Member of the two-component regulatory system PprA/PprB involved in biofilm formation by controlling the expression of many related genes including type IVb pili major subunit flp pilin, adhesin bapA or cupE fimbriae (PubMed:19151143, PubMed:21091863, PubMed:23209420, PubMed:31492668). Functions as a transcription regulator by direct binding to promoter regions (PubMed:12499175, PubMed:19151143). Negatively regulates its own transcription (PubMed:31492668). By carbon starvation. This increased expression is controlled by RpoS. Phosphorylated by PprA. Expression of flp in response to carbon starvation stress is completely eliminated in the deletion mutant. An article reported the role of PprB in modulation of the quorum-sensing signal production. However, this paper was later retracted as the authors' main conclusion on the regulatory role of PprB on AHL signal production in wild type P.aeruginosa is not correct.