The androgen receptor was purified from rat ventral prostate. The purified receptor migrated as a single band of mol. wt. 87000 on SDS-polyacrylamide gels, had a Kd for R-1881 (17 β-hydroxy-17α-methyl-estra-4,9,11-trien-3-one) binding as 6 nM, and sedimentation coefficient of 4.5 S. Phosphorylation of the purified receptor was studied by incubating it with [γ-32P]ATP in the presence of several purified protein kinases including cAMP-dependent protein kinase, and four cAMP-independent protein kinases (which were active towards substrates such as phosvitin and casein). Phosphorylation of the 87000 mol. wt. androgen receptor protein occurred only in the presence of a nuclear cAMP-independent protein kinase (of the N2 type). No auto-phosphorylation of the receptor was detected. The results indicate that the androgen receptor is a phosphoprotein. Further, phosphorylation of the androgen receptor by only a specific nuclear cAMP-independent protein kinase may be important in determining the dynamics of its function.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Sep 17 1984|
Bibliographical noteFunding Information:
Acknowledgements: This work was supported in part by the P.H.S. research grant CA-15062 awarded by National Cancer Institute, D.H.H.S., and by the Medical Research Fund of-the Veterans Admanistration. Expert-technical assistance of Miss Kathy Ferkul is gratefully acknowledged. Ms Margaret Chelmo assisted in the preparation of the manuscript.