一项研究发现了裸鼹鼠不同寻常的长寿的分子线索。裸鼹鼠的寿命大约是同样尺寸的其他啮齿动物的10倍，而且能抵御通常大多数动物因衰老而增加的脆弱性。
Vera Gorbunova及其同事研究了裸鼹鼠的细胞蛋白质制造机——核糖体，因为此前已经发现蛋白质翻译的改变涉及了几种生物的衰老。蛋白质翻译是核糖体根据RNA模板合成蛋白质的过程。这组作者发现，裸鼹鼠的28S核糖体RNA（rRNA）——它是真核生物核糖体的结构组件之一——出现了一个不寻常的分裂，变成了尺寸不同的两个片段，而小鼠的rRNA没有出现这种情况。
这组作者报告说，尽管存在这些结构差异，裸鼹鼠核糖体的翻译率类似于小鼠。相比之下，来自裸鼹鼠的细胞比小鼠细胞有更高的蛋白质翻译保真度，即便在裸鼹鼠细胞被迫以超过正常的速度生长的情况下也是如此。这组作者说，这些发现提示这种28S rRNA的结构可能增加蛋白质翻译的保真度，这可能对于这种动物的长寿有贡献。（生物谷Bioon.com）
生物谷推荐英文摘要：
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.
