  We here present a model of nonlinear dynamics of microtubules (MT) in the
context of modified extended tanh-function (METHF) method. We rely on the
ferroelectric model of MTs published earlier by Satari\'c et al [1] where the
motion of MT subunits is reduced to a single longitudinal degree of freedom per
dimer. It is shown that such nonlinear model can lead to existence of kink
solitons moving along the MTs. An analytical solution of the basic equation,
describing MT dynamics, was compared with the numerical one and a perfect
agreement was demonstrated. It is now clearer how the values of the basic
parameters of the model, proportional to viscosity and internal electric field,
impact MT dynamics. Finally, we offer a possible scenario of how living cells
utilize these kinks as signaling tools for regulation of cellular traffic as
well as MT depolymerisation.
