Transports inorganic anions (sulfate, sulfite, thiosulfate and phosphate) and, to a lesser extent, a variety of dicarboxylates (e.g. malonate, malate and citramalate) and, even more so, aspartate and glutamate and tricarboxylates. May catalyze the export of sulfite and thiosulfate (the hydrogen sulfide degradation products) from the mitochondria, thereby modulating the level of the hydrogen sulfide (Probable). Also can mediate a very low unidirectional transport of anions including sulfate, phosphate, (S)-malate, citrate, L-aspartate and L-glutamate. Maintains oxidative balance (through uncoupling activities) and ATP production (by modifying mitochondrial membrane potential). Is able to transport protons across lipid membranes. Also exhibits transmembrane chloride transport activity to a lesser extent. May modify mitochondrial respiratory efficiency and mitochondrial oxidant production.