Vesicle Fusion
Vesicle Fusion - Related Videos
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...
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...
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.
08:36
FM Dyes in Vesicle Recycling
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2023
FM dyes are a class of fluorescent molecules that has found important use in studying the vesicle recycling process. By virtue of a chemical structure, these molecules can insert themselves into the outer leaflet of phospholipid bilayer membranes. After membrane insertion, they are internalized into the cell via endocytosed vesicles, and released when these vesicles recycle back to the membrane. Since, these dyes fluoresce strongly in the hydrophobic environment within membranes and weakly in...
10:58
SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy
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Cited by 8 •
2016
Here, we present a protocol to detect single, SNARE-mediated fusion events between liposomes and supported bilayers in microfluidic channels using polarized TIRFM, with single molecule sensitivity and ~15 msec time resolution. Lipid and soluble cargo release can be detected simultaneously. Liposome size, lipid diffusivity, and fusion pore properties are measured.
FAQs
Specific recognition directs a vesicle toward the appropriate target membrane, helping establish the selectivity of intracellular exchange. Once the membranes are correctly paired, SNARE proteins bring their lipid bilayers into close contact. The membranes then undergo hemifusion, pore formation, and pore expansion, creating a controlled route for transferring vesicle contents and incorporating membrane components.
These stages describe progressively deeper membrane remodeling rather than a single abrupt event. Hemifusion represents an early rearrangement of the lipid bilayers, followed by formation of an opening and its expansion. Considering the stages separately helps researchers relate membrane structure to the eventual release of vesicle contents and exchange of membrane proteins or lipids.
Calcium ions can act as a trigger for rapid fusion in regulated exocytosis. This provides a direct connection between a calcium signal and the release of stored vesicle contents. The mechanism is especially relevant to secretion events that must respond quickly, including neurotransmitter release and hormone secretion, where timing depends on controlled membrane fusion.
Vesicle fusion supports several essential cellular activities, including neurotransmitter release, hormone secretion, and intracellular trafficking. These roles connect the mechanism to both cell communication and transport within the cell. By enabling vesicles to deliver their contents or membrane components to selected destinations, the process helps coordinate secretion and movement between organelles.
Fusion transfers proteins and lipids carried by vesicles into target membranes, allowing cells to modify membrane composition as materials move between organelles. This transport function extends beyond delivery of soluble contents. Studying it therefore helps explain how membranes maintain their distinct components while still exchanging selected material through intracellular trafficking pathways.
A detailed understanding of the recognition, SNARE-driven membrane remodeling, and calcium-triggered steps can clarify how secretion becomes disrupted. The same mechanistic knowledge may guide strategies for targeted drug delivery by informing how vesicle-based carriers could exchange contents with selected cellular membranes. Thus, the process links basic cell biology with disease research and therapeutic design.