Glycogen synthase kinase-3 inhibits the DNA binding activity of NFATc
Glycogen synthase kinase-3 inhibits the DNA binding activity of NFATc
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DOI：
10.1074/jbc.m004888200
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发表时间：
2001-02-02
影响因子：
4.8
通讯作者：
Clipstone, NA
中科院分区：
文献类型：
--
作者：
Neal, JW;Clipstone, NA
NFAT转录因子家族是许多重要免疫基因表达所必需的，在免疫应答的启动和协调中起着关键作用。NFAT家族成员似乎主要在其亚细胞定位水平上受到调节。在这里，我们表明NFATc在其DNA结合活性水平上受到额外的调节。通过凝胶迁移迁移实验，我们证明了NFATc的内在DNA结合活性受到磷酸化的负调控。我们发现细胞内钙调磷酸酶活性的激活和体外NFATc的去磷酸化增强了NFATc的DNA结合活性，而体外NFATc的磷酸化抑制了其结合DNA的能力。通过对NFATc突变体的分析，我们确定了保守的SerPro重复基序是NFATc DNA结合活性的关键定量决定因素。此外，我们提供了几条证据，表明糖原合成酶激酶-3对Ser-Pro重复序列的磷酸化抑制了NFATc结合DNA的能力。综上所述，这些研究为NFATc的调控提供了新的见解，并强调了糖原合成酶激酶-3在NFATc依赖性基因表达调控中的潜在作用。
The NFAT family of transcription factors is required for the expression of numerous immunologically important genes and plays a pivotal role in both the initiation and coordination of the immune response. NFAT family members appear to be regulated primarily at the level of their subcellular localization. Here we show that NFATc is additionally regulated at the level of its DNA binding activity. Using gel mobility shift assays, we demonstrate that the intrinsic DNA binding activity of NFATc is negatively regulated by phosphorylation. We found that activation of calcineurin activity in cells and dephosphorylation of NFATc in vitro enhanced NFATc DNA binding activity, whereas phosphorylation of NFATc in vitro inhibited its ability to bind DNA. Through the analysis of NFATc mutants, we identified the conserved SerPro repeat motifs as critical quantitative determinants of NFATc DNA binding activity. In addition, we provide several lines of evidence to suggest that the phosphorylation of the Ser-Pro repeats by glycogen synthase kinase-3 inhibits the ability of NFATc to bind DNA. Taken together, these studies afford new insights into the regulation of NFATc and underscore the potential role of glycogen synthase kinase-3 in the regulation of NFAT-dependent gene expression.