THE RAT NOREPINEPHRINE TRANSPORTER - MOLECULAR-CLONING FROM PC12 CELLS AND FUNCTIONAL EXPRESSION

The rat norepinephrine transporter (rNET) cDNA from the PC12 pheochrom ocytoma cell line has been cloned by RT-PCR and characterized. The cDN A encodes an integral membrane protein consisting of 617 amino acids w hich contains twelve putative transmembrane domains, two potential N-g lycosylation sites, two potential phosphorylation sites for protein ki nase C and one phosphorylation site for casein kinase II. The nucleoti de and deduced amino acid sequence shows a high level of homology to t he human and the bovine norepinephrine transporter and less homology t o the rat dopamine transporter (rDAT). Heterologous expression of rNET in HEK293 cells revealed that uptake of [H-3]norepinephrine is sodium -and chloride-dependent and highly sensitive to the selective norepine phrine transporter inhibitors desipramine and nisoxetine. The cloned r NET cDNA provides the opportunity to investigate this transporter in h eterologous expression systems and adds a new member to the family of sodium-and chloride-dependent neurotransmitter transporters. (C) 1997 Elsevier Science B.V.