Cyclic-di-GMP phosphodiesterase STM3615 regulates Salmonella physiology
Location
D.P. Culp Center Ballroom
Start Date
4-5-2024 9:00 AM
End Date
4-5-2024 11:30 AM
Poster Number
96
Name of Project's Faculty Sponsor
Erik Petersen
Faculty Sponsor's Department
Health Sciences
Competition Type
Competitive
Type
Poster Presentation
Presentation Category
Health
Abstract or Artist's Statement
Foodborne-related diseases pose a persistent and widespread global health threat. A highly clinically relevant etiological enteric pathogen in both humans and animals is Salmonella, which demands a comprehensive understanding of the molecular mechanisms governing Salmonella survival and adaptation. The second messenger cyclic-di-GMP relates to bacterial infections by influencing processes such as biofilm formation, flagellar motility, and virulence. Previous work has shown that the Salmonella Typhimurium cyclic-di-GMP-metabolizing enzyme STM3615 is required for proper survival within both macrophages and mice. Here, we examined the role of STM3615 in Salmonella physiology. Using an agar plate containing dyes designed to identify cell death, we determined that survival of an STM3615 deletion mutant decreased in the stationary phase. We turned to microscopy and found that this mutant also displayed a shortened bacterial morphology. Considering that both of these phenotypes are associated with the regulation of bacterial division, we exposed the STM3615 mutant to A22, an antimicrobial that targets the bacterial replication machinery and found that it displayed dramatically reduced survival. Observing the following phenotypes prompted focused testing of STM3615’s specific domains: two transmembrane domains, a periplasmic domain, a HAMP domain, and a cyclic-di-GMP phosphodiesterase domain. The periplasmic domain, rather than the PDE domain, emerged as the primary mediator of bacterial morphology and division regulation. A protein fold prediction algorithm suggested STM3615 is potentially interacting with a periplasmic partner to mediate this response. Using random transposon mutagenesis, we identified mutants associated with the Rcs outer membrane and periplasmic damage response pathway that reverted to wildtype phenotypes. Future research aims to address the role of STM3615 by testing the hypothesis that it interacts with a periplasmic protein partner, thereby regulating cell morphology. By investigating this mechanism, we can uncover a novel mechanism involved in the regulation of bacterial division. This investigation is motivated by the practical need to enhance our understanding of bacterial infections, with potential implications for targeted interventions, therapeutic strategies, and preventive measures.
Cyclic-di-GMP phosphodiesterase STM3615 regulates Salmonella physiology
D.P. Culp Center Ballroom
Foodborne-related diseases pose a persistent and widespread global health threat. A highly clinically relevant etiological enteric pathogen in both humans and animals is Salmonella, which demands a comprehensive understanding of the molecular mechanisms governing Salmonella survival and adaptation. The second messenger cyclic-di-GMP relates to bacterial infections by influencing processes such as biofilm formation, flagellar motility, and virulence. Previous work has shown that the Salmonella Typhimurium cyclic-di-GMP-metabolizing enzyme STM3615 is required for proper survival within both macrophages and mice. Here, we examined the role of STM3615 in Salmonella physiology. Using an agar plate containing dyes designed to identify cell death, we determined that survival of an STM3615 deletion mutant decreased in the stationary phase. We turned to microscopy and found that this mutant also displayed a shortened bacterial morphology. Considering that both of these phenotypes are associated with the regulation of bacterial division, we exposed the STM3615 mutant to A22, an antimicrobial that targets the bacterial replication machinery and found that it displayed dramatically reduced survival. Observing the following phenotypes prompted focused testing of STM3615’s specific domains: two transmembrane domains, a periplasmic domain, a HAMP domain, and a cyclic-di-GMP phosphodiesterase domain. The periplasmic domain, rather than the PDE domain, emerged as the primary mediator of bacterial morphology and division regulation. A protein fold prediction algorithm suggested STM3615 is potentially interacting with a periplasmic partner to mediate this response. Using random transposon mutagenesis, we identified mutants associated with the Rcs outer membrane and periplasmic damage response pathway that reverted to wildtype phenotypes. Future research aims to address the role of STM3615 by testing the hypothesis that it interacts with a periplasmic protein partner, thereby regulating cell morphology. By investigating this mechanism, we can uncover a novel mechanism involved in the regulation of bacterial division. This investigation is motivated by the practical need to enhance our understanding of bacterial infections, with potential implications for targeted interventions, therapeutic strategies, and preventive measures.