Notch-Jagged signaling complex defined by an interaction mosaic

• DOI: 10.1101/2021.02.19.432005
• Publication Date: 2021-02-20T04:45:53Z
• Authors: Matthieu R. Zeronian; Oleg Klykov; Júlia Portell i d...; Maria J. Konijnen...; Anamika Gaur; Richard A. Scheltema; Bert J.C. Janssen
• Keywords: Ectodomain; Cell fate determination

Abstract The Notch signaling system links cellular fate to that of its neighbors, driving proliferation, apoptosis, and cell differentiation in metazoans, whereas dysfunction leads debilitating developmental disorders cancers. Other than a five-by-five domain complex, it is unclear how the 40 extracellular domains Notch1 receptor collectively engage 19 canonical ligand Jagged1 activate signaling. Here, using cross-linking mass spectrometry (XL-MS), biophysical structural techniques on full complex targeted sites,we identify five distinct regions, two three Jagged1, form an interaction network.The membrane-proximal regulatory region individually binds established epidermal growth factor (EGF) 8-13 C2-EGF3 activation sites, as well additional EGF 8-11 cysteine-rich (CRD). XL-MS quantitative experiments show binding sites also intramolecularly.These interactions, together with ectodomain dimensions flexibility determined by small-angle X-ray scattering (SAXS), support formation backfolded architectures. Combined, data suggest critical regions are not distal, but directly control signaling, thereby redefining Notch1-Jagged1 mechanism indicating new routes for therapeutic applications.