(A) Schematic representation of hN1. NEC, Notch extracellular subunit; NTM, Notch transmembrane subunit; NRR, negative regulatory region; LNR, domain comprising the three LIN12/Notch repeats; NECC, C-terminal segment of NEC; NTMX, NTM extracellular region; TM, transmembrane segment; ICN, intracellular Notch; TAD, transactivation domain; S1, furin cleavage site. (B) Truncated hN1 polypeptides used in these studies.