This proposal is aimed at continuing Dr. Lee's genetic analysis of the S. aureus type 8 capsular polysaccharide (CP8).
The aims are: 1) to study the regulation of CP8 gene expression in response to environmental factors; 2) to characterize the function of the cap8 genes; and 3) to define the role of the microcapsules in virulence. To study the regulation of CP8 genes, the PI will use deletion and mutagenesis analyses of gene fusions to define which promoter sequences are required for gene regulation. He will clone regulatory genes that respond to different environmental stimuli by a reverse genetic approach and by transposon mutagenesis. The cloned gene will be inactivated by allelic replacement to study the regulation. He will study how CP8 genes are regulated by agr, a global regulator. To study the functions of CP8 genes, he will use chemical mutants that have already been generated. Each gene will be correlated with function by analyzing the accumulated intermediate resulting from a specific gene mutation. The focus will be on genes involved in chain-length regulation, transport, and polymerization. To define the role of microcapsules in pathogenesis, isogenic deletion mutants will be tested in an in vitro phagocytic assays and by mouse lethality studies.
|Gupta, Ravi Kr; Luong, Thanh T; Lee, Chia Y (2015) RNAIII of the Staphylococcus aureus agr system activates global regulator MgrA by stabilizing mRNA. Proc Natl Acad Sci U S A 112:14036-41|
|Medema, Marnix H; Kottmann, Renzo; Yilmaz, Pelin et al. (2015) Minimum Information about a Biosynthetic Gene cluster. Nat Chem Biol 11:625-31|
|Atwood, Danielle N; Loughran, Allister J; Courtney, Ashleah P et al. (2015) Comparative impact of diverse regulatory loci on Staphylococcus aureus biofilm formation. Microbiologyopen 4:436-51|
|Beenken, Karen E; Mrak, Lara N; Zielinska, Agnieszka K et al. (2014) Impact of the functional status of saeRS on in vivo phenotypes of Staphylococcus aureus?sarA mutants. Mol Microbiol 92:1299-312|
|Prax, Marcel; Lee, Chia Y; Bertram, Ralph (2013) An update on the molecular genetics toolbox for staphylococci. Microbiology 159:421-35|
|Gupta, Ravi Kr; Alba, Jimena; Xiong, Yan Q et al. (2013) MgrA activates expression of capsule genes, but not the ?-toxin gene in experimental Staphylococcus aureus endocarditis. J Infect Dis 208:1841-8|
|Graham, Justin W; Lei, Mei G; Lee, Chia Y (2013) Trapping and identification of cellular substrates of the Staphylococcus aureus ClpC chaperone. J Bacteriol 195:4506-16|
|Lei, Mei G; Cue, David; Alba, Jimena et al. (2012) A single copy integration vector that integrates at an engineered site on the Staphylococcus aureus chromosome. BMC Res Notes 5:5|
|Cue, David; Lei, Mei G; Lee, Chia Y (2012) Genetic regulation of the intercellular adhesion locus in staphylococci. Front Cell Infect Microbiol 2:38|
|Zielinska, Agnieszka K; Beenken, Karen E; Joo, Hwang-Soo et al. (2011) Defining the strain-dependent impact of the Staphylococcal accessory regulator (sarA) on the alpha-toxin phenotype of Staphylococcus aureus. J Bacteriol 193:2948-58|
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