On the specificity of antisense RNA to arrest in vitro translation of mRNA coding for Drosophila hsp 23.

The specificity of action of antisense RNA for one of Drosophila low molecular weight heat shock proteins (hsp 23) was tested at the translational level using the rabbit reticulocyte lysate cell-free system. T7 polymerase-driven transcripts of hsp 23 in the antisense orientation were mixed with mRNA from heat-shocked cells under various stringency conditions prior to translation in vitro. Although the four small hsps show considerable sequence homology in their coding sequences, antisense hsp 23 RNA was shown to specifically inhibit hsp 23 mRNA translation under both high (formamide, 45 degrees C) and low stringency (37 degrees C) conditions. This suggests that the 5' leader and the ribosome binding region of mRNA are of prime importance in the specificity of action of antisense RNA at the translational level.