Regulation of prostatic steroid binding protein mRNAs by testosterone

Testosterone regulates the expression of prostatic steroid binding protein by stimulating the accumulation of C1, C2 and C3 mRNA. We have used intervening sequence RNA probes to quantitate the primary transcript and a processed intermediate for C1 and C3 in nuclear RNA. Both C1 and C3 primary transcript concentration declined by about 100-fold 3 days after castration and were induced by testosterone within 1 h. In view of the magnitude and kinetics of the response we conclude that testosterone acts primarily within the cell nucleus to increase steady-state levels of nuclear RNA.