THE CRITICAL ROLES OF (P)PPGPP IN HOMEOSTASIS AND ANTIBIOTIC TOLERANCE IN GRAM POSITIVE BACTERIA

Abstract Bacteria, from commensals to pathogens, utilize stress responses to maintain cellularhomeostasis in fluctuating environments, enabling cells to survive nutrient deprivation, antibiotictreatments and host defenses. A well conserved key component of the bacterial stress responseis the small signaling molecule (p)ppGpp (guanosine tetraphosphate and pentaphosphate).(p)ppGpp can be produced in almost all bacteria to mediate stress resistance and adaptation.(p)ppGpp is also critical for the generation of persister cells that are metabolically dormant andrefractory to killing by antibiotics. However, (p)ppGpp regulation in Gram -positive bacteria,including many human pathogens, is poorly understood. The overall rationale of the proposedwork is to unravel (p)ppGpp regulation in Gram-positive bacteria, which will provide importantinsights into the bacterial stress response, antibiotic tolerance, and interactions between microbesand hosts.