The power of the 3′ UTR: translational control and development

Abstract

Many crucial decisions made during development are regulated by elements that are located in the 3′ untranslated region (3′ UTR) that control translation. In several organisms, including Drosophila and Caenorhabditis elegans, cascades of translational regulators have central roles in tissue patterning and embryonic axis formation. Many translational regulators are highly conserved and seem to control the activity of numerous mRNAs. Translational regulation often involves the interaction of a given regulator with other factors, and depending on its partners will determine if it is an activator or repressor of translation. Biochemical analysis of several translational control mechanisms indicates that there are many ways to regulate the translation of an mRNA. 3′-UTR binding factors control translation by regulating such diverse steps as ribosome binding, scanning, initiation and elongation. The 'nuclear history' of an mRNA can also affect its translational activity. Several recent papers indicate that factors might be loading onto mRNAs in the nucleus, possibly during processing, that might later affect ribosome recruitment in the cytoplasm.