title: Cytoskeletal and phosphoinositide requirements for muscarinic receptor signaling to focal adhesion kinase and paxillin.
abstract: The mechanism whereby agonist occupancy of muscarinic cholinergic receptors elicits an increased tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin has been examined. Addition of oxotremorine-M to SH-SY5Y neuroblastoma cells resulted in rapid increases in the phosphorylation of FAK (t(1/2) = 2 min) and paxillin that were independent of integrin-extracellular matrix interactions, cell attachment, and the production of phosphoinositide-derived second messengers. In contrast, the increased tyrosine phosphorylations of FAK and paxillin were inhibited by inclusion of either cytochalasin D or mevastatin, agents that disrupt the cytoskeleton. Furthermore, phosphorylation of FAK and paxillin could be prevented by addition of either wortmannin or LY-294002, under conditions in which the synthesis of phosphatidylinositol 4-phosphate was markedly attenuated. These results indicate that muscarinic receptor-mediated increases in the tyrosine phosphorylation of FAK and paxillin in SH-SY5Y neuroblastoma cells depend on both the maintenance of an actin cytoskeleton and the ability of these cells to synthesize phosphoinositides.
authors.affiliation: Department of Pharmacology, Mental Health Research Institute, University of Michigan, Ann Arbor 48104-1687, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Linseman
authors.forename: E L
authors.initials: EL
authors.lastname: McEwen
authors.forename: S D
authors.initials: SD
authors.lastname: Sorensen
authors.forename: S K
authors.initials: SK
authors.lastname: Fisher
mesh_terms: D000199:Actins / Q000378:metabolism; D000730:Androstadienes / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000378:metabolism* / Q000502:physiology; D002867:Chromones / Q000494:pharmacology; D015638:Cytochalasin D / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000502:physiology*; D003599:Cytoskeleton / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019204:GTP-Binding Proteins / Q000502:physiology; D006801:Humans; D008148:Lovastatin / Q000031:analogs & derivatives / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology; D018721:Muscarinic Agonists / Q000494:pharmacology; D009447:Neuroblastoma; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D051419:Paxillin; D018129:Phosphatidylinositol Phosphates / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000502:physiology*; D010750:Phosphoproteins / Q000502:physiology*; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011972:Receptor, Insulin / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000502:physiology*; D015290:Second Messenger Systems / Q000187:drug effects / Q000502:physiology*; D014407:Tumor Cells, Cultured / Q000201:enzymology; D014443:Tyrosine / Q000378:metabolism; D000077191:Wortmannin
chemical_list: D000199:Actins; D000730:Androstadienes; D015815:Cell Adhesion Molecules; D002867:Chromones; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D009025:Morpholines; D018721:Muscarinic Agonists; D019384:Nucleic Acid Synthesis Inhibitors; C496061:PXN protein, human; D051419:Paxillin; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D010750:Phosphoproteins; D010761:Phosphorus Radioisotopes; D011976:Receptors, Muscarinic; C037178:phosphatidylinositol 4-phosphate; C012258:mevastatin; D015638:Cytochalasin D; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D014443:Tyrosine; D008148:Lovastatin; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D019204:GTP-Binding Proteins; D000077191:Wortmannin