The 56 kDa androgen-binding protein in human genital skin fibroblasts: its relation to the human androgen receptor.
We have recently described in genital skin fibroblasts (GSF) a relatively abundant 56 kDa protein with androgen-binding activity. This protein is missing in GSF of most patients with complete androgen insensitivity syndrome (CAI). The protein has many characteristics compatible with the androgen receptor; it has in fact been tentatively considered as a precursor or degradation form of the prototypic (approximately 100 kDa) human androgen receptor. We have prepared an antiserum to this protein, which allowed us to detect it as a direct product by in vitro translation of mRNA from GSF. It is thus very unlikely to be a degradation product of a larger precursor. Furthermore, covalent photolytic labeling of this protein with the androgen analogue [3H]mibolerone revealed a much lower affinity for this protein than is known for the androgen receptor. Finally, the GSF of two exceptional patients with complete androgen insensitivity syndrome due to negligible androgen receptor-binding activity express this protein normally, as determined on two-dimensional gels by Western blot analysis with the antiserum and by photolytic covalent labeling with androgen analogues. These data indicate that the protein is not a precursor or a degradation product of the receptor; nor is it androgen-induced. They are more compatible with the idea that the protein is another member of the steroid/thyroid/retinoic acid receptor supergene family, perhaps as an unorthodox product of the human androgen receptor gene.
Pereira
F
F
Department of Biochemistry & Molecular Biology and Human Genetics, University of Manitoba, Winnipeg, Canada.
Belsham
D
D
Duerksen
K
K
Rosenmann
E
E
Kaufman
M
M
Pinsky
L
L
Wrogemann
K
K
D000727:Androgen-Binding Protein / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004351:Drug Resistance; D005347:Fibroblasts / Q000378:metabolism; D005835:Genitalia / Q000378:metabolism; D006801:Humans; D007120:Immunochemistry; D008970:Molecular Weight; D010449:Peptide Mapping; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011944:Receptors, Androgen / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D013577:Syndrome
D000727:Androgen-Binding Protein; D012333:RNA, Messenger; D011944:Receptors, Androgen