Enables calcium-dependent protein binding activity and syntaxin-1 binding activity. Involved in synaptic vesicle exocytosis. Located in dendrite; neuronal cell body; and synapse. Part of synaptobrevin 2-SNAP-25-syntaxin-1a-complexin II complex. Is active in postsynapse and presynapse. Orthologous to human CPLX2 (complexin 2). [provided by Alliance of Genome Resources, Apr 2022]