Nucleocapsid protein of SARS-CoV activates the expression of cyclooxygenase-2 by binding directly to regulatory elements for nuclear factor-kappa B and CCAAT/enhancer binding protein
Nucleocapsid protein of SARS-CoV activates the expression of cyclooxygenase-2 by binding directly to regulatory elements for nuclear factor-kappa B and CCAAT/enhancer binding protein
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DOI：
10.1016/j.biocel.2006.02.003
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发表时间：
2006-01-01
影响因子：
4
通讯作者：
Wu, Jianguo
中科院分区：
文献类型：
--
作者：
Yan, Xiaohong;Hao, Qian;Wu, Jianguo
SARS相关冠状病毒（SARS-CoV）引起肺部炎症和损伤，导致严重急性呼吸道综合征。为了评估这一事件背后的分子机制，我们研究了SARS-CoV蛋白在调节促炎因子环氧合酶-2（考克斯-2）中的作用。测试了单个病毒蛋白调节考克斯-2基因表达的能力。结果表明，考克斯-2启动子被核衣壳（N）蛋白以浓度依赖性方式激活。Western blot分析表明，N蛋白足以刺激哺乳动物细胞中考克斯-2蛋白的产生。考克斯-2启动子突变表明，考克斯-2转录的激活依赖于两个调控元件，核因子-κ B（NF-κ B B）结合位点和CCAAT/增强子结合蛋白（C/EBP）结合位点。电泳迁移率变动分析（EMSA）和染色质免疫沉淀（ChIP）结果表明，SARS-CoV N蛋白与这些调控序列直接结合。蛋白质突变分析表明，N蛋白富含赖氨酸的基序作为核定位信号，是激活考克斯-2所必需的。此外，一个富含亮氨酸的基序被发现是必需的N蛋白的功能。68个残基的序列被鉴定为激活考克斯-2表达所必需的潜在DNA结合结构域。我们认为SARS-CoV N蛋白通过直接与启动子结合激活考克斯-2基因表达导致肺部炎症，从而通过多个考克斯-2信号级联导致炎症。(c)2006爱思唯尔有限公司保留所有权利。
SARS-associated coronavirus (SARS-CoV) causes inflammation and damage to the lungs resulting in severe acute respiratory syndrome. To evaluate the molecular mechanisms behind this event, we investigated the roles of SARS-CoV proteins in regulation of the proinflammatory factor, cyclooxygenase-2 (COX-2). Individual viral proteins were tested for their abilities to regulate COX-2 gene expression. Results showed that the COX-2 promoter was activated by the nucleocapsid (N) protein in a concentration-dependent manner. Western blot analysis indicated that N protein was sufficient to stimulate the production of COX-2 protein in mammalian cells. COX-2 promoter mutations suggested that activation of COX-2 transcription depended on two regulatory elements, a nuclear factor-kappa B (NF-kappa B) binding site, and a CCAAT/enhancer binding protein (C/EBP) binding site. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) demonstrated that SARS-CoV N protein bound directly to these regulatory sequences. Protein mutation analysis revealed that a Lys-rich motif of N protein acted as a nuclear localization signal and was essential for the activation of COX-2. In addition, a Leu-rich motif was found to be required for the N protein function. A sequence of 68 residuals was identified as a potential DNA-binding domain essential for activating COX-2 expression. We propose that SARS-CoV N protein causes inflammation of the lungs by activating COX-2 gene expression by binding directly to the promoter resulting in inflammation through multiple COX-2 signaling cascades. (c) 2006 Elsevier Ltd. All rights reserved.