The Role of Ribosomal Subunits in Mammalian Cells
This extract was created in the absence of an abstract.
Excerpt
Ribosomal subunits (RSU) are found in the cytoplasm of all cells active in protein synthesis and represent approximately 10÷ of the total ribosome population. They have been designated “native” RSU to distinguish them from the RSU which are “derived” from ribosomes by treatment with agents that dissociate them. The term RSU will here be used to designate only native ribosomal subunits.
The ribosomal system has three components: polyribosomes, ribosomes, and RSU. The relative ratio of polyribosomes to ribosomes is determined by the physiological state of a cell. Unlimited supply of energy and amino acids causes in general recruitment of ribosomes into polyribosomes; limitation of some essential amino acid or of energy available causes polyribosome disaggregation and increase in ribosomes. When a drastic change in the polyribosomes to ribosomes ratio takes place, the level of RSU remains unchanged (Joklik and Becker, 1965; Hogan and Korner, 1968a). These observations have suggested that...
