mRNA Stability

Abstract The steady‐state level of a messenger ribonucleic acid (mRNA) is determined by both its rate of synthesis and degradation. The degradation of mRNA is an important tool employed by cells to control gene expression and to adjust the level of protein synthesis in response to physiological needs or environmental signals. The degradation of mRNA in all organisms is mastered by a rather restricted number of enzymes with major (endo‐ and exoribonucleases) and ancillary (e.g. RNA helicases) functions. Some of these enzymes are phylogenetically conserved across the three domains of life – bacteria, archaea and eukarya. Moreover, the main components of the RNA decay machinery can associate with each other to form multienzyme complexes, which makes it possible to coordinate and control mRNA decay in vivo . The stability of individual mRNAs varies and is dependent on intrinsic properties of transcripts (i.e. specific structure and sequence) and action of trans ‐encoded regulatory factors. The enzymes and ancillary factors involved in mRNA decay in pro‐ and eukaryotic organisms can associate with each other to form multienzyme complexes such as degradosomes or exosomes. Mechanisms of mRNA decay in pro‐ and eukaryotes share many common steps. Pro‐ and eukaryotic cells use specific mechanisms to eliminate defective mRNAs. Numerous noncoding RNAs control mRNA decay in pro‐ and eukaryotes.