Bacterial dynamin homolog regulates growth phase-dependent c-di-GMP production.

The bacterial second messenger bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) governs the transition from motile to sessile lifestyle by suppressing flagellar motility and promoting the synthesis of the extracellular biofilm matrix. In IMPORTANCE: As a central regulator of motile-to-sessile lifestyle switching, bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) needs to be dynamically modulated in response to growth phase transitions and environmental challenges. Our work characterizes a novel post-translational mechanism of c-di-GMP regulation, where a bacterial GTPase, RdcA, that is homologous to eukaryotic dynamins, couples the physiological state of cells to c-di-GMP production. This coupling includes a cell energy- or nutrient-dependent recruitment of RdcA to the cytoplasmic membrane, where it interacts with and activates a major c-di-GMP producing enzyme. In contrast to the established function of eukaryotic and bacterial dynamins in membrane remodeling, our study establishes an example of a dynamin-like protein functioning as a GTP-sensitive switch and trigger enzyme that controls second messenger signaling in bacteria.