Xanthoudakis S, Hiscott J
J Biol Chem. 1987 Jun 15;262(17):8298-302.
Nuclear protein extracts were prepared from uninduced myeloid leukemic KG-1 cells and analyzed for interferon-specific DNA binding by a gel electrophoresis DNA binding assay. A protein was detected that bound specifically to a 163-base pair upstream region of the IFN-beta promoter. A series of competition studies were performed to assess whether this was a general DNA binding protein; binding of this factor was competed from radiolabeled beta 163 fragment only by an excess of cold unlabeled beta 163 or a 67-base pair fragment (beta 67) derived from beta 163. Other promoter and enhancer transcriptional domains including 1) c-fos serum responsive element, 2) c-fos promoter, 3) SV40 enhancer, 4) IFN-alpha 1 promoter, and 5) plasmid pAT153 did not compete effectively for binding of the protein. These results indicate that this protein is not a general enhancer or promoter binding factor and may be unique to IFN-beta. Analysis of beta 67 DNA sequences revealed no homology to known recognition sequences for Sp1 or CTF transcription factors.
从未诱导的髓系白血病KG-1细胞中制备核蛋白提取物，并通过凝胶电泳DNA结合试验分析干扰素特异性DNA结合情况。检测到一种蛋白，它特异性结合到IFN-β启动子上游163个碱基对的区域。进行了一系列竞争研究以评估这是否是一种通用的DNA结合蛋白；仅过量的冷未标记β163或源自β163的67个碱基对片段（β67）能将该因子的结合从放射性标记的β163片段上竞争下来。其他启动子和增强子转录结构域，包括1）c-fos血清反应元件、2）c-fos启动子、3）SV40增强子、4）IFN-α1启动子和5）质粒pAT153，不能有效竞争该蛋白的结合。这些结果表明该蛋白不是一种通用的增强子或启动子结合因子，可能是IFN-β特有的。对β67 DNA序列的分析显示与Sp1或CTF转录因子的已知识别序列无同源性。
