How does UTR diversity contribute to regulation of gene expression?
5’ untranslated regions (UTRs) influence translational efficiency of mRNAs through diverse mechanisms: long and/or structured 5’UTRs are more difficult to scan, yet may afford resistance to 5’ to 3’ exonucleases; specific sequence or structure elements provide internal recruitment sites for translation factors or regulatory proteins; and upstream open reading frames (uORFs) modulate translation initiation site choice and efficiency. Alternative 5’UTR production is ubiquitous in eukaryotes and has enormous regulatory potential, perhaps comparable to that afforded by alternative splicing (which may also serve to increase 5’UTR diversity). We are combining high-throughput 5’end sequencing with translation-state profiling to obtain comprehensive knowledge of 5’UTR utilization under various growth states. We will use this rich dataset to propose and then test the ‘rules’ that govern translational efficiency in vivo. Are ribosomes specialized? Ribosomes are magnificent and versatile molecula
