Linseman D A, McEwen E L, Sorensen S D, Fisher S K
Department of Pharmacology, Mental Health Research Institute, University of Michigan, Ann Arbor 48104-1687, USA.
J Neurochem. 1998 Mar;70(3):940-50. 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 (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.
毒蕈碱型胆碱能受体激动剂占据引发粘着斑激酶（FAK）和桩蛋白酪氨酸磷酸化增加的机制已得到研究。向SH-SY5Y神经母细胞瘤细胞中添加氧化震颤素-M会导致FAK（t(1/2) = 2分钟）和桩蛋白的磷酸化迅速增加，这与整合素-细胞外基质相互作用、细胞附着以及磷酸肌醇衍生的第二信使的产生无关。相比之下，FAK和桩蛋白酪氨酸磷酸化的增加被细胞松弛素D或美伐他汀抑制，这两种药物会破坏细胞骨架。此外，在磷脂酰肌醇4-磷酸的合成明显减弱的条件下，添加渥曼青霉素或LY-294002可阻止FAK和桩蛋白的磷酸化。这些结果表明，毒蕈碱受体介导的SH-SY5Y神经母细胞瘤细胞中FAK和桩蛋白酪氨酸磷酸化的增加既依赖于肌动蛋白细胞骨架的维持，也依赖于这些细胞合成磷酸肌醇的能力。
