Syntaxin-1A is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''STX1A''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Function

Synaptic vesicle In a neuron, synaptic vesicles (or neurotransmitter vesicles) store various neurotransmitters that are released at the synapse. The release is regulated by a voltage-dependent calcium channel. Vesicles are essential for propagating nerve impulse ...

s store

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neuro ...

s that are released during

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...

-regulated

exocytosis Exocytosis () is a form of active transport and bulk transport in which a cell transports molecules (e.g., neurotransmitters and proteins) out of the cell ('' exo-'' + ''cytosis''). As an active transport mechanism, exocytosis requires the use o ...

. The specificity of neurotransmitter release requires the localization of both synaptic vesicles and

calcium channel A calcium channel is an ion channel which shows selective permeability to calcium ions. It is sometimes synonymous with voltage-gated calcium channel, although there are also ligand-gated calcium channels. Comparison tables The following tables e ...

s to the

presynaptic In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from ...

active zone. Syntaxins function in this

vesicle fusion Vesicle fusion is the merging of a vesicle with other vesicles or a part of a cell membrane. In the latter case, it is the end stage of secretion from secretory vesicles, where their contents are expelled from the cell through exocytosis. Vesicles c ...

process. Syntaxin-1A is a member of the

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). Syntaxin ...

superfamily. Syntaxins are nervous system-specific proteins implicated in the docking of synaptic vesicles with the presynaptic plasma membrane. Syntaxins possess a single

C-terminal The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is ...

transmembrane domain, a

SNARE SNARE proteins – " SNAP REceptor" – are a large protein family consisting of at least 24 members in yeasts, more than 60 members in mammalian cells, and some numbers in plants. The primary role of SNARE proteins is to mediate vesicle fu ...

oluble NSF (N-ethylmaleimide-sensitive fusion protein)-Attachment protein REceptordomain (known as H3), and an

N-terminal The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...

regulatory domain (Habc). Syntaxins bind

synaptotagmin Synaptotagmins (SYTs) constitute a family of membrane-trafficking proteins that are characterized by an N-terminal transmembrane region (TMR), a variable linker, and two C-terminal C2 domains - C2A and C2B. There are 17 isoforms in the mammalian s ...

in a calcium-dependent fashion and interact with voltage dependent calcium and potassium channels via the C-terminal H3 domain. Syntaxin-1A is a key protein in ion channel regulation and synaptic exocytosis.

Clinical significance

Syntaxins serve as a substrate for

botulinum Botulinum toxin, or botulinum neurotoxin (BoNT), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromusc ...

neurotoxin type C, a metalloprotease that blocks exocytosis and has high affinity for a molecular complex that includes the alpha-latrotoxin receptor which produces explosive exocytosis. The expression level of STX1A is directly correlated with intelligence in

Williams syndrome Williams syndrome (WS) is a genetic disorder that affects many parts of the body. Facial features frequently include a broad forehead, underdeveloped chin, short nose, and full cheeks. Mild to moderate intellectual disability is observed in people ...

. *

Interactive pathway map

Interactions

STX1A has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...

with: *

CPLX1 Complexin-1 is a protein that in humans is encoded by the ''CPLX1'' gene. Function Proteins encoded by the complexin/synaphin gene family are cytosolic proteins that function in synaptic vesicle exocytosis. These proteins bind syntaxin, part ...

, *

CFTR Cystic fibrosis transmembrane conductance regulator (CFTR) is a membrane protein and anion channel in vertebrates that is encoded by the ''CFTR'' gene. Geneticist Lap-Chee Tsui and his team identified the CFTR gene in 1989 as the gene linked wit ...

, * NAPA, *

RNF40 E3 ubiquitin-protein ligase BRE1B is an enzyme that in humans is encoded by the ''RNF40'' gene. Function The protein encoded by this gene contains a RING finger, a motif known to be involved in protein-protein and protein-DNA interactions. Thi ...

, *

SCNN1G The SCNN1G gene encodes for the γ subunit of the epithelial sodium channel ENaC in vertebrates. ENaC is assembled as a heterotrimer composed of three homologous subunits α, β, and γ or δ, β, and γ. The other ENAC subunits are encoded by SC ...

, *

SLC6A1 GABA transporter 1 (GAT1) also known as sodium- and chloride-dependent GABA transporter 1 is a protein that in humans is encoded by the ''SLC6A1'' gene and belongs to the solute carrier 6 (SLC6) family of transporters. It mediates gamma-aminobutyr ...

, *

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 comp ...

, *

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 ...

, *

STXBP1 Syntaxin-binding protein 1 (also known as Munc18-1) is a protein that in humans is encoded by the ''STXBP1'' gene. This gene encodes a syntaxin-binding protein. The encoded protein appears to play a role in release of neurotransmitters via regul ...

, *

STXBP5 Syntaxin-binding protein 5 is a protein that in humans is encoded by the ''STXBP5'' gene. It is also known as tomosyn, after , "friend" in Japanese, for its role as a binding protein. Function Syntaxin 1 is a component of the 7S and 20S SNARE ...

, *

SYT1 Synaptotagmin-1 is a protein that in humans is encoded by the ''SYT1'' gene. Function Synaptotagmins are integral membrane proteins of synaptic vesicles thought to serve as sensors for calcium ions (Ca2+) in the process of vesicular trafficking ...

UNC13B Protein unc-13 homolog B is a protein that in humans is encoded by the ''UNC13B'' gene. Function This gene is expressed in the kidney cortical epithelial cells and is upregulated by hyperglycemia. The encoded protein shares a high level of sim ...

, *

VAMP2 Vesicle-associated membrane protein 2 (VAMP2) is a protein that in humans is encoded by the ''VAMP2'' gene. Function Synaptobrevins/VAMPs, syntaxins, and the 25-kD synaptosomal-associated protein SNAP25 are the main components of a protein ...

, and *

VAMP8 Vesicle-associated membrane protein 8 is a protein that in humans is encoded by the ''VAMP8'' gene. Synaptobrevins/VAMPs, syntaxins, and the 25-kD synaptosomal-associated protein SNAP25 are the main components of a protein complex involved in the ...

References

External links

* {{NLM content