Syntaxin-1A 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 ''STX1A''

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

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 store

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 ...

s that are released during

calcium Calcium is a chemical element; it has 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 it ...

-regulated

exocytosis Exocytosis is a term for the active transport process that transports large molecules from cell to the extracellular area. Hormones, proteins and neurotransmitters are examples of large molecules that can be transported out of the cell. Exocytosis ...

. 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, which are a type of calcium channel regulated by changes in membrane potential. Some calcium chan ...

s to the

presynaptic In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...

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 ...

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). Syntaxi ...

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, carboxy 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 t ...

transmembrane domain, a

SNARE SNARE proteins – "Soluble NSF attachment protein, SNAP REceptors" – are a large protein family consisting of at least 24 members in yeasts and more than 60 members in mammalian and plant cells. The primary role of SNARE proteins is to m ...

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 amin ...

regulatory domain (Habc). Syntaxins bind

synaptotagmin Synaptotagmins (SYTs) constitute a family of cell membrane, 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 Protein isof ...

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 (commonly called botox), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon endi ...

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), also Williams–Beuren syndrome (WBS), 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 int ...

. *

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 advocating for the legal and human rights of children with intersex traits. The organization was founded in 2006 and fo ...

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 o ...

, *

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 lin ...

, * 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 b ...

, *

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-aminobuty ...

, *

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 ...

, * STXBP1, *

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 protei ...

, 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 th ...

References

External links

* {{NLM content