Regulation of Protein Synthesis in Mouse Liver by Steroid Hormon

• Published in: Journal of biochemistry (Tokyo) 1967-06, Vol.61 (6), p.679-686
• Main Authors: KOIKE, KATSURO, OTAKA, TADAHIKO, OKUI, SEIICHI
• Format: Article
• Language: English
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a128602

1. The activity of the s-20 fluid, prepared from cortisone-treated liver, to incorporate amino acid into protein in vitro depended on the concentration of circulating cortisone in the mouse, and yet little change was observed in the incorporating activity of the s-20 fluid from liver of hydrocortisone-treated mouse. Cortisone was able to exert its stimulatory effect on the protein-synthetic activity of polysomes incubated with the s-105 fluid from normal liver. Polysomes prepared from the hydrocortisone-treated liver showed a slight inhibition in the incorporation as compared with normal polysomes. 2. Cortisone treatment slightly increased the incorporation of 32P-orthophosphate into high-molecular RNA obtained from cytoplasm. A different extent of the labelling of the RNA was noted when hydro-cortisone was given. A part of the high-molecular RNA formed as a result of cortisone treatment was not ribosomal or transfer RNA and was similar to messenger RNA. 3. The high-molecular RNA labelled with 32P-orthophosphate, prepared from cortisone-treated livers, was polydisperse and had a molar nucleotide composition which is richer in the adenine plus uridine content than that of the high-molecular RNA obtained from normal liver. The adenine plus uridine content of the newly-synthesized RNA remained almost unaltered by the treatment with hydrocortisone. 4. The mass distribution of the polysomes obtained after the treatment with cortisone showed two peaks of heavy polysomes (very unstable to the mild ribonuclease [EC 2.7.7.16] digestion) and light polysomes (resistant to the mild ribonuclease digestion). The heavy polysomes were predominant after injection of cortisone. On treatment with hydro-cortisone, however, the heavy polysomes tended to decrease.