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.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Actins / metabolism
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Androstadienes / pharmacology
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Cell Adhesion / physiology
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Cell Adhesion Molecules / metabolism*
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Cell Adhesion Molecules / physiology
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Chromones / pharmacology
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Cytochalasin D / pharmacology
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Cytoskeletal Proteins / physiology*
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Cytoskeleton / physiology
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Enzyme Inhibitors / pharmacology
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Focal Adhesion Kinase 1
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Focal Adhesion Protein-Tyrosine Kinases
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GTP-Binding Proteins / physiology
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Humans
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Lovastatin / analogs & derivatives
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Lovastatin / pharmacology
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Morpholines / pharmacology
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Muscarinic Agonists / pharmacology
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Neuroblastoma
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Nucleic Acid Synthesis Inhibitors / pharmacology
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Paxillin
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Phosphatidylinositol Phosphates / pharmacology
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Phosphatidylinositols / physiology*
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Phosphoproteins / physiology*
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Phosphorus Radioisotopes
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Phosphorylation
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Protein-Tyrosine Kinases / metabolism*
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Receptor, Insulin / metabolism
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Receptors, Muscarinic / physiology*
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Second Messenger Systems / drug effects
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Second Messenger Systems / physiology*
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Tumor Cells, Cultured / enzymology
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Tyrosine / metabolism
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Wortmannin
Substances
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Actins
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Androstadienes
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Cell Adhesion Molecules
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Chromones
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Cytoskeletal Proteins
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Enzyme Inhibitors
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Morpholines
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Muscarinic Agonists
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Nucleic Acid Synthesis Inhibitors
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PXN protein, human
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Paxillin
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Phosphatidylinositol Phosphates
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Phosphatidylinositols
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Phosphoproteins
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Phosphorus Radioisotopes
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Receptors, Muscarinic
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phosphatidylinositol 4-phosphate
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mevastatin
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Cytochalasin D
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2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
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Tyrosine
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Lovastatin
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Protein-Tyrosine Kinases
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Receptor, Insulin
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Focal Adhesion Kinase 1
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Focal Adhesion Protein-Tyrosine Kinases
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PTK2 protein, human
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GTP-Binding Proteins
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Wortmannin