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Studies of Molecular Species of the Human Androgen Receptor (AR): Comparison of the Physicochemical Properties of the [3H]methyltrienolone-AR Complex Formed in Cytosol to the Complex Produced in Intact Genital Skin Fibroblasts*

1986; Oxford University Press; Volume: 63; Issue: 1 Linguagem: Inglês

10.1210/jcem-63-1-222

1945-7197

Bruce S. Keenan, NANCY C. GREGER, Anne-Marie Hedge,

Effects and risks of endocrine disrupting chemicals

Two forms of the human genital skin fibroblast (GSF) androgen receptor (AR)complexed with [3H]17β-methyltrienolone were compared: 1) the intact complex formedin cytosol at 4 C (broken cell or B/C complex); and 2) the complex formed in the whole cell at 37 C (W/C complex). The intact form of the B/C complex was distinguished from partly degraded forms by the gel filtration profile in 0.5 M KC1. The W/C complex was consideredto represent the transformed state of the receptor. The W/C complex had a smaller molecular radius than the B/C complex by gel filtration (Kav = 0.26–0.28 us. 0.11–0.18).By lowsalt density gradient centrifugation, the B/C complex sedimented at 8.8S and the W/C complex at 6.6S. However, in 0.5 M KC1, each sedimented at 5.IS, and they were homogeneous,indicating that the monomeric forms differed markedly in molecular radius, but by only about 20,000 daltons in calculated mol wt (134,500 us. 114,300 daltons). The complexes were separated from DNA, desalted, and compared by chromatography on DEAE-Sephaceland hydroxylapatite (HAP). The B/C complex bound readily to both column matrices and eluted fro each as a sharp homogeneous peak: from DEAE at 172–190 mM KC1 and from HAP at 123 mM phosphate. The W/C complex, however, was heterogeneous. One component did not bindto DEAE,and one eluted at 22–40 mM KC1. The W/C complex eluted from HAP as a peak at 42mM, with ashoulder at 102 mM phosphate. Thus, transformation of the human genital skin fibroblast androgen receptor involves a major decrease in molecular radius and loss of negative charge with a possible loss of a 20,000-dalton macromolecular component. (J ClinEndocrinol Metab63: 222, 1986)