Salmonellosis continues to be a major health problem in the United States and the rest of the world. Penetration of intestinal epithelial cells is a common feature of all Salmonella species. Despite the central importance of this event in the pathogenicity of these organisms, little is known about its molecular bases. The broad objective of this study is to understand the molecular mechanisms of Salmonella invasion of non- phagocytic cells and to identify all the biochemical components involved in this interaction. The principal investigator has recently cloned a group of genes (invA, B, C and D) that allow S. typhimurium to penetrate tissue culture cells. The functional study of these genes by a combination of biochemical, tissue culture and genetic techniques will be the main focus of this research. Mutated inv genes will be introduced into wild-type S. typhimurium to determine their specific role in invasion to cultured epithelial cells. The localization of the inv gene products in the bacterial cell as well as their ability to bind to eukaryotic cells will be examined. Fusions to reporter genes will be employed to examine the regulation of expression of the inv genes in response to exposure to tissue culture cells as well as to other environmental influences. The role of DNA supercoiling in this context will be particularly examined using in vivo and in vitro techniques. Mutations that affect expression of the inv genes will be isolated to characterize regulatory loci. Additional pathways of Salmonella invasion to tissue culture cells will be sought by isolating invasion defective mutants and characterizing the mutated loci. The studies proposed will increase the understanding of the molecular bases of Salmonella invasion to non-phagocytic cells. This knowledge will in turn facilitate the developing of new strategies to prevent and treat diseases caused by these and other invasive bacteria.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29AI030492-04
Application #
2065645
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Project Start
1991-01-01
Project End
1995-12-31
Budget Start
1994-01-01
Budget End
1994-12-31
Support Year
4
Fiscal Year
1994
Total Cost
Indirect Cost
Name
State University New York Stony Brook
Department
Genetics
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Tsou, Lun K; Lara-Tejero, María; RoseFigura, Jordan et al. (2016) Antibacterial Flavonoids from Medicinal Plants Covalently Inactivate Type III Protein Secretion Substrates. J Am Chem Soc 138:2209-18
Monjarás Feria, Julia V; Lefebre, Matthew D; Stierhof, York-Dieter et al. (2015) Role of autocleavage in the function of a type III secretion specificity switch protein in Salmonella enterica serovar Typhimurium. MBio 6:e01459-15
Kato, Junya; Lefebre, Matthew; Galán, Jorge E (2015) Structural Features Reminiscent of ATP-Driven Protein Translocases Are Essential for the Function of a Type III Secretion-Associated ATPase. J Bacteriol 197:3007-14
Lefebre, Matthew D; Galán, Jorge E (2014) The inner rod protein controls substrate switching and needle length in a Salmonella type III secretion system. Proc Natl Acad Sci U S A 111:817-22
Rathinavelan, Thenmalarchelvi; Lara-Tejero, Maria; Lefebre, Matthew et al. (2014) NMR model of PrgI-SipD interaction and its implications in the needle-tip assembly of the Salmonella type III secretion system. J Mol Biol 426:2958-69
Galán, Jorge E; Lara-Tejero, Maria; Marlovits, Thomas C et al. (2014) Bacterial type III secretion systems: specialized nanomachines for protein delivery into target cells. Annu Rev Microbiol 68:415-38
Carleton, Heather A; Lara-Tejero, Maria; Liu, Xiaoyun et al. (2013) Engineering the type III secretion system in non-replicating bacterial minicells for antigen delivery. Nat Commun 4:1590
Zhong, Dalian; Lefebre, Matthew; Kaur, Kawaljit et al. (2012) The Salmonella type III secretion system inner rod protein PrgJ is partially folded. J Biol Chem 287:25303-11
Button, Julie E; Galan, Jorge E (2011) Regulation of chaperone/effector complex synthesis in a bacterial type III secretion system. Mol Microbiol 81:1474-83
Lara-Tejero, Maria; Kato, Junya; Wagner, Samuel et al. (2011) A sorting platform determines the order of protein secretion in bacterial type III systems. Science 331:1188-91

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