Identification of PprM: a modulator of the PprI-dependent DNA damage response in Deinococcus radiodurans
Identification of PprM: a modulator of the PprI-dependent DNA damage response in Deinococcus radiodurans
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DOI：
10.1007/s00792-009-0232-8
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发表时间：
2009-02
期刊：
影响因子：
2.9
通讯作者：
H. Ohba;K. Satoh;H. Sghaier;T. Yanagisawa;I. Narumi
中科院分区：
文献类型：
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作者：
H. Ohba;K. Satoh;H. Sghaier;T. Yanagisawa;I. Narumi
耐辐射异常球菌具有DNA损伤反应机制，其通过PprI蛋白诱导RecA和PprA蛋白，这两者都是赋予极端辐射抗性所必需的。为了进一步阐明耐辐射果蝇DNA损伤反应机制的本质，我们着手鉴定PprI依赖的信号转导通路中响应辐射应激的新组分。在这里，我们证明了一种新的调节蛋白，PprM（PprI依赖的DNA损伤反应的调节剂），这是一个同源的冷休克蛋白（CSP）的发现。pprM基因的破坏使D.抗辐射铀对γ射线敏感。PprM调节PprA的诱导，但不调节RecA的诱导。PprM与D.地热和嗜热栖热菌。纯化的PprM在生理条件下以同源二聚体存在，如大肠杆菌CspD的情况。pprApprM双破坏菌株比pprAorpprM单破坏菌株表现出更高的敏感性，这表明PprM调节除了PprA之外的其他迄今未知的对辐射抗性重要的蛋白质。这项研究强烈表明，PprM参与了由PprI介导的辐射反应。
Deinococcus radioduranspossesses a DNA damage response mechanism that acts via the PprI protein to induce RecA and PprA proteins, both of which are necessary in conferring extreme radioresistance. In an effort to further delineate the nature of the DNA damage response mechanism inD. radiodurans, we set out to identify novel components of the PprI-dependent signal transduction pathway in response to radiation stress. Here we demonstrate the discovery of a novel regulatory protein, PprM (a modulator of the PprI-dependent DNA damage response), which is a homolog of cold shock protein (Csp). Disruption of thepprMgene renderedD. radioduranssignificantly sensitive to γ-rays. PprM regulates the induction of PprA but not that of RecA. PprM belongs in a distinct clade of a subfamily together with Csp homologs fromD. geothermalisandThermus thermophilus. Purified PprM is present as a homodimer under physiological conditions, as the case withEscherichia coliCspD. ThepprApprMdouble-disruptant strain exhibited higher sensitivity than thepprAorpprMsingle disruptant strains, suggesting that PprM regulates other hitherto unknown protein(s) important for radioresistance besides PprA. This study strongly suggests that PprM is involved in the radiation response mediated by PprI inD. radiodurans.