Cocaine receptor identified as BASP1

Abstract

Cocaine is a behavioral stimulant with substantial abuse potential related to its positively rewarding actions 1,2. Cocaine inhibits the reuptake inactivation of neurotransmitters such as dopamine, serotonin, and norepinephrine at high nanomolar to low micromolar concentrations 2. There is evidence for substantially more potent influences of cocaine. For instance, Calligaro and Eldefrawi reported binding of [3H]cocaine to brain membranes with a dissociation constant of about 16 nM 3. At 10 nM concentration, cocaine elicits environmental place conditioning in planarians 4. Furthermore, 1nM cocaine enhances dopamine D2 receptor agonist-mediated signaling 5. Inhibition of amine reuptake by cocaine is substantially less potent than some of these high affinity actions. Thus, evidence for a specific, high affinity receptor for cocaine that mediates its behavioral actions has been lacking. We now report high affinity binding of cocaine to the membrane-associated brain acid soluble protein-1 (BASP1) with a Kd of 7 nM. Knocking down BASP1 in the striatum inhibits [3H]cocaine binding to striatal synaptosomes. Depletion of BASP1 in the nucleus accumbens diminishes locomotor stimulation, acquisition, and expression of locomotor sensitization to cocaine. Our findings indicate that BASP1 is a pharmacologically relevant receptor for cocaine and a putative therapeutic target for psychostimulant addiction.