Both introns and long 3'-UTRs operate as cis-acting elements to trigger nonsense-mediated decay in plants

• Published in: Nucleic acids research Vol. 34; no. 21; pp. 6147 - 6157
• Main Authors: Kertész, Sándor, Kerényi, Zoltán, Mérai, Zsuzsanna, Bartos, Imre, Pálfy, Tamás, Barta, Endre, Silhavy, Dániel
• Format: Journal Article
• Language: English
• Published: England Oxford Publishing Limited (England) 01.12.2006; Oxford University Press
• Subjects: 3' untranslated regions; 3' Untranslated Regions - chemistry; 5' Untranslated Regions - chemistry; ancestry; Arabidopsis - genetics; Arabidopsis Proteins - physiology; Codon, Nonsense; Decay; eukaryotic cells; Gene Expression Regulation, Plant; Introns; Mammals; Quality control; Regulatory Sequences, Ribonucleic Acid; Rhizobium - genetics; RNA; RNA Helicases - physiology; RNA, Messenger - metabolism; stop codon; Yeasts
• ISSN: 0305-1048; 1362-4962; 1362-4962
• DOI: 10.1093/nar/gkl737

Nonsense-mediated mRNA decay (NMD) is a eukaryotic quality control mechanism that identifies and eliminates aberrant mRNAs containing a premature termination codon (PTC). Although, key trans-acting NMD factors, UPF1, UPF2 and UPF3 are conserved in yeast and mammals, the cis-acting NMD elements are different. In yeast, short specific sequences or long 3'-untranslated regions (3'-UTRs) render an mRNA subject to NMD, while in mammals' 3'-UTR located introns trigger NMD. Plants also possess an NMD system, although little is known about how it functions. We have elaborated an agroinfiltration-based transient NMD assay system and defined the cis-acting elements that mediate plant NMD. We show that unusually long 3'-UTRs or the presence of introns in the 3'-UTR can subject mRNAs to NMD. These data suggest that both long 3'-UTR-based and intron-based PTC definition operated in the common ancestors of extant eukaryotes (stem eukaryotes) and support the theory that intron-based NMD facilitated the spreading of introns in stem eukaryotes. We have also identified plant UPF1 and showed that tethering of UPF1 to either the 5'- or 3'-UTR of an mRNA results in reduced transcript accumulation. Thus, plant UPF1 might bind to mRNA in a late, irreversible phase of NMD.