类固醇激素受体（SHR）如何调节转录活动的机制部分尚未明确。激活后，SHR联合辅助调控因子结合基因组，至关重要地诱导基因表达。然而，SHR招募的辅助调控因子复合物的哪些成分对于在荷尔蒙刺激下驱动转录至今仍不清楚。通过一项基于FACS的全基因组CRISPR筛选，我们功能性分析了糖皮质激素受体（GR）复合物。我们描述了PAXIP1和粘连蛋白亚基STAG2之间的功能性交互作用，对于GR调节基因表达至关重要。在不改变GR cistrome的情况下，PAXIP1和STAG2的缺失改变了GR transcriptome的组成，破坏了招募3D基因组组织蛋白到GR复合物中的功能。重要的是，我们证明了PAXIP1对染色质上粘连蛋白的稳定性、其定位到GR占据的位置以及增强子-启动子相互作用的维持都是必需的。在肺癌中，GR作为肿瘤抑制因子，PAXIP1/STAG2的丧失通过修改局部染色质相互作用来增强GR介导的肿瘤抑制因子活性。总之，我们介绍了PAXIP1和STAG2作为GR的新型辅助调控因子，需要维持3D基因组结构并在激素刺激后驱动GR转录程序。©作者2023年。由牛津大学出版社代表核酸研究出版

How steroid hormone receptors (SHRs) regulate transcriptional activity remains partly understood. Upon activation, SHRs bind the genome together with a co-regulator repertoire, crucial to induce gene expression. However, it remains unknown which components of the SHR-recruited co-regulator complex are essential to drive transcription following hormonal stimuli. Through a FACS-based genome-wide CRISPR screen, we functionally dissected the Glucocorticoid Receptor (GR) complex. We describe a functional cross-talk between PAXIP1 and the cohesin subunit STAG2, critical for regulation of gene expression by GR. Without altering the GR cistrome, PAXIP1 and STAG2 depletion alter the GR transcriptome, by impairing the recruitment of 3D-genome organization proteins to the GR complex. Importantly, we demonstrate that PAXIP1 is required for stability of cohesin on chromatin, its localization to GR-occupied sites, and maintenance of enhancer-promoter interactions. In lung cancer, where GR acts as tumor suppressor, PAXIP1/STAG2 loss enhances GR-mediated tumor suppressor activity by modifying local chromatin interactions. All together, we introduce PAXIP1 and STAG2 as novel co-regulators of GR, required to maintain 3D-genome architecture and drive the GR transcriptional programme following hormonal stimuli.© The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research.