Offermanns S, Bombien E, Schultz G
Institut für Pharmakologie, Freie Universität Berlin, Federal Republic of Germany.
Biochem J. 1993 Sep 1;294 ( Pt 2)(Pt 2):545-50. doi: 10.1042/bj2940545.
Activation of the G-protein-coupled muscarinic (M3) receptor in human neuroblastoma SH-SY5Y cells is known to lead to phosphoinositol hydrolysis and noradrenaline release. In this study, the effect of carbachol on tyrosine phosphorylation and mitogen-activated protein (MAP) kinase activity in SH-SY5Y cells was examined. Carbachol concentration-dependently induced tyrosine phosphorylation of several proteins, including one of 42 kDa. This tyrosine-phosphorylated 42 kDa protein co-eluted from a Mono Q anion-exchange column with MAP kinase activity and with immunologically detected MAP kinase. Stimulation of tyrosine phosphorylation and activation of MAP kinase were also observed after incubation of cells with phorbol 12-myristate 13-acetate (PMA) and epidermal growth factor (EGF). Down-regulation or inhibition of protein kinase C (PKC) abolished the stimulatory effects of both carbachol and PMA on MAP kinase activity, whereas EGF-stimulated MAP kinase activity remained unaffected. Thus carbachol acting through the muscarinic (M3) receptor PKC-dependently induced tyrosine phosphorylation and activation of a 42 kDa MAP kinase in SH-SY5Y cells, whereas EGF-induced MAP kinase activation occurred independently of PKC.
已知在人神经母细胞瘤SH-SY5Y细胞中，G蛋白偶联的毒蕈碱（M3）受体的激活会导致磷酸肌醇水解和去甲肾上腺素释放。在本研究中，检测了卡巴胆碱对SH-SY5Y细胞中酪氨酸磷酸化和丝裂原活化蛋白（MAP）激酶活性的影响。卡巴胆碱浓度依赖性地诱导了几种蛋白质的酪氨酸磷酸化，包括一种42 kDa的蛋白质。这种酪氨酸磷酸化的42 kDa蛋白质与MAP激酶活性以及免疫检测到的MAP激酶一起从Mono Q阴离子交换柱上共同洗脱。在用佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）和表皮生长因子（EGF）孵育细胞后，也观察到了酪氨酸磷酸化的刺激和MAP激酶的激活。蛋白激酶C（PKC）的下调或抑制消除了卡巴胆碱和PMA对MAP激酶活性的刺激作用，而EGF刺激的MAP激酶活性不受影响。因此，通过毒蕈碱（M3）受体起作用的卡巴胆碱以PKC依赖性方式诱导SH-SY5Y细胞中42 kDa MAP激酶的酪氨酸磷酸化和激活，而EGF诱导的MAP激酶激活独立于PKC发生。
