New Discovery - Human cells can write RNA into DNA


Well-known member
  • Mar 29, 2017
    Till now it was known that our cell machinery can duplicate the DNA to form a new cell, and also use a DNA sequence to transcribe an RNA molecule to generate a protein. The polymerases which did this process worked was believed to work only one way - ie. DNA into DNA or DNA into RNA.

    Now, in a major twist, turning everything upside down, scientists have found evidence of reverse transcription, in which RNA molecules get written as DNA, in mammalian cells.
    This came into the picture when the scientists were studying the unusual polymerase - Polθ.

    Out of the 14 DNA polymerases in mammalian cells, only 3 do the bulk of the work of replicating the genome before the cell divides. the other 11 mainly detect errors and make repairs when the double-stranded helix nicks, breaks or incorporates a base it should not have.
    Polθ repairs DNA, but not very well, its carelessness resulting in many errors or mutations in its repair efforts. This made the scientists to study on this to find out more. Eventually they found that Polθ is more efficient and accurate when using an RNA template to write new DNA messages, than when duplicating DNA, suggesting that this function may be its primary cellular function.

    A team at Thomas Jefferson University made this finding and here's the statement....
    "Our research suggests that polymerase theta's main function is to act as a reverse transcriptase," says Dr. Pomerantz. "In healthy cells, the purpose of this molecule may be toward RNA-mediated DNA repair. In unhealthy cells, such as cancer cells, polymerase theta is highly expressed and promotes cancer cell growth and drug resistance. It will be exciting to further understand how polymerase theta's activity on RNA contributes to DNA repair and cancer-cell proliferation."

    Full research article....
    "Polθ reverse transcribes RNA and promotes RNA-templated DNA repair"

    PS: I mentioned about Polθ on another post by @Stimulus mind♋💊-new-drugs-could-treat-cancers-with-mutated-brca-genes-💊♋.1996736/#post-26606053
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