Mitotic motors coregulate microtubule patterns in axons and dendrites

Area of Science:

• Neuroscience
• Cell Biology
• Molecular Motors

Background:

• Microtubules exhibit uniform orientation in neuronal axons but non-uniform orientation in dendrites.
• Previous studies proposed microtubule transport into axons and dendrites, followed by opposite orientation transport into dendrites.

Purpose of the Study:

• To investigate the role of kinesin-6 and kinesin-12 in establishing distinct microtubule orientations in neuronal axons and dendrites.
• To confirm the function of kinesin-6 and kinesin-12 in regulating microtubule polarity within developing dendrites.

Main Methods:

• Utilized contemporary molecular tools to deplete kinesin-6 and kinesin-12 in rat sympathetic neurons.
• Observed the effects of motor depletion on microtubule orientation and neuronal morphology, specifically in dendrites and axons.

Main Results:

• Depletion of kinesin-6 reduced minus-end-distal microtubules in dendrites, causing them to develop axon-like morphology.
• Depletion of kinesin-12 produced similar dendritic morphological changes.
• Depletion of either motor led to faster axon growth and increased mobile microtubules, while kinesin-6 depletion did not affect axonal branching.

Conclusions:

• Kinesin-6 and kinesin-12, traditionally known as mitotic motors, play a crucial role in regulating microtubule patterns in both axons and dendrites.
• These motors attenuate plus-end-distal microtubule transport into axons and drive minus-end-distal transport into dendrites.
• The study proposes a model where these motors coregulate microtubule orientation, influencing neuronal development and structure.