Synthesis of Protein, Ribonucleic Acid, and Ribosomes by Individual Bacterial Cells in Balanced Growth

AUTOR(ES)

Ecker, R. E.

RESUMO

Relative rates of protein synthesis in individual cells were determined by allowing random populations to incorporate tritiated leucine for very short periods (pulses) and then examining autoradiographs of these cells to assess the amount of incorporation (grains per cell) as a function of cell size. Relative rates of ribonucleic acid (RNA) synthesis were determined in the same way by using tritiated uracil. Unless the uracil pulse was very short (less than 1/20 generation), the RNA labeled during the pulse was predominantly ribosomal. The rate of protein synthesis in individual cells is directly proportional to cell size. The rate of RNA synthesis also increases linearly with size in larger cells, but there appears to be a slight delay in RNA synthesis immediately after cell division. Total cellular content of protein, RNA, and ribosomes is directly proportional to cell size. Thus, we conclude that, in individual cells during the cell cycle (i) the average rate of protein synthesis per ribosome is constant and (ii) the increase in macromolecular mass of the cell is exponential with age.

Documentos Relacionados

• Ethylene-stimulated Synthesis of Ribosomes, Ribonucleic Acid, and Protein in Developing Fig Fruits
• Synthesis of deoxyribonucleic acid, ribonucleic acid, and protein during sporulation of Clostridium perfringens.
• Incorporation of Precursors into Ribonucleic Acid, Protein, Glycoprotein, and Lipoprotein of Avian Myeloblastosis Virions
• Polysomes, Ribonucleic Acid, and Protein Synthesis During Germination of Neurospora crassa Conidia
• Inhibition of Peptidoglycan, Ribonucleic Acid, and Protein Synthesis in Tolerant Strains of Streptococcus mutans