Vesicle-associated membrane protein 2 (VAMP2) is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''VAMP2''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
Synaptobrevin
Synaptobrevins (''synaptobrevin isotypes 1-2'') are small integral membrane proteins of secretory vesicles with molecular weight of 18 kilodalton (kDa) that are part of the vesicle-associated membrane protein (VAMP) family.
Synaptobre ...
s/VAMPs,
syntaxin
Syntaxins are a family of membrane integrated Q-SNARE proteins participating in exocytosis.
Domains
Syntaxins possess a single C-terminal transmembrane domain, a SNARE domain (known as H3), and an N-terminal regulatory domain (Habc).
Syntaxi ...
s, and the 25-kD synaptosomal-associated protein
SNAP25 are the main components of a protein complex involved in the docking and/or fusion of
synaptic vesicle
In a neuron, synaptic vesicles (or neurotransmitter vesicles) store various neurotransmitters that are exocytosis, released at the chemical synapse, synapse. The release is regulated by a voltage-dependent calcium channel. Vesicle (biology), Ves ...
s with the presynaptic membrane. VAMP2 is a member of the
vesicle-associated membrane protein (VAMP)/synaptobrevin family. VAMP2 is thought to participate in
neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell.
Neurotra ...
release at a step between docking and
fusion. Mice lacking functional synaptobrevin2/VAMP2 gene cannot survive after birth, and have a dramatically reduced synaptic transmission, around 10% of control.
The protein forms a stable complex with syntaxin, synaptosomal-associated protein, 25 kD, and
complexin
Complexin (also known as synaphin) refers to a one of a small set of eukaryotic cytoplasmic neuronal proteins which binds to the SNARE protein , SNARE protein complex (''SNAREpin'') with a high affinity. These are called synaphin 1 and 2. In the ...
. It also forms a distinct complex with
synaptophysin
Synaptophysin, also known as the major synaptic vesicle protein p38, is a protein that in humans is encoded by the ''SYP'' gene.
Gene
The gene is located on the short arm of X chromosome (Xp11.23-p11.22). It is 12,406 bases in length and li ...
.
Clinical significance
Heterozygous
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism.
Mos ...
mutations
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosi ...
in VAMP2 cause a
neurodevelopmental disorder
Neurodevelopmental disorders are a group of mental conditions negatively affecting the development of the nervous system, which includes the brain and spinal cord. According to the American Psychiatric Association Diagnostic and Statistical Manu ...
with
hypotonia
Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength. Hypotonia is not a specific medical disorder, but it is a potential manifestation of many different dis ...
and
autistic
Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing di ...
features (with or without
hyperkinetic movements).
Interactions
VAMP2 has been shown to
interact with:
*
RABAC1,
*
SNAP-25
Synaptosomal-Associated Protein, 25kDa (SNAP-25) is a Target Soluble NSF (''N''-ethylmaleimide-sensitive factor) Attachment Protein Receptor ( t-SNARE) protein encoded by the ''SNAP25'' gene found on chromosome 20p12.2 in humans. SNAP-25 is a com ...
,
*
SNAP23
Synaptosomal-associated protein 23 is a protein that in humans is encoded by the ''SNAP23'' gene. Two alternative transcript variants encoding different protein isoforms have been described for this gene.
Function
Specificity of vesicular tran ...
,
* STX1A
Syntaxin-1A is a protein that in humans is encoded by the ''STX1A'' gene.
Function
Synaptic vesicles store neurotransmitters that are released during calcium-regulated exocytosis. The specificity of neurotransmitter release requires the localiz ...
, and
* STX4
Syntaxin-4 is a protein that in humans is encoded by the ''STX4'' gene.
Interactions
STX4 has been shown to Protein-protein interaction, interact with:
* Gelsolin,
* NAPA (gene), NAPA,
* RAB4A,
* SNAP-25,
* SNAP23,
* STXBP1,
* STXBP5,
...
.
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
{{Vesicular transport proteins