Kurebayashi Shogo, Nakajima Takeshi, Kim Seong-Chul, Chang Ching-Yi, McDonnell Donald P, Renaud Jean-Paul, Jetten Anton M
Cell Biology Section, Division of Intramural Research, National Institute of Environmental Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
Biochem Biophys Res Commun. 2004 Mar 19;315(4):919-27. doi: 10.1016/j.bbrc.2004.01.131.
The retinoid-related orphan receptor gamma (RORgamma) has been shown to function as a positive regulator of transcription in many cell lines. Transcriptional activation by nuclear receptors involves recruitment of co-activators that interact with receptors through their LXXLL motifs (NR box). In this study, we analyze the interaction of RORgamma with the co-activator SRC1 and use a series of LXXLL-containing peptides to probe for changes in the conformation of the co-activator interaction surface of the RORgamma LBD. We demonstrate that the H3-4/H12 co-activator interaction surface of RORgamma displays a selectivity for LXXLL peptides that is distinct from those of other nuclear receptors. LXXLL peptides that interacted with RORgamma efficiently antagonized RORgamma-mediated transcriptional activation. Mutations E502Q and Y500F in H12, and K334A, Q347A, and I348D in H3 and H4 of RORgamma, severely impact the recruitment of LXXLL peptides. The effects of these mutations are consistent with predictions made on the basis of the structure of the RORgamma(LBD) derived through homology modeling. These peptide antagonists provide a useful tool to analyze the conformation changes in the RORgamma(LBD) and to study RORgamma receptor signaling.
维甲酸相关孤儿受体γ（RORγ）已被证明在许多细胞系中作为转录的正调控因子发挥作用。核受体介导的转录激活涉及共激活因子的募集，这些共激活因子通过其LXXLL基序（NR盒）与受体相互作用。在本研究中，我们分析了RORγ与共激活因子SRC1的相互作用，并使用一系列含LXXLL的肽来探测RORγ配体结合域（LBD）共激活因子相互作用表面构象的变化。我们证明，RORγ的H3-4/H12共激活因子相互作用表面对LXXLL肽表现出与其他核受体不同的选择性。与RORγ有效相互作用的LXXLL肽可拮抗RORγ介导的转录激活。RORγ的H12中的E502Q和Y500F突变以及H3和H4中的K334A、Q347A和I348D突变严重影响LXXLL肽的募集。这些突变的影响与基于同源建模推导的RORγ（LBD）结构所做的预测一致。这些肽拮抗剂为分析RORγ（LBD）的构象变化和研究RORγ受体信号传导提供了有用的工具。
