Gex1 is a glutathione exchanger mostly found at the vacuolar membrane. The expression of Gex1 and Gex2 is induced under conditions of iron depletion, and Gex1 is regulated principally by the iron transcription factor Aft2. Loss of or high Gex1/2 activity modulates PKA and MAPK signaling events.

Many yeast and some mammalian multivesicular body (MVB) cargoes display modification by K63-linked ubiquitin chains (K63Ub), which are required for their efficient sorting. Yeast UBD-containing ESCRT proteins are modified by the ubiquitin ligase Rsp5—some likely by K63Ub. A failure to generate K63Ub in yeast leads to MVB ultrastructure alteration.