Nonlinear ionic pulses along microtubules

Abstract

Microtubules are cylindrically shaped cytoskeletal biopolymers that are essential for cell motility, cell division and intracellular trafficking. Here, we investigate their polyelectrolyte character that plays a very important role in ionic transport throughout the intra-cellular environment. The model we propose demonstrates an essentially nonlinear behavior of ionic currents which are guided by microtubules. These features are primarily due to the dynamics of tubulin C-terminal tails which are extended out of the surface of the microtubule cylinder. We also demonstrate that the origin of nonlinearity stems from the nonlinear capacitance of each tubulin dimer. This brings about conditions required for the creation and propagation of solitonic ionic waves along the microtubule axis. We conclude that a microtubule plays the role of a biological nonlinear transmission line for ionic currents. These currents might be of particular significance in cell division and possibly also in cognitive processes taking place in nerve cells.

Intrinsic microtubule GTP-cap dynamics in semi-confined systems: kinetochore–microtubule interface

“…Solitons have been predicted and used in the rationalization of a variety of microtubule related phenomena, including the downstream modulation of neurotransmitter signaling, ionic transport throughout the cytoplasm, learning and memory, local information transfer, bioenergetic transformations within the cytoplasm, chromosome separation, polar vibrations in the wall lattice, microtuble growth and energy-transfer mechanism in microtubules [40,[43][44][45][46][47][48][49][50].…”

Ionic Pulses along Cytoskeletal Protophilaments

“…Our theoretical modeling of these currents was developed in three stages [11,12,13,14]. The first stage [11,12] is similar to that one applied for AF s [8] in the way that the roles of nano-pores (N P s ) existing between protofilaments of M T were ignored.…”

“…Recently the more advanced version of the same concept was presented [14] in which the N P s are treated according to within the numerical simulations performed the group led by Tuszynski [17].…”

“…Theoretical considerations of ionic currents along M T s were performed by J Tuszynski et al [10] and in many stages by M Satarić et al [11,12,13,14].…”

Propagation of Dark Solitary Waves in the Korteveg-Devries-Burgers Equation Describing the Nonlinear RLC Transmission

“…Interestingly, in constructing proposed nonlinear RLC network, we were motivated with a very interesting example of nanobio electronics problem. Namely, Sekulić et al [7] have recently modeled ionic currents along microtubules in the eukaryotic cells, they have analytically analyzed the possible use of microtubules as protein structure for building biomolecular nanoscale NLTLs in the context of the polyelectrolyte character of these cytoskeletal filaments [8]. Solitary wave propagation is one of the important phenomena associated with the NLTL.…”