Proximity labeling of active and inactive neuronal Rab2 in flies

Neuropeptide-containing dense core vesicles (DCVs) are generated in the neuronal cell body and circulate throughout the axonal arbor to supply distal release sites. This circulation depends on the anterograde kinesin-1 and kinesin-3 motors and the retrograde dynein-dynactin motor, however the adaptor proteins involved are poorly understood. Knock-out of the small GTPase Rab2 selectively disrupts retrograde DCV transport in Drosophila axons indicating that it is involved in regulation of dynein. To identify specific interactors of active neuronal Rab2 in flies, we performed proximity labeling based on a pan-neuronally expressed constitutively active GTP-locked TurboID-Rab2Q65L chimera, as well as an inactive GDP-locked TurboID-Rab2S20N variant.