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Related Concept Videos

Fusion of Secretory Vesicles with the Plasma Membrane01:26

Fusion of Secretory Vesicles with the Plasma Membrane

10.9K
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...
10.9K
SNAREs and Membrane Fusion01:43

SNAREs and Membrane Fusion

10.8K
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...
10.8K
Vesicular Tubular Clusters01:45

Vesicular Tubular Clusters

2.4K
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
2.4K
Pinching-off of Coated Vesicles01:32

Pinching-off of Coated Vesicles

3.1K
Vesicle budding is orchestrated by distinct cytosolic proteins such as adaptor proteins, coat proteins, and GTPases. To initiate vesicle budding, membrane-bending proteins containing crescent-shaped BAR domains bind to the lipid heads in the bilayer and distort the membrane to form a protein-coated vesicle bud. Adaptors proteins such as AP2 for clathrin-coated vesicles can nucleate on the deformed membrane. Finally, coat proteins such as clathrin or COPI and COPII assemble into a coat forming...
3.1K
Coat Assembly and GTPases01:33

Coat Assembly and GTPases

3.5K
Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
3.5K
Clathrin Coated Vesicles01:12

Clathrin Coated Vesicles

6.8K
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
6.8K
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  11. Vesicle Docking And Fusion Pore Modulation By The Neuronal Calcium Sensor Synaptotagmin-1

Vesicle docking and fusion pore modulation by the neuronal calcium sensor Synaptotagmin-1

Maria Tsemperouli1, Sudheer Kumar Cheppali1, Félix Rivera-Molina2

  • 1Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, Connecticut; Nanobiology Institute, Yale University, West Haven, Connecticut.

Biophysical Journal
|December 25, 2024

Related Experiment Videos

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy
10:58

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

Published on: August 24, 2016

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Confocal Microscopy to Measure Three Modes of Fusion Pore Dynamics in Adrenal Chromaffin Cells
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Confocal Microscopy to Measure Three Modes of Fusion Pore Dynamics in Adrenal Chromaffin Cells

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Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay
09:19

Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay

Published on: October 19, 2012

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View abstract on PubMed

Summary
This summary is machine-generated.

Synaptotagmin-1 (Syt1) is crucial for rapid neurotransmitter and hormone release. Neutralizing key Syt1 regions impairs vesicle docking and release, but paradoxically increases fusion pore size and release speed.

Area of Science:

  • Neuroscience
  • Cell Biology
  • Biochemistry

Background:

  • Synaptotagmin-1 (Syt1) acts as a primary calcium sensor regulating neurotransmitter and hormone release.
  • Syt1's C2 domains bind calcium, phospholipids, and SNAREs, mediating exocytosis, vesicle docking, and fusion pore dynamics.
  • The precise mechanism by which Syt1 binding and calcium trigger exocytosis remains incompletely understood.

Purpose of the Study:

  • To investigate the role of conserved polybasic patches in Syt1's C2 domains on dense-core vesicle (DCV) release.
  • To determine how Syt1 mutations affect vesicle docking, fusion triggering, and fusion pore characteristics.

Main Methods:

  • Utilized a human neuroendocrine cell line model.
  • Introduced mutations neutralizing conserved polybasic patches in Syt1's C2 domains.

Related Experiment Videos

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy
10:58

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

Published on: August 24, 2016

10.8K
Confocal Microscopy to Measure Three Modes of Fusion Pore Dynamics in Adrenal Chromaffin Cells
12:30

Confocal Microscopy to Measure Three Modes of Fusion Pore Dynamics in Adrenal Chromaffin Cells

Published on: March 16, 2022

2.1K
Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay
09:19

Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay

Published on: October 19, 2012

14.0K
  • Assessed serotonin release from DCVs, including measurements of vesicle docking and fusion pore dynamics.

    • Main Results:

    • Neutralization of polybasic patches in Syt1's C2 domains significantly impaired DCV docking and efficient serotonin release.
    • The same mutations led to the formation of larger fusion pores during exocytosis.
    • Individual fusion events exhibited faster serotonin release kinetics with the mutated Syt1.

    Conclusions:

    • Syt1's conserved polybasic regions are essential for proper DCV docking and regulated release.
    • Syt1 plays a critical role in controlling fusion pore size and dynamics.
    • The functions of Syt1 in vesicle docking, fusion triggering, and fusion pore regulation are interconnected.