The inner workings of intracellular heterotypic and homotypic membrane fusion mechanisms.

Intracellular trafficking is a field that has been intensively studied for years and yet there remains much to be learned. Part of the reason that there is so much obscurity remaining in this field is due to all the pathways and the stages that define cellular trafficking. One of the major steps in cellular trafficking is fusion.

Yeast dynamin and Ypt6 function in parallel for the endosome-to-Golgi retrieval of Snc1.

Protein recycling is an important cellular process required for cell homeostasis. Results from prior studies have shown that vacuolar sorting protein-1 (Vps1), a dynamin homolog in yeast, is implicated in protein recycling from the endosome to the trans-Golgi Network (TGN). However, the function of Vps1 in relation to Ypt6, a master GTPase in the recycling pathway, remains unknown.

Yeast dynamin Vps1 associates with clathrin to facilitate vesicular trafficking and controls Golgi homeostasis.

The yeast dynamin Vps1 acts cooperatively with many proteins at diverse cellular locations for endocytosis, protein sorting, and membrane fusion and fission. It has been proposed that Vps1 is functionally linked to clathrin heavy chain 1 (Chc1), but the question of how, where, and when they function together remains unknown. Here we report that Vps1 arrives at the Golgi after clathrin, and that loss of Vps1 leads to a shift in the cellular localization of clathrin to the late endosome and vacuole, not vice versa.