The E3 ubiquitin ligase FBXW7, a homologue of C. elegans sel-10, binds to Notch1 intracellular domain NICD1. This interaction was demonstrated by co-immunoprecipitation of the human recombinant FBXW7 and mouse recombinant NICD1 (Oberg et al. 2001). FBXW7 binds phosphorylated intracellular domain of Notch proteins, as shown for mouse NICD1 (Fryer et al. 2004) and mouse NICD4 (Wu et al. 2001).