How can proteolipids be central players in membrane fusion?

Proton transport ATPases have been celebrated as rotating motors that energize membranes. Now studies of membrane fusion in yeast suggest that the hydrophobic subunits of the vacuolar ATPase participate in formation of fusion pores. This work confirms previous studies showing that membrane approximation by alpha-helical protein bundles is inadequate for complete intracellular fusion and reopens a debate over whether the core of the central intermediate of membrane fusion is lipidic or proteinaceous.