Cells getting them right is important in preventing disease:
In Science, Michael R. Lawson and six colleagues play the role of forensic investigators, figuring out what goes wrong when mRNA transcripts run a red light, so to speak. Their paper, “Mechanisms that ensure speed and fidelity in eukaryotic translation termination,” begins with a statement of the law: “How Translation Stops.” It includes a shocking statistic:
Protein synthesis concludes when a ribosome encounters a stop codon in a transcript, which triggers the recruitment of highly conserved release factors to liberate the protein product. Lawson et al. used traditional biochemical methods and single-molecule fluorescence assays to track the interplay of release factors with ribosomes and reveal the molecular choreography of termination. They identified two distinct classes of effectors, small molecules and mRNA sequences, that directly inhibited the release factors and promoted stop codon readthrough. These findings may buttress ongoing efforts to treat diseases caused by premature stop codons, which cause 11% of all heritable human diseases.
The diseases include “cystic fibrosis, muscular dystrophy, and hereditary cancers.” Correct translation termination is a vital process, therefore, occurring constantly in every cell; it “must occur rapidly and accurately.”
Evolution News, “The Stop Lights in the Cell” at Evolution News and Science Today
The paper is closed access.
All that stuff just sort of clumped together a long time ago and happened to work, right? Just like traffic signals.