MOLECULAR-CLONING AND EXPRESSION OF A CDNA-ENCODING AN OLFACTORY-SPECIFIC MOUSE PHENOL SULFOTRANSFERASE

Previously we demonstrated the presence of phenol sulphotransferase (P -ST) in mouse nasal cytosols and identified its zonal location in mous e nasal cavity by staining with an antiserum raised against a rat live r P-ST isoenzyme, PSTG, In the present study a cDNA was isolated from a mouse olfactory cDNA library by immunological screening with the ant iserum. The isolated cDNA consisted of 1347 bp with a 912 bp open read ing frame encoding a 304-residue polypeptide. Both the nucleotide and deduced amino acid sequences of the cDNA were 94% identical with those of a rat liver P-ST isoenzyme, ST1C1, The expressed enzyme in Escheri chia coli displayed high P-ST activity towards phenolic odorants such as eugenol and guaiacol, and it showed a high N-hydroxy-2-acetylaminof luorene sulphation activity in comparison with the rat ST1C1 enzyme, T hese results indicate that the olfactory P-ST encoded by the cDNA is a mouse orthologue of rat ST1C1; however, expression of the olfactory P -ST mRNA is specific for nasal tissues as revealed by reverse transcri ptase-mediated PCR (RT-PCR).