( An international team of researchers ha...)Researchers image molecular motor structural changes

The knowledge could lead to better understanding of the underlying mechanisms of a range of human disorders such as Down syndrome caused by faulty molecular motors, and possibly to the development of new treatments, the researchers said. For example, molecular motors are responsible for dividing genetic material during cell division, and understanding how motors work in cancer cells, which undergo unchecked cellular division, might lead to new anticancer therapies.

The team, from Duke University Medical Center, the National Institute of Advanced Industrial Science and Technology in Japan, and the Medical Research Council's Laboratory of Molecular Biology in the United Kingdom, reported its findings Sept. 15, 2006, in the journal Molecular Cell.

The research was supported by the U.S. National Institutes of Health; Japan's Ministry of Education, Culture, Sports, Science and Technology; the U.K.'s Medical Research Council, and the Human Frontiers Science Program, an international agency that funds innovative research.

As they move nutrients or other cellular loads around the cell, molecular motors travel along microtubules, infinitesimal "railroad tracks" within the cell. To date, cell biologists had not been able to capture actual images of the structural changes that a molecular motor undergoes as it breaks down adenosine triphosphate (ATP), the source of energy in all cells, into the power necessary to move along the microtubules.

"In order to visualize the actual structure of the motor molecule bound to a microtubule, we combined the images generated by high-resolution electron microscopy," said study investigator Sharyn Endow, Ph.D., a Duke cell biologist. "We were able to see for the first time the actual point at which the molecular motors attach to the m
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Source:Duke University Medical Center