Enhanced Processivity and Collective Force Production of Kinesin-1 at Low Radial Forces

Area of Science:

• Cellular Biology
• Biophysics
• Molecular Motors

Background:

• Kinesin-1 motors transport intracellular cargo along microtubules.
• Previous studies suggested kinesin-1 is 'slippery' and multiple motors struggle to generate collective force.
• This perception may stem from vertical forces in optical trapping assays.

Purpose of the Study:

• To re-evaluate kinesin-1's robustness and collective force generation capabilities.
• To investigate the impact of reduced vertical (z) forces on kinesin-1 function.
• To understand how multiple kinesin-1 motors cooperate for cellular transport.

Main Methods:

• Utilized a long DNA handle in optical trapping assays to minimize vertical (z) forces.
• Characterized the motility and force generation of single kinesin-1 motors.
• Assessed the collective force generation of multiple kinesin-1 motors.

Main Results:

• Kinesin-1 motors resist detachment until high hindering loads are reached.
• Motors detach rapidly under assisting loads, even at low z-forces.
• Multiple kinesin-1 motors demonstrate highly efficient collective force generation.

Conclusions:

• Kinesin-1 is a robust motor, contrary to previous 'slippery' classifications.
• Vertical forces significantly influence motor detachment dynamics.
• Multiple kinesin-1 motors effectively team up to generate substantial forces for cellular functions.