A New Mechanism for an Old Disease

A study in today's Cell, shows how the loss of E3 ubiquitin ligase can cause Angelman syndrome, a genetic disorder that causes developmental problems in children. More than 10 years ago, researchers found that Angelman was caused by a single gene mutation, but could not explain the mechanism. Harvard's Michael Greenberg and his colleagues found that the loss of Ube3A interferes with the brain's ability to use environmental experiences to fine-tune neuronal circuits. Under normal conditions, the Ube3A enzyme tags cellular proteins, such as the synaptic protein Arc, for destruction. However, with a mutated Ube3A, Arc accumulates to higher-than-normal levels, causing an abnormal lowering of neuronal signaling. This study also connects the mutation to other mental retardation disorders. Based on these findings, the researchers are hoping to find a treatment for Angelman syndrome.