Cells age because of long-lived proteins
Biologists have called eternal proteins the cause of cell aging
Leonid Popov, Membrane, based on Salk News:
Discovery of extremely long-lived proteins may provide insight into cell aging and neurodegenerative diseasesOne of the important causes of cell aging, paradoxical as it may sound, turned out to be the presence of proteins with an extremely long lifespan in it.
The discovery provides new clues to the mechanism of aging, as well as to the emergence of neurodegenerative diseases.
Researchers from the Salk Biological Institute found that proteins of the same age as the animal itself are present on the surface of the nucleus of neurons taken from the brain of an adult rat (in this experiment – more than a year).
This is an amazing moment, because polypeptides in the cell exist mostly for a very short time. They change their shape, get damaged and disintegrate, and therefore are regularly replaced with new copies. The lifespan of most of the proteins inside the cell is only a few days, and some even hours or even minutes.
Extremely long-lived ELLP proteins (extremely long–lived proteins - VM), found by Martin Hetzer's group, work all the life of the body without replacement. And scientists called this not an advantage, but the Achilles' heel of the cell.
The fact is that ELLPS are part of the Nuclear Pore Complex (NPC). These are complex gates, consisting of about 30 proteins. Nuclear pores are responsible for the transport of substances from the nucleus to the cytoplasm and back.
Extremely long-lived proteins (glow green) on the surface of the nuclei of rat brain cells.
DNA is marked in blue (photo by Brandon Toyama, Salk Institute for Biological Studies).
Deviations in the ELLP structure, accumulating due to chemical or other damage, lead to disruption of the functions of nuclear pores. And because of this, the latter, according to Professor Hetzer, begin to pass toxins inside the nucleus that can affect DNA. As a result, the activity of genes changes, and the normal operation of the cell is disrupted.
The discovery should contribute to a better understanding of the molecular causes of aging and also Alzheimer's and Parkinson's diseases. Martin believes that both the aging of the cell (hence the body) and neurodegenerative diseases are largely to blame for the failures in the work of the NPC caused by the amazing fact that non-replaceable molecules are present in this complex.
Details of the study can be found in the article in Science: Savas et al., Extremely Long-Lived Nuclear Pore Proteins in the Rat Brain.
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06.02.2012