title: Inhibition of elongation steps of protein synthesis at reduced potassium concentrations in reticulocytes and reticulocyte lysate.
abstract: We treated intact reticulocytes with nystatin to make them permeable to small cations and varied the concentration of K+ in the medium; the ionic strength was kept constant by adjusting Na+. As the intracellular K+ was lowered, the rate of protein synthesis decreased. In a reticulocyte lysate, the dependence of the rate of protein synthesis on K+ concentration (at constant ionic strength) was similar to that seen in nystatin-treated cells. We observed no loss of polysomes at low K+. Even when initiation was blocked with aurintricarboxylic acid, decreased K+ inhibited protein synthesis. Analysis of the kinetics of synthesis showed that lowering the K+ concentration inhibits the rate of elongation of nascent chains, but has little effect on the relative rate of initiation of chains.
mesh_terms: D000818:Animals; D005914:Globins / Q000096:biosynthesis; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D010441:Peptide Chain Elongation, Translational / Q000187:drug effects*; D011188:Potassium / Q000494:pharmacology*; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology
chemical_list: D005914:Globins; D012964:Sodium; D008274:Magnesium; D011188:Potassium