title: Ligand endocytosis drives receptor dissociation and activation in the Notch pathway.
abstract: Endocytosis of the ligand delta; is required for activation of the receptor Notch during Drosophila development. The Notch extracellular domain (NotchECD) dissociates from the Notch intracellular domain (NotchICD) and is trans-endocytosed into delta;-expressing cells in wild-type imaginal discs. Reduction of dynamin-mediated endocytosis in developing eye and wing imaginal discs reduces Notch dissociation and Notch signalling. Furthermore, dynamin-mediated delta endocytosis is required for Notch trans-endocytosis in Drosophila cultured cell lines. Endocytosis-defective delta proteins fail to mediate trans-endocytosis of Notch in cultured cells, and exhibit aberrant subcellular trafficking and reduced signalling capacity in Drosophila. We suggest that endocytosis into delta-expressing cells of NotchECD bound to delta plays a critical role during activation of the Notch receptor and is required to achieve processing and dissociation of the Notch protein.
authors.affiliation: Department of Biology, Indiana University, Bloomington, IN 47405, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Parks
authors.forename: K M
authors.initials: KM
authors.lastname: Klueg
authors.forename: J R
authors.initials: JR
authors.lastname: Stout
authors.forename: M A
authors.initials: MA
authors.lastname: Muskavitch
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D004330:Drosophila / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D029721:Drosophila Proteins; D034281:Dynamins; D004705:Endocytosis / Q000502:physiology*; D020558:GTP Phosphohydrolases / Q000502:physiology; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D051880:Receptors, Notch; D012160:Retina / Q000254:growth & development; D015398:Signal Transduction; D014921:Wings, Animal / Q000254:growth & development
chemical_list: D017931:DNA Primers; D029721:Drosophila Proteins; D019476:Insect Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D008565:Membrane Proteins; C497759:N protein, Drosophila; D051880:Receptors, Notch; C064045:delta protein; D020558:GTP Phosphohydrolases; D034281:Dynamins