Evaluation of the use of antisense tRNA(met) as an inhibitor for eukaryotic protein synthesis.

We attempted to explore the use of antisense RNAs against tRNA as an inhibitor of eukaryotic protein synthesis. For this purpose, antisense RNA against the 5'-end half of the initiator tRNA of wheat germ was synthesized, and its effect on translation of the Brome mosaic virus mRNA was investigated in a wheat germ cell-free system. When the antisense RNA against the 5'-end half of the initiator tRNA including the anticodon sequence was added at the concentration of 8 microM to the cell-free system, protein synthesis was completely inhibited. This inhibitory effect could be suppressed by the addition of wheat germ tRNA. In contrast, sense and control RNA showed slight inhibitory effects, which were not, however, suppressed by wheat germ tRNA. The antisense tRNA formed a double-stranded RNA duplex with the target methionine tRNA in the wheat germ extract which became resistant to ribonuclease treatment. These experiments suggest that antisense tRNA could be utilized for control of tRNA functions and to block protein synthesis.