title: c-Src is involved in regulating signal transmission from PDGFbeta receptor-GPCR(s) complexes in mammalian cells.
abstract: We have reported that the platelet-derived growth factor receptor-beta (PDGFbeta) forms a novel signaling complex with G protein-coupled receptors (GPCR) (e.g. S1P(1) receptor) that enables more efficient activation of p42/p44 mitogen-activated protein kinase (MAPK) in response to PDGF and sphingosine 1-phosphate (S1P). We now demonstrate that c-Src participates in regulating the endocytosis of PDGFbeta receptor-GPCR complexes in response to PDGF. This leads to association of cytoplasmic p42/p44 MAPK with the receptor complex in endocytic vesicles. c-Src is regulated by G protein betagamma subunits and can interact with beta-arrestin. Indeed, the PDGF-dependent activation of p42/p44 MAPK was reduced by over-expression of the C-terminal domain of GRK2 (sequesters Gbetagamma subunits), the clathrin-binding domain of beta-arrestin and by inhibitors of c-Src and clathrin-mediated endocytosis. Moreover, PDGF and S1P induce the recruitment of c-Src to the PDGFbeta receptor-S1P(1) receptor complex. This leads to a G protein/c-Src-dependent tyrosine phosphorylation of Gab1 and accumulation of dynamin II at the plasma membrane, a step required for endocytosis of the PDGFbeta receptor-GPCR complex. These findings provide important information concerning the molecular organisation of novel receptor tyrosine kinase (RTK)-GPCR signal relays in mammalian cells.
authors.affiliation: Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor St., Glasgow G4 ONR, UK.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Waters
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Connell
authors.forename: Susan
authors.initials: S
authors.lastname: Pyne
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Pyne
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D019390:Arrestins / Q000235:genetics / Q000378:metabolism; D002103:Cadaverine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002460:Cell Line; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D034285:Dynamin II / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051380:GRB2 Adaptor Protein; D006168:Guinea Pigs; D006801:Humans; D047468:Immunoprecipitation; D008246:Lysophospholipids / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D037342:Pertussis Toxin / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism / Q000502:physiology*; D011743:Pyrimidines / Q000494:pharmacology; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D049349:Receptors, Lysosphingolipid / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D014162:Transfection; D022161:Transport Vesicles / Q000737:chemistry / Q000378:metabolism; D051552:beta-Adrenergic Receptor Kinases; D000071557:beta-Arrestins
chemical_list: C412373:AG 1879; D048868:Adaptor Proteins, Signal Transducing; D019390:Arrestins; D004791:Enzyme Inhibitors; C098587:GAB1 protein, human; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D008246:Lysophospholipids; D010750:Phosphoproteins; D010982:Platelet-Derived Growth Factor; D011743:Pyrimidines; D043562:Receptors, G-Protein-Coupled; D049349:Receptors, Lysosphingolipid; D000071557:beta-Arrestins; D003208:Concanavalin A; C060506:sphingosine 1-phosphate; D037342:Pertussis Toxin; D019869:Phosphatidylinositol 3-Kinases; D020797:Receptor, Platelet-Derived Growth Factor beta; D016392:Proto-Oncogene Proteins pp60(c-src); D017868:Cyclic AMP-Dependent Protein Kinases; D051552:beta-Adrenergic Receptor Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D034285:Dynamin II; C008542:monodansylcadaverine; D002103:Cadaverine; D013110:Sphingosine