alarmone

Alarmone, also known scientifically as cyclic di-GMP, is a ubiquitous second messenger molecule found in bacteria. It plays a critical role in regulating a wide range of cellular processes and behaviors. Alarmone is synthesized by diguanylate cyclases (DGCs) and degraded by phosphodiesterases (PDEs), with its intracellular concentration fluctuating based on environmental cues and cellular signals.

The levels of cyclic di-GMP act as a switch, controlling transitions between different bacterial lifestyles and phenotypes. For instance, it is a key regulator of bacterial motility, biofilm formation, virulence factor production, and cell cycle progression. High levels of alarmone are typically associated with sessile, surface-attached lifestyles, promoting biofilm development and stability. Conversely, lower levels often favor planktonic growth and motility.

The intricate regulatory networks involving alarmone ensure that bacteria can adapt efficiently to changing environments. Researchers are actively investigating alarmone signaling pathways to understand bacterial physiology and to identify potential targets for antimicrobial therapies. Disrupting alarmone homeostasis could offer novel strategies to combat bacterial infections by disarming bacterial virulence or promoting their clearance.