Molecular identification of a rat novel organic anion transporter moat1, which transports prostaglandin D-2, leuko-triene C-4, and taurocholate

We have isolated a rat novel multispecific organic anion transporter, moat1 , The isolated clones were originated by alternative splicing of the moat1 mRNA. The nucleotide sequences predict a protein of 682 amino acids with mo derate sequence similarity to LST-1, the oatp family, and the prostaglandin transporter. Northern blot analysis of rat moat1 identified a predominant transcript of 4.4 kilonucleotides in all tissues. Northern blot and in situ hybridization analyses of rat brain further indicated that moat1 mRNA is w idely distributed in neuronal cells of the central nervous system, especial ly in the hippocampus and cerebellum. moat1 transports prostaglandin D-2 (K -m; 35.5 nM), leukotriene C-4 (K-m; 3.2 mu M) and taurocholate (K-m; 17.6 m u M) in a sodium-independent manner, moat1 also transports prostaglandin E- 1, E-2, thromboxane B-2, and iloprost but not dehydroepiandrosterone sulfat e and digoxin, of which the substrate specificity is similar, but definitiv ely different from those of any other organic anion transporters, (C) 2000 Academic Press.