May L G, Johnson S, Krebs S, Newman A, Aronstam R S
Guthrie Research Institute, Sayre, PA 18840, USA.
Cell Signal. 1999 Mar;11(3):179-87. doi: 10.1016/s0898-6568(98)00053-9.
The involvement of protein kinase C (PKC) and protein kinase A (PKA) in cholinergic signalling in CHO cells expressing the M3 subtype of the muscarinic acetylcholine receptor was examined. Muscarinic signalling was assessed by measuring carbachol-induced activation of phospholipase C (PLC), arachidonic acid release, and calcium mobilisation. Carbachol activation of PLC was not altered by inhibition of PKC with chelerythrine chloride, bisindolylmaleimide or chronic treatment with phorbol myristate acetate (PMA). Activation of PKC by acute treatment with PMA was similarly without effect. In contrast, inhibition of PKC blocked carbachol stimulation of arachidonic acid release. Likewise, PKC inhibition resulted in a decreased ability of carbachol to mobilise calcium, whereas PKC activation potentiated calcium mobilisation. Inhibition of PKA with H89 or Rp-cAMP did not alter the ability of carbachol to activate PLC. Similarly, PKA activation with Sp-cAMP or forskolin had no effect on PLC stimulation by carbachol. Carbachol-mediated release of arachidonic acid was decreased by H89 but only slightly increased by forskolin. Forskolin also increased calcium mobilisation by carbachol. These results suggest a function for PKC and PKA in M3 stimulation of arachidonic acid release and calcium mobilisation but not in PLC activation.
研究了蛋白激酶C（PKC）和蛋白激酶A（PKA）在表达毒蕈碱型乙酰胆碱受体M3亚型的CHO细胞胆碱能信号传导中的作用。通过测量卡巴胆碱诱导的磷脂酶C（PLC）激活、花生四烯酸释放和钙动员来评估毒蕈碱信号传导。用氯化白屈菜红碱、双吲哚马来酰亚胺抑制PKC或用佛波酯（PMA）长期处理，均未改变卡巴胆碱对PLC的激活作用。用PMA急性处理激活PKC同样无效。相反，抑制PKC可阻断卡巴胆碱对花生四烯酸释放的刺激。同样，抑制PKC会导致卡巴胆碱动员钙的能力下降，而激活PKC则增强钙动员。用H89或Rp-cAMP抑制PKA不会改变卡巴胆碱激活PLC的能力。同样，用Sp-cAMP或福斯高林激活PKA对卡巴胆碱刺激PLC也没有影响。H89可降低卡巴胆碱介导的花生四烯酸释放，但福斯高林仅使其略有增加。福斯高林还增强了卡巴胆碱引起的钙动员。这些结果表明，PKC和PKA在M3刺激花生四烯酸释放和钙动员中起作用，但在PLC激活中不起作用。
