Proposed model. Lysosomes (magenta) and autophagosomes (green) are enriched on a small subset of microtubules that are detyrosinated, where they can encounter each other, interact, and undergo fusion. KIF5B preferentially biases the localization of lysosomes to detyrosinated microtubules, where their mobility is hindered (wiggly line compared with long arrows). KIF1B, on the other hand, is more involved in lysosome motility along tyrosinated microtubules. The potential preference of KIF5B for detyrosinated microtubules and/or its hindered motility on detyrosinated microtubules may help concentrate lysosomes on this small population of microtubules, enabling their efficient fusion with autophagosomes to initiate autophagy.