title: Coupled oscillations of a protein microtubule immersed in cytoplasm: an orthotropic elastic shell modeling.
abstract: Revealing vibration characteristics of sub-cellular structural components such as membranes and microtubules has a principal role in obtaining a deeper understanding of their biological functions. Nevertheless, limitations and challenges in biological experiments at this scale necessitates the use of mathematical and computational models as an alternative solution. As one of the three major cytoskeletal filaments, microtubules are highly anisotropic structures built from tubulin heterodimers. They are hollow cylindrical shells with a ∼ 25 nm outer diameter and are tens of microns long. In this study, a mechanical model including the effects of the viscous cytosol and surrounding filaments is developed for predicting the coupled oscillations of a single microtubule immersed in cytoplasm. The first-order shear deformation shell theory for orthotropic materials is used to model the microtubule, whereas the motion of the cytosol is analyzed by considering the Stokes flow. The viscous cytosol and the microtubule are coupled through the continuity condition across the microtubule-cytosol interface. The stress and velocity fields in the cytosol induced by vibrating microtubule are analytically determined. Finally, the influences of the dynamic viscosity of the cytosol, filament network elasticity, microtubule shear modulus, and circumferential wave-number on longitudinal, radial, and torsional modes of microtubule vibration are elucidated.
authors.affiliation: School of Mechanical Engineering, Shiraz University, Shiraz, 71348-51154 Iran ; Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street W., Montreal, Québec Canada H3A 2K6.
authors.forename: Farhang
authors.initials: F
authors.lastname: Daneshmand
authors.forename: Marco
authors.initials: M
authors.lastname: Amabili
keywords: Cell mechanics; Coupled frequency; Microtubule-cytoplasm system; Orthotropic elastic shell