Year: 2008
Type: article
Abstract: BACKGROUND: Extracellular domains of the Notch family of signalling receptors contain many EGF repeat domains, as do their major ligands. Some EGF repeats are modified by O-fucosylation, and most have no identified role in ligand binding. RESULTS: Using a binding assay with purified proteins in vitro, it was determined that, in addition to binding to Delta, the ligand binding region of Notch bound to EGF repeats 22-27 of Notch, but not to other EGF repeat regions of Notch. EGF repeats 22-27 of Drosophila Notch overlap the genetically-defined 'Abruptex' region, and competed with Delta for binding to proteins containing the ligand-binding domain. Delta differed from the Abruptex domain in showing markedly enhanced binding at acid pH. Both Delta and the Abruptex region are heavily modified by protein O-fucosylation, but the split mutation of Drosophila Notch, which affects O-fucosylation of EGF repeat 14, did not affect binding of Notch to either Delta or the Abruptex region. CONCLUSION: The Abruptex region may serve as a barrier to Notch activation by competing for the ligand-binding domain of Notch.
Source: BMC Developmental Biology
Authors: Zifei Pei, Nicholas E Baker
Institution: Albert Einstein College of Medicine
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $2,290
OpenAlex ID: W1975410351