FOS AND JUN BIND COOPERATIVELY TO THE AP-1 SITE - RECONSTITUTION INVITRO
FOS AND JUN BIND COOPERATIVELY TO THE AP-1 SITE - RECONSTITUTION INVITRO
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DOI：
10.1101/gad.2.12b.1687
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发表时间：
1988-12-01
影响因子：
10.5
通讯作者：
CURRAN, T
中科院分区：
文献类型：
--
作者：
RAUSCHER, FJ;VOULALAS, PJ;CURRAN, T
已显示fos（Fos）和jun（Jun）原癌基因的蛋白产物与称为转录因子激活蛋白-1（AP-1）结合位点的DNA元件相关联。Jun（以前称为Fos结合蛋白p39）和Fos在细胞核中形成蛋白质复合物。为了研究Fos和Jun与AP-1位点的结合的性质，并确定蛋白质复合物形成在DNA结合中的作用，我们使用网织红细胞裂解物中合成的Fos和Jun在体外重建了蛋白质-蛋白质和蛋白质-DNA相互作用。Fos-Jun复合物在体外形成非常迅速，并具有类似的，但不相同的，色谱和沉降性能的复杂的细胞提取物分离。Jun表现出低水平的AP-1结合活性;然而，这仅在高浓度的DNA下是明显的。Fos本身并不与AP-1位点结合;然而，它与Jun协同作用以增强DNA结合活性。Fos-Jun复合物对DNA的亲和力增加是由于蛋白质-DNA复合物的稳定化。这些数据证明了两个原癌基因的蛋白质产物与参与转录调控的DNA元件之间的合作相互作用。
The protein products of the fos (Fos) and jun (Jun) proto-oncogenes have been shown to associate with a DNA element known as the transcription factor activator protein-1 (AP-1) binding site. Jun (previously known as the Fos-binding protein p39) and Fos form a protein complex in the nucleus. To investigate the nature of the association of Fos and Jun with the AP-1 site, and to determine the role of protein complex formation in DNA-binding, we have reconstituted the protein-protein and protein-DNA interactions in vitro using Fos and Jun synthesized in reticulocyte lysates. The Fos-Jun complex formed extremely rapidly in vitro and possessed similar, though not identical, chromatographic and sedimentation properties to the complex isolated from cell extracts. Jun exhibited a low level of AP-1 binding activity; however, this was evident only at high concentrations of DNA. Fos did not bind to the AP-1 site on its own; however, it acted cooperatively with Jun to give enhanced DNA-binding activity. The increased affinity of the Fos-Jun complex for DNA resulted from a stabilization of the protein-DNA complex. These data demonstrate a cooperative interaction between the protein products of two proto-oncogenes with a DNA element involved in transcriptional regulation.