title: Docking protein FRS2 links the protein tyrosine kinase RET and its oncogenic forms with the mitogen-activated protein kinase signaling cascade.
abstract: The receptor tyrosine kinase RET functions as the signal transducing receptor for the GDNF (for "glial cell-derived neurotrophic factors") family of ligands. Mutations in the RET gene were implicated in Hirschsprung disease (HSCR), multiple endocrine neoplasia type 2 (MEN 2), and thyroid carcinomas. In this report we demonstrate that the docking protein FRS2 is tyrosine phosphorylated by ligand-stimulated and by constitutively activated oncogenic forms of RET. Complex formation between RET and FRS2 is mediated by binding of the phosphotyrosine-binding domain of FRS2 to pY1062, a residue in RET that also functions as a binding site for Shc. However, overexpression of FRS2 but not Shc potentiates mitogen-activated protein (MAP) kinase activation by RET oncoproteins. We demonstrate that oncogenic RET-PTC proteins are associated with FRS2 constitutively, leading to tyrosine phosphorylation of FRS2, MAP kinase stimulation, and cell proliferation. However, loss-of-function HSCR-associated RET mutants exhibit impaired FRS2 binding and reduced MAP kinase activation. These experiments demonstrate that FRS2 couples both ligand-regulated and oncogenic forms of RET, with the MAP kinase signaling cascade as part of the response of RET under normal biological conditions and pathological conditions, such as MEN 2 and papillary thyroid carcinomas.
authors.affiliation: Centro di Endocrinologia ed Oncologia Sperimentale del CNR, Dipartimento di Biologia e Patologia Cellulare e Molecolare, Naples, Italy.
authors.forename: R M
authors.initials: RM
authors.lastname: Melillo
authors.forename: M
authors.initials: M
authors.lastname: Santoro
authors.forename: S H
authors.initials: SH
authors.lastname: Ong
authors.forename: M
authors.initials: M
authors.lastname: Billaud
authors.forename: A
authors.initials: A
authors.lastname: Fusco
authors.forename: Y R
authors.initials: YR
authors.lastname: Hadari
authors.forename: J
authors.initials: J
authors.lastname: Schlessinger
authors.forename: I
authors.initials: I
authors.lastname: Lax
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D002460:Cell Line; D029721:Drosophila Proteins; D017930:Genes, Reporter / Q000235:genetics; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D006627:Hirschsprung Disease / Q000235:genetics; D006801:Humans; D008024:Ligands; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018813:Multiple Endocrine Neoplasia Type 2a / Q000235:genetics; D009154:Mutation; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D029721:Drosophila Proteins; C106534:FRS2 protein, human; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D008024:Ligands; D008565:Membrane Proteins; D010750:Phosphoproteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; D020928:Mitogen-Activated Protein Kinases