Figure 4.

The Cpx response senses and responds to a variety of envelope stresses. Proposed inducing cues of the Cpx response are shown with red arrows and corresponding red lettering: (A) stresses that lead to protein misfolding; (B) damage to peptidoglycan; (C) surface signals; (D) monitoring periplasmic redox states; (E) OM lipoprotein trafficking defects. In the absence of induction, the phosphatase activity of CpxA keeps CpxR unphphosphorylated. Upon induction, phosphotransfer from phosphorylated CpxA to CpxR leads to CpxR-P modulation of transcription of genes involved in several processes. Genes shown are representative, but not exhaustive of the Cpx regulon.