Phytic acid is present in all eukaryotic cells. In plants, it is known to function as a [PO4]3? storage depot and precursor for other inositol phosphates and pyrophosphates. Its high surface negative charge makes it a potent chelator of divalent and trivalent cations in vitro, and it is most likely associated with Ca2+ or Mg2+ ions in vivo. In yeast, phytic acid acts with the nuclear pore protein Gle1 to regulate the nuclear export of mRNA by coactivating the RNA-dependent ATPase activity of DExD-box protein 5 (Dbp5).