The DNA-repair protein BRCA1 is known to increase the risk of breast and ovarian cancer when it is mutated. But the normal protein might also have a central role in Alzheimer's disease.

Elsa Suberbielle and Lennart Mucke at the Gladstone Institute of Neurological Disease in San Francisco, California, and their colleagues lowered BRCA1 protein levels in mouse brains by blocking the BRCA1 gene using a small piece of RNA. They found that some neurons shrank in size and that the animals had a reduced ability to learn and remember their way around a maze. The researchers also showed that BRCA1 levels were depleted in the post-mortem brains of people with Alzheimer's. By looking at this process in cultured neurons and in mice, the authors suggest that BRCA1 is degraded when amyloid-β proteins accumulate in the brain in Alzheimer's disease.

Nature Commun. (2015)