Mechanism of New "Sudden-Death" Arrhythmia Detailed
Heart Muscle Cell
Researchers have now determined the molecular mechanism underlying a cardiac arrhythmia syndrome they discovered that can lead to sudden death in young, seemingly healthy people.
The researchers, from Duke University Medical Center, Vanderbilt University Medical Center and the Howard Hughes Medical Institute (HHMI), found that the disorder is caused by a mutation in an integral component of a four-protein complex that coordinates the inflow and outgo of key chemicals, especially calcium, in heart muscle cells. The passage of such ions in and out of heart muscle cells controls the beating of the heart.
The researchers found that patients with a mutation in the gene that codes for the protein known as ankyrin-B are at high risk of sudden death from cardiac arrhythmia. Ankyrin-B serves as a molecular scaffold and "cellular chaperone" for the complex.
These findings are important, the researchers said, because the new knowledge of the structure and location of the ankyrin-B complex, as well as its importance in maintaining calcium equilibrium within heart muscle cells, gives them targets for potential new drugs. Furthermore, the researchers said, their findings provide new insights into other disorders involving the pancreas and the eyes.
The results of the researchers were published Nov. 16, 2005, in the Public Library of Science