Untranslated regions (UTRs) orchestrate translation reprogramming in cellular stress responses

Abstract

Stress is the result of an organism's interaction with environmental challenges. Regulations of gene expression including translation modulations are critical for adaptation and survival under stress. Untranslated regions (UTRs) of the transcripts play significant roles in translation regulation and continue to raise many intriguing questions in our understanding of cellular stress physiology. IRES (Internal ribosome entry site) and uORF (upstream open reading frame) mediated alternative translation initiations are emerging as unique mechanisms. Recent studies have revealed novel means of mRNAs stabilization in stress granules and their reversible modifications. Differential regulation of select transcripts is possible by the interplay between the adenine/uridine-rich elements (AREs) in 3'UTR with their binding proteins (AUBP) and by microRNA-mediated effects. Coordination of these various mechanisms control translation and thereby enables appropriate responses to environmental stress. In this review, we focus on the role of sequence signatures both at 5' and 3'UTRs in translation reprogramming during cellular stress responses.