Discovery helps scientists unravel why cell division goes haywire

January 10th, 2009 - 1:38 pm ICT by IANS  

London, Jan 10 (IANS) Researchers have discovered how a protein plays a vital role in the intricacies of cell division and how it can go wrong, creating cancerous cells. Researchers studied a protein called NOD, distantly related to the motor proteins that power diverse cellular activities, including intracellular transport, signalling, and cell division.

They used X-ray crystallography to determine its structure, and then they used enzyme kinetics to find out how it performed. While this protein is found in fruit flies, the results are helpful in determining how related proteins work in humans and what happens if they go wrong.

“This study on NOD provided evidence for a new way a kinesin motor could function,” said Jared Cochran, postdoctoral fellow at Dartmouth College and co-author of the study, which was published in the current issue of Cell.

“Rather than moving on its own, it hitches a ride on the ends of microtubules which results in a dynamic cross-linking between the arms of chromosomes and the cell’s growing spindle of microtubules,” he said, according to a Dartmouth release.

“If NOD doesn’t function properly, then the two cells end up with either both or none of that particular chromosome, which is lethal [to the cell and the organism] in most cases.”

“Before this study, it had been shown that kinesin motors either walked along their microtubule tracks or functioned to break microtubules apart,” said Jon Kull, a co-author and associate professor of chemistry at Dartmouth.

“This work describes a novel mode for kinesin function, in which NOD does not walk, but rather alternates between grabbing on to and letting go of the end of the growing filament, thereby tracking the end as it grows. The diversity of function of these proteins is remarkable,” Kull added.

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