Cell biology: new insights into the life of microtubules

Every second, around 25 million cell divisions take place in our bodies. This process is driven by microtubule filaments which continually grow and shrink. A new study shows how so-called motor proteins in the cytosol can control their dynamics.

The cytoskeleton plays a central role in the process of . It is composed in large part of known as microtubules, which also help determine the size, shape and mobility of a cell. In a new study, Ludwig Maximilian University biophysicist Erwin Frey and his colleagues Anna Melbinger and Louis Reese have used a theoretical model to show how cells control the construction and breakdown of microtubules. The dy-namics of this process affect how cells divide, and how they maintain the cytoskeleton. In particular, it is responsible for regulating the size and shape of the .

Theoretical modeling has now revealed that the regulation of microtubule length relies on the length of the filament itself: The longer the filament the more can attach to it. These all move towards the 'plus end' of the microtubule and tend to pile up as they do so. Upon arrival at the plus-end they shorten the filament. In parallel, new microtubule building blocks bind to precisely the same 'plus end' through spontaneous polymerization from the surrounding , and the filament grows.

It has now been demonstrated that such interplay between growth and length-dependent shrinkage indeed results in the maintenance of a precisely regulated microtubule length. This kind of length regulation might be essential for many intracellular tasks which depend on microtubules of a certain length.


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More information: Microtubule Length Regulation by Molecular Motors, Anna Melbinger, Louis Reese, and Erwin Frey, Phys. Rev. Lett. 108, 258104 (2012). Published online June 22, 2012
Journal information: Physical Review Letters

Citation: Cell biology: new insights into the life of microtubules (2012, July 2) retrieved 22 May 2019 from https://phys.org/news/2012-07-cell-biology-insights-life-microtubules.html
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Jul 02, 2012
The fact that the microtubules are involved in cell-division as well as general transport of bio-products inside the cell spells an ominous problem for the evolutionary theory that requires life to arise spontaneously from scum ponds[or whatever other location one cares to mention]. The double involvement means that the functionality could not have arisen spontaneously with such precision in either function. In fact it is simply impossible.

From neutrafil extravasation, one can see another involvement that allows such impossible metamorphosis that any spontaneous generation of microtubules will present an impossible task for those who are now involved in explaning how life arose on earth. Without the microtubules, life processes inside the cell will be very difficult indeed. Furthermore, the fact that they are made of protein creates a veritable chicken and egg situation for spontaneous start of life-you need the tubules to deliver the products but you need the products to create them

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