A September 30 report from the University of Rochester, New York, offered an interesting explanation for the longevity of naked mole rats which, with a lifespan of 30 years, makes the animal the world’s longest-living rodent: more robustly constructed proteins. The results of the study, conducted by Rochester biologists Vera Gorbunova and Andrei Seluanov, appear in the latest issue of the Proceedings of the National Academy of Sciences.
Proteins are essential to the survival of all organisms, as they are involved in virtually all functions of an animal cell. However, proteins must fold into the appropriate shapes that allow them to connect and to interact with other cellular structures. In the naked mole rat, that process leads to near-perfect protein production.
“While this is basic research,” said Gorbunova, “we hope our findings encourage further studies on better protein synthesis.”
Gorbunova and Seluanov’s work focused on analysis of naked mole rat ribosomes, and the discovery emerged by coincidence. While working with ribosome RNA, the biologists found that, after applying dye to a sample and studying it under UV light, three dark bands appeared – which represented concentrations of different rRNA molecules – instead of the two bands that are characteristic of other animals. This suggested the presence of a “hidden break” in the naked mole rat rRNA, so the biologists decided to investigate the potential effects on the quality of the rodent’s proteins.
Gorbunova and Seluanov discovered that the naked mole rat’s rRNA structure is unique. The rRNA strands split at two specific locations and dispose of the intervening segment. Instead of floating off on their own, the two lingering pieces from each strand stay close to each other and act as a scaffold on which ribosomal proteins are assembled to create a functional ribosome.
During the process of the ribosome connecting amino acids together to create a protein, a gaffe sometimes occurs when an incorrect amino acid is inserted. However, the biologists discovered that the proteins produced by naked mole rat cells are roughly 40 times less likely to harbor such mistakes than the proteins made by mouse cells.
“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,” wrote the researchers in the study’s abstract.
“This is important because proteins with no aberrations help the body to function more efficiently,” said Seluanov.
On the path ahead, the biologists want to split mouse rRNA in the same way to discover whether it would lead to improved protein creation. Eventually, the biologists hope that their work will result in pharmaceutical treatments that control protein synthesis in humans. However, the biologists contend that any medical solution is a distant possibility.