γ-secretase activity of presenilin 1 regulates acetylcholine muscarinic receptor-mediated signal transduction
γ-secretase activity of presenilin 1 regulates acetylcholine muscarinic receptor-mediated signal transduction
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DOI：
10.1074/jbc.m306041200
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发表时间：
2004-02-20
影响因子：
4.8
通讯作者：
Cowburn, RF
中科院分区：
文献类型：
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作者：
Popescu, BO;Cedazo-Minguez, A;Cowburn, RF
家族性阿尔茨海默氏病 (FAD) 早老素 1 (PS1) 突变可增强对不同刺激的钙反应、减弱钙的钙进入能力、增加细胞凋亡的敏感性以及增加 γ 分泌酶活性。我们之前表明，导致 PS1 中外显子 9 缺失的 FAD 突变导致基础磷脂酶 C (PLC) 活性增强（Cedazo-Minguez, A.、Popescu, B. O.、Ankarcrona, M.、Nishimura, T. 和 Cowburn, R. F. (2002) J. Biol. Chem. 277, 36646-36655）。为了进一步阐明 PS1 干扰 PLC-钙信号传导的机制，我们研究了另外两种 FAD PS1 突变体（M146V 和 L250S）和两种显性失活 PS1 突变体（D257A 和 D385N）对 SH-SY5Y 神经母细胞瘤细胞中基础和卡巴胆碱刺激的磷酸肌醇 (PI) 水解和细胞内钙浓度 ([Ca2+](i)) 的影响。我们发现 PS1 M146V 细胞中的基础 PI 水解显着增加，但 PS1 L250S 细胞中没有。与未转染或野生型 PS1 转染细胞相比，PS1 M146V 和 PS1 L250S 细胞均显示卡巴胆碱诱导的 [Ca2+](i) 显着增加。 PLC 抑制剂新霉素、兰尼定受体拮抗剂丹曲林、通用天冬氨酰蛋白酶抑制剂胃酶抑素 A 和特异性 γ 分泌酶抑制剂 N-[N-(3,5-二氟苯乙酰基)-L-丙氨酰]-S-苯基甘氨酸叔丁酯可逆转卡巴胆碱诱导的 [Ca2+](i) 信号升高。表达 PS1 D257A 或 PS1 D385N 的细胞减弱了卡巴胆碱刺激的 PI 水解和 [Ca2+](i) 反应。在未转染或 PS1 野生型转染细胞中，N-[N-(3,5-二氟苯乙酰基)-L-丙氨酰]-S-苯基甘氨酸叔丁酯和胃酶抑素 A 还可减弱卡巴胆碱刺激的 PI 水解和 [Ca2+](i) 反应至 PS1 D257A 或 PS1 D385N 显性阴性细胞中发现的水平。我们的研究结果表明 PS1 可以调节 PLC 活性，并且该功能依赖于 γ 分泌酶活性。
Familial Alzheimer's disease (FAD) presenilin 1 (PS1) mutations give enhanced calcium responses upon different stimuli, attenuated capacitative calcium entry, an increased sensitivity of cells to undergo apoptosis, and increased gamma-secretase activity. We previously showed that the FAD mutation causing an exon 9 deletion in PS1 results in enhanced basal phospholipase C (PLC) activity (Cedazo-Minguez, A., Popescu, B. O., Ankarcrona, M., Nishimura, T., and Cowburn, R. F. (2002) J. Biol. Chem. 277, 36646-36655). To further elucidate the mechanisms by which PS1 interferes with PLC-calcium signaling, we studied the effect of two other FAD PS1 mutants (M146V and L250S) and two dominant negative PS1 mutants (D257A and D385N) on basal and carbachol-stimulated phosphoinositide (PI) hydrolysis and intracellular calcium concentrations ([Ca2+](i)) in SH-SY5Y neuroblastoma cells. We found a significant increase in basal PI hydrolysis in PS1 M146V cells but not in PS1 L250S cells. Both PS1 M146V and PS1 L250S cells showed a significant increase in carbachol-induced [Ca2+](i) as compared with nontransfected or wild type PS1 transfected cells. The elevated carbachol-induced [Ca2+](i) signals were reversed by the PLC inhibitor neomycin, the ryanodine receptor antagonist dantrolene, the general aspartyl protease inhibitor pepstatin A, and the specific gamma-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester. The cells expressing either PS1 D257A or PS1 D385N had attenuated carbachol-stimulated PI hydrolysis and [Ca2+](i) responses. In nontransfected or PS1 wild type transfected cells, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester and pepstatin A also attenuated both carbachol-stimulated PI hydrolysis and [Ca2+](i) responses to levels found in PS1 D257A or PS1 D385N dominant negative cells. Our findings suggest that PS1 can regulate PLC activity and that this function is gamma-secretase activity-dependent.