Brain transfer RNA. I. Methylation of newly synthesized tRNA.

Present study demonstrates differences between the labeling patterns of rat cerebral cortex and cerebellum. Although the initial rates of synthesis and methylation of tRNA from these two regions of brain are different, their final degree of methylation is the same in both the cases. Differences in the rates of incorporation of radioactivities in both the tissues can be explained by the differences in the rates of equilibrium of the labeled precursors with the pools. Increased incorporation of labeled uridine into cerebral cortical tRNA following dibutyryl cAMP treatment probably resulted from higher uptake of the labeled precursor due to permeability changes.