Morphological transitions of axially-driven microfilaments.

Area of Science:

• Cellular biophysics
• Biomechanical modeling

Background:

• Microtubule-motor protein interactions are crucial for cellular motility and cargo transport.
• In vitro assays show diverse microtubule dynamics, from straight to curved forms.

Purpose of the Study:

• To theoretically investigate dynamic instabilities in elastic filaments driven by follower forces, mimicking molecular motors.
• To explain the rich repertoire of microtubule behaviors observed experimentally.

Main Methods:

• Utilized resistive force theory at low Reynolds number.
• Employed a combination of numerical techniques and linear stability analysis.
• Modeled free-ended elastic filaments driven by single follower forces.

Main Results:

• Identified four distinct regimes of filament behavior.
• Discovered a novel buckled state with locked curvature.
• Demonstrated that these instabilities explain experimentally observed microtubule dynamics.

Conclusions:

• The rich dynamics of motor-driven microtubules can arise from fundamental physical instabilities.
• Neither structural nor actuation asymmetry is required to generate complex microtubule motion.
• Theoretical framework provides insights into microtubule-based cellular processes.