NF-κB site interacts with Sp factors and up-regulates the NR1 promoter during neuronal differentiation
NF-κB site interacts with Sp factors and up-regulates the NR1 promoter during neuronal differentiation
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DOI：
10.1074/jbc.m311267200
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发表时间：
2004-04-23
影响因子：
4.8
通讯作者：
Bai, G
中科院分区：
文献类型：
--
作者：
Liu, AG;Hoffman, PW;Bai, G
NR 1基因在神经发生中主要通过启动子去阻遏进行诱导，并在神经元分化过程中通过未确定的机制上调。在这里，我们表明，在远端区域的NR 1启动子有一个活跃的NF-κ B位点共享的共识与免疫球蛋白（IG）/人类免疫缺陷病毒NF-κ B位点。该位点的突变显著降低了P19细胞神经元分化过程中NR 1启动子的上调。电泳迁移率变动分析表明，P19细胞核组成性含有p50和神经元分化不仅增加核p50，但也诱导p65核转位。对这种变化的反应是NF-κ B依赖性启动子活性的上调。然而，IkappaB α超级抑制子或诱饵DNA对NF-kappaB核转位的抑制仅适度抑制NR 1启动子上调。有趣的是，在P19核提取物中，NR 1 NF-κ B位点与Sp3/Sp1强烈相互作用，而不是NF-κ B因子。这种相互作用减少了Sp3神经元分化后，伴随着SP因子的动态表达。SP因子（SP 1，3，或4）共转染上调NR 1 NF-κ B位点显着分化的神经元，但只有适度的未分化的P19细胞。这种上调是强烈的分化细胞中的Sp1和未分化细胞中的Sp3。染色质免疫沉淀实验进一步证明Sp1和Sp3与NR 1 NF-κ B位点原位相互作用，而Sp3在神经元分化后失去其相互作用。我们的结论是，NF-κ B的网站积极调节NR 1启动子在神经元分化过程中，主要通过相互作用与SP因子和神经元分化减少了SP 3因子对这个网站的影响。
The NR1 gene undergoes induction in neurogenesis mainly via promoter de-repression, and up-regulation during neuronal differentiation by undefined mechanism(s). Here, we show that in the distal region the NR1 promoter has an active NF-kappaB site sharing the consensus with the immunoglobulin (Ig)/human immunodeficiency virus NF-kappaB site. Mutation of this site significantly reduced NR1 promoter up-regulation during neuronal differentiation of P19 cells. Electrophoretic mobility shift assays revealed that P19 nuclei constitutively contained p50 and that neuronal differentiation not only increased nuclear p50 but also induced p65 nuclear translocation. Responding to this change was an up-regulation of NF-kappaB-dependent promoter activity. However, inhibition of NF-kappaB nuclear translocation by an IkappaBalpha super-repressor or decoy DNA only moderately inhibited NR1 promoter up-regulation. Interestingly, the NR1 NF-kappaB site strongly interacted with Sp3/Sp1, instead of NF-kappaB factors, in P19 nuclear extracts. This interaction was reduced for Sp3 following neuronal differentiation, accompanied by dynamic expression of Sp factors. Cotransfection of Sp factors (Sp1, 3, or 4) up-regulated the NR1 NF-kappaB site dramatically in differentiated neurons, but only moderately in undifferentiated P19 cells. This up-regulation was strong for Sp1 in differentiated cells and for Sp3 in undifferentiated cells. Chromatin-immunoprecipitation assays further demonstrated that Sp1 and Sp3 interacted with the NR1 NF-kappaB site in situ, and Sp3 lost its interaction after neuronal differentiation. We conclude that the NF-kappaB site positively regulates the NR1 promoter during neuronal differentiation via interacting mainly with Sp factors and neuronal differentiation reduces the effect of Sp3 factor on this site.