CHARACTERIZATION OF PROTEINS BINDING TO ETS2 REGULATORY SEQUENCES

ETS 2启动子含有嘌呤/嘧啶链的延伸区域 在转录起始位点上游的不对称性（CT轨道）。 的 这些序列的存在是ETS 2完全表达所必需的。 在 CT轨道的至少两个区域，其在细胞中形成蛋白质复合物， 电泳迁移率变动分析（EMSA）。 的 发现一个主要复合物与转录因子Sp1竞争良好 共有寡核苷酸。 还发现它与 纯Sp1的蛋白复合物，并与产生的抗体超移 针对SP1。 Sp1和细胞核提取物均显示类似的DNaseI 足迹模式 EMSA中与单链DNA形成的蛋白质-DNA复合物被 观察 它具有与人淋巴细胞非常相似的结合序列特异性， Pur-alpha因子 然而，与之形成的复合物的流动性 来自核提取物因子不同于来自重组体的因子 Pur-alpha。

The ETS2 promoter contains an extended region of purine/pyrimidine strand asymmetry (CT track) upstream from the start site for transcription. The presence of these sequences are required for full ETS2 expression. At least two regions of the CT track that form protein complexes in the electrophoretic mobility shift assay (EMSA) have been identified. The major complex was found to compete well with a transcription factor Sp1 consensus oligonucleotide. It was also found to comigrate with the protein complex of pure Sp1 and to supershift with antibodies raised against Sp1. Both Sp1 and nuclear extracts exhibit similar DNaseI footprint patterns. A protein-DNA complex in the EMSA that forms with single-strand DNA was observed. It has a binding sequence specificity that is very similar to the Pur-alpha factor. However, the mobility of complexes that form with the factor from nuclear extracts differs from that of recombinant Pur-alpha.