Specification of Dendritogenesis Site in Drosophila aCC Motoneuron by Membrane Enrichment of Pak1 through Dscam1.

摘要: Precise positioning of dendritic branches is a critical step in the establishment neuronal circuitry. However, there limited knowledge on how environmental cues translate into dendrite initiation or branching at specific position. Here, through combination mutation, RNAi, and imaging experiments, we found that Dscam-Dock-Pak1 hierarchical interaction defines stereotypical growth site Drosophila aCC motoneuron. This localizes Cdc42 effector Pak1 to plasma membrane before activation Cdc42. Ectopic expression membrane-anchored overrides this spatial specification dendritogenesis, confirming its function guiding signaling. We further discovered Dscam1 localization occurs an inter-neuronal contact involves partner MP1 neuron. These findings elucidate mechanism by which controls morphogenesis regulation signaling and, subsequently, cytoskeletal remodeling.