A point mutation in the second zinc finger of the DNA-binding domain of the androgen receptor gene causes complete androgen insensitivity in two siblings with receptor-positive androgen resistance

• Published in: Molecular endocrinology (Baltimore, Md.) Vol. 7; no. 7; p. 861
• Main Authors: Mowszowicz, I, Lee, H J, Chen, H T, Mestayer, C, Portois, M C, Cabrol, S, Mauvais-Jarvis, P, Chang, C
• Format: Journal Article
• Language: English
• Published: United States 01-07-1993
• Subjects: 3-Oxo-5-alpha-Steroid 4-Dehydrogenase - analysis; Adolescent; Amino Acid Sequence; Androgens - metabolism; Androgens - pharmacology; Arginine - analysis; Base Sequence; Blotting, Northern; Cells, Cultured; Chloramphenicol O-Acetyltransferase - analysis; DNA - analysis; DNA - genetics; DNA - metabolism; Drug Resistance; Exons; Female; Fibroblasts - chemistry; Fibroblasts - cytology; Fibroblasts - ultrastructure; Gene Amplification; Histidine - analysis; Humans; Male; Molecular Sequence Data; Pedigree; Plasmids; Point Mutation - genetics; Receptors, Androgen - genetics; Receptors, Androgen - metabolism; Receptors, Androgen - physiology; RNA, Messenger - analysis; RNA, Messenger - genetics; Transcription, Genetic - genetics; Transfection; Zinc Fingers - genetics
• ISSN: 0888-8809
• DOI: 10.1210/me.7.7.861

We have analyzed the nucleotide sequence of complementary and genomic DNAs of the human androgen receptor (AR) gene in two siblings (patients 9006 and 9030) with receptor-positive complete androgen insensitivity (Rec(+)-CAI). Northern analysis indicated that mRNA of the AR was normal in size. However, its expression was relatively reduced in both patients. Consistent with the normal androgen-binding capacity (496 and 552 fmol/mg DNA for patients 9006 and 9030, respectively) but decreased DNA-binding ability (168 fmol/mg DNA) measured in genital skin fibroblasts, no mutation was found in both N-terminal and ligand-binding domains of the AR. However, a single base substitution (G-->A) was found in the second zinc finger of the DNA-binding domain at nucleotide 2372 of the AR cDNA in both cases. This resulted in the replacement of a highly conserved arginine residue (amino acid 614) by a histidine. When the mutated receptor plasmid was cotransfected into PC-3 cells together with the reporter chloramphenicol acetyltransferase gene, chloramphenicol acetyltransferase activity was not induced by 5 alpha-dihydrotestosterone treatment, confirming that the mutation renders the AR nonfunctional and can, therefore, be held responsible for the clinical features in these patients. These results highlight the importance of Arginine-614 in the second zinc finger of the DNA-binding domain of the AR in the protein-DNA interaction.