Enables protein domain specific binding activity. Predicted to be involved in several processes, including cAMP-mediated signaling; modulation of chemical synaptic transmission; and signal release. Predicted to act upstream of or within adenylate cyclase-modulating G protein-coupled receptor signaling pathway and neurotransmitter secretion. Located in synapse. Part of protein-containing complex. Is active in photoreceptor ribbon synapse and presynaptic active zone cytoplasmic component. Orthologous to human RIMS2 (regulating synaptic membrane exocytosis 2). [provided by Alliance of Genome Resources, Apr 2022]