title: Evidence that intracellular magnesium is present in cells at a regulatory concentration for protein synthesis.
abstract: When extracellular magnesium is reduced by a factor of 50 (from 1.0 to 0.02 mM), the total intracellular magnesium of a spontaneously transformed clone of 3T3 cells decreases by 30-50%. Protein synthesis rates in these cells were measured as the intracellular magnesium decreased. Protein synthesis rates and magnesium content were found to decrease in parallel with each other. At 3 hr, a decrease to 84% of control values of magnesium content was accompanied by a decrease to 85% of control values of leucine incorporation rates. A larger inhibition had occurred by 12 hr, when the magnesium had decreased to 67% and leucine incorporation rates had decreased to 57%. When magnesium was restored to magnesium-deprived cells, both magnesium content and leucine incorporation increased about 2-fold by 1 hr. In the experiments reported here, initial small changes in magnesium content are associated with changes in protein synthesis rates. This strongly suggests that magnesium is present at a regulatory rather than excess concentration for protein synthesis. The results are consistent with a role for intracellular magnesium in the regulation of protein synthesis and support the hypothesis that magnesium has a central role in the regulation of metabolism and growth.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism; D007424:Intracellular Fluid / Q000032:analysis; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D014176:Protein Biosynthesis / Q000187:drug effects; D011522:Protons
chemical_list: D011522:Protons; D000255:Adenosine Triphosphate; D008274:Magnesium; D002118:Calcium