RNA Quality Control
RNA can accumulate mutations through transcription of mutated DNA, through errors in transcription of wild-type DNA, or through damage to the RNA itself from mutagens. Some mutant or damaged mRNAs cause stalls in translation elongation or termination. Eukaryotic cells have developed several RNA quality control mechanisms that trigger the decay of such mRNAs. Without these surveillance mechanisms, the cell would produce mutant proteins or would lose ribosomes that remained stalled on aberrant transcripts. While this section focuses on quality control of mRNA, mRNA represents a fraction of the RNA in a cell and other RNAs are also subject to quality control.
It has long been appreciated that DNA can be damaged by mutagens and that extensive repair pathways exist to repair damaged DNA. Many of the same agents that damage DNA also damage RNA. RNA is more...