Inhibition of rabbit globin mRNA translation by sequence-specific oligodeoxyribonucleotides

Abstract

Oligodeoxyribonucleotides 8-12 nucleotides in length whose sequences are complementary to the 5' end, the initiation codon regions, or the coding regions of rabbit globin mRNA were tested for their ability to inhibit translation in a rabbit reticulocyte lysate and in a wheat germ extract. The oligomers interact specifically with their target mRNAs as shown by their ability to serve as primers with reverse transcriptase. In the reticulocyte lysate, oligomers complementary to the 5' end or the initiation codon regions inhibit translation of both alpha- and beta-globin mRNA, whereas oligomers complementary to the coding regions have little or no effect. This suggests that reticulocyte ribosomes are able to displace the oligomers from the mRNA during the elongation but not the initiation step of translation. In the wheat germ system, translation was effectively inhibited by all oligomers regardless of their binding site on the message. In contrast to their behavior in the reticulocyte system, the oligomers inhibited alpha- and beta-globin synthesis in a specific manner. This observation suggests that control of alpha- and beta-globin mRNA translation is coordinated in the reticulocyte lysate system but not in the wheat germ extract. The results of our studies indicate that oligodeoxyribonucleotides may be useful probes for studying control of mRNA translation in cell-free systems.