PprI:: a general switch responsible for extreme radioresistance of Deinococcus radiodurans
PprI:: a general switch responsible for extreme radioresistance of Deinococcus radiodurans
复制标题
DOI：
10.1016/s0006-291x(03)00965-3
复制
发表时间：
2003-06-27
影响因子：
3.1
通讯作者：
Shen, BH
中科院分区：
文献类型：
--
作者：
Hua, YJ;Narumi, I;Shen, BH
耐辐射球菌表现出非凡的抵抗DNA损伤剂，特别是电离辐射的致死和诱变效应的能力。现有证据表明，DNA损伤的有效修复和染色体结构的保护是辐射抗性的主要原因。人们对这种现象的生化基础知之甚少。我们已经从一个自然突变中鉴定出一个独特的基因PprI，它是下游DNA修复和保护途径的通用开关，在这个突变中，PprI被转座子干扰。野生型基因的完全功能中断导致了对电离辐射的极大敏感性。干扰物的辐射抗性可以通过与PPRI互补而完全恢复。对于辐射胁迫，PPRI不能显著和特异地诱导recA和PPRA的基因表达，并增强过氧化氢酶的酶活性。这些结果有力地表明PPRI在调节多条DNA修复和保护通路以响应辐射应激中起着至关重要的作用。(C)2003 Elsevier Science(美国)。版权所有。
Deinococcus radiodurans exhibits an extraordinary ability to withstand the lethal and mutagenic effects of DNA damaging agents, particularly, ionizing radiation. Available evidence indicates that efficient repair of DNA damage and protection of the chromosomal structure are mainly responsible for the radioresistance. Little is known about the biochemical basis for this phenomenon. We have identified a unique gene, pprI, as a general switch for downstream DNA repair and protection pathways, from a natural mutant, in which pprI is disrupted by a transposon. Complete functional disruption of the gene in wild-type leads to dramatic sensitivity to ionizing radiation. Radioresistance of the disruptant could be fully restored by complementation with pprI. In response to radiation stress, PprI can 'significantly and specifically induce the gene expression of recA and pprA and enhance the enzyme activities of catalases. These results strongly suggest that PprI plays a crucial role in regulating multiple DNA repair and protection pathways in response to radiation stress. (C) 2003 Elsevier Science (USA). All rights reserved.