一項研究發(fā)現(xiàn)了裸鼴鼠不同尋常的長壽的分子線索。裸鼴鼠的壽命大約是同樣尺寸的其他嚙齒動物的10倍,，而且能抵御通常大多數(shù)動物因衰老而增加的脆弱性,。
Vera Gorbunova及其同事研究了裸鼴鼠的細(xì)胞蛋白質(zhì)制造機(jī)——核糖體，因為此前已經(jīng)發(fā)現(xiàn)蛋白質(zhì)翻譯的改變涉及了幾種生物的衰老,。蛋白質(zhì)翻譯是核糖體根據(jù)RNA模板合成蛋白質(zhì)的過程。這組作者發(fā)現(xiàn),，裸鼴鼠的28S核糖體RNA（rRNA）——它是真核生物核糖體的結(jié)構(gòu)組件之一——出現(xiàn)了一個不尋常的分裂,，變成了尺寸不同的兩個片段，而小鼠的rRNA沒有出現(xiàn)這種情況,。
這組作者報告說,，盡管存在這些結(jié)構(gòu)差異，裸鼴鼠核糖體的翻譯率類似于小鼠,。相比之下,，來自裸鼴鼠的細(xì)胞比小鼠細(xì)胞有更高的蛋白質(zhì)翻譯保真度，即便在裸鼴鼠細(xì)胞被迫以超過正常的速度生長的情況下也是如此,。這組作者說,，這些發(fā)現(xiàn)提示這種28S rRNA的結(jié)構(gòu)可能增加蛋白質(zhì)翻譯的保真度，這可能對于這種動物的長壽有貢獻(xiàn),。（生物谷Bioon.com）
生物谷推薦英文摘要：
PNAS doi: 10.1073/pnas.1313473110
Naked mole-rat has increased translational fidelity compared with the mouse, as well as a unique 28S ribosomal RNA cleavage
The naked mole-rat (Heterocephalus glaber) is a subterranean eusocial rodent with a markedly long lifespan and resistance to tumorigenesis. Multiple data implicate modulation of protein translation in longevity. Here we report that 28S ribosomal RNA (rRNA) of the naked mole-rat is processed into two smaller fragments of unequal size. The two breakpoints are located in the 28S rRNA divergent region 6 and excise a fragment of 263 nt. The excised fragment is unique to the naked mole-rat rRNA and does not show homology to other genomic regions. Because this hidden break site could alter ribosome structure, we investigated whether translation rate and amino acid incorporation fidelity were altered. We report that naked mole-rat fibroblasts have significantly increased translational fidelity despite having comparable translation rates with mouse fibroblasts. Although we cannot directly test whether the unique 28S rRNA structure contributes to the increased fidelity of translation, we speculate that it may change the folding or dynamics of the large ribosomal subunit, altering the rate of GTP hydrolysis and/or interaction of the large subunit with tRNA during accommodation, thus affecting the fidelity of protein synthesis. In summary, our results show that naked mole-rat cells produce fewer aberrant proteins, supporting the hypothesis that the more stable proteome of the naked mole-rat contributes to its longevity.
