The Escherichia coli CpxA-CpxR envelope stress response system regulates expression of the porins ompF and ompC.

ABSTRACT: We performed transposon mutagenesis of a two-color fluorescent reporter strain to identify new regulators of the porin genes ompF and ompC in Escherichia coli. Screening of colonies by fluorescence microscopy revealed numerous mutants that exhibited interesting patterns of porin expression. One mutant harbored an insertion in the gene encoding the histidine kinase CpxA, the sensor for a two-component signaling system that responds to envelope stress. The cpxA mutant exhibited increased transcription of ompC and a very strong decrease in transcription of ompF under conditions in which acetyl phosphate levels were high. Subsequent genetic analysis revealed that this phenotype is dependent on phosphorylation of the response regulator CpxR and that activation of CpxA in wild-type cells results

SUBMITTER: Batchelor E 

PROVIDER: S-EPMC1196077 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature