The branching of dendrites and axons is a key determinant of neural circuit formation. In this issue of Neuron, Kawabe et al. demonstrate that the ubiquitin ligase Nedd4 promotes the branching of developing dendrites by targeting the small G protein Rap2. In a complementary study, Drinjakovic et al. show that Nedd4 promotes the branching of developing axons by ubiquitinating a different target, the phosphatase PTEN.