STX1A Gene - Syntaxin-1A: Function, Mutations, and Associated Diseases

STX1A encodes syntaxin-1A, a member of the syntaxin family of proteins that serve as key components of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex. Syntaxin-1A is predominantly expressed in neurons and neuroendocrine cells, where it localizes to the plasma membrane and mediates the docking and fusion of synaptic vesicles with the presynaptic membrane. This process is essential for calcium-triggered neurotransmitter release. STX1A interacts with SNAP-25, VAMP2, and synaptotagmin-1 to form the core SNARE complex. Mutations and dysregulation of STX1A have been implicated in neurological disorders including epilepsy, autism spectrum disorder, and intellectual disability.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Neurotransmitter release cycle (Reactome R-HSA-112310)

• Synaptic vesicle cycle (KEGG hsa04721)

• SNARE interactions in vesicular transport (KEGG hsa04130)

Syntaxin-1A is a 288-amino-acid integral membrane protein with a C-terminal transmembrane domain and an N-terminal Habc domain that regulates SNARE complex formation. It localizes to the presynaptic plasma membrane and serves as the t-SNARE that binds SNAP-25 and VAMP2 to form the four-helical bundle SNARE complex. This complex brings synaptic vesicles into close apposition with the plasma membrane, enabling calcium-triggered fusion and neurotransmitter release. Syntaxin-1A also interacts with Munc18-1, which stabilizes its closed conformation and regulates SNARE assembly. Post-translational modifications include palmitoylation at cysteine residues, which influences membrane targeting.