Molecular Cloning and Expression of an Amine Sulfotransferase cDNA: A New Gene Family of Cytosolic Sulfotransferases in Mammals

• Published in: Journal of biochemistry (Tokyo) Vol. 123; no. 3; pp. 479 - 486
• Main Authors: Yoshinari, Kouichi, Nagata, Kiyoshi, Ogino, Makoto, Fujita, Ken-ichi, Shiraga, Toshifumi, Iwasaki, Kazuhide, Hata, Takehisa, Yamazoe, Yasushi
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.03.1998
• Subjects: Amino Acid Sequence; amino compound; Animals; bacterial expression; Base Sequence; Blotting, Northern; cDNA; Cloning, Molecular; Cytosol - enzymology; Escherichia coli - genetics; Immunoblotting; Liver - enzymology; Male; Mammals; Molecular Sequence Data; rabbit; Rabbits; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Sequence Analysis, DNA; Sequence Homology, Amino Acid; sulfotransferase; Sulfotransferases - genetics; Sulfotransferases - metabolism
• ISSN: 0021-924X
• DOI: 10.1093/oxfordjournals.jbchem.a021961

A cDNA of amine sulfotransferase-RB1 (AST-RB1), which efficiently catalyzes 4-phenyl-1,2,3,6-tetrahydropyridine (PTHP) sulfation, has been isolated by immunoscreening of a rabbit liver cDNA library. The cDNA consisted of 1,117 base pairs and encoded a protein of 301 amino acids with a molecular weight of 35,876. The deduced amino acid sequence matched at six positions those of peptide fragments obtained from purified AST-RB1 protein. The sequence had less than 38% identity at the amino acid level with cytosolic sulfotransferases in mammals, although high degrees of similarity were observed with regions conserved throughout mammalian sulfotransferases. These results indicate that AST-RB1, arbitrarily named sulfotransferase 3A1 (ST3A1), constitutes a new and third gene family of cytosolic sulfotransferases in mammals. ST3A1 expressed in Escherichia coli as a fused protein catalyzed sulfation of amines such as PTHP, aniline, 4-chloroaniline, 2-naphthylamine, and desipramine, but barely O-sulfation of typical aryl and hydroxy-steroid sulfotransferase substrates. These data unequivocally demonstrate the existence of a cytosolic sulfotransferase showing a high selectivity for amine substrates, and indicate that multiple forms of sulfotransferase mediate sulfation of xenobiotics in mammalian livers.