Laboratory of Biopharmaceuticals and Molecular Pharmacology, School of Pharmaceutical Sciences, Hainan University, Haikou, Hainan, 570228, China.
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, 999078, China.
Biochimie. 2023 Aug;211:68-77. doi: 10.1016/j.biochi.2023.03.002. Epub 2023 Mar 14.
Oxidative stress is one of the elements causing aging and related diseases. Inhibiting Nrf2 activity or increasing oxidative pressure can replicate the deficits of premature aging. SIRT6 is one of the few proteins that can regulate both life span and aging. Deletion of SIRT6 in human cells impairs the antioxidant capacity of cells, which results in the accumulation of intracellular reactive oxygen species and DNA oxidation products. Characterization of the binding of Nrf2 with SIRT6 is critical for understanding the modulation of Nrf2-correlated cell activities by SIRT6. The yeast two-hybrid experiments showed that the binding of Nrf2 with SIRT6 is mediated by Neh1 and Neh3 domains. The elimination of the Neh1 and Neh3 domains decreased the binding stability and free energy, according to the molecular dynamic analysis. The roles of theses domains in mediating the binding were confirmed by co-immunoprecipitation. In cells transfected with the small interfering RNA (siRNA) targeting the Nrf2 Neh1 domain and plasmids overexpressing domain-mutant Nrf2, it was discovered that Nrf2 lost its activity to stimulate the transcription of antioxidant genes in the absence of Neh1 and Neh3 domains.
氧化应激是导致衰老和相关疾病的因素之一。抑制 Nrf2 活性或增加氧化压力可以复制早衰的缺陷。SIRT6 是少数既能调节寿命又能调节衰老的蛋白质之一。在人类细胞中删除 SIRT6 会损害细胞的抗氧化能力，导致细胞内活性氧和 DNA 氧化产物的积累。Nrf2 与 SIRT6 结合的特征对于理解 SIRT6 对 Nrf2 相关细胞活性的调节至关重要。酵母双杂交实验表明，Nrf2 与 SIRT6 的结合是由 Neh1 和 Neh3 结构域介导的。分子动力学分析显示，消除 Neh1 和 Neh3 结构域降低了结合的稳定性和自由能。这些结构域在介导结合中的作用通过共免疫沉淀得到了证实。在转染靶向 Nrf2 Neh1 结构域的小干扰 RNA(siRNA)和过表达结构域突变 Nrf2 的质粒的细胞中，发现 Nrf2 在缺乏 Neh1 和 Neh3 结构域的情况下失去了刺激抗氧化基因转录的活性。
