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 domain, and an N-terminal regulatory domain. 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.