Under the Tucson sun: A meeting in the desert on mRNA decay

Abstract

Scientists from all over the world gathered this past June in Tucson, Arizona, for a FASEB-sponsored meeting organized by George Mackie (Univ. of British Columbia) and Roy Parker (Univ. of Arizona) highlighting new developments in the area of posttranscriptional gene regulation by mRNA degradation. The researchers in attendance represented two biological realms, eubacteria and eukaryotes, and while the molecular players, pathways, and regulation of mRNA turnover in these two phyla are clearly distinct, recurrent themes were unmistakable. Regardless of the organism, data were presented reinforcing our understanding that mRNA degradation in all systems is modulated by trans-acting factors, ribonucleolytic or not, in response to cis-acting RNA sequences. Furthermore, the adjustment of trans-effector activity and the accessibility of the cis-acting regulatory sequences is used by both prokaryotes and eukaryotes to provide additional layers of complexity to the process. A role for RNA polyadenylation in destabilizing eukaryotic RNA, reminiscent of the decay of stable RNAs in bacteria, was recently uncovered, and in both organisms, alternative fates for mRNAs engaged in translation were presented. Structural information for ribonucleases and accessory RNA decay proteins is proving to offer insight into catalytic function and possible regulatory mechanisms governing mRNA turnover. Moreover, the characterization of mRNA degradation in new model organisms, both bacterial and eukaryotic, is leading to both the confirmation of existing decay pathways and the discovery of new ones.