Thermal Fluctuation Induced Piezoelectric Effect in Cytoskeletal Microtubules: Model for Energy Harvesting and Their Intracellular Communication

Arindam Kushagra

doi:10.4236/jbise.2015.88048

Abstract

Cytoskeletal microtubules have long been conjectured to have piezoelectric properties. They have been shown to behave as nematic liquid crystals which oscillate along their director axis due to the prevalent thermal fluctuations. In this work, we develop a theoretical model of the mechanics of microtubules in the cytosolic space based on the buckling of its structure due to these thermal fluctuations. This cytosolic space has been considered as a viscoelastic medium in which microtubule oscillations have been considered. As a result of resilience of cytosol and neighbouring filaments from the axial force due to thermal fluctuations, the surface traction acting laterally on the microtubule structure has been further used to elucidate its piezoelectric behaviour in vivo. After the piezoelectric properties induced by thermal fluctuations (in addition to the buckling) of microtubules have been discussed, we propose a model discussing how microtubules behave as energy harvesters and communicate via electromagnetic radiation, with each other, in an intracellular environment.

Highlights

Microtubules are ubiquitous cytoskeletal elements that provide rigidity to otherwise blobby and gel-like living cell
We have considered the buckling behaviour of microtubules in a viscoelastic environment provided by the cytoskeletal components in addition to surrounding cytoplasm
We have studied the piezoelectric effect in cytoskeletal microtubules using ZnO nanorods as a model system and for the first time we have generated a quantitative estimate of the buckling that happens due to thermal fluctuations during dynamic instability i.e. GTP hydrolysis

Summary

Introduction

Microtubules are ubiquitous cytoskeletal elements that provide rigidity to otherwise blobby and gel-like living cell. According to the Euler’s model, a filament of microtubule is considered as a very thin elastic rod which is buckled due to the loading forces acting on it due to its functionality as a cytoskeletal element. When this buckling happens, the neighbouring cytosol tries to restore the microtubule filament to its original position owing to the viscoelastic properties of the cytosolic space. After analyzing the traction force induced piezoelectric behaviour of microtubules, we propose a mechanism by which microtubules can interact with each other as long as the dynamic instability process of addition of GTP-tubulin and secession of GDP-tubulin subunits is taking place

Buckling Mechanism in Viscoelastic Conditions

Results and discussion

Conclusions