Force and length-dependent catastrophe activities explain fission yeast interphase microtubules organization

Dietrich Foethke, Tatyana Makushok, Damian Brunner and Francois Nedelec
Molecular Systems Biology, 5:241, Mar 2009.



The cytoskeleton is essential for the maintenance of cell morphology in eukaryotes. In fission yeast for example, polarized growth sites are organized by actin whereas microtubules (MT) acting upstream control where growth occurs. Growth is limited to the cell poles when MTs undergo catastrophes there and not elsewhere on the cortex. Here we report that the modulation of MT dynamics by forces as observed in vitro can quantitatively explain the localization of MT catastro- phes in S. pombe. However, we found that it is necessary to add length-dependent ca- tastrophe rates to make the model fully consistent with other previously measured traits of MTs. We explain the measured statistical distribution of microtubules/cortex contact times and re-examine the curling behavior of MTs in un-branched straight tea1Δ cells. Importantly, the model demonstrates that MTs together with associated proteins such as depolymerizing kinesins are in principle sufficient to mark the cell poles.

Supplementary movies: (Quicktime, 5 MB) (Quicktime, 5 MB) (Quicktime, 5 MB)

Simulation package:

Mac OSX: pombe.dmg (2 MB)
Windows 32: available later.


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