Research Frontiers

Dr. Ron Kopito and Dr. Brigit Riley

Autophagy, or “self-eating”

While Dr. Kopito’s lab focuses mainly on the role of the proteosome in HD, some members of his lab look at other mechanisms that the cell uses to break down and clear out unwanted proteins. Christina and Justine met with Dr. Brigid Riley, a post-doctoral student in the Kopito lab who studies a process known as autophagy, and how it is involved in HD. Autophagy literally means “self-eating”. In autophagy, the cell’s membrane encircles organelles, proteins, and parts of the cytoplasm into spheres called vesicles. These vesicles are sent to a part of the cell called the lysosome to release their contents. Then, proteins in the lysosome degrade the contents of the vesicles . See Figure 1 below). Both the proteosome and autophagy are methods the cell has to recycle proteins. But, there are some important differences between the two processes. While the proteosome can selectively target certain proteins that are supposed to live for a short period of time, autophagy is used to digest large organelles and long-lived proteins, and it cannot select for certain proteins.

Figure 1

Autophagy has many purposes in the cell. During development, it helps the cell take up amino acids. If the cell is starving and does not have enough nutrients or energy, autophagy is used to recycle unnecessary proteins to make more important proteins. Autophagy can also be used to defend the cell against invading bacteria or viruses. It is also thought to play a protective role against the progression of human diseases like cancer, Alzheimer's disease, Parkinson’s disease, and HD. (For more on other neurodegenerative and related diseases, click here.

Last Modified: 01/22/2008

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