Syntaxin-binding protein 1

Syntaxin-binding protein 1 (STXBP1) is a 594-amino acid protein that plays a critical role in synaptic vesicle docking and fusion (UniProt: P61764). It binds syntaxins 1, 2, and 3 and mediates assembly of the SNARE complex at synaptic membranes, thereby regulating neurotransmitter release from neurons. Through these interactions, STXBP1 is essential for neurotransmission and may determine specificity of intracellular fusion reactions.

STXBP1 is expressed in neuronal tissues where it functions at the presynaptic terminal. Mutations in STXBP1 are associated with developmental and epileptic encephalopathy 4 (DEE4), a severe early-onset epilepsy characterized by tonic seizures or spasms, suppression-burst EEG patterns, profound intellectual disability, and brain hypomyelination.

STXBP1 is curated in SFARI as a Category 1 (high confidence) autism-risk gene with syndromic classification (SFARI Cat 1), reflecting evidence that mutations in this gene contribute to neurodevelopmental disorders including autism spectrum disorder, typically in the context of severe epileptic encephalopathy presentations.