Two biologists at Penn State have discovered a master regulator that controls metabolic responses to a deficiency of essential amino acids in the diet. They also discovered that this regulatory substance, an enzyme named GCN2 eIF2alpha kinase, has an unexpectedly profound impact on fat metabolism. "Some results of our experiments suggest interventions that might help treat obesity, prevent Type II diabetes and heart attacks, or ameliorate protein malnutrition," said Douglas Cavener, professor and head of the Department of Biology, who led the research along with Feifan Guo, a research assistant professor. Their research will appear in the 7 February 2007 issue of the scientific journal Cell Metabolism.
Organisms adapt metabolically to episodes of malnutrition and starvation by shutting down the synthesis of new proteins and fats and by using stores of these nutrients from muscle, fat, and the liver in order to continue vital functions. Cavener and Guo found that the removal of a single amino acid, leucine, from the diet is sufficient to provoke a starvation response that affects fat metabolism. "These findings are important for treating two major problems in the world," Cavener says. "The starvation response we discovered can repress fat synthesis and induce the body to consume virtually all of its stored fat within a few weeks of leucine deprivation. Because this response causes a striking loss of fatty tissue, we may be able to formulate a powerful new treatment for obesity."
The second problem is not excess food intake but insufficient protein intake, which plagues the populations of the poorer nations of Asia and Africa. The Food and Agriculture Organization of the United Nations estimates that 850 million people were malnourished between 1999 and 2005.[1] Those who eat a diet with sufficient calories that is lacking in an essential amino acid may suffer from stunted growth, developmental disorders, or even death. On the other ha
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Contact: Barbara K. Kennedy
science@psu.edu
814-863-4682
Penn State
6-Feb-2007