Scientists have discovered a protein that can directly halt DNA damage. Better yet, a new study shows it appears to be ‘plug and play’, theoretically able to slot into any organism, making it a promising candidate for a cancer vaccine.
DNA damage response protein C (DdrC) was found in a hardy little bacterium called Deinococcus radiodurans. DdrC seems to be very effective at detecting DNA damage, putting a stop to it and alerting the cell to start the repair process.
But DdrC’s best feature might be that it’s pretty self-contained, doing its job without the help of other proteins.
Every cell has a DNA repair mechanism to fix damage. “With a human cell, if there are any more than two breaks in the entire billion base pair genome, it can’t fix itself and it dies,” he says. “But in the case of DdrC, this unique protein helps the cell to repair hundreds of broken DNA fragments into a coherent genome.”
Turns out that DdrC scans for breaks along the DNA and when it detects one it snaps shut – like a mousetrap. This trapping action has two key functions: “It neutralizes it (the DNA damage), and prevents the break from getting damaged further. And it acts like a little molecular beacon. It tells the cell ‘Hey, over here. There’s damage. Come fix it.”
The team was curious whether the protein might function as a “plug-in” for other DNA repair systems. They tested this by adding it to a different bacterium: E. coli. “To our huge surprise, it actually made the bacterium over 40 times more resistant to UV radiation damage,” he says. “This seems to be a rare example where you have one protein and it really is like a standalone machine.”
He says that, in theory, this gene could be introduced into any organism – plants, animals, humans – and it should increase the DNA repair efficiency of that organism’s cells. “The ability to rearrange and edit and manipulate DNA in specific ways is the holy grail in biotechnology,” says Szabla. “What if you had a scanning system such as DdrC which patrolled your cells and neutralized damage when it happened? This might form the basis of a potential cancer vaccine.”
And here’s the actual study (pretty deep science - hard to interpret).