Biochemical characterization of the zinc-finger protein 217 transcriptional repressor complex: identification of a ZNF217 consensus recognition sequence
Biochemical characterization of the zinc-finger protein 217 transcriptional repressor complex: identification of a ZNF217 consensus recognition sequence
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DOI：
10.1038/sj.onc.1210126
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发表时间：
2007-05-17
期刊：
影响因子：
8
通讯作者：
Torchia, J.
中科院分区：
文献类型：
--
作者：
Cowger, J. J. M.;Zhao, Q.;Torchia, J.
锌指蛋白217（ZnF217）是一种在重复的最大扩增区域内，位于20q13.2的Kruppel样锌指蛋白。在这里，我们证明ZnF217是一种转录阻遏蛋白，并报告了ZnF217复合物的纯化和表征。纯化的ZNF217复合物由大约六种蛋白质组成，并包含转录共抑制剂Corest，BHC110/LSD1，组蛋白脱乙酰基酶（HDAC）2和C末端结合蛋白（CTBP1）。纯化的ZnF217复合物具有脱乙酰基酶活性以及赖氨酸4组蛋白H3特异性脱甲基酶活性，最有可能由BHC110/LSD1成分介导。为了确定ZnF217是否是一种序列特异性结合蛋白，我们使用了环状扩增和选择靶标（CAST）测定的选择，并首次识别Znf217 DNA共有识别序列（CRS），在人E中高度保存在人E中。 - 辅助蛋白启动子。染色质免疫沉淀（CHIP）实验表明，ZnF217以及ZnF217复合物的其他成分在近端E-钙粘蛋白启动子的区域中发现，其中包含VIVO中已鉴定的ZnF217 CRS的ZnF217 CRS。使用瞬态转染和小型干扰RNA的组合，我们证明了ZnF217抑制了E-钙粘蛋白启动子。总的来说，我们的结果暗示了ZnF217及其相关蛋白在新的途径中可能对癌症进展产生深远影响。
Zinc-finger protein 217 (ZNF217) is a Kruppel-like zinc-finger protein located at 20q13.2, within a region of recurrent maximal amplification. Here, we demonstrate that ZNF217 is a transcriptional repressor protein and report the purification and characterization of a ZNF217 complex. The purified ZNF217 complex consists of approximately six proteins and contains the transcriptional co-repressors CoREST, BHC110/LSD1, histone deacetylase (HDAC) 2 and C-terminal binding protein (CtBP1). The purified ZNF217 complex possesses deacetylase activity as well as lysine 4 histone H3-specific demethylase activity that is most likely mediated by the BHC110/LSD1 component. To determine if ZNF217 is a sequence-specific binding protein, we have made use of cyclic amplification and selection of targets (CAST) assay and identify for the first time a ZNF217 DNA consensus recognition sequence (CRS) that is highly conserved in the human E-cadherin promoter. Chromatin immunoprecipitation (ChIP) experiments demonstrate that ZNF217, as well as the other components of the ZNF217 complex, are found on the region of the proximal E-cadherin promoter that contains the identified ZNF217 CRS in vivo. Using a combination of transient transfections and small interfering RNA, we demonstrate that ZNF217 represses the E-cadherin promoter. Collectively, our results implicate ZNF217 and its associated proteins in a novel pathway that may have profound effects on cancer progression.