Function
Response regulator member of the two-component regulatory system CpxA/CpxR which responds to envelope stress response by activating expression of downstream genes including cpxP, degP, dsbA and ppiA (PubMed:7883164, PubMed:9401031). Required for efficient binding of stationary phase cells to hydrophobic surfaces, part of the process of biofilm formation (PubMed:11830644). Induced upon cell surface binding, subsequently induces genes it controls (cpxP, dsbA and spy, degP is only partially induced) (PubMed:11830644). Binds and activates transcription from the degP promoter (PubMed:7883164); binding is enhanced by phosphorylation (PubMed:9401031). This system combats a variety of extracytoplasmic protein-mediated toxicities by increasing the transcription of the periplasmic protease, DegP in concert with sigma factor E (PubMed:7883164), as well as that of CpxP protein. Other downstream effectors may include SrkA (PubMed:23416055).