Resistance of Bacillus subtilis Spore DNA to Lethal Ionizing Radiation Damage Relies Primarily on Spore Core Components and DNA Repair, with Minor Effects of Oxygen Radical Detoxification
Resistance of Bacillus subtilis Spore DNA to Lethal Ionizing Radiation Damage Relies Primarily on Spore Core Components and DNA Repair, with Minor Effects of Oxygen Radical Detoxification
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DOI：
10.1128/aem.03136-13
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发表时间：
2014-01-01
影响因子：
4.4
通讯作者：
Nicholson, Wayne L.
中科院分区：
文献类型：
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作者：
Moeller, Ralf;Raguse, Marina;Nicholson, Wayne L.
各种核心成分的作用，包括α/β/γ型小酸可溶性孢子蛋白（SASP）、吡啶二羧酸（DPA）、核心含水量以及无嘌呤/无嘧啶（AP）核酸内切酶或非同源末端连接（NHEJ）的DNA修复。枯草杆菌孢子对不同类型的电离辐射（包括X射线、质子和高能带电铁离子）的抵抗力已被研究。缺乏NHEJ或AP核酸内切酶DNA修复、氧化应激反应或主要α/β型SASP、DPA保护以及核心含水量降低的孢子对电离辐射的敏感性显著高于野生型孢子，对高能带电铁离子的敏感性最高。通过NHEJ和AP核酸内切酶的DNA修复似乎是孢子抵抗电离辐射的最重要的机制，而通过MrgA介导的氧化应激反应或KatX过氧化氢酶活性的氧自由基解毒只起很小的作用。还鉴定了α/β-型而非γ-型SASP的协同辐射防护作用，表明α/β-型SASP与孢子DNA的结合在防止由于电离辐射产生的活性氧物质引起的DNA损伤中是重要的。
The roles of various core components, including alpha /beta/gamma -type small acid-soluble spore proteins (SASP), dipicolinic acid (DPA), core water content, and DNA repair by apurinic/apyrimidinic (AP) endonucleases or nonhomologous end joining (NHEJ), in Bacillus subtilis spore resistance to different types of ionizing radiation including X rays, protons, and high-energy charged iron ions have been studied. Spores deficient in DNA repair by NHEJ or AP endonucleases, the oxidative stress response, or protection by major alpha /beta-type SASP, DPA, and decreased core water content were significantly more sensitive to ionizing radiation than wild-type spores, with highest sensitivity to high-energy-charged iron ions. DNA repair via NHEJ and AP endonucleases appears to be the most important mechanism for spore resistance to ionizing radiation, whereas oxygen radical detoxification via the MrgA-mediated oxidative stress response or KatX catalase activity plays only a very minor role. Synergistic radioprotective effects of alpha/beta -type but not gamma-type SASP were also identified, indicating that alpha/beta -type SASP's binding to spore DNA is important in preventing DNA damage due to reactive oxygen species generated by ionizing radiation.