A sweet development in Notch regulation.

The transmembrane signaling protein Notch, which is crucial for embryonic cell fate decisions, has 36 extracellular EGF domains that are glycosylated in variable and complex ways. A new study shows that O-fucose and O-glucose stabilize the repeats but that extension of glucose by xylose weakens stability, explained by the binding of the glycan to a protein groove. This work shows how different types of glycosylation can distinctly influence protein stability and structure.