Interestingly , EnvZ was not absolutely necessary for OmpR-dependent acid induction of ompF suggesting that unlike osmolarity , the EnvZ sensor is not required for full expression of the pH-dependent OmpR regulon .
Forst S , Delgado J , Rampersaud A et al In vivo phosphorylation of OmpR , the transcription activator of the ompF genes in Escherichia coli .
These data indicate that an OmpR-independent ompF induction contribute towards the genetic expression of ompF .