Stressed-DNA repair protein identified
Vera Gorbunova and Andrei Seluanov of the University of Rochester have found that human cells undergoing oxidative stress caused by environmental chemicals or routine cellular processes produce a protein (SIRT6) that stimulates cells to repair DNA double-strand breaks, thought to be associated with premature aging and cancer.
The team first measured levels of SIRT6 in stressed cells, then treated a second group of stressed cells with a drug that deactivates the protein. DNA repair in the second group stopped, confirming SIRT6′s role. The team also found that SIRT6 acts in concert with another protein, called PARP1, to make the repairs.
Furthermore, the team found that increased levels of SIRT6 lead to faster DNA repair. They suspect that the protein acts as a “master regulator,” coordinating stress and DNA repair activities.
Ref.: Zhiyong Mao, Christopher Hine, Xiao Tian, Michael Van Meter, Matthew Au, Amita Vaidya, Andrei Seluanov, and Vera Gorbunova. SIRT6 Promotes DNA Repair Under Stress by Activating PARP1. Science 17 June 2011: 1443-1446. [DOI:10.1126/science.1202723]