Crystal structure of a mammalian Wnt–frizzled complex

Wnt signaling plays fundamental roles in organogenesis, tissue regeneration and cancer, but high-resolution structural information of mammalian Wnt proteins is lacking. We solved a 2.8-A resolution crystal structure of human Wnt3 in complex with mouse Frizzled 8 Cys-rich domain (CRD). Wnt3 grabs the receptor in a manner very similar to that found in Xenopus Wnt8 complexed with the same receptor. Unlike Xenopus Wnt8-bound CRD, however, Wnt3-bound...