Signaling Central

Wnt growth factors activate a signaling cascade that plays a key role in animal development, stem cell biology, and human cancer. Although many of the cascade components have been identified, how they come together to transmit the signal from the plasma membrane inside the cell is not clear. Bilić et al . show that Wnt ligands induce formation of large, ribosome-sized complexes, termed the low-density lipoprotein receptor-related protein 6 (LRP6) signalosome at the plasma membrane. The large protein assemblies contain activated Wnt receptors and cytoplasmic adaptor proteins. The scaffold protein Dishevelled and the Wnt co-receptor LRP6 play a central role in LRP6-signalosome formation, triggering subsequent molecular interactions that regulate the level of nuclear β-catenin. J. Bilić, Y.-L. Huang, G. Davidson, T. Zimmermann, C.-M. Cruciat, M. Bienz, C, Niehrs, Wnt induces LRP6 signalosomes and promotes Dishevelled-dependent LRP6 phosphorylation. Science 316 , 1619-1622 (2007). [Abstract] [Full Text]