Detection of human tRNAs with antisense oligonucleotides

Regulated expression and modification of tRNA isoacceptors may play an important role in the control of gene expression during such processes as differentiation and immune activation. However, the development of techniques for the identification and quantitation of multiple tRNA isoaccepting species has been hindered by the relative physicochemical similarity among individual isoacceptors and their high degree of post-transcriptional modification. We have used antisense DNA oligonucleotides derived from the T stem to acceptor stem region of six human tRNAs and one murine tRNA to detect individual tRNA isoacceptors in slot blots, Northern blots, and dot blots of human tRNA. This hybridization protocol was used in combination with tRNA fractionation by electrophoresis on a partially denaturing gel by reversed-phase low pressure chromatography and reversed-phase HPLC to identify multiple tRNA isoacceptors in a single sample of tRNA. Using this technique, it should be possible to monitor changes in the cellular tRNA repertoire that may be involved in the regulation of gene expression.