The findings suggest a novel mechanism in which dietary fat can attach directly to proteins that regulate bioelectricity. This can affect the performance of nerve and heart cells, with potentially broad-ranging health implications.
The researchers report in the April 26 issue of the Proceedings of the National Academy of Sciences that the proteins in specific electrically responsive cell pores--voltage-sensing potassium channels--can bind to molecules of palmitate. Palmitate is a saturated fatty acid previously linked to "hardening" of the arteries and obesity and is a common fat in unhealthy diets.
"In effect, the attachment of palmitate makes these potassium channels, called Kv1.1 channels, open more easily, and this can influence the transmission of electrical impulses along nerve cells and the contraction of heart muscle cells," says senior author Richard Gross, M.D., Ph.D., professor of medicine, of chemistry and of molecular biology and pharmacology and director of the Division of Bioorganic Chemistry and Molecular Pharmacology.
Potassium channels are among the most important cell channels used for propagating electrical signals in nerve and heart muscle. Their protein units form pores that permeate the outer wall or membrane of the cell and selectively allow the passage of potassium ions, which are essential components of cell signaling systems.
Like a meter that measures charge in a battery, a Kv1.1 channel senses the amount of voltage between the interior and exterior of cells and can open and close in response to voltage changes.
Because they are embedded in the cell membrane, Kv1.1 channels are tightly surrounded by the fatty molecules of the membrane, which line up next to each othe
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Contact: Gwen Ericson
ericsong@wustl.edu
314-286-0141
Washington University School of Medicine
14-Apr-2005