Androgen receptor mutants that affect normal growth and development.

The elucidation of the molecular structure of the human androgen receptor has facilitated the study of molecular defects associated with androgen insensitivity. In this overview, data are presented on the functional domain structure of the wild type human androgen receptor and on the molecular structure of the androgen receptor from different subjects with the complete form of androgen insensitivity. Mutational domain analysis of the human androgen receptor has revealed that a large carboxyterminal region constitutes the hormone binding domain and that DNA binding is associated with a central basic domain. In addition, separate domains that control trans-activation and nuclear translocation have been identified. Reports on androgen receptor gene structure in individuals with the complete and incomplete forms of androgen insensitivity indicate that gross deletions within the androgen receptor gene are uncommon. The locations of the different point mutations reported cannot be assigned to a single site but are spread throughout the ligand binding and DNA binding domains. A point mutation found in the ligand binding domain of the human androgen receptor in a prostate tumour cell line is the cause of the altered steroid binding specificity observed for the androgen receptor in these prostate tumour cells. A considerable variation in the length of one of the polyglutamine repeats has been reported in the aminoterminal transcription regulating domain of the wild type androgen receptor. Doubling of the length of this particular polyglutamine stretch is correlated with a progressive spinal/bulbar muscular atrophy in a small group of middle aged men.