Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, 430072, P. R. China.
Medical Science Research Center, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China.
Cell Death Differ. 2019 Nov;26(11):2300-2313. doi: 10.1038/s41418-019-0303-z. Epub 2019 Feb 18.
The transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) is one of the master regulators that control hundreds of genes containing antioxidant response elements (AREs). The NRF2-ARE pathway plays a complex role in colorectal cancer (CRC). NRF2 activity is known to be regulated by KEAP1-CUL3 E3 ligase-mediated ubiquitination, indicating the importance of deubiquitination regulation. However, the deubiquitinase (DUB) of NRF2 remains unknown. Here, by screening a DUB library, we identified DUB3 as a DUB that remarkably stabilized NRF2. Further experiments demonstrated that DUB3 promoted NRF2 stability and transcriptional activity by decreasing the K48-linked ubiquitination of NRF2. Coimmunoprecipitation studies revealed interactions between NRF2 and DUB3, as well as between KEAP1 and DUB3, indicating that NRF2, DUB3, and KEAP1 formed a large functional complex. Importantly, ectopic expression of DUB3 caused NRF2-dependent chemotherapy resistance in colon cancer cell lines. Thus, to the best of our knowledge, our findings are the first to identify DUB3 as a NRF2 DUB and may provide a new strategy against chemotherapy resistance in CRC and other NRF2-related diseases.
转录因子核因子（红系衍生 2）样 2（NRF2）是控制包含抗氧化反应元件（ARE）的数百个基因的主要调节因子之一。NRF2-ARE 途径在结直肠癌（CRC）中发挥着复杂的作用。众所周知，NRF2 的活性受 KEAP1-CUL3 E3 连接酶介导的泛素化调节，表明去泛素化调节的重要性。然而，NRF2 的去泛素酶（DUB）仍然未知。在这里，通过筛选 DUB 文库，我们鉴定出 DUB3 是一种能显著稳定 NRF2 的 DUB。进一步的实验表明，DUB3 通过减少 NRF2 的 K48 连接泛素化来促进 NRF2 的稳定性和转录活性。免疫共沉淀研究揭示了 NRF2 和 DUB3 之间以及 KEAP1 和 DUB3 之间的相互作用，表明 NRF2、DUB3 和 KEAP1 形成了一个大型功能复合物。重要的是，DUB3 的异位表达导致结肠癌细胞系中 NRF2 依赖性化疗耐药。因此，据我们所知，我们的发现首次鉴定 DUB3 为 NRF2 的 DUB，并可能为 CRC 和其他与 NRF2 相关的疾病的化疗耐药提供新的策略。
