title: The neuronal scaffold protein Shank3 mediates signaling and biological function of the receptor tyrosine kinase Ret in epithelial cells.
abstract: Shank proteins, initially also described as ProSAP proteins, are scaffolding adaptors that have been previously shown to integrate neurotransmitter receptors into the cortical cytoskeleton at postsynaptic densities. We show here that Shank proteins are also crucial in receptor tyrosine kinase signaling. The PDZ domain-containing Shank3 protein was found to represent a novel interaction partner of the receptor tyrosine kinase Ret, which binds specifically to a PDZ-binding motif present in the Ret9 but not in the Ret51 isoform. Furthermore, we show that Ret9 but not Ret51 induces epithelial cells to form branched tubular structures in three-dimensional cultures in a Shank3-dependent manner. Ret9 but not Ret51 has been previously shown to be required for kidney development. Shank3 protein mediates sustained Erk-MAPK and PI3K signaling, which is crucial for tubule formation, through recruitment of the adaptor protein Grb2. These results demonstrate that the Shank3 adaptor protein can mediate cellular signaling, and provide a molecular mechanism for the biological divergence between the Ret9 and Ret51 isoform.
authors.affiliation: MaxDelbrück-Center for Molecular Medicine, Berlin, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Schuetz
authors.forename: Marta
authors.initials: M
authors.lastname: Rosário
authors.forename: Jan
authors.initials: J
authors.lastname: Grimm
authors.forename: Tobias M
authors.initials: TM
authors.lastname: Boeckers
authors.forename: Eckart D
authors.initials: ED
authors.lastname: Gundelfinger
authors.forename: Walter
authors.initials: W
authors.lastname: Birchmeier
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D001665:Binding Sites / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D045744:Cell Line, Tumor; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism*; D051380:GRB2 Adaptor Protein; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology; D051379:Mice; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D009474:Neurons / Q000378:metabolism; D038081:Organogenesis / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D020033:Protein Isoforms / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; C495949:Grb2 protein, mouse; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D011518:Proto-Oncogene Proteins; C492356:Shank3 protein, mouse; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C494999:Ret protein, mouse