title: Nedd4-1 binds and ubiquitylates activated FGFR1 to control its endocytosis and function.
abstract: Fibroblast growth factor receptor 1 (FGFR1) has critical roles in cellular proliferation and differentiation during animal development and adult homeostasis. Here, we show that human Nedd4 (Nedd4-1), an E3 ubiquitin ligase comprised of a C2 domain, 4 WW domains, and a Hect domain, regulates endocytosis and signalling of FGFR1. Nedd4-1 binds directly to and ubiquitylates activated FGFR1, by interacting primarily via its WW3 domain with a novel non-canonical sequence (non-PY motif) on FGFR1. Deletion of this recognition motif (FGFR1-Δ6) abolishes Nedd4-1 binding and receptor ubiquitylation, and impairs endocytosis of activated receptor, as also observed upon Nedd4-1 knockdown. Accordingly, FGFR1-Δ6, or Nedd4-1 knockdown, exhibits sustained FGF-dependent receptor Tyr phosphorylation and downstream signalling (activation of FRS2α, Akt, Erk1/2, and PLCγ). Expression of FGFR1-Δ6 in human embryonic neural stem cells strongly promotes FGF2-dependent neuronal differentiation. Furthermore, expression of this FGFR1-Δ6 mutant in zebrafish embryos disrupts anterior neuronal patterning (head development), consistent with excessive FGFR1 signalling. These results identify Nedd4-1 as a key regulator of FGFR1 endocytosis and signalling during neuronal differentiation and embryonic development.
authors.affiliation: Programs in Cell Biology and Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Avinash
authors.initials: A
authors.lastname: Persaud
authors.forename: Philipp
authors.initials: P
authors.lastname: Alberts
authors.forename: Madeline
authors.initials: M
authors.lastname: Hayes
authors.forename: Sebastian
authors.initials: S
authors.lastname: Guettler
authors.forename: Ian
authors.initials: I
authors.lastname: Clarke
authors.forename: Frank
authors.initials: F
authors.lastname: Sicheri
authors.forename: Peter
authors.initials: P
authors.lastname: Dirks
authors.forename: Brian
authors.initials: B
authors.lastname: Ciruna
authors.forename: Daniela
authors.initials: D
authors.lastname: Rotin
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019521:Body Patterning / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002490:Central Nervous System / Q000196:embryology; D004705:Endocytosis / Q000502:physiology*; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000502:physiology*; D055785:Gene Knockdown Techniques; D006801:Humans; D008969:Molecular Sequence Data; D000075702:Nedd4 Ubiquitin Protein Ligases; D009474:Neurons / Q000166:cytology; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D051381:Rats; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D013045:Species Specificity; D013234:Stem Cells / Q000166:cytology; D013379:Substrate Specificity; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000502:physiology*; D054875:Ubiquitination; D015027:Zebrafish / Q000196:embryology
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; C000618479:NEDD4L protein, rat; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618483:Nedd4 protein, human; C000618484:Nedd4 protein, rat; D044767:Ubiquitin-Protein Ligases; C496348:FGFR1 protein, human; D051496:Receptor, Fibroblast Growth Factor, Type 1