Abstract
Nonsense-mediated messenger RNA decay (NMD) represents one of the main surveillance pathways used by eukaryotic cells to control the quality and abundance of mRNAs and to degrade viral RNA. NMD recognises mRNAs with a premature termination codon (PTC) and targets them to decay. Markers for a mRNA with a PTC, and thus NMD, are a long a 3′-untranslated region and the presence of an exon-junction complex (EJC) downstream of the stop codon. Here, we review our structural understanding of mammalian NMD factors and their functional interplay leading to a branched network of different interconnected but specialised mRNA decay pathways. We discuss recent insights into the potential impact of EJC composition on NMD pathway choice. We highlight the coexistence and function of different isoforms of up-frameshift protein 1 (UPF1) with an emphasis of their role at the endoplasmic reticulum and during stress, and the role of the paralogs UPF3B and UPF3A, underscoring that gene regulation by mammalian NMD is tightly controlled and context-dependent being conditional on developmental stage, tissue and cell types.
Original language | English |
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Pages (from-to) | 973-993 |
Number of pages | 21 |
Journal | Biochemical Journal |
Volume | 479 |
Issue number | 9 |
Early online date | 12 Apr 2022 |
DOIs | |
Publication status | Published - 12 May 2022 |
Bibliographical note
Funding Information:We would like to thank Drs. Kyle Powers, George Orriss, Sathish Yadav Kadapalakere, Lingling Sun, and Jenn-Yeu Alvin Szeto for discussing the manuscript, critical reading and helpful comments. C.S. is Investigator of the Wellcome Trust (210701/Z/18/Z). M.V.V. and C.S. acknowledge support by a Marie Sklodowska-Curie Fellowship from the EC (101024558). For the purpose of Open Access, the authors have applied a CC BY public copyright license to any Author Accepted Manuscript version arising from this submission.
Publisher Copyright:
© 2022 The Author(s)
Keywords
- Nonsense-mediated mRNA decay
- up-frameshift proteins
- exon-junction complexes
- SMG proteins
- cellular stress response
- X-ray crystallography
- cryogenic electron microscopy