A fix for RNA

摘要

It has long been known that cells repair chemically or physically damaged DNA. But the discovery that damaged RNA can also be repaired may come as a surprise. What's more, some of the same enzymes are involved. The 'central dogma' of biology states that DNA makes RNA makes protein, and that this relationship governs the flow of genetic information in almost all living organisms. Damage to any one of these molecules can subvert the normal information flow. Because DNA provides the ultimate repository for genetic information, however, and because DNA damage can lead to permanent sequence changes (mutations), the study of how cells repair damaged DNA has prevailed, to the extent that the repair of damaged RNA (and proteins) has been considered unlikely to even exist. This is in part because, unlike the genome, of which there are just two to four copies per cell, RNAs and proteins are present at tens to thousands of copies and are readily replaced. Damaged RNAs and proteins have thus been considered dispensable.