title: Functional analysis of the NHR2 domain indicates that oligomerization of Neuralized regulates ubiquitination and endocytosis of Delta during Notch signaling.
abstract: The Notch pathway plays an integral role in development by regulating cell fate in a wide variety of multicellular organisms. A critical step in the activation of Notch signaling is the endocytosis of the Notch ligands Delta and Serrate. Ligand endocytosis is regulated by one of two E3 ubiquitin ligases, Neuralized (Neur) or Mind bomb. Neur is comprised of a C-terminal RING domain, which is required for Delta ubiquitination, and two Neur homology repeat (NHR) domains. We have previously shown that the NHR1 domain is required for Delta trafficking. Here we show that the NHR1 domain also affects the binding and internalization of Serrate. Furthermore, we show that the NHR2 domain is required for Neur function and that a point mutation in the NHR2 domain (Gly430) abolishes Neur ubiquitination activity and affects ligand internalization. Finally, we provide evidence that Neur can form oligomers in both cultured cells and fly tissues, which regulate Neur activity and, by extension, ligand internalization.
authors.affiliation: The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, Ontario, Canada.
authors.forename: Sili
authors.initials: S
authors.lastname: Liu
authors.forename: Julia Maeve
authors.initials: JM
authors.lastname: Bonner
authors.forename: Soline
authors.initials: S
authors.lastname: Chanet
authors.forename: Cosimo
authors.initials: C
authors.lastname: Commisso
authors.forename: Lara C
authors.initials: LC
authors.lastname: Skwarek
authors.forename: François
authors.initials: F
authors.lastname: Schweisguth
authors.forename: Gabrielle L
authors.initials: GL
authors.lastname: Boulianne
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D030801:Animals, Genetically Modified; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002460:Cell Line; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D004705:Endocytosis; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D000072100:Jagged-1 Protein; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism*; D008954:Models, Biological; D017354:Point Mutation; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D051880:Receptors, Notch / Q000378:metabolism*; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D002135:Calcium-Binding Proteins; D029721:Drosophila Proteins; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008024:Ligands; D008565:Membrane Proteins; C497759:N protein, Drosophila; D051880:Receptors, Notch; C000606278:Ser protein, Drosophila; D000072099:Serrate-Jagged Proteins; C064045:delta protein; D044767:Ubiquitin-Protein Ligases; C071006:neur protein, Drosophila