Enables syntaxin-1 binding activity. Involved in exocytosis; neurotransmitter receptor internalization; and regulation of neuron projection development. Acts upstream of or within several processes, including associative learning; neurotransmitter secretion; and regulation of synaptic plasticity. Located in several cellular components, including glutamatergic synapse; synaptic vesicle; and trans-Golgi network. Is extrinsic component of cytoplasmic side of plasma membrane. Part of synaptobrevin 2-SNAP-25-syntaxin-1a-complexin I complex. Is expressed in adrenal gland; jaw; nervous system; and sensory organ. Used to study attention deficit hyperactivity disorder; obesity; schizophrenia; and type 2 diabetes mellitus. Human ortholog(s) of this gene implicated in Down syndrome and congenital myasthenic syndrome 18. Orthologous to human SNAP25 (synaptosome associated protein 25). [provided by Alliance of Genome Resources, Apr 2022]