Dynein scaffolding on axonal autophagosomes is regulated by maturation. Graphic summary of the model. Autophagosomes form in the distal tip (left) where they fuse with endolysosomes and bind JIP1, promoting the initiation of retrograde motility. In the mid-axon (middle), HAP1 binds autophagosomes via Htt and activates their dynein-driven motility. As the autophagosome matures, HAP1 and JIP1 disassociate and JIP3 promotes the continued retrograde motility in the mid- and proximal axon (right). Finally, degradation and recycling are completed in the soma.