Rab11 is required for neurite pruning and developmental membrane protein degradation in Drosophila sensory neurons.

Neurons, with their distinct neurites, require elaborate membrane trafficking pathways and regulation to uphold neurite identity and to be able to respond to neuronal or developmental stimuli. In a survey of trafficking regulators required for developmental dendrite pruning in Drosophila sensory neurons, we identified the small GTPase Rab11, a regulator of recycling endosomes. Dendrite pruning requires the developmentally regulated degradation of the cell adhesion molecule Neuroglian, and loss of Rab11 causes defects in the developmental degradation of Neuroglian and another target, the ion channel Ppk26. Rab11 often links vesicles to molecular motors, and we find that loss of the microtubule motor dynein also leads to defective Neuroglian and Ppk26 degradation. Loss of Rab11 also leads to defects in larval dendrite elaboration, and Neuroglian and Ppk26 localization is already altered at this stage. Our data highlight the importance of membrane protein recycling during development.