Binding to a structural protein may be a route by which abnormal (hyperphosphorylated) tau protein contributes to Alzheimer's and other neurological diseases, according to Harvard Medical School pathologists Mel B. Feany and Tudor A. Fulga and their colleagues (Nat. Cell Biol., DOI: 10.1038/ncb1528). Working with fruit flies and mice, the team found that the hyperphosphorylated tau binds to and stabilizes the cytoskeletal protein actin. β-Amyloid protein, which is also involved in Alzheimer's, enhances the effect. The interaction of these three proteins causes actin filaments to aggregate and eventually form rods. The rods might be toxic to neurons, according to the researchers. Alternatively, the rods might be less toxic than an intermediate aggregate form of actin and result from a protective mechanism by which brain cells neutralize the more toxic actin intermediate by sequestering it into rods.