Member of the two-component regulatory system PilS/PilR that regulates the expression of multiple genes including the type IV pilus (T4P) major subunit PilA (PubMed:8097014, PubMed:7911557). Thereby, plays a major role in the regulation of multiple motility pathways (PubMed:30042200). Functions as a membrane-associated protein kinase that phosphorylates PilR in response to environmental signals leading to activation of specific gene promoters including the pilin gene (PubMed:8550520, PubMed:27162347). ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. Interacts with PilA. Localizes at both poles of P.aeruginosa. Accumulates also at the septum of dividing cells, so when the daughter cells separate, PilS is already in place at both poles. The linker domain is the critical region for polar localization. Deletion mutant results in changes in swimming, swarming and/or twitching motility associated with virulence in specific hosts.