Catalyzes the electroneutral exchange or flux of physiologically important metabolites such as dicarboxylates (malonate, malate, succinate), inorganic sulfur-containing anions, and phosphate, across mitochondrial inner membrane (PubMed:29211846). Plays an important role in gluconeogenesis, fatty acid metabolism, urea synthesis, and sulfur metabolism, particularly in liver, by supplying the substrates for the different metabolic processes. Regulates fatty acid release from adipocytes, and contributes to systemic insulin sensitivity (By similarity). (S)-malate(in) + phosphate(out) = (S)-malate(out) + phosphate(in) (S)-malate(in) + malonate(out) = (S)-malate(out) + malonate(in) (S)-malate(in) + succinate(out) = (S)-malate(out) + succinate(in) (S)-malate(in) + sulfate(out) = (S)-malate(out) + sulfate(in) malonate(out) + phosphate(in) = malonate(in) + phosphate(out) phosphate(in) + succinate(out) = phosphate(out) + succinate(in) phosphate(in) + sulfate(out) = phosphate(out) + sulfate(in) malonate(out) + succinate(in) = malonate(in) + succinate(out) Present in high amounts in liver and kidney, and at lower levels in all the other tissues analyzed. The disease may be caused by variants affecting the gene represented in this entry. Belongs to the mitochondrial carrier (TC 2.A.29) family.