The Effect of Intracellular Crowding on the Diffusion Dynamics of Neurofilaments and Microtubules
Abstract
Neurofilaments are a class of cytoskeletal proteins which are essential for providing structural support for axons and for regulating axon diameter. Neurofilaments are primarily synthesized in the cell body of neurons and are cargoes of slow axonal transport. Several studies have established that neurofilaments are transported as assembled polymers along microtubule tracks driven by motor proteins. The transport kinetics of neurofilaments have been explained by a ``Stop-and-go'' model where neurofilaments move intermittently in a bidirectional manner. However, the established models do not take into account the intracellular crowding which can severely limit the diffusion kinetics and in turn affect the reaction rates. We model the neurofilament and microtubules as a bi-disperse population of hard disks in a circular domain representing the cross section of the axon. We find that both cellular confinement and steric repulsion play important roles in modulating the diffusion dynamics and in turn the reaction rates. We are also using our model to study whether phase transition effects at high crowding densities can explain the segregated neurofilament and microtubule populations typically found in some neurodegenerative diseases.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARL70297J