Regulation of phospholipase D2:: Selective inhibition of mammalian phospholipase D isoenzymes by α- and β-synucleins
Regulation of phospholipase D2:: Selective inhibition of mammalian phospholipase D isoenzymes by α- and β-synucleins
复制标题
DOI：
10.1021/bi972776r
复制
发表时间：
1998-04-07
期刊：
影响因子：
2.9
通讯作者：
Morris, AJ
中科院分区：
文献类型：
--
作者：
Jenco, JM;Rawlingson, A;Morris, AJ
已鉴定出两种广泛表达的哺乳动物磷脂酰胆碱（PC）特异性磷脂酶D（PLD），PLD 1和PLD 2。恶性表达的PLD 2具有高基础活性，并且对PLD 1的GTP结合蛋白激活剂不敏感[Colley，W. C.的方法，等人（1997）Curr. 7，191-201]。为了研究PLD 2的调节，我们通过免疫亲和层析从小鼠脑中分离PLD 2。天然和重组蛋白具有不可区分的特性：PLD 2被具有邻位4，5-磷酸对的磷酸肌醇有效激活，但不被鸟苷5 '-O-（3-硫代三磷酸）激活的ADP-核糖基化因子-1，Rho家族GTP结合蛋白或蛋白激酶C-α或-β刺激（1）。我们在重组试验中使用重组PLD 2来寻找细胞和组织提取物中的调节剂。牛脑中含有一种热稳定蛋白因子，可在体外抑制PLD 2的活性。将该因子纯化至同质，并通过微测序和Western印迹鉴定为α-和β-突触核蛋白的混合物。恶性表达的α-和β-突触核蛋白在体外抑制PLD 2活性（K-0.5 10 nM）。PLD 1的蛋白质或脂质激活剂不能克服抑制作用。突触核蛋白与帕金森病和阿尔茨海默病有关。我们的研究结果表明，抑制PLD 2可能是突触核蛋白的功能。突触核蛋白对PLD 2活性的调节可能在表征这些神经退行性疾病的病理生理学的某些方面发挥作用。
Two widely expressed mammalian phosphatidylcholine (PC)-specific phospholipases D (PLD), PLD1 and PLD2, have been identified. Recombinantly expressed PLD2 has high basal activity and is insensitive to GTP-binding protein activators of PLD1 [Colley, W. C., et al. (1997) Curr. Biol. 7, 191-201]. To investigate the regulation of PLD2 we isolated PLD2, from mouse brain by immunoaffinity chromatography. The native and recombinant proteins have indistinguishable properties: PLD2 is potently activated by phosphoinositides with a vicinal 4,5-phosphate pair but is not stimulated by guanosine 5'-O-(3-thio triphosphate)-activated ADP-ribosylation factor-1, Rho family GTP-binding proteins, or protein kinases C-alpha, or -beta(1). We used recombinant PLD2 in a reconstitution assay to search for regulators in cell and tissue extracts. Bovine brain contains a heat-stable protein factor that inhibits PLD2 activity in vitro. This factor was purified to homogeneity and identified as a mixture of alpha- and beta-synucleins by microsequencing and Western blotting. Recombinantly expressed alpha- and beta-synucleins inhibit PLD2 activity in vitro (K-0.5 10 nM). Inhibition is not overcome by the protein or lipid activators of PLD1. Synucleins have been implicated in Parkinson's and Alzheimer's diseases. Our findings suggest that inhibition of PLD2 may be a function of synucleins. Modulation of PLD2 activity by synucleins may play a role in some aspects of the pathophysiologies that characterize these neurodegenerative diseases.