Genome complexity: RNA helps repair DNA breaks (Introduction)

by David Turell , Friday, June 09, 2017, 22:30 (2514 days ago) @ David Turell

It also involves a specialized protein:

https://www.sciencedaily.com/releases/2017/06/170608123648.htm

"Drexel University and Georgia Institute of Technology researchers have discovered how the Rad52 protein is a crucial player in RNA-dependent DNA repair. The results of their study, published in Molecular Cell, reveal a surprising function of the homologous recombination protein Rad52. They also may help to identify new therapeutic targets for cancer treatment.

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"Alexander Mazin, PhD, a professor at Drexel University's College of Medicine, and Francesca Storici, PhD, an associate professor at Georgia Tech, have dedicated their research to studying mechanisms and proteins that promote DNA repair.

"In 2014, Storici and Mazin made a major breakthrough when they discovered that RNA can serve as a template for the repair of a DNA double-strand break in budding yeast, and Rad52, a member of the homologous recombination pathway, is an important player in that process.
"We provided evidence that RNA can be used as a donor template to repair DNA and that the protein Rad52 is involved.'"

"In their current study, the research team uncovered the unusual, important role of Rad52: It promotes "inverse strand exchange" between double-stranded DNA and RNA, meaning that the protein has a novel ability to bring together homologous DNA and RNA molecules. In this RNA-DNA hybrid, RNA can then be used as a template for accurate DNA repair.

"It appeared that this ability of Rad52 is unique in eukaryotes, as otherwise similar proteins do not possess it.

"'Strikingly, such inverse strand exchange activity of Rad52 with RNA does not require extensive processing of the broken DNA ends, suggesting that RNA-templated repair could be a relatively fast mechanism to seal breaks in DNA," Storici said.

"As a next step, the researchers hope to explore the role of Rad52 in human cells."

Comment: Once again a complex protective mechanism to maintain DNA integrity. Must have been present since the origin of life as reproducibility of accurate DNA copies is ital. for life to continue once originated.