Spatial cytoskeleton organization supports targeted intracellular transport

Abstract

The efficiency of intracellular cargo transport from specific source to target locations is strongly dependent upon molecular motor-assisted motion along the cytoskeleton. Radial transport along microtubules and lateral transport along the filaments of the actin cortex underneath the cell membrane are characteristic for cells with a centrosome. The interplay between the specific cytoskeleton organization and the motor performance realizes a spatially inhomogeneous intermittent search strategy. In order to analyze the efficiency of such intracellular search strategies we formulate a random velocity model with intermittent arrest states. We evaluate efficiency in terms of mean first passage times for three different, frequently encountered intracellular transport tasks: i) the narrow escape problem, which emerges during cargo transport to a synapse or other specific region of the cell membrane, ii) the reaction problem, which considers the binding time of two particles within the cell, and iii) the reaction-escape problem, which arises when cargo must be released at a synapse only after pairing with another particle. Our results indicate that cells are able to realize efficient search strategies for various intracellular transport tasks economically through a spatial cytoskeleton organization that involves only a narrow actin cortex rather than a cell body filled with randomly oriented actin filaments.

13 pages, 7 figures

References in corpus (7)

• First passages for a search by a swarm of independent random searchers
• Intracellular transport driven by cytoskeletal motors: General mechanisms and defects
• Cytoskeletal network morphology regulates intracellular transport dynamics
• Run-and-pause dynamics of cytoskeletal motor proteins
• Optimality of spatially inhomogeneous search strategies
• Spatial Organization of the Cytoskeleton enhances Cargo Delivery to Specific Target Areas on the Plasma Membrane of Spherical Cells
• Numerical analysis of homogeneous and inhomogeneous intermittent search strategies

Cited by in corpus (7)

• Full distribution of first exit times in the narrow escape problem
• Towards a full quantitative description of single-molecule reaction kinetics in biological cells
• Distribution of first-reaction times with target regions on boundaries of shell-like domains
• The narrow escape problem in a circular domain with radial piecewise constant diffusivity
• Narrow escape problem in two-shell spherical domains
• A molecular relay race: sequential first-passage events to the terminal reaction centre in a cascade of diffusion controlled processes
• Cytoskeletal filament length controlled dynamic sequestering of intracellular cargo