Effect of 17β‐Estradiol on the Synthesis of Non‐Histone Nuclear Proteins in Chick Liver

At 2 h following the injection of 17β‐estradiol into immature chicks, the rate of [3H]leucine incorporation into total nuclear protein of liver, after correction for the free leucine pool, was increased 3.6‐fold over that of the controls. By means of a double‐labelling technique it could be shown in addition, after basic and acidic nucleoproteins were extracted from highly purified liver nuclei, that the stimulation by 17β‐estradiol in vivo resulted within 3 h in the selective synthesis of two non‐histone nuclear proteins of molecular weights of 26000 and 20000. The latter exhibited multiple isoelectric points of 5.0, 5.35 and 6.2.