SEPTEMBER 15, 2022
Can we live longer? Physicist makes discovery about telomeres
by Dagmar Aarts, Leiden University
With the aid of physics and a minuscule magnet, researchers have discovered a new structure of telomeric DNA. Telomeres are sometimes seen as the key to living longer. They protect genes from damage but get a bit shorter each time a cell divides. If they become too short, the cell dies. The new discovery will help us understand aging and disease.
Physics is not the first scientific discipline that springs to mind at the mention of DNA. But John van Noort from the Leiden Institute of Physics (LION) is one of the scientists who found the new DNA structure. A biophysicist, he uses methods from physics for biological experiments. This also caught the attention of biologists from Nanyan Technological University in Singapore. They asked him to help study the DNA structure of telomeres. They have published the results in Nature.
String of beads
In every cell of our bodies are chromosomes that carry genes that determine our characteristics (what we look like, for instance). At the ends of these chromosomes are telomeres, which protect the chromosomes from damage. They're a bit like aglets, the plastic tips at the end of a shoelace.
The DNA between the telomeres is two meters long, so it has to be folded to fit in a cell. This is achieved by wrapping the DNA is wrapped around packages of proteins; together, the DNA and proteins are called a nucleosome. These are arranged into something similar to a string of beads, with a nucleosome, a piece of free (or unbound) DNA, a nucleosome and so on.
This string of beads then folds up even more.