The histidine kinase NahK regulates denitrification and nitric oxide accumulation through RsmA in <i>Pseudomonas aeruginosa</i>

<i>Pseudomonas aeruginosa</i> is an opportunistic multi-drug resistance pathogen that is associated with hospital-acquired infections. <i>P. aeruginosa</i> is highly virulent, in part due to its versatile metabolism and ability to form biofilms. Therefore, better understanding of the molecular mechanisms that regulate these processes should lead to new therapeutics to treat <i>P. aeruginosa</i> infections. The histidine kinase NahK has been previously shown to be involved in both nitric oxide (NO) signaling and quorum sensing through RsmA. The data presented here demonstrate that NahK is responsive to NO produced during denitrification to regulate cell morphology. Understanding the role of NahK in metabolism under anaerobic conditions has larger implications in determining its role in a heterogeneous metabolic environment such as a biofilm.