Enables protein domain specific binding activity and signaling receptor binding activity. Involved in exocytic insertion of neurotransmitter receptor to postsynaptic membrane and regulation of exocytosis. Located in presynaptic active zone membrane. Human ortholog(s) of this gene implicated in generalized epilepsy with febrile seizures plus 9. Orthologous to human STX1B (syntaxin 1B). [provided by Alliance of Genome Resources, Apr 2022]