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 localization of both synaptic vesicles and calcium channels to the presynaptic active zone. Syntaxins function in this vesicle fusion process.

Syntaxin-1A is a member of the 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 transmembrane domain, a SNARE [Soluble NSF (N-ethylmaleimide-sensitive fusion protein)-Attachment protein REceptor] domain (known as H3), and an N-terminal regulatory domain (Habc). Syntaxins bind synaptotagmin 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 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.

Interactions
STX1A has been shown to interact with:


 * CPLX1,
 * CFTR,
 * NAPA,
 * RNF40,
 * SCNN1G,
 * SLC6A1,
 * SNAP-25,
 * SNAP23,
 * STXBP1,
 * STXBP5,
 * SYT1
 * UNC13B,
 * VAMP2,    and
 * VAMP8.