Molecular and functional characterization of cytosolic sulfotransferases in cynomolgus macaque.

Cytosolic sulfotransferases (SULTs), drug-metabolizing enzymes essential for the metabolism of endogenous biochemicals and foreign compounds, have been characterized in humans, but remain to be investigated in cynomolgus macaques, important species in drug metabolism studies. In this study, based on the genome data, cynomolgus SULT1A1, SULT1A3, SULT1B1, SULT1C2v1, SULT1C2v2, SULT1C4, SULT1E1, and SULT2A1 cDNAs were isolated and characterized. Among these, cynomolgus SULT1C2v2 was highly homologous to human SULT1C2P1 (pseudogene). These cynomolgus SULT cDNAs had high sequence identities (95-97%) to, and closely clustered with their human orthologs in a phylogenetic tree. Gene structure and genomic organization of each cynomolgus SULT were similar to those of the human ortholog. Among the 10 tissue types analyzed, cynomolgus SULTs showed distinct expression patterns similar to human SULTs; more specifically, mRNA was most abundantly expressed in livers (SULT1A1, SULT1C2v2, SULT1C4, and SULT2A1), jejunum (SULT1A3, SULT1B1, and SULT1E1), or kidneys (SULT1C2v1). The most abundant SULT mRNA was SULT2A1, SULT1E1, and SULT1C4 found in livers, jejunum, and kidneys, respectively. Recombinant cynomolgus SULT1A1, SULT1A3, SULT1B1, SULT1C2v1, SULT1C2v2, SULT1C4, SULT1E1, and SULT2A1 in bacterial cytosolic fractions mediated 3'-phosphoadenosine-5'-phosphosulfate-dependent sulfate conjugations of typical human SULT substrates, 1-naphthol, p-nitrophenol, dopamine, dehydroepiandrosterone, and estradiol. Taken together, these results suggest molecular and functional similarities of SULTs between cynomolgus macaques and humans.