Structures Of Naked Mole-Rat, Tuco-Tuco, And Guinea Pig Ribosomes-Is Rrna Fragmentation Linked To Translational Fidelity?
Scientists have long been fascinated by the remarkable longevity and disease resistance of certain animals, like the naked mole-rat and tuco-tuco. A key area of investigation is how these creatures maintain healthy cells over their long lives. One intriguing clue lies in their ribosomes, the tiny cellular machines responsible for building all the proteins our bodies need.
In most mammals, a crucial component of these ribosomes, called 28S ribosomal RNA (rRNA), is a single, continuous molecule. However, in naked mole-rats and tuco-tucos, this rRNA is surprisingly fragmented into smaller pieces. Despite this unusual fragmentation, these animals exhibit exceptionally high “translational fidelity,” meaning their ribosomes are very accurate at translating genetic instructions into proteins, leading to fewer errors in protein production.
Using a powerful imaging technique called cryo-electron microscopy, researchers investigated the detailed structures of these unique ribosomes. They discovered that even with fragmented rRNA, the core functional architecture of the naked mole-rat and tuco-tuco ribosomes remains intact. However, compared to a typical rodent like the guinea pig, which has unfragmented rRNA, the ribosomes of the long-lived species showed some differences in flexible regions known as expansion segments.
These findings suggest that the fragmented rRNA might not disrupt the ribosome’s fundamental operation but could instead introduce subtle changes in its dynamics. These subtle alterations may enhance the accuracy of protein synthesis, potentially contributing to the naked mole-rat and tuco-tuco’s ability to maintain a more stable and functional set of proteins throughout their extended lifespans. This research offers new insights into the complex mechanisms that underpin longevity and cellular health.
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