Biochemical characterization of prostatic nuclei. II. Relationship between DNA synthesis and protein synthesis.

Abstract 1. The maximum rate of DNA synthesis is observed at 72 h in the ventral prostate of a castrated rat that has been stimulated by exogenous testosterone. However, the maximal rate of the synthesis of all classes of nuclear proteins precedes by 24–48 h the peak of DNA synthesis. 2. The rates of synthesis of various fractions of nuclear proteins were determined. The membrane proteins appeared to have the highest rate of synthesis. 3. Studies with inhibitors indicated that the synthesis of prostatic nuclear proteins is not directly coupled to DNA synthesis. 4. DNA synthesis but not RNA synthesis in the prostate is significantly inhibited if total cellular protein synthesis is completely blocked. Inhibition of RNA synthesis by actinomycin D did not alter the rate of DNA synthesis. 5. In comparison to all the nuclear proteins studied, the inhibition of synthesis of the membrane fractions correlated most closely with the rate of decrease DNA synthesis.