Nonsense-mediated mRNA decay (NMD) is an mRNA degradation pathway that regulates gene expression and mRNA quality. A complex network of macromolecular interactions regulates NMD initiation, which is only partially understood. According to prevailing models, NMD begins by the assembly of the SURF (SMG1-UPF1-eRF1-eRF3) complex at the ribosome, followed by UPF1 activation by additional factors suc...

In Saccharomyces cerevisiae, rapid degradation of nonsense-containing mRNAs requires the decapping enzyme Dcp1p, the 5'-to-3' exoribonuclease Xrn1p, and the three nonsense-mediated mRNA decay (NMD) factors, Upf1p, Nmd2p, and Upf3p. To identify specific functions for the NMD factors, we analyzed the mRNA decay phenotypes of yeast strains containing deletions of DCP1 or XRN1 and UPF1, NMD2, or UP...

Introduction: It has been reported the alkaline response of pancreas to duodenal acidification is partly mediated through duodenal release of H2S, but till now the effect of duodenal acidification on gastric H2S release has not been investigated. Therefore, the present study designed to evaluate the effects of duodenal acidification on gastric H2S release and level of mRNA expression of cys...

1.1. Matching regular semisimple conjugacy classes. Let X(F ) = F × F×, viewed as the space of semisimple conjugacy classes in GL2(F ) via GL2(F ) → X(F ) sending γ 7→ (Tr(γ),det(γ)). Similarly we have D× → X(F ) sending γ′ 7→ (TrD/F (γ),NmD/F (γ′)), where TrD/F and NmD/F mean reduced trace and norm. For regular semisimple γ ∈ GL2(F ) and γ′ ∈ D×, we write γ ∼ γ′ if they have the same image in ...

The history of biomedical research clearly shows that, with exception of a very few, scientific findings could be realised only with the help of animal experiments. Unfortunately, in the past the life of animals was treated negligently and, at times, in fact criminally. Only the researchers' willingness to apply ethical principles toward laboratory animals could create a climate in which resear...

Smg1 is a key component of nonsense-mediated decay (NMD) in Caenorhabditis elegans and mammals. Here we report that two nonsense alleles of the ortholog of Smg1 do not affect NMD in Drosophila melanogaster.

In metazoans, cleavage by the endoribonuclease SMG6 is often the first degradative event in non-sense-mediated mRNA decay (NMD). However, the exact sites of SMG6 cleavage have yet to be determined for any endogenous targets, and most evidence as to the identity of SMG6 substrates is indirect. Here, we use Parallel Analysis of RNA Ends to specifically identify the 5' termini of decay intermediat...

The navigation of axons to their final destination can involve a sequence of steps that require different sets of guidance receptors. In this issue, Colak et al. show that regulated intra-axonal protein synthesis coupled to nonsense-mediated mRNA decay (NMD) controls a switch in Robo3.2 expression that is critical for navigation.

This Commentary discusses new data from the laboratory of Matthias Hentze (Schell et al., in this issue) that begins to dissect the RNA-protein and protein-protein interactions important for the process of nonsense-mediated decay (NMD). Schell and co-workers have developed a novel tool for analysis of such interactions in vivo. Using a proteomics approach, they have identified two different pro...