By Rob O’Brien

Huntington’s disease (HD) is a genetic disorder that affects roughly 1 in 10,000 Americans. While the genetic basis of the disease was identified in 1993, there are still gaps in our understanding of what the protein that causes the disease (called, appropriately, Huntingtin) does in healthy people. The protein is ubiquitous (it is present in all of the tissues of the body) and is essential (meaning that mice without the protein do not survive).

Last week, researchers at UC Irvine published results showing that there is a portion of the huntingtin protein not associated with the disease that can physically stick to some fragments of the protein that is associated with the disease. This newly characterized portion of the protein seems to be important for the process of autophagy (literally “self-eating”), a process by which cells get rid of damaged organelles and proteins and which is known to be important for healthy aging. So why is this exciting? Sticky aggregates of the huntingtin protein can be removed by two processes: autophagy and via the proteasome. Autophagy is disrupted in neurodegenerative diseases in general, and Huntington’s disease specifically.

Crystallographic structure of the N-terminal region of the human Huntingtin protein.

Crystallographic structure of the N-terminal region of the human Huntingtin protein.

So what does this mean for neurodegenerative disorders of aging? Well, this new function of a protein implicated in a major neurodegenerative disease may give us clues about what is going wrong in this disease, as well as others that show similar dysregulation of the autophagy system. This means that investigation of how to increase or fix autophagy in Huntington’s disease, possibly by changing the activity of the portion of the protein important for autophagy, may be beneficial for more than just HD.