Identification of human prostaglandin E synthase:: A microsomal, glutathione-dependent, inducible enzyme, constituting a potential novel drug target
Identification of human prostaglandin E synthase:: A microsomal, glutathione-dependent, inducible enzyme, constituting a potential novel drug target
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DOI：
10.1073/pnas.96.13.7220
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发表时间：
1999-06-22
影响因子：
11.1
通讯作者：
Samuelsson, B
中科院分区：
文献类型：
--
作者：
Jakobsson, PJ;Thorén, S;Samuelsson, B
人前列腺素（PG） E合成酶（EC 5.3.99.3）是最近发现的一个蛋白质超家族的成员，该家族由参与类二十碳酸和谷胱甘肽代谢的膜相关蛋白（MAPEG家族）组成。该蛋白以前的名称是PIG12和MGST1-L1。在大肠杆菌中表达了PGE合成酶，并制备了细胞质和膜两种组分。Western blot分析在膜组分中特异性检测到15- 16kda蛋白。在还原性谷胱甘肽存在或不存在的情况下，用前列腺素H-2孵育两种组分，发现膜组分而非胞质组分具有高的谷胱甘肽依赖性PGE合成酶活性（0.25 μ mol/min/mg）。采用Northern blot分析人体组织分布。PGE合成酶mRNA在A549和HeLa癌细胞中高表达。在胎盘、前列腺、睾丸、乳腺和膀胱中有中等水平的表达，而在其他组织中也有lon mRNA的表达。以A549细胞为模型系统研究IL-1 β对环氧化酶-2的诱导作用，如果A549细胞在IL-1 β存在下生长，通过Western blot分析观察到PGE合成酶的显著诱导作用。此外，Western blot分析在绵羊精囊中特异性检测到一种16kda蛋白。总之，我们已经确定了一个人膜结合的PGE合成酶。酶活性依赖谷胱甘肽，蛋白表达受促炎细胞因子IL-1 β诱导，PGE合成酶是药物开发的潜在新靶点。
Human prostaglandin (PG) E synthase (EC 5.3.99.3) is a member of a recently recognized protein superfamily consisting of membrane associated proteins involved in eicosanoid and glutathione metabolism (the MAPEG family). Previous designations of the protein are PIG12 and MGST1-L1. PGE synthase was expressed in Escherichia coli, and both cytosolic and membrane fractions were prepared. Western blot analysis specifically detected a 15- to 16-kDa protein in the membrane fraction. Both fractions were incubated with prostaglandin H-2 in the presence or absence of reduced glutathione, The membrane but not the cytosolic fraction was found to possess high glutathione-dependent PGE synthase activity (0.25 mu mol/min/mg). The human tissue distribution was analyzed by Northern blot analysis. High expression of PGE synthase mRNA was detected in A549 and HeLa cancer cell lines. Intermediate level of expression was demonstrated in placenta, prostate, testis, mammary gland, and bladder whereas lon mRNA expression was observed in several other tissues. A549 cells have been used as a model system to study cyclooxygenase-2 induction by IL-1 beta, If A549 cells were grown in the presence of IL-1 beta, a significant induction of the PGE synthase was observed by Western blot analysis. Also, Western blot analysis specifically detected a 16-kDa protein in sheep seminal vesicles. In summary, we have identified a human membrane bound PGE synthase. The enzyme activity is glutathione-dependent, and the protein expression is induced by the proinflammatory cytokine IL-1 beta, PGE synthase is a potential novel target for drug development.