NosP modulates cyclic-di-GMP signaling in Legionella pneumophila

Biofilms form when bacteria adhere to a surface and secrete an extracellular polymeric substance. Bacteria embedded within a biofilm benefit from increased resistance to antibiotics, host immune responses, and harsh environmental factors. Nitric oxide (NO) is a signaling molecule that can modulate communal behavior, including biofilm formation, in many bacteria. In many cases, NO-induced biofilm dispersal is accomplished through signal transduction pathways that ultimately lead to a decrease in intracellular cyclic-di-GMP. H-NOX (heme-nitric oxide/oxygen binding) proteins are the best characterized bacterial NO sensors and have been implicated in NO-mediated cyclic-di-GMP signaling, but we have recently discovered a second family of NO-sensitive proteins in bacteria named NosP (NO sensing protein); to date there has not been a clearly established link between NosP signaling and cyclic-di-GMP metabolism. Here we present evidence that NosP (Lpg0279) binds to NO and directly affects cyclic-di-GMP production ...