New discovery denied the foundations of modern cell biology16 октября, 2021
For cell reproduction, the mechanism of synthesis of polymers of nucleic acids is used. It is believed that the DNA polymerase and RNA-polymerase enzymes act in only one direction: copy DNA to DNA or RNA. This prevents the introduction of unnecessary corrections to the «cookbook» of the genome. However, researchers from the United States found the first evidence that RNA segments can be recorded back to DNA. This discovery can affect the set of biology areas. In particular, this may mean that RNA messages can be used as a template for repair or rewrite DNA genome.
The team of Professor Richard Pomeranian from the University of Thomas Jefferson explored an unusual teta-polymerase. Of the 14 DNA polymerazs in mammalian cells, only three perform most of the work on copying the entire genome when preparing for cell division. The remaining 11 is mainly engaged in searching and troubleshooting DNA chains. Theta polymerase is rotating DNA, but it makes many mistakes,
Scientists noticed that some of these errors appear in another cellular mechanism, more common in viruses — in reverse transcriptase. After conducting a series of elegant experiments, they checked theta polymerase on reverse transcriptase with HIV. And they proved that theta polymerase is able to convert RNA messages to DNA, and it copes better with it than when copies DNA to DNA.
It turned out to be more efficient and did less errors when used RNA template to record new DNA messages than when DNA was dunted. It can be assumed that this is its basic function in the cell.
«Our study indicates that the main function of theta polymerase is reverse transcriptase,» said Pomeranz. In healthy cells, the purpose of this molecule is the repair of DNA with RNA. In patients, for example, in cancer, theta polymerase ensures the growth of tumor cells and the resistance to drugs.
Scientists from the USA
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