Sequential dynein effectors regulate axonal autophagosome motility in a maturation-dependent pathway.

Area of Science:

• Cell Biology
• Neuroscience
• Molecular Biology

Background:

• Autophagy is crucial for cellular homeostasis.
• Neuronal autophagosomes are transported along axons via dynein motors.
• The regulation of dynein-autophagosome interaction remains unclear.

Purpose of the Study:

• To identify and characterize dynein effectors involved in neuronal autophagosome transport.
• To elucidate the regulatory mechanisms governing the dynein-autophagosome interaction during axonal transport.
• To understand the linkage between autophagosome maturation and transport.

Main Methods:

• Identification of dynein effectors on transiting axonal autophagosomes in primary neurons.
• Biochemical analysis of HAP1 interaction with the dynein-dynactin complex.
• Functional assays to assess the impact of inhibiting transport or maturation on effector association and function.

Main Results:

• JIP1 initiates autophagosomal transport in the distal axon.
• HAP1 and Huntingtin are required for mid-axon transport.
• HAP1 acts as a dynein activator.
• JIP3 regulates mature autolysosome transport.
• Autophagosome maturation and transport are interdependent.

Conclusions:

• A novel maturation-based dynein effector handoff mechanism governs neuronal autophagosome motility.
• This process is critical for cargo degradation and maintaining axonal health.
• The findings provide new insights into the regulation of axonal transport and neuronal homeostasis.