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Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Medical Specialties

Dartmouth Scholarship

2009

Metabolism

Articles 1 - 5 of 5

Full-Text Articles in Medicine and Health Sciences

Gbdr Regulates Pseudomonas Aeruginosa Plch And Pchp Transcription In Response To Choline Catabolites, Matthew J. Wargo, Tiffany C. Ho, Maegan J. Gross, Laurie A. Whittaker, Deborah A. Hogan Dec 2009

Gbdr Regulates Pseudomonas Aeruginosa Plch And Pchp Transcription In Response To Choline Catabolites, Matthew J. Wargo, Tiffany C. Ho, Maegan J. Gross, Laurie A. Whittaker, Deborah A. Hogan

Dartmouth Scholarship

Pseudomonas aeruginosa hemolytic phospholipase C, PlcH, can degrade phosphatidylcholine (PC) and sphingomyelin in eukaryotic cell membranes and extracellular PC in lung surfactant. Numerous studies implicate PlcH in P. aeruginosa virulence. The phosphorylcholine released by PlcH activity on phospholipids is hydrolyzed by a periplasmic phosphorylcholine phosphatase, PchP. Both plcH gene expression and PchP enzyme activity are positively regulated by phosphorylcholine degradation products, including glycine betaine. Here we report that the induction of plcH and pchP transcription by glycine betaine is mediated by GbdR, an AraC family transcription factor. Mutants that lack gbdR are unable to induce plcH and pchP in media …


Wnt Pathway Reprogramming During Human Embryonal Carcinoma Differentiation And Potential For Therapeutic Targeting, Grace E. Snow, Allison C. Kasper, Alexander M. Busch, Elisabeth Schwarz, Katherine E. Ewings, Thomas Bee, Michael J. Spinella, Ethan Dmitrovsky, Sarah J. Freemantle Oct 2009

Wnt Pathway Reprogramming During Human Embryonal Carcinoma Differentiation And Potential For Therapeutic Targeting, Grace E. Snow, Allison C. Kasper, Alexander M. Busch, Elisabeth Schwarz, Katherine E. Ewings, Thomas Bee, Michael J. Spinella, Ethan Dmitrovsky, Sarah J. Freemantle

Dartmouth Scholarship

Testicular germ cell tumors (TGCTs) are classified as seminonas or non-seminomas of which a major subset is embryonal carcinoma (EC) that can differentiate into diverse tissues. The pluripotent nature of human ECs resembles that of embryonic stem (ES) cells. Many Wnt signalling species are regulated during differentiation of TGCT-derived EC cells. This study comprehensively investigated expression profiles of Wnt signalling components regulated during induced differentiation of EC cells and explored the role of key components in maintaining pluripotency.


Sarz Promotes The Expression Of Virulence Factors And Represses Biofilm Formation By Modulating Sara And Agr In Staphylococcus Aureus, Sandeep Tamber, Ambrose L. Cheung Oct 2009

Sarz Promotes The Expression Of Virulence Factors And Represses Biofilm Formation By Modulating Sara And Agr In Staphylococcus Aureus, Sandeep Tamber, Ambrose L. Cheung

Dartmouth Scholarship

Staphylococcus aureus is a remarkably adaptable organism capable of multiple modes of growth in the human host, as a part of the normal flora, as a pathogen, or as a biofilm. Many of the regulatory pathways governing these modes of growth are centered on the activities of two regulatory molecules, the DNA binding protein SarA and the regulatory RNAIII effector molecule of the agr system. Here, we describe the modulation of these regulators and their downstream target genes by SarZ, a member of the SarA/MarR family of transcriptional regulators. Transcriptional and phenotypic analyses of a sarZ mutant demonstrated that the …


Long-Distance Delivery Of Bacterial Virulence Factors By Pseudomonas Aeruginosa Outer Membrane Vesicles, Jennifer M. Bomberger, Daniel P. Maceachran, Bonita A. Coutermarsh, Siying Ye, George A. O'Toole, Bruce A. Stanton, Frederick M. Ausubel Apr 2009

Long-Distance Delivery Of Bacterial Virulence Factors By Pseudomonas Aeruginosa Outer Membrane Vesicles, Jennifer M. Bomberger, Daniel P. Maceachran, Bonita A. Coutermarsh, Siying Ye, George A. O'Toole, Bruce A. Stanton, Frederick M. Ausubel

Dartmouth Scholarship

Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane–derived vesicles (OMV) secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including β-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma …


Interconnections Between Sigma B, Agr, And Proteolytic Activity In Staphylococcus Aureus Biofilm Maturation, Katherine J. Lauderdale, Blaise R. Boles, Ambrose L. Cheung, Alexander R. Horswill Feb 2009

Interconnections Between Sigma B, Agr, And Proteolytic Activity In Staphylococcus Aureus Biofilm Maturation, Katherine J. Lauderdale, Blaise R. Boles, Ambrose L. Cheung, Alexander R. Horswill

Dartmouth Scholarship

Staphylococcus aureus is a proficient biofilm former on host tissues and medical implants. We mutagenized S. aureus strain SH1000 to identify loci essential for ica-independent mechanisms of biofilm maturation and identified multiple insertions in the rsbUVW-sigB operon. Following construction and characterization of a sigB deletion, we determined that the biofilm phenotype was due to a lack of sigma factor B (SigB) activity. The phenotype was conserved in a sigB mutant of USA300 strain LAC, a well-studied community-associated methicillin-resistant S. aureus isolate. We determined that agr RNAIII levels were elevated in the sigB mutants, and high levels of RNAIII expression are …