Although it is frequently assumed that translation does not occur in eukaryotic nuclei, recent evidence suggests that some translation can take place and that it is closely coupled to transcription. The first evidence concerns the destruction of nuclear mRNAs containing premature termination codons by nonsense-mediated decay (NMD). Only ribosomes can detect termination codons, and as some NMD o...

Among the different cellular surveillance mechanisms that ensure accurate gene expression, nonsense-mediated mRNA decay rapidly degrades mRNAs harbouring PTCs (premature translation-termination codons) and thereby prevents the accumulation of potentially deleterious proteins with C-terminal truncations. In the present article, I review recent data from yeast, fluitflies, nematode worms and huma...

Translational stop codons were introduced at various locations in the protein-coding regions of the monocistronic bla and ompA gene transcripts of Escherichia coli, and the decay characteristics of the upstream and downstream mRNA segments were analyzed. Premature termination of translation at codon position 26 reduced the stability of both the translated and ribosome-free segments of bla mRNA,...

Codon usage biases are found in all genomes and influence protein expression levels. The codon usage effect on protein expression was thought to be mainly due to its impact on translation. Here, we show that transcription termination is an important driving force for codon usage bias in eukaryotes. Using Neurospora crassa as a model organism, we demonstrated that introduction of rare codons res...

Translation is an important mechanism to monitor the quality of messenger RNAs (mRNAs), as exemplified by the translation-dependent recognition and degradation of transcripts harboring premature termination codons (PTCs) by the nonsense-mediated mRNA decay (NMD) pathway. We demonstrate in yeast that mRNAs lacking all termination codons are as labile as nonsense transcripts. Decay of "nonstop" t...

OBJECTIVES Haemostasis prevents blood loss following vascular injury. It depends on the unique concert of events involving platelets and specific blood proteins, known as coagulation factors. The clotting system requires precise regulation and coordinated reactions to maintain the integrity of the vasculature. Clotting insufficiency mostly occurs due to genetically inherited coagulation factor ...

In phage P4, transcription of the left operon may occur from both the constitutive PLE promoter and the regulated PLL promoter, about 400 nucleotides upstream of PLE. A strong Rho-dependent termination site, timm, is located downstream of both promoters. When P4 immunity is expressed, transcription starting at PLE is efficiently terminated at timm, whereas transcription from PLL is immunity ins...

Nonsense-mediated mRNA decay (NMD) is a cellular surveillance pathway that recognizes and degrades mRNAs with premature termination codons (PTCs). The mechanisms underlying translation termination are key to the understanding of RNA surveillance mechanisms such as NMD and crucial for the development of therapeutic strategies for NMD-related diseases. Here, we have used a fully reconstituted in ...

Terminating protein translation accurately and efficiently is critical for both protein fidelity and ribosome recycling for continued translation. The three bacterial release factors (RFs) play key roles: RF1 and 2 recognize stop codons and terminate translation; and RF3 promotes disassociation of bound release factors. Probing release factors mutations with reporter constructs containing progr...