Suspect protein promotes DNA repair

Researchers from the MD Anderson Cancer Centre in Texas have found a protein suspected of blocking DNA repair might actually enhance it.

The protein, HMGB1, is an abundant chromosomal protein that attaches to sites of damaged DNA and was suspected of preventing repair. It also has a role in inflammation and is being targeting in drug development for rheumatoid arthritis.

The researchers, led by Karen Vasquez and Sabine Lange, tracked the protein's activity in the three steps of DNA restoration: access to damage, repair and repackaging of chromatin.

They found evidence that HMGB1 works by summoning other DNA repair factors to the damaged site. They also found the presence of the protein resulted in a much higher rate of chromatin re-assembly in damaged cells.

"Our findings suggest that depleting this protein may leave patients more vulnerable to developing cancer," Vasquez said.

The findings were reported online this week in the US Proceedings of the National Academies of Science.