Microtubules and intracellular transport - A microscopic perspective.

Abstract

Microtubules are a major class of cytoskeletal filaments responsible for a range of cellular functions such as cell motility, mitosis and intracellular transport. Structurally, microtubules are rigid cylindrical arrangement of alpha-beta hetero dimers with an outer diameter of about 25 nm. Experimental reports have noted microtubule bundling and cross-sectional deformation as a response to crowding-induced depletion forces. Moreover, since microtubules are highly charged structures, the salt concentration can also have unique implications. Molecular dynamics simulations can be useful to explore these systems and understand how macroscopic properties develop from microscopic details, but the spatio-temporal complexity makes it impossible to study such large biomolecular systems with all-atom resolution. Here we investigate these macromolecular assemblies using coarse-grained molecular dynamics (CG-MD). We explore macroscopic structural features of microtubules such as the response to salt concentration, microtubule bundling, microtubule-kinesin interactions and the impact of C-terminal disordered tails on microtubule cohesion.