MOLECULAR-CLONING OF AN ORPHAN TRANSPORTER - A NEW MEMBER OF THE NEUROTRANSMITTER TRANSPORTER FAMILY

A complementary DNA clone predicted to encode a novel transporter was isolated from rat brain and the localization of its mRNA was examined, The cDNA, designated rB21a, predicts a protein with 12 putative trans membrane domains that exhibits significant sequence homology with neur otransmitter transporters, Expression studies have not yet identified the endogenous substrate for this transporter, but the presence of rB2 1a mRNA within the leptomeninges of the brain suggests the transporter may regulate CSF levels of its substrate, The cloning of rB21a provid es the means to determine its physiological functions and the potentia l to design novel, transporter-based therapeutic agents for neurologic al and psychiatric disorders.