Cytoskeletal and Phosphoinositide Requirements for Muscarinic Receptor Signaling to Focal Adhesion Kinase and Paxillin

• Published in: Journal of neurochemistry 1998-03, Vol.70 (3), p.940-950
• Main Authors: Linseman, Daniel A., McEwen, Edward L., Sorensen, Scott D., Fisher, Stephen K.
• Format: Article
• Language: English
• Subjects: Actin polymerization; Actins - metabolism; Androstadienes - pharmacology; Biological and medical sciences; Cell Adhesion - physiology; Cell Adhesion Molecules - metabolism; Cell Adhesion Molecules - physiology; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Chromones - pharmacology; Cytochalasin; Cytochalasin D - pharmacology; Cytoskeletal Proteins - physiology; Cytoskeleton - physiology; Enzyme Inhibitors - pharmacology; Focal Adhesion Kinase 1; Focal Adhesion Protein-Tyrosine Kinases; Fundamental and applied biological sciences. Psychology; GTP-Binding Proteins - physiology; Humans; Lovastatin - analogs & derivatives; Lovastatin - pharmacology; LY‐294002; Mevastatin; Morpholines - pharmacology; Muscarinic Agonists - pharmacology; Neuroblastoma; Nucleic Acid Synthesis Inhibitors - pharmacology; Paxillin; Phosphatidylinositol 4‐phosphate; Phosphatidylinositol Phosphates - pharmacology; Phosphatidylinositols - physiology; Phosphoproteins - physiology; Phosphorus Radioisotopes; Phosphorylation; Protein-Tyrosine Kinases - metabolism; Receptor, Insulin - metabolism; Receptors, Muscarinic - physiology; Second Messenger Systems - drug effects; Second Messenger Systems - physiology; Tumor Cells, Cultured - enzymology; Tyrosine - metabolism; Vertebrates: nervous system and sense organs; Wortmannin
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1046/j.1471-4159.1998.70030940.x

: 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 (t1/2 = 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.