Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ 85721.
Department of Medicine, University of Arizona Health Sciences, University of Arizona, Tucson, AZ 85721.
Proc Natl Acad Sci U S A. 2018 Oct 30;115(44):E10352-E10361. doi: 10.1073/pnas.1812125115. Epub 2018 Oct 11.
NRF2 regulates cellular redox homeostasis, metabolic balance, and proteostasis by forming a dimer with small musculoaponeurotic fibrosarcoma proteins (sMAFs) and binding to antioxidant response elements (AREs) to activate target gene transcription. In contrast, NRF2-ARE-dependent transcriptional repression is unreported. Here, we describe NRF2-mediated gene repression via a specific seven-nucleotide sequence flanking the ARE, which we term the NRF2-replication protein A1 (RPA1) element (NRE). Mechanistically, RPA1 competes with sMAF for NRF2 binding, followed by interaction of NRF2-RPA1 with the ARE-NRE and eduction of promoter activity. Genome-wide in silico and RNA-seq analyses revealed this NRF2-RPA1-ARE-NRE complex mediates negative regulation of many genes with diverse functions, indicating that this mechanism is a fundamental cellular process. Notably, repression of , which encodes the nonmuscle myosin light chain kinase, by the NRF2-RPA1-ARE-NRE complex disrupts vascular integrity in preclinical inflammatory lung injury models, illustrating the translational significance of NRF2-mediated transcriptional repression. Our findings reveal a gene-suppressive function of NRF2 and a subset of negatively regulated NRF2 target genes, underscoring the broad impact of NRF2 in physiological and pathological settings.
NRF2 通过与小肌肉-aponeurotic 纤维肉瘤蛋白(sMAFs)形成二聚体并结合到抗氧化反应元件(AREs)上来激活靶基因转录,从而调节细胞氧化还原稳态、代谢平衡和蛋白质稳态。相比之下,NRF2-ARE 依赖性转录抑制作用尚未报道。在这里,我们描述了 NRF2 通过 ARE 侧翼的特定七个核苷酸序列介导的基因抑制,我们将其称为 NRF2-复制蛋白 A1(RPA1)元件(NRE)。从机制上讲,RPA1 与 sMAF 竞争与 NRF2 的结合,然后是 NRF2-RPA1 与 ARE-NRE 的相互作用,并降低启动子活性。全基因组计算机分析和 RNA-seq 分析显示,这种 NRF2-RPA1-ARE-NRE 复合物介导了许多具有不同功能的基因的负调控,表明这种机制是一种基本的细胞过程。值得注意的是,NRF2-RPA1-ARE-NRE 复合物对编码非肌肉肌球蛋白轻链激酶的基因的抑制作用破坏了临床前炎症性肺损伤模型中的血管完整性,说明了 NRF2 介导的转录抑制的转化意义。我们的研究结果揭示了 NRF2 的基因抑制功能和一组负调控的 NRF2 靶基因,强调了 NRF2 在生理和病理环境中的广泛影响。