Enables SNARE binding activity and neurotransmitter transmembrane transporter activity. Involved in insulin secretion; regulation of synaptic vesicle fusion to presynaptic active zone membrane; and synaptic vesicle exocytosis. Acts upstream of or within regulation of neurotransmitter secretion. Located in cytosol; photoreceptor ribbon synapse; and plasma membrane. Is anchored component of presynaptic active zone membrane and anchored component of synaptic vesicle membrane. Is expressed in cerebral cortex and cortical layer V. Orthologous to human CPLX3 (complexin 3). [provided by Alliance of Genome Resources, Apr 2022]