ALTERED PROTEIN CONFORMATION ON DNA-BINDING BY FOS AND JUN
ALTERED PROTEIN CONFORMATION ON DNA-BINDING BY FOS AND JUN
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DOI：
10.1038/347572a0
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发表时间：
1990-10-11
期刊：
影响因子：
64.8
通讯作者：
CURRAN, T
中科院分区：
文献类型：
--
作者：
PATEL, L;ABATE, C;CURRAN, T
c-fos和c-jun原癌基因（分别为Fos和Jun）的蛋白产物形成异二聚体蛋白复合物，与激活蛋白-1（AP-1）结合位点相互作用，调节细胞外刺激引起的基因转录。蛋白质二聚化主要由称为亮氨酸拉链的卷曲螺旋样结构介导，DNA结合主要通过每个蛋白质中富含碱性氨基酸的区域发生，这些区域接触AP-1位点的两条链2 -8。蛋白质-DNA相互作用的确切性质是未知的，因为有关Fos和Jun的二聚化和DNA结合的研究依赖于间接方法来研究蛋白质-蛋白质-DNA相互作用。在这里，我们已经开发了检测系统，使用荧光光谱和圆二色性直接监测二聚化和DNA结合。结果表明，Fos和Jun与DNA的相互作用导致蛋白质二聚体构象改变，α-螺旋含量增加。这些技术可广泛应用于转录调控蛋白与特定DNA靶序列相互作用的研究。
THE protein products of the c-fosand c-junproto-oncogenes (Fos and Jun, respectively) form a heterodimeric protein complex that interacts with the activator protein-1 (AP-1) binding site and regulates gene transcription in response to extracellular stimuli1. Protein dimerization is mediated primarily by a coiled-coil-like structure termed the leucine-zipper and DNA binding occurs primarily through regions of each protein rich in basic amino acids that contact both strands of the AP-1 site2–8. The precise nature of the protein–DNA interaction is unknown as studies concerned with dimerization and DNA binding by Fos and Jun have relied on indirect methods to investigate protein–protein–DNA interactions. Here we have developed assay systems using fluorescence spectroscopy and circular dichroism to monitor dimerization and DNA binding directly. The results indicate that the interaction of Fos and Jun with DNA results in an altered conformation of the protein dimers and an increased α-helical content. These techniques may have general application in studies concerning the interaction of transcriptional regulatory proteins with specific DNA target sequences.