Enables transmembrane transporter binding activity. A structural constituent of presynaptic active zone. Involved in neurotransmitter secretion; positive regulation of gene expression; and regulation of nervous system process. Acts upstream of or within calcium ion-regulated exocytosis of neurotransmitter; regulation of long-term neuronal synaptic plasticity; and regulation of membrane potential. Located in several cellular components, including GABA-ergic synapse; glutamatergic synapse; and presynaptic active zone cytoplasmic component. Human ortholog(s) of this gene implicated in cone-rod dystrophy 7. Orthologous to human RIMS1 (regulating synaptic membrane exocytosis 1). [provided by Alliance of Genome Resources, Apr 2022]