Jiménez-Panizo Alba, Johnson Thomas A, Wagh Kaustubh, Alegre-Martí Andrea, Novoa Inés Montoya, Lafuente Agustina L, Eckhard Ulrich, Rodríguez-Lumbreras Luis Ángel, Hoang Le, Stortz Martín, Abella Montserrat, Goldstein Ido, Valledor-Fernández Annabel, Varticovski Lyuba, Arias Irwin, Presman Diego M, Stavreva Diana A, Fernández-Recio Juan, Fuentes-Prior Pablo, Hager Gordon L, Estébanez-Perpiñá Eva
Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona (UB). Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona (UB), 08028 Barcelona, Spain.
National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, USA.
bioRxiv. 2025 May 16:2025.05.13.653693. doi: 10.1101/2025.05.13.653693.
The glucocorticoid receptor (GR) is an essential transcription factor that controls metabolism and homeostasis. Glucocorticoids (GCs) activate the GR upon occupying the internal ligand-binding pocket (LBP) of its ligand-binding domain (GR-LBD), which has been the focus of most previous structure-function studies. Synthetic GCs such as dexamethasone are widely used to treat inflammatory diseases, but their chronic use results in major side effects, whose molecular underpinnings remain unresolved. Here we present a thorough analysis of the topography of GR-LBD and its ability to bind small-molecule compounds, especially cholesterol derivatives. We show that one important class of steroids, bile acids, bind to previously unidentified and highly conserved, surface-exposed cavities on GR-LBD. We show that bile acids affect GR turnover and self-assembly in living cells, modulating receptor transcriptional activity. These findings reveal a previously unrecognized mechanism of GR regulation, with implications for the design of GCs with novel mechanisms of action.
糖皮质激素受体（GR）是一种控制新陈代谢和体内平衡的重要转录因子。糖皮质激素（GCs）占据其配体结合域（GR-LBD）的内部配体结合口袋（LBP）后会激活GR，这一直是以往大多数结构-功能研究的重点。地塞米松等合成糖皮质激素被广泛用于治疗炎症性疾病，但其长期使用会导致严重的副作用，其分子基础仍未得到解决。在这里，我们对GR-LBD的拓扑结构及其结合小分子化合物（尤其是胆固醇衍生物）的能力进行了全面分析。我们发现一类重要的类固醇——胆汁酸，可与GR-LBD上以前未被识别且高度保守的表面暴露腔结合。我们表明胆汁酸会影响活细胞中GR的周转和自组装，调节受体转录活性。这些发现揭示了一种以前未被认识的GR调节机制，对具有新作用机制的糖皮质激素的设计具有重要意义。
