Membrane Fusion
Membrane Fusion - Related Videos
09:19
Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay
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2012
We have developed a cell fusion assay that quantifies SNARE-mediated membrane fusion events by activated expression of β-galactosidase.
01:43
SNAREs and Membrane Fusion
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2023
Once a transport vesicle has recognized its target organelle, the vesicular membrane needs to fuse with the target membrane to unload the cargo. Transmembrane proteins called SNAREs present on organelle membranes and their vesicles, mediate vesicle fusion. SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
01:26
Fusion of Secretory Vesicles with the Plasma Membrane
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2023
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25. In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
07:22
A High-throughput Cre-Lox Activated Viral Membrane Fusion Assay to Identify Inhibitors of HIV-1 Viral Membrane Fusion
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Cited by 8 •
2018
We describe a cell-based assay to report on HIV-1 fusion via the expression of green fluorescent protein detectable by flow cytometry or fluorescence microscopy. It can be used to test inhibitors of viral entry (specifically at the fusion step) in cell-free and cell-to-cell infection systems.
02:45
Nuclear Fusion
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2020
The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process called fusion. The principal source of energy in the sun is a net fusion reaction in which four hydrogen nuclei fuse and ultimately produce one helium nucleus and two positrons. A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
FAQs
Specialized proteins help overcome the repulsive forces that keep closely apposed lipid bilayers from merging. Once that barrier is reduced, the lipids can rearrange through defined intermediate configurations. This protein-driven step is critical because membrane fusion requires more than physical contact; it requires active remodeling that leads toward a fusion pore and eventual continuity between the membranes.
The hemifusion diaphragm identifies an intermediate stage between initial membrane contact and formation of a fusion pore. Its importance is mechanistic: it indicates that lipid rearrangement has progressed, but the membranes have not yet completed the transition to a continuous structure. Researchers can therefore use this stage to distinguish partial progression from completed fusion.
Membrane contact alone does not complete membrane fusion. Contact brings the bilayers close, but specialized proteins must overcome repulsive forces and promote lipid rearrangement. The distinction matters in biology because cells need fusion to be a controlled event, rather than an automatic consequence of membranes approaching one another.
A useful mechanistic sequence begins with close membrane apposition, continues with protein-assisted reduction of repulsive forces and lipid rearrangement, passes through a hemifusion diaphragm, and ends with fusion-pore opening. Following these stages helps researchers interpret the progression of a fusion event and connect molecular changes with the resulting membrane continuity.
Neurotransmitter release, hormone secretion, fertilization, endocytosis, and intracellular trafficking all depend on membrane-fusion events. In these settings, fusion provides a way to move materials or information between cellular compartments or across the cell surface. Comparing these examples shows how one core mechanism supports both rapid communication and organized intracellular transport.
Membrane fusion has broader relevance because it helps explain viral entry, supports research on drug delivery, and provides context for disorders involving defective vesicle transport. Studying the process also clarifies how cells maintain compartmentalization while exchanging materials and information, linking molecular membrane behavior with disease-related and applied biological questions.