Metal Ions Control Protein-Protein Interactions

Researchers would like to understand more about the biological roles of protein-protein interactions and other protein assembly processes. A new approach that uses metal ions to induce protein-protein interactions, developed by F. Akif Tezcan of the University of California, San Diego, and coworkers, could further this goal (Nat. Chem. Biol., DOI: 10.1038/nchembio.1163). To make protein-protein interactions controllable, the team modifies native protein surfaces in two ways: They graft complementary metal-binding sites onto the surfaces so metal ions can induce protein-protein interactions, and they disable the proteins’ native interactions, making metal ions the sole factor controlling interface formation. They demonstrate the technique by using divalent copper binding to induce formation of ferritin, a cagelike 24-mer protein, from its monomers. Tezcan notes that the technique could be used to study self-assembly mechanisms of protein complexes and cell-signaling processes.