Mammalian cells can write RNA sequences into DNA

New discoveries challenge previous views of biology

Mammalian cells can write RNA sequences into DNA

New discoveries challenge the past views of biology New discoveries challenge the past views of biology New discoveries challenge the past views of biologyMammalian cells can write RNA sequences into DNA Mammalian cells can write RNA sequences into DNA

Science and Technology Daily, Beijing, June 15 (Intern reporter Zhang Jiaxin) Researchers at Thomas Jefferson University in Philadelphia, USA, discovered for the first time that mammalian cells can convert RNA sequences back to DNA, which is more common in viruses than in eukaryotic cells
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This discovery may challenge the long-standing views of biology and may have a wide-ranging impact on many areas of biology

Cells contain a mechanism that can copy DNA into a new set of DNA and then enter a newly formed cell
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The machine called polymerase that accomplishes this mechanism can also construct RNA information, which is like notes copied from the recipe center, the DNA repository, so that they can be read into proteins more efficiently

The research team first studied a polymerase called polymerase theta
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Of the 14 DNA polymerases in mammalian cells, only 3 are responsible for most of the work of replicating the entire genome in preparation for cell division

AIDS

In the experiment, the researchers tested the role of polymerase θ and HIV reverse transcriptase
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Studies have shown that polymerase θ can convert RNA information into DNA, which is the same as HIV reverse transcriptase, and it actually does a better job than copying DNA

When researchers used X-ray crystallography to define the structure of a polymerase, they found that this molecule can change shape to fit a larger RNA molecule—a "unique feat" among polymerases
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Studies have shown that the main function of polymerase θ is to act as a reverse transcriptase
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In healthy cells, the purpose of polymerase θ may be to promote RNA-mediated DNA repair; in unhealthy cells such as cancer cells, this molecule is highly expressed and promotes cancer cell growth and drug resistance