mRNA translation: influence of the 5' and 3' untranslated regions

Eukaryotic messenger RNA utilization is a tightly controlled process. Control of translation is exerted at several levels, but the predominant step is ribosome binding, which is rate limiting for translation of most mRNAs. There appear to be several alternative modes by which ribosomes bind to the mRNA and initiate translation. Recent data show that both the 5' and 3' untranslated regions of eukaryotic mRNAs play critical roles in mRNA recruitment for translation, and several cis-acting elements have been characterized in detail. In addition, a few trans-acting factors that bind to these elements have been identified. It is possible that the terminal regions of mRNAs interact to enhance translation.