Release from Myosin V via Regulated Recruitment of an E3 Ubiquitin Ligase Controls Organelle Localization

Molecular motors transport organelles to specific subcellular locations. Upon arrival at their correct locations, motors release organelles via unknown mechanisms. The yeast myosin V, Myo2, binds the vacuole-specific adaptor Vac17 to transport the vacuole from the mother cell to the bud. Here, we show that vacuole detachment from Myo2 occurs in multiple regulated steps along the entire pathway of vacuole transport. Detachment initiates in the mother cell with the phosphorylation of Vac17 that recruits the E3 ligase Dma1 to the vacuole. However, Dma1 recruitment also requires the assembly of the vacuole transport complex and is first observed after the vacuole enters the bud. Dma1 remains on the vacuole until the bud and mother vacuoles separate. Subsequently, Dma1 targets Vac17 for proteasomal degradation. Notably, we find that the termination of peroxisome transport also requires Dma1. We predict that this is a general mechanism that detaches myosin V from select cargoes. [Display omitted] •Release from Myo2 is critical for the localization of vacuoles and peroxisomes•Dma1, an E3 ligase, is required for the regulated release of Myo2 from its cargoes•Phosphorylation of the Myo2 cargo adaptor Vac17 recruits Dma1 to the vacuole•Dma1 terminates vacuole transport via targeting Vac17 for proteasomal degradation Placement of organelles at their correct subcellular locations requires regulated detachment from molecular motors after transport. Yau et al. report that phosphorylation of the myosin V vacuole-specific adaptor Vac17 recruits an E3 ubiquitin (Ub) ligase, Dma1. This triggers Vac17 degradation via the Ub-proteasome system and regulates detachment of the vacuole from myosin V.