Resolving kinesin stepping: one head at a time.

Area of Science:

• Cell Biology
• Molecular Motors
• Biophysics

Background:

• Kinesins are crucial for intracellular transport in eukaryotic cells.
• Kinesin activity is regulated, with the tail domain proposed to mediate autoinhibition.
• Understanding kinesin regulation is key to deciphering cellular transport mechanisms.

Purpose of the Study:

• To investigate the regulatory influence of the kinesin tail domain on processive stepping.
• To characterize the individual head domain properties during kinesin-2 motor function.
• To elucidate the mechanism of autoinhibition in kinesin motors.

Main Methods:

• Utilized dual-color super-resolution microscopy (dcFIONA).
• Simultaneously tracked the two distinct head domains of kinesin-2.
• Analyzed individual head domain properties during processive stepping.

Main Results:

• Demonstrated that autoinhibition selectively affects one head in the kinesin-2 heterodimer.
• Revealed distinct functional properties of individual head domains during stepping.
• Provided direct experimental evidence for differential head regulation.

Conclusions:

• The autoinhibitory mechanism in kinesin-2 is asymmetric, impacting only one head.
• This finding offers novel insights into the regulation of processive stepping.
• Challenges previous assumptions about uniform head regulation in kinesin motors.