Analysis of the preexisting and nuclear forms of nuclear factor of activated T cells.
Analysis of the preexisting and nuclear forms of nuclear factor of activated T cells.
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DOI：
10.4049/jimmunol.151.2.837
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发表时间：
1993-07
影响因子：
4.4
通讯作者：
J. Jain;Zoe Miner;Anjana Rao
中科院分区：
文献类型：
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作者：
J. Jain;Zoe Miner;Anjana Rao
活化T细胞核因子（NF-AT）3是一种诱导型DNA结合蛋白，在T细胞活化过程中对IL-2基因的转录诱导至关重要。NF-AT被认为由两种组分组成：一种是普遍存在的、可诱导的核组分，我们已经将其鉴定为Fos和Jun蛋白，另一种是预先存在的T细胞特异性组分（NF-ATp），它是免疫抑制剂环孢菌素A（CsA）和FK 506的靶点。我们以前已经表明，从活化的T细胞的核提取物形成两个可诱导的NF-AT复合物与对应于小鼠IL-2启动子的远端NF-AT位点的寡核苷酸，虽然未刺激的T细胞的低渗提取物形成含有NF-AT β的单一复合物。我们表明，在凝胶迁移试验中检测NF-AT p的能力，这是必不可少的这种蛋白质的纯化和生化研究，是惊人的依赖于作为标记探针的NF-AT寡核苷酸的精确序列。此外，我们提出的证据表明，形成更快的迁移（“低”）核NF-AT复合物的组件是由钙依赖性，环孢素敏感，NF-AT p的翻译后修饰，以及Fos和Jun蛋白稳定其与DNA的相互作用。结果进行了讨论的背景下的模型有关的两个核NF-AT复合物NF-ATp。
The nuclear factor of activated T cells (NF-AT)3 is an inducible DNA-binding protein that is essential for transcriptional induction of the IL-2 gene during T cell activation. NF-AT is thought to consist of two components: a ubiquitous, inducible nuclear component that we have identified as Fos and Jun proteins, and a preexisting, T cell-specific component (NF-ATp) which is the target for the immunosuppressive agents cyclosporin A (CsA) and FK506. We have previously shown that nuclear extracts from activated T cells form two inducible NF-AT complexes with an oligonucleotide corresponding to the distal NF-AT site of the murine IL-2 promoter, although hypotonic extracts of unstimulated T cells form a single complex containing NF-ATp. We show that the ability to detect NF-ATp in a gel shift assay, which is essential for purification and biochemical studies of this protein, is strikingly dependent on the precise sequence of the NF-AT oligonucleotide used as the labeled probe. Moreover we present evidence that the component that forms the faster-migrating ("lower") nuclear NF-AT complex is derived by a calcium-dependent, cyclosporin-sensitive, posttranslational modification of NF-ATp, and that Fos and Jun proteins stabilize its interaction with DNA. The results are discussed in the context of a model relating the two nuclear NF-AT complexes to NF-ATp.