Characterization of Calmodulin Binding to the Orphan Nuclear Receptor ERRγ
Characterization of Calmodulin Binding to the Orphan Nuclear Receptor ERRγ
复制标题
钙调蛋白与孤儿核受体 ERRγ 结合的表征
作者：
M. Hentschke;C. Schulze;U. Süsens;U. Borgmeyer
雌激素受体相关受体γ (ERγ/ERR3/NR3B3)是核受体超家族的一员，在没有配体的情况下激活转录。为了确定与配体无关的激活机制，我们测试了钙调素（CaM）是否与ERRγ相互作用，钙调素是许多细胞过程的关键调节剂和Ca2+信号的主要细胞内受体。钙调素- sepharose的体外下拉实验证明了Ca2+依赖性与细胞表达的ERRγ的相互作用。截断分析显示，CaM结合位点非常不寻常，因为它由两个不连续的元素组成。此外，通过表面等离子体共振（SPR）生物传感器技术，我们检测到固定化细菌表达的ERRγ融合蛋白与Ca2+钙调蛋白的直接相互作用。这最好用一个模型来描述，该模型假定最初形成的络合物的构象变化为更稳定的形式。尽管体外DNA结合是钙调素独立的，但瞬时转染分析显示，钙离子流入依赖err γ介导的荧光素酶报告基因的转录激活。因此，我们提出CaM在Ca2+依赖性的ERRγ调节中起中介作用。
Abstract The estrogen receptorrelated receptor γ (ERγ/ERR3/NR3B3), a member of the nuclear receptor superfamily, activates transcription in the absence of ligands. In order to identify ligand-independent mechanisms of activation, we tested whether calmodulin (CaM), a key regulator of numerous cellular processes and a predominant intracellular receptor for Ca2+-signals, interacts with ERRγ. In vitro pulldown experiments with calmodulin-Sepharose demonstrated a Ca2+-dependent interaction with cellularly expressed ERRγ. As shown by truncation analysis, the CaM binding site is highly unusual in that it is composed of two discontinuous elements. Moreover, by surface plasmon resonance (SPR) biosensor technology, we detected a direct interaction of immobilized bacterially expressed ERRγ fusion protein with Ca2+-calmodulin. This is best described by a model which assumes a conformational change of the initially formed complex to a more stable form. Whereas in vitro DNA binding was calmodulinindependent, transient transfection analysis revealed a Ca2+-influxdependent ERRγmediated transcriptional activation of a luciferase reporter gene. Thus, we propose that CaM acts as a mediator in the Ca2+-dependent modulation of ERRγ.
滋养细胞中视黄醇相关睾丸相关受体 (RTR) 表达的表征。
影响因子：
3.8
作者：
Mehta,DV;Kim,Y-S;Dixon,D;Jetten,AM
通讯作者：
Jetten,AM
影响因子：
5.3
作者：
Zou, Yuhua;Niu, Wenze;Zhang, Chun-Li
通讯作者：
Zhang, Chun-Li