N-acetylation Pharmacogenetics: A Gene Deletion Causes Absence of Arylamine N-acetyltransferase in Liver of Slow Acetylator Rabbits

• Published in: Proceedings of the National Academy of Sciences - PNAS 1989-12, Vol.86 (23), p.9554-9557
• Main Authors: Blum, Martin, Grant, Denis M., Demierre, Anne, Meyer, Urs A.
• Format: Article
• Language: English
• Subjects: Acetylation; Acetyltransferases - genetics; Animals; Arylamine N-Acetyltransferase - genetics; Arylamine N-Acetyltransferase - isolation & purification; Arylamine N-Acetyltransferase - metabolism; Biological and medical sciences; Blotting, Southern; Blotting, Western; Cell Line; Chromosome Deletion; Classical genetics, quantitative genetics, hybrids; Complementary DNA; COS cells; Cultured cells; Cytosol; DNA; DNA - genetics; Enzymes; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes; Genetics of eukaryotes. Biological and molecular evolution; Genomics; Liver; Liver - enzymology; Messenger RNA; Phenotype; Rabbits; Restriction Mapping; Transfection; Vertebrata
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.86.23.9554

The New Zealand White rabbit provides a widely used animal model for the human acetylation polymorphism, which confers marked interindividual variation in the effect and toxicity of numerous drugs, chemicals, and potential carcinogens. The relationship of a recently isolated cDNA clone, designated rnat, to genetically polymorphic arylamine N-acetyltransferase (NAT; acetyl-CoA:arylamine N-acetyltransferase, EC 2.3.1.5) of rabbit liver was established by its expression in monkey kidney COS-1 cells: (i) cytosols from transfected cultures contained high levels of an Ac-CoA-dependent NAT activity, which was kinetically indistinguishable from that observed in cytosols from livers of genetically rapid-acetylator rabbits; (ii) transfected cells also contained an immunoreactive protein, recognized by NAT-specific antibodies, with identical electrophoretic mobility to NAT from rabbit liver. The rnat clone and anti-NAT antibodies were then used to study the relationship between NAT activity, liver enzyme protein, and the level of mRNA in livers from in vivo phenotyped rapid- and slow-acetylator rabbits. Livers from slow acetylators were devoid of both immunodetectable NAT protein and its corresponding mRNA. Analysis of genomic DNA with a panel of restriction enzymes revealed the loss of specific hybridizing bands in the DNA of slow-acetylator rabbits. These data strongly suggest that defective arylamine N-acetylation in the rabbit model is caused by a gene deletion resulting in an absence of specific mRNA and NAT enzyme protein.