Cyclic-di-GMP phosphodiesterase STM3615 regulates Salmonella physiology
Abstract
Foodborne-related diseases pose a widespread global health threat. A clinically relevant etiological agent in both humans and animals is Salmonella. To survive in varying environments, Salmonella must constantly sense and regulate a wide variety of internal mechanisms. The secondary signaling molecule cyclic-di-GMP (c-di-GMP) is one mechanism used to regulate such adaptations by influencing processes such as biofilm formation, flagellar motility, and virulence. Previous work has shown that the Salmonella Typhimurium c-di-GMP-specific phosphodiesterase (PDE) STM3615 is one of three PDEs required for proper survival within mouse macrophages and virulence during systemic infection. Deletion of STM3615 also resulted in bacteria with decreased survival in stationary phase, an altered rod shape, and sensitivity to peptidoglycan stress. Here, we examine the role of STM3615 in Salmonella physiology. Focused testing of STM3615’s specific domains revealed that the periplasmic domain, rather than the enzymatically active PDE domain, is the primary mediator of the observed physiological phenotypes. A transposon reversion screen and protein-protein interaction assays suggest that STM3615 interacts with members of the Rcs bacterial phosphorelay stress response system. Future research aims to address the link between these two systems by testing the hypothesis that STM3615 participates within the Rcs stress pathway, and that the Rcs pathway regulates STM3615 PDE activity. By investigating this regulatory interaction, we seek to define a novel mechanism linking c-di-GMP signaling with the Rcs stress response, providing new insight into how bacterial pathogens coordinate stress adaptation and its physiological state.
Start Time
15-4-2026 9:00 AM
End Time
15-4-2026 10:00 AM
Room Number
303
Presentation Type
Oral Presentation
Presentation Subtype
Grad/Comp Orals
Presentation Category
Science, Technology, and Engineering
Student Type
Graduate
Faculty Mentor
Erik Petersen
Cyclic-di-GMP phosphodiesterase STM3615 regulates Salmonella physiology
303
Foodborne-related diseases pose a widespread global health threat. A clinically relevant etiological agent in both humans and animals is Salmonella. To survive in varying environments, Salmonella must constantly sense and regulate a wide variety of internal mechanisms. The secondary signaling molecule cyclic-di-GMP (c-di-GMP) is one mechanism used to regulate such adaptations by influencing processes such as biofilm formation, flagellar motility, and virulence. Previous work has shown that the Salmonella Typhimurium c-di-GMP-specific phosphodiesterase (PDE) STM3615 is one of three PDEs required for proper survival within mouse macrophages and virulence during systemic infection. Deletion of STM3615 also resulted in bacteria with decreased survival in stationary phase, an altered rod shape, and sensitivity to peptidoglycan stress. Here, we examine the role of STM3615 in Salmonella physiology. Focused testing of STM3615’s specific domains revealed that the periplasmic domain, rather than the enzymatically active PDE domain, is the primary mediator of the observed physiological phenotypes. A transposon reversion screen and protein-protein interaction assays suggest that STM3615 interacts with members of the Rcs bacterial phosphorelay stress response system. Future research aims to address the link between these two systems by testing the hypothesis that STM3615 participates within the Rcs stress pathway, and that the Rcs pathway regulates STM3615 PDE activity. By investigating this regulatory interaction, we seek to define a novel mechanism linking c-di-GMP signaling with the Rcs stress response, providing new insight into how bacterial pathogens coordinate stress adaptation and its physiological state.
