Related Experiment Video
Updated: Aug 12, 2026
08:38
Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals
Published on: May 25, 2011
Tomosyn: a syntaxin-1-binding protein that forms a novel complex in the neurotransmitter release process
Y Fujita1, H Shirataki, T Sakisaka
1Department of Molecular Biology and Biochemistry, Osaka University Medical School, Suita, Japan.
Neuron
|June 10, 1998
Summary
Researchers discovered tomosyn, a novel protein that interacts with syntaxin-1, impacting neurotransmitter release. Tomosyn may play a key role in stimulating soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) complex formation for effective exocytosis.
Area of Science:
- Neuroscience
- Molecular Biology
- Cell Biology
Background:
- Syntaxin-1 is a crucial protein in the soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) complex involved in synaptic vesicle docking and membrane fusion.
- Syntaxin-1 also forms a distinct heterodimer with Munc18.
Purpose of the Study:
- To identify novel syntaxin-1-binding proteins.
- To investigate the role of tomosyn in the regulation of neurotransmitter release and SNARE complex formation.
Main Methods:
- Protein-protein interaction studies to identify syntaxin-1 binding partners.
- Characterization of novel protein complexes using biochemical assays.
- Analysis of exocytosis in PC12 cells under conditions of altered syntaxin-1 or tomosyn expression.
Main Results:
- A novel syntaxin-1-binding protein, tomosyn, was identified.
- Tomosyn dissociates Munc18 from syntaxin-1, forming a new 10S complex with syntaxin-1, SNAP-25, and synaptotagmin.
- High expression of tomosyn or syntaxin-1 reduces calcium-dependent exocytosis in PC12 cells.
Conclusions:
- Tomosyn is a novel regulator of the neurotransmitter release process.
- Tomosyn may stimulate SNARE complex formation, influencing exocytosis.
- The 130 kDa isoform of tomosyn is brain-specific and co-localizes with syntaxin-1 in nerve terminals.
Related Concept Videos
01:26Fusion of Secretory Vesicles with the Plasma Membrane
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...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
01:39Mitochondrial Protein Sorting
Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death. Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
01:19Translocation of Proteins into the Mitochondria
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
01:37Energy to Drive Translocation
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...