Université de Paris-Descartes, Faculté de Médecine, INSERM U1001, 156 Rue de Vaugirard, 75015 Paris, France.
Microbiol Mol Biol Rev. 2011 Mar;75(1):133-91. doi: 10.1128/MMBR.00015-10.
Deinococcus radiodurans is a robust bacterium best known for its capacity to repair massive DNA damage efficiently and accurately. It is extremely resistant to many DNA-damaging agents, including ionizing radiation and UV radiation (100 to 295 nm), desiccation, and mitomycin C, which induce oxidative damage not only to DNA but also to all cellular macromolecules via the production of reactive oxygen species. The extreme resilience of D. radiodurans to oxidative stress is imparted synergistically by an efficient protection of proteins against oxidative stress and an efficient DNA repair mechanism, enhanced by functional redundancies in both systems. D. radiodurans assets for the prevention of and recovery from oxidative stress are extensively reviewed here. Radiation- and desiccation-resistant bacteria such as D. radiodurans have substantially lower protein oxidation levels than do sensitive bacteria but have similar yields of DNA double-strand breaks. These findings challenge the concept of DNA as the primary target of radiation toxicity while advancing protein damage, and the protection of proteins against oxidative damage, as a new paradigm of radiation toxicity and survival. The protection of DNA repair and other proteins against oxidative damage is imparted by enzymatic and nonenzymatic antioxidant defense systems dominated by divalent manganese complexes. Given that oxidative stress caused by the accumulation of reactive oxygen species is associated with aging and cancer, a comprehensive outlook on D. radiodurans strategies of combating oxidative stress may open new avenues for antiaging and anticancer treatments. The study of the antioxidation protection in D. radiodurans is therefore of considerable potential interest for medicine and public health.
耐辐射球菌是一种强大的细菌，以其高效准确地修复大量 DNA 损伤的能力而闻名。它对许多 DNA 损伤剂具有极强的抵抗力，包括电离辐射和紫外线辐射（100 至 295nm）、干燥和丝裂霉素 C，这些损伤剂不仅会导致 DNA 发生氧化损伤，还会通过产生活性氧物种导致所有细胞大分子发生氧化损伤。耐辐射球菌对氧化应激的极端弹性是通过有效保护蛋白质免受氧化应激和有效 DNA 修复机制协同赋予的，这两个系统的功能冗余增强了这种弹性。这里广泛回顾了耐辐射球菌预防和从氧化应激中恢复的策略。像耐辐射球菌这样的辐射和干燥抗性细菌的蛋白质氧化水平明显低于敏感细菌，但 DNA 双链断裂的产量相似。这些发现挑战了 DNA 是辐射毒性主要靶点的概念，同时推进了蛋白质损伤以及蛋白质免受氧化损伤的保护，作为辐射毒性和存活的新范式。通过酶和非酶抗氧化防御系统赋予 DNA 修复和其他蛋白质免受氧化损伤的保护，该系统由二价锰配合物主导。鉴于活性氧物种积累引起的氧化应激与衰老和癌症有关，对耐辐射球菌对抗氧化应激策略的全面展望可能为抗衰老和抗癌治疗开辟新途径。因此，研究耐辐射球菌中的抗氧化保护具有相当大的医学和公共卫生潜力。
