The hexameric AAA ATPase VPS4 facilitates ESCRT III filament disassembly on diverse intracellular membranes. ESCRT III components and VPS4 have been localized to the ciliary transition zone and spindle poles and reported to affect centrosome duplication and spindle pole stability. How the canonical ESCRT pathway could mediate these events is unclear. We studied the association of VPS4 with centrosomes and found that GFP-VPS4 was a dynamic component of both mother and daughter centrioles. A mutant, VPS4, which can't hydrolyze ATP, was less dynamic and accumulated at centrosomes. Centrosome localization of the VPS4mutant, caused reduced γ-tubulin levels at centrosomes and consequently decreased microtubule growth and altered centrosome positioning. In addition, preventing VPS4 ATP hydrolysis nearly eliminated centriolar satellites and paused ciliogensis after formation of the ciliary vesicle. Zebrafish embryos injected with GFP-VPS4mRNA were less viable, exhibited developmental defects and had fewer cilia in Kupffer's vesicle. Surprisingly, ESCRT III proteins seldom localized to centrosomes and their depletion did not lead to these phenotypes. Our data support an ESCRT III-independent function for VPS4 at the centrosome and reveal that this evolutionary conserved AAA ATPase influences diverse centrosome functions and, as a result, global cellular architecture and development.

At the center of the secretory pathway, the Golgi complex ensures correct processing and sorting of cargos toward their final destination. Cargos are diverse in topology, function and destination. A remarkable feature of the Golgi complex is its ability to sort and process these diverse cargos destined for secretion, the cell surface, the lysosome, or retained within the secretory pathway. Just as these cargos are diverse so also are their sorting requirements and thus, their trafficking route. There is no one-size-fits-all sorting scheme in the Golgi. We propose a coexistence of models to reconcile these diverse needs. We review examples of differential sorting mediated by proteins and lipids. Additionally, we highlight recent technological developments that have potential to uncover new modes of transport.