Characterization and localization of cocaine- and amphetamine-regulated transcript (CART) binding sites

Cocaine- and amphetamine-regulated transcript (CART) is widely expressed in the brain and various endocrine tissues. CART is implicated in many physiological functions including food intake, drug reward, stress and nociception. No CART receptor has been identified yet. We fused CART(55-102) to the green fluorescent protein (GFP) and found that the ligand suppresses significantly food intake after intracerebroventricular (i.c.v.) injection in mice. Using this ligand, we show specific CART binding sites on HepG2 cells and hypothalamic dissociated cells. In brain sections, CART displaceable binding sites were observed on cell bodies mainly localized in hypothalamic periventricular areas.