Control of Ribosome Synthesis in Normal and Regenerating Liver

• Published in: The Journal of biological chemistry Vol. 243; no. 1; pp. 29 - 33
• Main Authors: Chaudhuri, Sukhen, Lieberman, Irving
• Format: Journal Article
• Language: English
• Published: American Society for Biochemistry and Molecular Biology 01.01.1968
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)99321-X

Partial hepatectomy of the rat leads to a 10- to 12-fold increase in the rate of liver ribosome formation. To learn about the mechanism of the increase as well as the controls that ordinarily govern hepatic ribosome synthesis, the effects of cycloheximide were studied in normal and in partially hepatectomized animals. Ribosome formation in normal animals can be only partly governed by protein synthesis since the liver contains preformed proteins that are available to make ribosomes. The rise in ribosome formation in regenerating liver, on the other hand, is totally dependent upon protein synthesis, presumably upon an enhanced rate of formation of ribosomal proteins. An unsuccessful effort was made to learn whether the greater ribosome production after partial hepatectomy depends upon an enhanced synthesis of RNA as well as of protein. A large increase in the incorporation of 14 C-orotate into ribosomal precursor RNAs occurred in regenerating liver. Reason was found, however, to believe that the increased incorporation is not a valid measure of the rate of synthesis of ribosomal precursor RNA.