Coupling of Active Motion and Advection Shapes Intracellular Cargo Transport

TL;DR

This paper investigates how the coupling between active motion and fluid advection influences intracellular cargo transport, revealing conditions that optimize cargo localization and providing insights into cytoskeletal network organization.

Contribution

It introduces a reaction-advection-diffusion model to analyze the impact of coupling on cargo transport and localization within confined cellular geometries.

Findings

Low diffusion enhances cargo localization to target zones.

Disordered cytoskeletal networks with weak bias can optimize localization.

Coupling affects transport efficiency and spatial distribution.

Abstract

Intracellular cargo transport can arise from passive diffusion, active motor-driven transport along cytoskeletal filament networks, and passive advection by fluid flows entrained by such motor/cargo motion. Active and advective transport are thus intrinsically coupled as related, yet different representations of the same underlying network structure. A reaction-advection-diffusion system is used here to show that this coupling affects the transport and localization of a passive tracer in a confined geometry. For sufficiently low diffusion, cargo localization to a target zone is optimized either by low reaction kinetics and decoupling of bound and unbound states, or by a mostly disordered cytoskeletal network with only weak directional bias. These generic results may help to rationalize subtle features of cytoskeletal networks, for example as observed for microtubules in fly oocytes.