Nonsense-mediated mRNA decay in Saccharomyces cerevisiae

Cell survival depends on the precise and correct production of polypeptides . Eukaryotic cells have evolved conserved proofreading mechanisms to get ri d of incomplete and potentially deleterious proteins. The nonsense-mediated mRNA decay (NMD) pathway is an example of a surveillance mechanism that mo nitors premature translation termination and promotes degradation of aberra nt transcripts that code for nonfunctional or even harmful proteins. In thi s review we will describe our current knowledge of the NMD pathway, analyzi ng primarily the results obtained from the yeast Saccharomyces cerevisiae, but establishing functional comparisons with those obtained in higher eukar yotes. Based on these observations, we present two related working models t o explain how this surveillance pathway recognizes and selectively degrades aberrant mRNAs. (C) 2001 Published by Elsevier Science B.V.