A far-upstream Oct-1 motif regulates cytokine-induced transcription of the human inducible nitric oxide synthase gene.
A far-upstream Oct-1 motif regulates cytokine-induced transcription of the human inducible nitric oxide synthase gene.
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DOI：
10.1016/j.jmb.2009.05.036
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发表时间：
2009-07-24
影响因子：
5.6
通讯作者：
Geller, David A.
中科院分区：
文献类型：
--
作者：
Park, Kyung Soo;Guo, Zhong;Shao, Lifang;Du, Qiang;Geller, David A.
人诱导型一氧化氮合酶（hiNOS）基因的转录调控是高度复杂的，需要与特定的顺式作用上游反应元件结合的正转录因子和负转录因子的协调流动。关于hiNOS基因的远上游区域的具体信息很少。Oct-1蛋白属于POU结构域转录因子家族，在所有分裂细胞中组成型表达。它对增殖、分化和其他关键细胞过程至关重要。然而，Oct-1在调节人iNOS基因表达中的作用还未见报道。本研究通过体外电泳迁移率变动试验（EMSA）和体内染色质免疫沉淀试验（ChIP），证实hiNOS启动子中-10.2kb的5′-ATGCAAAT-3′八聚体序列与Oct-1具有高亲和力结合。在hiNOS启动子中-10.2kb的Oct-1基序的突变使马槟榔碱诱导的hiNOS启动子活性降低40%。Oct-1 siRNA靶向也显著降低了细胞因子诱导的hiNOS启动子活性。Oct-1的过表达增加了原代人肝细胞中精氨酸诱导的hiNOS蛋白表达。此外，在hiNOS启动子的~ 10.2kb处的Oct-1基序赋予异源胸苷激酶（TK）启动子增加的转录活性，而与细胞因子诱导无关。总之，这项工作确定了一个远上游的功能性Oct-1增强子基序在-10.2 kb的hiNOS启动子，调节精氨酸诱导的hiNOS基因转录，并进一步强调了严格的控制机制，调节人iNOS基因的表达。
Transcriptional regulation of human iNOS (hiNOS) gene is highly complex and requires an orchestrated flow of positive and negative transcription factors that bind to specific cis-acting upstream response elements. Very little specific information exists about the far upstream region of the hiNOS gene. Oct-1 protein belongs to the POU domain transcription factor family and is constitutively expressed in all dividing cells. It's essential for proliferation, differentiation and other key cell processes. However, the role of Oct-1 in regulating human iNOS gene expression has not been reported. In this work, the octamer sequence 5′-ATGCAAAT-3′ at -10.2 kb in the hiNOS promoter was identified as high-affinity Oct-1 binding by electrophoretic mobility shift assay (EMSA) in vitro and chromatin immunoprecipitation (ChIP) assay in vivo. Mutation of Oct-1 motif at -10.2 kb in the hiNOS promoter decreased cytokine-induced hiNOS promoter activity by 40%. Cytokine-induced hiNOS promoter activity was also significantly reduced by Oct-1 siRNA targeting. Overexpression of Oct-1 increased cytokine-induced hiNOS protein expression in primary human hepatocytes. Furthermore, the Oct-1 motif at -10.2 kb of the hiNOS promoter conferred increased transcriptional activity to the heterologous thymidine kinase (TK) promoter irrespective of cytokine induction. Taken together, this work identifies a far-upstream functional Oct-1 enhancer motif at -10.2 kb in the hiNOS promoter that regulates cytokine-induced hiNOS gene transcription, and further underscores the tight control mechanisms regulating expression of the human iNOS gene.
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细胞因子和内毒素刺激人肝细胞中的一氧化氮合酶途径。
DOI：
10.1084/jem.176.1.261
发表时间：
1992-07-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Nussler AK;Di Silvio M;Billiar TR;Hoffman RA;Geller DA;Selby R;Madariaga J;Simmons RL
通讯作者：
Simmons RL
影响因子：
3.6
作者：
Korhonen, Riku;Linker, Katrin;Kleinert, Hartmut
通讯作者：
Kleinert, Hartmut
人肝细胞中诱导型一氧化氮合酶的分子克隆和表达
DOI：
10.1073/pnas.90.8.3491
发表时间：
1993-04-15
影响因子：
11.1
作者：
GELLER, DA;LOWENSTEIN, CJ;BILLIAR, TR
通讯作者：
BILLIAR, TR
影响因子：
3.6
作者：
Fechir, M;Linker, K;Kleinert, H
通讯作者：
Kleinert, H
影响因子：
4.8
作者：
Marks-Konczalik, J;Chu, SC;Moss, J
通讯作者：
Moss, J