The Escherichia coli Envelope Stress Sensor CpxA Responds to Changes in Lipid Bilayer Properties
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- 作者：Rebecca Keller ; Candan Ari枚z ; Nicole Hansmeier ; Filippa Stenberg-Bruzell ; Malin Burstedt ; David Vikstr枚m ; Amelie Kelly ; 脜ke Wieslander ; Daniel O. Daley ; Sabine Hunke
- 刊名：Biochemistry
- 出版年：2015
- 出版时间：June 16, 2015
- 年：2015
- 卷：54
- 期：23
- 页码：3670-3676
- 全文大小：302K
- ISSN：1520-4995
文摘
The Cpx stress response system is induced by various environmental and cellular stimuli. It is also activated in Escherichia coli strains lacking the major phospholipid, phosphatidylethanolamine (PE). However, it is not known whether CpxA directly senses changes in the lipid bilayer or the presence of misfolded proteins due to the lack of PE in their membranes. To address this question, we used an in vitro reconstitution system and vesicles with different lipid compositions to track modulations in the activity of CpxA in different lipid bilayers. Moreover, the Cpx response was validated in vivo by monitoring expression of a PcpxP-gfp reporter in lipid-engineered strains of E. coli. Our combined data indicate that CpxA responds specifically to different lipid compositions.