Fission of SNX-BAR-coated endosomal retrograde transport carriers is promoted by the dynamin-related protein Vps1

Retromer is an endosomal sorting device that orchestrates capture and packaging of cargo into transport carriers coated with sorting nexin BAR domain proteins (SNX-BARs). We report that fission of retromer SNX-BAR coated tubules from yeast endosomes is promoted by Vpsl, a dynamin-related protein that localizes to endosomes decorated by retromer SNX-BARs and Mvpl, a SNX-BAR that is homologous to human SNX8. Mvpl exhibits potent membrane remodeling activity in vitro, and it promotes association of Vpsl with the endosome in vivo. Retrograde transport carriers bud from the endosome coated by retromer and Mvpl, and cargo export is deficient in mvp1- and vps1-null cells, but with distinct endpoints; cargo export is delayed in mvp1-null cells, but cargo export completely fails in vps1-null cells. The results indicate that Mvpl promotes Vpsl-mediated fission of retromer- and Mvpl-coated tubules that bud from the endosome, revealing a functional link between the endosomal sorting and fission machineries to produce retrograde transport carriers.