Cell ‘railways’ adapt to be as useful as possible

(Credit: Getty Images)

A microscopic “railway” system in our cells can change its structure to best meet our bodies’ needs, new research shows.

Almost every cell in our body contains this railway network, a system of tiny tracks called microtubules that link important destinations inside the cell.

“Imagine if the tracks of a real railway were able to ask themselves, ‘am I useful?'”

Researchers found that this system of microtubule rails inside cells can adjust its own stability depending on whether it’s being used or not.

“The microtubule tracks of the cellular railway are almost unimaginably small—just 25 nanometers across (a nanometer being a millionth of a millimeter),” says Robert Cross, director of the center for mechanochemical cell biology at the University of Warwick Medical School, whose team has been looking at how the microtubule “railway tracks” inside cells are built.

“The railway is just as crucial to a well-run cell as a full-size railway is to a well-run country. For cells and for countries the problem is very much the same—how to run a better railway?”

“Imagine if the tracks of a real railway were able to ask themselves, ‘am I useful?’ To find out, they would check how often a railway engine passed along them.

“It turns out that the microtubule railway tracks inside cells can do exactly that—they check whether or not they are in contact with tiny railway engines (called kinesins). If they are, then they remain stably in place. If they are not, they disassemble themselves.

“We think this allows the sections of microtubule rail to be recycled to build new and more useful rails elsewhere in the cell.”

As reported in Nature Nanotechnology, the researchers found that when the kinesin railway engines contact their microtubule rails, they subtly change their structure, producing a very slight lengthening that stabilizes the rail.

Using the Warwick Open Source Microscope, researchers detected a 1.6 percent increase in the length of microtubules attached to kinesins, with a 200 times increase in their lifetime.

By revealing how microtubules are stabilized and destabilized, the team hope to throw new light on the workings of a number of human diseases linked to abnormalities in microtubule function (Alzheimer’s, for example) .

Scientists control tiny ‘factories’ in engineered cells

Researchers say they are also hopeful that their work may ultimately lead to improved cancer therapy because the railway is so vital (for cell division, for example), as its microtubule tracks are a key target for cancer drugs such as Taxol. Exactly how Taxol stabilizes microtubules in cells remains poorly understood.

“Our new work shows that the kinesin railway engines stabilize microtubules in a Taxol-like way. We need to understand as much as we can about how microtubules can be stabilized and destabilized, to pave and illuminate the road to improved therapies,” Cross adds.

Funding for the research came from the Biotechnology and Biological Sciences Research Council via the Systems Biology Doctoral Training Centre at University of Warwick and the Wellcome Trust.

Source: University of Warwick