Mechanism of regulation of E. coli cell duplication by DNA-, RNA- binding protein Hfq

DNA、RNA 结合蛋白 Hfq 调节大肠杆菌细胞复制的机制

• 批准号: 12660069
• 负责人: WACHI Masaaki
• 金额: $ 2.62万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12660069/
• 关键词: iron ion; oxidative stress; Hfq; RNaseE; RNase G; mRNA; rRNA; 大腸菌; 細胞増殖; Hfqタンパク質; DNA損傷

FepA and FhuE proteins involved in iron transport in the outer-membrane were overproduced in the hfq::cat mutant cells. The hfq::cat mutant was more susceptible to killing by hydrogen peroxide, probably due to the excess incorporation of iron. Direct measurement of intracellular iron concentrations by electroparamagnetic resonance spectroscopy revealed that the mutant cells indeed accumulated significantly higher levels of iron than the wild type cells. The Hfq protein protected DNA from iron-induced oxidative damages in vitro. These results suggest that the Hfq protein is involved in the mechanism of cell survival by protecting cells from oxidative stress.Genetic interaction between hfq and RNazes was examined. Temperature sensitivity of the ams-1 (RNaze E^<ts>) mutant strain was suppressed by introduction of the hfq::cat mutation. Its suppression was cancelled by introduction of mg::cat (RNaze G defective) mutation. These results suggest that the Hfq protein is involved in the mechanism of regulation of mRNA stability by RNaze E and RNaze G.

参与外膜铁转运的FepA和FhuE蛋白在hfq：：cat突变细胞中过量产生。hfq：：cat突变体更容易被过氧化氢杀死，这可能是由于铁的过量掺入。通过电顺磁共振光谱法直接测量细胞内铁浓度显示，突变体细胞确实比野生型细胞积累了显著更高水平的铁。Hfq蛋白在体外保护DNA免受铁诱导的氧化损伤。这些结果表明Hfq蛋白通过保护细胞免受氧化应激而参与细胞存活机制。通过引入hfq：：cat突变抑制了ams-1（RNaze E^）突变株的温度敏感<ts>性。其抑制通过引入mg：：cat（RNaze G缺陷型）突变而被取消。这些结果表明，Hfq蛋白参与了RNazeE和RNazeG调节mRNA稳定性的机制。

项目成果

Hirasawa, T.: "L-Glutamate production by lysozyme-sensitive Corynebacterium glutamicum ltsA mutant strains"BMC Biotechnol.. 1. 9 (2001)

Hirasawa，T.：“溶菌酶敏感的谷氨酸棒杆菌ltsA突变菌株生产L-谷氨酸”BMC Biotechnol.. 1. 9 (2001)

Genryon Vmitsuki: "Involvement of RNase G in inviro mRNA metabolism in Escherichia cdi"Genes to Cells. 6・5. (2001)

Genryon Vmitsuki：“RNase G 参与大肠杆菌体内 mRNA 代谢”《Genes to Cells》（2001 年）。

Umitsuki, G.: "Involvement of RNase G in in vivo mRNA metabolism in Eschcrichia coli"Genes Cells. 6. 403-410 (2001)

Umitsuki, G.：“RNase G 参与大肠杆菌体内 mRNA 代谢”Genes Cells。

Wijayarathna, C.D.: "Isolation of ftsI and murE genes involved in peptidoglycan synthesis from Corynebactcrium glutamicum"Appl. Microbiol. Biotechnol.. 55. 466-470 (2001)

Wijayarathna，C.D.：“从谷氨酸棒杆菌中分离参与肽聚糖合成的 ftsI 和 murE 基因”Appl。

和地正明: "大腸菌RNase G"日本農芸化学会誌. 75. 121-127 (2001)

Masaaki Waji：“大肠杆菌 RNase G”日本农业化学学会杂志 75. 121-127 (2001)。