Elution profiles of lysine and tyrosine transfer RNA during avian development

Efficiency and fidelity of cell-free protein synthesis by transfer RNA from aged mice

Transfer RNAs (tRNAs) from heart, kidney, liver, and spleen of mature (10-12 months old) and aged (29 months old) C57BL/6 mice were tested for their ability to translate encephalomyocarditis viral RNA in a tRNA-dependent cell-free system derived from mouse ascites tumor cells. The rates of in vitro protein synthesis were compared as a function of tRNA concentration, and the fidelity of translation was examined by sodium dodecyl sulfate gel electrophoresis and isoelectric focusing of the viral polypeptides synthesized in vitro. No significant age-related differences in either the efficiency or fidelity of synthesis were discovered, indicating that alterations in tRNAs are probably not involved in the cellular aging of these tissues.

Theorectical mechanisms for synthesis of carcinogen-induced embryonic proteins: III. The tRNA methylases; methylation mechanism and function

It is contended that redundant repressed tRed) with carcinogens in adult cells. Supportive evidence, especially from molecular model building, is presented for a mechanism of tRNA methylation. In this mechanism the adenine moiety of S-adenosyl-L-methionine base-pairs with uracil for all tRNA methylations. Furthermore it is proposed that such methylations are required during the transcription of a tRNA molecule in order to limit the number of possible conformers that can occur before further development of the molecule takes place. This theory of the function for methyl groups is discussed in the light of the properties found for hypomethylated tRNAs.

Effects of simian virus 40-induced transformation on isoaccepting species of transfer RNA from mouse fibroblasts

Alterations in isoaccepting species of tRNA in mouse fibroblasts transformed by simian virus 40 were determined for alanine, arginine, histidine, leucine, lysine, phenylalanine, serine, tyrosine, and valine. Significant differences between transformed cells in culture and newborn mouse cells are attributed to tRNA alterations accompanying differentiation of mouse cells.