Researchers at the University of Mainz and the Institute for Molecular Biology (Germany) have found that a type of RNA called TERRA is capable of repairing telomeres. Thanks to this mechanism, premature cell aging is blocked. Scientists published the results of their research in the Cell.
Telomeres are regions located at the ends of chromosomes that are made up of repetitive sequences of nucleotides that do not encode a protein. Telomeres are shortened in the process of DNA copying. This process, according to scientists, is one of the main causes of premature biological aging. When these sections become too short, the cell can no longer divide. On the other hand, the same phenomenon is a defense against cancer (if it were not so, malignant cells could multiply indefinitely).
According to experts, there is a well-regulated mechanism for maintaining a balance between preventing malignancy and maintaining telomere length. The researchers have established how the process of recognition and repair of the shortened ends of chromosomes in yeast occurs.
It was found that in the absence of an enzyme that repairs telomeres (telomerase), RNA molecules that do not encode a protein (TERRA) begin to attach to the shortened telomeres, triggering reactions to damage to the DNA molecule. In addition, RNA binds to long telomeres, but they are rapidly removed by the RNase H2 and Rat1 proteins.
The presence of TERRA is characteristic not only for yeast, but also for other organisms, including humans. Therefore, the researchers intend to begin studying the functions of RNA in human cells.
