Nerve growth factor uses Ras/ERK and phosphatidylinositol 3-kinase cascades to up-regulate the N-methyl-D-aspartate receptor 1 promoter
Nerve growth factor uses Ras/ERK and phosphatidylinositol 3-kinase cascades to up-regulate the N-methyl-D-aspartate receptor 1 promoter
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DOI：
10.1074/jbc.m105399200
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发表时间：
2001-11-30
影响因子：
4.8
通讯作者：
Bai, G
中科院分区：
文献类型：
--
作者：
Liu, A;Prenger, MS;Bai, G
我们以前报道过神经生长因子（NGF）上调N-甲基-D-天冬氨酸受体1（NR 1）启动子的活性。我们已经探索了NGF信号转导在调节NR 1启动子中的途径和核靶点。PD 98059和渥曼青霉素（但不是雷帕霉素）显着减弱了NR 1启动子-荧光素酶构建体的NGF诱导的转录活性。共表达Ras、Raf或MAPK/ERK激酶1（MEK 1）的组成型活性形式显著增加启动子活性。MEK 1诱导的增加在很大程度上是由启动子中串联GC盒的突变阻止的。启动子活性也显着增加共表达GC盒结合蛋白（Sp1，3，或4）在nonstimulated PC 12细胞。无论是细胞外信号调节激酶-1（ERK 1）-或Sp1-特异性抗体共沉淀Sp1与ERK，和共沉淀增强显着的NGF处理的PC 12细胞。ERK 2还将[γ P-32]ATP的放射性掺入到重组Sp1中。然而，ERK 2处理的Sp1和PC 12核提取物或从神经生长因子处理的细胞的核提取物表现出减少结合的启动子或共识GC盒。我们的研究结果表明，神经生长因子利用Ras/ERK和磷脂酰肌醇3-激酶途径上调NR 1启动子的活性和SP 1是一种新的底物的神经生长因子激活的ERK。NGF增加NR 1启动子活性可能涉及Sp1磷酸化和可能的转录因子交换的复杂机制。
We reported previously that nerve growth factor (NGF) up-regulates activity of the N-methyl-D-aspartate receptor 1 (NR1) promoter. We have explored the pathways and nuclear targets of NGF signaling in regulating the NR1 promoter. PD98059 and wortmannin, but not rapamycin, significantly attenuated NGF-induced transcriptional activity from an NR1 promoter-luciferase construct. Coexpressing constitutively active forms of Ras, Raf, or MAPK/ERK kinase 1 (MEK1) increased promoter activity dramatically. The MEK1-induced increase was largely prevented by mutations of the tandem GC boxes in the promoter. Promoter activity was also increased significantly by coexpressed GC box-binding proteins (Sp1, 3, or 4) in nonstimulated PC12 cells. Either an extracellular signal-regulated kinase-1 (ERK1)- or Sp1-specific antibody coprecipitated Spl with ERKs, and the coprecipitation was enhanced significantly by NGF treatment of PC12 cells. ERK2 also incorporated radioactivity of [gamma P-32]ATP into recombinant Sp1. However, ERK2-treated Sp1 and PC12 nuclear extracts or nuclear extracts from NGF-treated cells exhibited reduced binding to the promoter or a consensus GC box. Our results suggest that NGF utilizes both the Ras/ERK and phosphatidylinositol 3-kinase pathways to up-regulate NR1 promoter activity and that Sp1 is a novel substrate of NGF-activated ERKs. NGF-increased NR1 promoter activity may involve a complicated mechanism of Sp1 phosphorylation and possible transcription factor exchange.