title: Identification and characterization of outer membrane vesicle-associated proteins in Salmonella enterica serovar Typhimurium.
abstract: Salmonella enterica serovar Typhimurium is a primary cause of enteric diseases and has acquired a variety of virulence factors during its evolution into a pathogen. Secreted virulence factors interact with commensal flora and host cells and enable Salmonella to survive and thrive in hostile environments. Outer membrane vesicles (OMVs) released from many Gram-negative bacteria function as a mechanism for the secretion of complex mixtures, including virulence factors. We performed a proteomic analysis of OMVs that were isolated under standard laboratory and acidic minimal medium conditions and identified 14 OMV-associated proteins that were observed in the OMV fraction isolated only under the acidic minimal medium conditions, which reproduced the nutrient-deficient intracellular milieu. The inferred roles of these 14 proteins were diverse, including transporter, enzyme, and transcriptional regulator. The absence of these proteins influenced Salmonella survival inside murine macrophages. Eleven of these proteins were predicted to possess secretion signal sequences at their N termini, and three (HupA, GlnH, and PhoN) of the proteins were found to be translocated into the cytoplasm of host cells. The comparative proteomic profiling of OMVs performed in this study revealed different protein compositions in the OMVs isolated under the two different conditions, which indicates that the OMV cargo depends on the growth conditions and provides a deeper insight into how Salmonella utilizes OMVs to adapt to environmental changes.
authors.affiliation: Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, South Korea.
authors.forename: Jaewoo
authors.initials: J
authors.lastname: Bai
authors.affiliation: Department of Senior Healthcare, BK21 plus program, Graduate School, Eulji University, Seongnam, South Korea.
authors.forename: Seul I
authors.initials: SI
authors.lastname: Kim
authors.affiliation: Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, South Korea.
authors.forename: Sangryeol
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Department of Food Technology and Services, Eulji University, Seongnam, South Korea Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, South Korea yoonhy@eulji.ac.kr.
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Yoon
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D003470:Culture Media / Q000737:chemistry; D040901:Proteomics / Q000379:methods; D012486:Salmonella typhimurium / Q000737:chemistry*; D022142:Secretory Vesicles / Q000737:chemistry*; D037521:Virulence Factors / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D037521:Virulence Factors