Dynein-Inspired Multilane Exclusion Process with Open Boundary Conditions.

Area of Science:

• Biophysics
• Statistical Mechanics
• Motor Protein Dynamics

Background:

• Dynein motors exhibit complex sidewise motions.
• Understanding multistep dynamics is crucial for cellular processes.

Purpose of the Study:

• To model dynein motor multistep dynamics on a cylinder with open ends.
• To investigate the emergence of a novel phase diagram under varied load conditions.
• To compare dynein dynamics with the Totally Asymmetric Simple Exclusion Process (TASEP) model.

Main Methods:

• Utilized a variant of the exclusion process for modeling.
• Simulated quasi-two-dimensional topology with varied particle step sizes.
• Analyzed numerical findings under high-, medium-, and low-load conditions.
• Measured single dynein particle dynamics and dwell time distributions.

Main Results:

• A novel phase diagram emerged based on load conditions.
• High-load conditions showed standard TASEP phases (LD, HD, MC).
• Medium- to low-load conditions lacked the MC phase, showing only LD and HD phases.
• Single dynein particle dynamics were logarithmically slower than TASEP particles.
• Dwell time distributions were exponential (less crowded) and double exponential (overcrowded).

Conclusions:

• The exclusion process model effectively captures dynein motor dynamics.
• Load conditions significantly influence the phase behavior of dynein motors.
• Dynein motor behavior deviates from standard TASEP under reduced load.
• Crowding affects dynein dwell time distributions, aligning with experimental observations.