New alleles of Notch draw a blueprint for multifunctionality

The Drosophila Notch protein is one of a family of receptors that mediate an essential and perhaps universal function in the assignation of cell fates during development. Activation of Notch by its ligand, Delta, leads to the cleavage of the intracellular domain of the receptor. This domain relocates to the nucleus, where it combines with the transcription factor Suppressor of Hairless to regulate gene expression. In a recent report, Ramain, Heitzler and colleagues reveal the existence of a second Notch signalling activity that is independent of Suppressor of Hairless and might be used to link Notch activity to that of other signalling pathways, most notably Wingless/Wnt signalling. This link might be a central element in many processes of cell-fate assignation during development.