[Effects of monovalent cations on synthesis and degradation kinetics of RNA in cells of Ehrlich carcinoma].
The changes in intracellular ratio of Na+/K+ by equilibrating the cells in saline media at 0-4 degrees C cause changes in the rate of RNA synthesis in the cells. The optimum of [3H]uridine incorporation lies within the range of the Na+/K+-ratio of 7 : 1 to 3 : 1. Within the Na+/K+ ratio of 3 : 1 to 1 : 1 the rate of RNA synthesis is decreased about 2.5-fold, showing a further fall at the Na+/K+ ratio of about 1 : 3. Using competitive hybridization of labelled and non-labelled heterogenous nuclear RNA with DNA, it was shown that the total rate of synthesis and the nature of newly formed transcripts are changed. When the cells equilibrated with a certain saline medium were labelled with [3H]uridine for 15 min and their cationic equilibrium was changed by another equilibration in a medium having a different Na+/K+ ratio, the processing of labelled heterogenous nuclear RNA was drastically changed, i.e. part of the labelled RNA was rapidly depolymerized, while the other part was deposited in the nuclei or cell cytoplasm. Hence the intracellular cationic homeostasis can control the transcription and its changes cause recoding of gene expression. Besides, the cells contain an active system which controls the transcription program and depends on intracellular ionic homeostasis. This system prevents the release of non-essential mRNAs into the cytoplasm by depolymerizing or depositing them in the nuclei.
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D011188:Potassium / Q000494:pharmacology*; D012334:RNA, Neoplasm / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*
D012334:RNA, Neoplasm; D012964:Sodium; D011188:Potassium
Vliianie monovalentnykh kationov na sintez i kinetiku raspada RNK v kletkakh raka Erlikha.