Can we extend our lives? A Pioneering Finding in the Genetic Protective Layer by Physicists.

A novel telomeric DNA structure identified by researchers may hold the answer to living longer.

With the help of physics and a small magnet, researchers have identified a new structure for telomeric DNA. Many experts believe that telomeres hold the answer to extending life. They shield genes from harm, although they shrink slightly with each cell division. If they shrink too much, the cell perishes. This ground-breaking discovery will improve our understanding of disease and aging.

Physics is typically not the first branch of knowledge that comes to mind when discussing DNA. But one of the researchers that discovered the novel DNA structure is John van Noort from the Leiden Institute of Physics (LION) in the Netherlands. He conducts biological studies using physics techniques as a biophysicist. He was approached to assist in studying the DNA composition of telomeres by biologists from Nanyan Technological University in Singapore after their attention was also drawn to this. On September 14, the findings were published in the peer-reviewed journal Nature.

Beads on a string:

Our chromosomes, which carry the genes that define our characteristics, are found in every cell of our bodies (what we look like, for instance). Telomeres, which guard the chromosomes against harm, are located at the ends of these chromosomes. They resemble aglets, the plastic tips on shoelace ending.

Figure 1 shows telomeres, a cell, and a chromosome. Leiden University as source.

The two meters of DNA between the telomeres must be folded to fit inside a cell. The DNA is wrapped around the bundles of proteins to do this. The combination of DNA and proteins is referred to as a nucleosome. A nucleosome, a bit of free (or unbound) DNA, a nucleosome, and so on are arranged in a pattern like a string of beads.

The bead string then contracts even further. The length of the DNA between the nucleosomes—the beads on the line—determines how it achieves this. There were already two known post-folding structures. One of them has free DNA hanging in the space between two nearby beads that cling together (figure 2A). The nearby beads fail to bind together if their DNA gap is too small. Then two stacks form side by side (figure 2B).

Van Noort and associates found a new telomere structure in their research. Because the nucleosomes are closer, there is no longer any free DNA between the beads. This culminates forming a single, substantial DNA spiral (figure 2C).

The three various DNA structures are shown in Figure 2. Leiden University as source.

Magnet:

Combining electron microscopy and molecular force spectroscopy, a novel structure was found. The latter method was developed in Van Noort's lab. Here, a tiny magnetic ball adheres to one DNA end connected to a glass slide. The string of pearls is subsequently torn apart by a series of powerful magnets above this ball. You can learn more about how the line is folded by counting how much force is required to separate each bead. The Singaporean researchers then used an electron microscope to grasp the structure better.

Building materials:

Van Noort calls structure "the holy grail of molecular biology." Knowing the design of the molecules will help us understand how genes are activated and inactivated as well as how cellular enzymes deal with telomeres, such as when they repair and copy DNA. Our knowledge of the structural components in the body will be enhanced by finding the new telomeric structure. And ultimately, that will aid in our understanding of aging, diseases like cancer, and the development of medications to treat them.

A chromosome's end contains a stretch of repeating DNA sequences known as a telomere. Chromosome ends are shielded from fraying or tangling by telomeres. The telomeres get a tiny bit shorter each time a cell divides. Eventually, they accelerate to the point where the cell can no longer divide properly and dies. Credit should go to the National Human Genome Research Institute.