems, suggesting that SNAREs may have other functions. Considering recent advances in the SNARE literature, it appears that SNAREs may actually function as part of a complex fusion “machine.” Their role in the machinery could be any one or a combination of roles, including establishing tight membrane contact, formation of a scaffolding on which to build the machine, binding of lipid surfaces, and many others. It is also possible that complexations other than the classic SNARE complex participate in membrane fusion.

scholarly journals Secretory and viral fusion may share mechanistic events with fusion between curved lipid bilayers

1998 ◽  
Vol 95 (16) ◽  
pp. 9274-9279 ◽  
Author(s):  
JinKeun Lee ◽  
Barry R. Lentz
Keyword(s):  
Membrane Fusion ◽  
Lipid Bilayers ◽  
Biological Membrane ◽  
Activation Energies ◽  
Membrane Lipid ◽  
Striking Similarity ◽  
Fusion Pore ◽  
Viral Fusion ◽  
Lipid Molecule ◽  
Free Model

Activation energies for the individual steps of secretory and viral fusion are reported to be large [Oberhauser, A. F., Monck, J. R. & Fernandez, J. M. (1992) Biophys. J. 61, 800–809; Clague, M. J., Schoch, C., Zech, L. & Blumenthal, R. (1990) Biochemistry 29, 1303–1308]. Understanding the cause for these large activation energies is crucial to defining the mechanisms of these two types of biological membrane fusion. We showed recently that the fusion of protein-free model lipid bilayers mimics the sequence of steps observed during secretory and viral fusion, suggesting that these processes may involve common lipid, rather than protein, rearrangements. To test for this possibility, we determined the activation energies for the three steps that we were able to distinguish as contributing to the fusion of protein-free model lipid bilayers. Activation energies for lipid rearrangements associated with formation of the reversible first intermediate, with conversion of this to a semi-stable second intermediate, and with irreversible fusion pore formation were 37 kcal/mol, 27 kcal/mol, and 22 kcal/mol, respectively. The first and last of these were comparable to the activation energies observed for membrane lipid exchange (42 kcal/mol) during viral fusion and for the rate of fusion pore opening during secretory granule release (23 kcal/mol). This striking similarity suggests strongly that the basic molecular processes involved in secretory and viral fusion involve a set of lipid molecule rearrangements that also are involved in model membrane fusion.

The fusion pore and mechanisms of biological membrane fusion

1996 ◽  
Vol 8 (6) ◽  
pp. 890 ◽  
Author(s):  
Jonathan R Monck ◽  
Julio M Fernandez
Keyword(s):  
Membrane Fusion ◽  
Biological Membrane ◽  
Fusion Pore

The fusion pore and mechanisms of biological membrane fusion

1996 ◽  
Vol 8 (4) ◽  
pp. 524-533 ◽  
Author(s):  
Jonathan R Monck ◽  
Julio M Fernandez
Keyword(s):  
Membrane Fusion ◽  
Biological Membrane ◽  
Fusion Pore

scholarly journals Liposome fusion with orthogonal coiled-coil peptides as fusogens: The efficacy of roleplaying peptides

2021 ◽  
Author(s):  
Geert G.A. Daudey ◽  
Meng-Jie Shen ◽  
Ankush Singhal ◽  
Patrick Van der Est ◽  
Agur Sevink ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Biological Membrane ◽  
Coiled Coil ◽  
Complex Environment ◽  
Target Delivery ◽  
Liposome Fusion

Biological membrane fusion is a highly specific and coordinated process as a multitude of vesicular fusion events proceed simultaneously in a complex environment with minimal off-target delivery. In this study,...

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