Unbalanced phospholipid composition of Escherichia coli membranes affects P sub(PHO) promoter activity

The activity of phosphatase P sub(PHO) or arabinose P sub(BAD) promoters of Escherichia coli has been studied as dependent on the content of zwitterionic phosphatidylethanolamine (PE) and anionic phospholipids in membranes. In the absence of PE or upon a significant decrease in the content of anionic phospholipids, the activity of the P sub(PHO) promoter (but not that of the P sub(BAD) promoter) was inhibited. Since the P sub(PHO) promoter belongs to the Pho regulon, a member of the family of two-component regulatory systems of signal transduction that have membrane sensors, the regulation of gene expression by phospholipids is presumed to be accomplished through a membrane sensor.