Nonsense-Mediated mRNA Decay in Yeast Does Not Require PAB1 or a Poly(A) Tail

• Published in: Molecular cell Vol. 29; no. 1; pp. 134 - 140
• Main Authors: Meaux, Stacie, van Hoof, Ambro, Baker, Kristian E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 18.01.2008
• Subjects: Codon, Nonsense; DNA; Galactokinase - genetics; Genes, Reporter; Genes, Synthetic; Green Fluorescent Proteins - genetics; Open Reading Frames - genetics; Poly(A)-Binding Proteins - physiology; Recombinant Fusion Proteins - genetics; RNA Stability - physiology; RNA, Catalytic - genetics; RNA, Messenger - physiology; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - physiology; DNA
• ISSN: 1097-2765; 1097-4164
• DOI: 10.1016/j.molcel.2007.10.031

Eukaryotic mRNAs harboring premature translation termination codons are recognized and rapidly degraded by the nonsense-mediated mRNA decay (NMD) pathway. The mechanism for discriminating between mRNAs that terminate translation prematurely and those subject to termination at natural stop codons remains unclear. Studies in multiple organisms indicate that proximity of the termination codon to the 3′ poly(A) tail and the poly(A) RNA-binding protein, PAB1, constitute the critical determinant in NMD substrate recognition. We demonstrate that mRNA in yeast lacking a poly(A) tail can be destabilized by introduction of a premature termination codon and, importantly, that this mRNA is a substrate of the NMD machinery. We further show that, in cells lacking Pab1p, mRNA substrate recognition and destabilization by NMD are intact. These results establish that neither the poly(A) tail nor PAB1 is required in yeast for discrimination of nonsense codon-containing mRNA from normal by NMD.