Expression of OmpC and OmpF porin proteins and survival of Escherichia coli under photooxidative stress in Black Sea water
Expression of OmpC and OmpF porin proteins and survival of Escherichia coli under photooxidative stress in Black Sea water
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黑海水中 OmpC 和 OmpF 孔蛋白的表达以及大肠杆菌在光氧化应激下的存活
DOI：
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
C. Darcan
中科院分区：
文献类型：
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作者：
C. Darcan
本研究研究了黑海水中光氧化应激条件下大肠杆菌外膜蛋白C和外膜蛋白F （OmpC和OmpF）的合成，以及RpoS（饥饿/固定相sigma因子，σ 38）和EnvZ（跨膜环境传感器蛋白）在改变孔蛋白表达中的作用。野生型大肠杆菌W3110和MSZ31 （envZ−）在光氧化胁迫下的t99 （2 log还原所需时间）值分别为14.3和16.8 h，而孔蛋白缺陷突变体MKC505 （ompC−）、MH621 （ompF−）、MKCF36 （ompF−ompC−）和MSR31 （ompR−）的t99值分别为10.6、10.2、9.8和9.1 h。此外，当孔蛋白或compr缺失时，其抗光氧化胁迫能力下降。在对照环境中，所有研究的转录融合菌株（野生型和突变型）的OmpC和OmpF孔蛋白表达均有所增加，而在添加亚甲基蓝作为光敏剂的光氧化环境中，OmpC和OmpF孔蛋白表达几乎完全下降。由此可见，RpoS和EnvZ对OmpC和OmpF合成的调控不依赖于光氧化。本研究首次确定了微咸水中ompC的表达受RpoS的影响。
In the present study, the synthesis of OmpC and OmpF porins (outer membrane pro- teins C and F, respectively) of Escherichia coli under photooxidative stress in Black Sea water and the roles of RpoS (the starvation/stationary phase sigma factor, σ 38 ) and EnvZ (a transmembrane environmental sensor protein) in changing porin protein expression were investigated. The t99 (time required for a 2 log reduction) values for wild-type E. coli W3110 and MSZ31 (envZ − ) under photooxidative stress were observed to be 14.3 and 16.8 h, respectively, while for porin-deficient mutants MKC505 (ompC − ), MH621 (ompF − ), MKCF36 (ompF − ompC − ), and MSR31 (ompR � ) they were 10.6, 10.2, 9.8 and 9.1 h, respectively. Further, when the porins or ompR were deleted, the resistance to photooxidative stress decreased. OmpC and OmpF porin expression increased in all studied transcriptional fusion strains (wild type and mutants) in control microcosms, and almost completely decreased under photooxidative stress in the test microcosms, which consisted of light exposure with methylene blue added as a photosensitizer. Thus, it could be concluded that RpoS and EnvZ regulation of the synthesis of OmpC and OmpF is not photooxidation-dependent. This study determined for the first time that the expression of ompC in brackish water is influenced by RpoS.
DOI：
10.1073/pnas.86.16.6052
发表时间：
1989-08-01
影响因子：
11.1
作者：
FORST, S;DELGADO, J;INOUYE, M
通讯作者：
INOUYE, M