Buckling of Microtubules on a 2D Elastic Medium.

Arif Md Rashedul Kabir,Tanjina Afrin,Kazuki Sada,Hiroyuki Mayama,Akira Kakugo,Daisuke Inoue

doi:10.1038/srep17222

Arif Md Rashedul Kabir, Tanjina Afrin + Show 4 more

Open Access

https://doi.org/10.1038/srep17222

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Abstract

We have demonstrated compression stress induced mechanical deformation of microtubules (MTs) on a two-dimensional elastic medium and investigated the role of compression strain, strain rate, and a MT-associated protein in the deformation of MTs. We show that MTs, supported on a two-dimensional substrate by a MT-associated protein kinesin, undergo buckling when they are subjected to compression stress. Compression strain strongly affects the extent of buckling, although compression rate has no substantial effect on the buckling of MTs. Most importantly, the density of kinesin is found to play the key role in determining the buckling mode of MTs. We have made a comparison between our experimental results and the ‘elastic foundation model’ that theoretically predicts the buckling behavior of MTs and its connection to MT-associated proteins. Taking into consideration the role of kinesin in altering the mechanical property of MTs, we are able to explain the buckling behavior of MTs by the elastic foundation model. This work will help understand the buckling mechanism of MTs and its connection to MT-associated proteins or surrounding medium, and consequently will aid in obtaining a meticulous scenario of the compression stress induced deformation of MTs in cells.

Highlights

We have demonstrated compression stress induced mechanical deformation of microtubules (MTs) on a two-dimensional elastic medium and investigated the role of compression strain, strain rate, and a MT-associated protein in the deformation of MTs
Participation of cytoskeletal components in mechanical stimulation of cells is significantly important with respect to the mechano-responsiveness of cells that triggers a variety of physiological functions of the cells[4]
Unlike the classical Euler buckling, compression stress induced deformation of slender MT filaments in living cells has been manifested by short wavelength multiwave buckling mode[10,12,16,26,27]

Summary

Methods

10 μ L of K560-GFP solution of prescribed concentrations, e.g. 10, 30, 50, 100 and 200 nM (~80 mM PIPES, ~40 mM NaCl, 1 mM EGTA, 1 mM MgCl2, 1 mM DTT, 10 μ M paclitaxel; pH 6.8) was introduced in respective case and incubated for 3 min to bind the kinesins to the antibody. Using the standard curve (the linear correlation factor) and fluorescence intensity, kinesin density on PDMS substrate of the compression tests were determined for different kinesin concentrations. Measurement of applied strain, buckling wavelength, amplitude and radius of curvature. In order to compare the experimental results with the predictions by the elastic foundation model, we selected the wavelength of buckled MTs by considering the dependence of buckling wavelength on applied strain. We used the critical buckling wavelength i.e., wavelength at the critical strain, for verification of the elastic foundation model

Results and Discussion

EI Ec

EI k

Ld Ldc α

Additional Information