Key Terms - Synaptic Vesicle Exocytosis Flashcards
Chapter 3
Describe the steps in synaptic vesicle exocytosis (general)
- Action potential
- Depolarisation of presynaptic plasma membrane
- Opening of Ca2+ channels
- Calcium influx
- Calcium binding to synaptotagmin
- Exocytosis of synaptic vesicles
- NT release in the synaptic cleft
What are SNARE proteins
Proteins containing a SNARE domain
What is SNARE
A soluble NSF attachment protein receptor
Which 3 SNARE proteins are essential for synaptic vesicle exocytosis?
- Vesicular SNARE protein synaptobrevin/VAMP
- SNAP-25
- Syntaxin-1
What fuels the membrane fusion?
The energy released during SNARE complex assembly
Describe the 4 steps of the SNARE/SM protein cycle
- Priming
- Fusion pore opening
- Fusion pore expansion
- SNARE complex disassembly & vesicle recycling
What happens during the priming phase in the SNARE/SM protein cycle
The N- to C-terminal zippering of trans-SNARE complexes
What happens during the fusion pore expansion phase in the SNARE/SM protein cycle
The trans-SNARE complexes are converted into cis-SNARE complex (i.e. SNARE complexes on a single membrane)
What happens during the SNARE complex disassembly & vesicle recycling phase in the SNARE/SM protein cycle
The ATPase NSF and SNAPs dissociate cis-SNARE complexes into monomers. SNF is also the ATPase that loads SNARE proteins with energy
What are
Chaperone
They are proteins which assist in the conformational folding or unfolding of proteins, as well as the assembly or disassembly of multi-protein complexes
What are the 2 types of chaperones that support SNARE protein functioning ?
- The classical chaperone complex (CPS-alpha, Hsc70 & SGT
- The non-classical chaperone complex (alpha/beta/gamma-synucleins, phospholipids, syanptobrevin/VAMP)
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