These storage cells copy the DNA into a new set and attach it to the newly formed cell. At the same time, this replication machinery (called polymerase) also constructs RNA messages based on notes copied from the central DNA repository. But the polymerase only copies in one direction from DNA to DNA or from DNA to RNA. This prevents RNA messages from being transcribed into the DNA master repository.
Recently, however, researchers at Thomas Jefferson University provided the first evidence that fragments of RNA are converted back into DNA. This will be a major challenge for the bioengineering center and will have major implications for many other areas of biology.
According to Richard Pomerantz, PhD, associate professor of biochemistry and molecular biology at Thomas Jefferson University, “This work opens the door to many other studies that will help us understand the importance of the mechanism by which RNA messages are. converted into DNA in cells. In fact, a human polymerase can do this with greater efficiency. For example, RNA messages can be used as a template. to repair or rewrite the DNA of the gene. ”The study was published June 11 in the journal Science Advances.
With Richard Pomerantz, Gurushankar Chandramouly and others set out to study an unusual polymerase, called theta polymerase. Of the 14 DNA polymerases found in mammalian cells, only three are primarily responsible for duplication of the entire genome for cell division. The remaining 11 DNA polymerases are mainly involved in detecting and repairing errors that occur in DNA strands.
Theta polymerase also repairs DNA errors, but they are prone to errors and mutations. As a result, the researchers found that the “bad” functions of theta polymerase were shared with other cell production machines. Unlike cells, the common substance in viruses that plays a role in reverse transcriptase are enzymes. Like theta polymerase, HIV reverse transcriptase acts like DNA polymerase, which can bind RNA and convert RNA into DNA.
The researchers tested the resistance of theta polymerase against HIV reverse transcriptase. As a result, theta polymerase is able to convert RNA messages to DNA, which like HIV reverse transcriptase does this conversion better than copy DNA to DNA. The use by theta polymerase of the RNA template to convert to DNA also shows better efficiency, less errors than during DNA-to-DNA replication, which also implicitly proves that this is the main function of theta polymerases in the cell.
Dr Pomerantz concluded: “Our study shows that the main function of theta polymerase is to act as a reverse transcriptase. In healthy cells, these molecules are able to repair DNA using RNA. In unhealthy cells, such as cancer cells, theta polymerase is abundant, promoting the growth of cancer cells and drug-resistant cells. Then, how theta polymerase acts on RNA and its role in DNA repair and cancer cell proliferation. “