Nonsense-mediated mRNA decay (NMD), which is arguably the best-characterized translation-dependent regulatory pathway in mammals, selectively degrades mRNAs as a means of post-transcriptional gene control. Control can be for the purpose of ensuring the quality of gene expression. Alternatively, control can facilitate the adaptation of cells to changes in their environment. The key to NMD, no matter what its purpose, is the ATP-dependent RNA helicase upstream frameshift 1 (UPF1), without which NMD fails to occur. However, UPF1 does much more than regulate NMD. As examples, UPF1 is engaged in functionally diverse mRNA decay pathways mediated by a variety of RNA-binding proteins that include staufen, stem–loop-binding protein, glucocorticoid receptor, and regnase 1. Moreover, UPF1 promotes tudor-staphylococcal/ micrococcal-like nuclease-mediated microRNA decay. In this review, we first focus on how the NMD machinery recognizes an NMD target and triggers mRNA degradation. Next, we compare and contrast the mechanisms by which UPF1 functions in the decay of other mRNAs and also in microRNA decay. UPF1, as a protein polymath, engenders cells with the ability to shape their transcriptome in response to diverse biological and physiological needs.
Bibliographical noteFunding Information:
We thank Max Popp, Tatsuaki Kurosaki, Incheol Ryu, and Joori Park for comments on the manuscript, and Bill Marzluff for a helpful email. We apologize to colleagues whose work was not cited due to length limitations. This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIP; NRF-2015R1A3A2033665 and NRF-2018R1A5A1024261 to Y.K.K.), and a Korea University grant to Y.K.K. Work on NMD, SMD, TumiD, and other functions of UPF1 in the Maquat laboratory is funded by National Institutes of Health R01 GM059614 and R37 GM074593 to L.E.M.
© 2019 Kim and Maquat.
- Nonsense-mediated mRNA decay
- Staufen-mediated mRNA decay
ASJC Scopus subject areas
- Molecular Biology