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Medical Biochemistry Commons

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Full-Text Articles in Medical Biochemistry

A New Class Of Inhibitors Of The Arac Family Virulence Regulator Vibrio Cholerae Toxt, Anne K. Woodbrey, Evans O. Onyango, Maria Pellegrini, Gabriela Kovacikova, Ronald Taylor, Gordon Gribble, F. Jon Kull Mar 2017

A New Class Of Inhibitors Of The Arac Family Virulence Regulator Vibrio Cholerae Toxt, Anne K. Woodbrey, Evans O. Onyango, Maria Pellegrini, Gabriela Kovacikova, Ronald Taylor, Gordon Gribble, F. Jon Kull

Dartmouth Scholarship

Vibrio cholerae is responsible for the diarrheal disease cholera that infects millions of people worldwide. While vaccines protecting against cholera exist, and oral rehydration therapy is an effective treatment method, the disease will remain a global health threat until long-term solutions such as improved sanitation and access to clean water become widely available. Because of this, there is a pressing need for potent therapeutics that can either mitigate cholera symptoms, or act prophylactically to prevent the virulent effects of a cholera infection. Here we report the design, synthesis, and characterization of a set of compounds that bind and inhibit ToxT, …


Epoxide-Mediated Cifr Repression Of Cif Gene Expression Utilizes Two Binding Sites In Pseudomonas Aeruginosa, Alicia E. Ballok, Christopher D. Bahl, Emily L. Dolben, Allia K. Lindsay, Jessica D. St. Laurent, Deborah Hogan, Dean Madden, George A. O'Toole Jul 2012

Epoxide-Mediated Cifr Repression Of Cif Gene Expression Utilizes Two Binding Sites In Pseudomonas Aeruginosa, Alicia E. Ballok, Christopher D. Bahl, Emily L. Dolben, Allia K. Lindsay, Jessica D. St. Laurent, Deborah Hogan, Dean Madden, George A. O'Toole

Dartmouth Scholarship

Pseudomonas aeruginosa secretes an epoxide hydrolase virulence factor that reduces the apical membrane expression of ABC transporters such as the cystic fibrosis transmembrane conductance regulator (CFTR). This virulence factor, named CFTR inhibitory factor (Cif), is regulated by a TetR-family, epoxide-responsive repressor known as CifR via direct binding and repression. We identified two sites of CifR binding in the intergenic space between cifR and morB, the first gene in the operon containing the cif gene. We have mapped these binding sites and found they are 27 bp in length, and they overlap the -10 and +1 sites of both the cifR …


Chloroquine Treatment Of Arpe-19 Cells Leads To Lysosome Dilation And Intracellular Lipid Accumulation: Possible Implications Of Lysosomal Dysfunction In Macular Degeneration, Patrick M. Chen, Zoë J. Gombart, Jeff W. Chen Mar 2011

Chloroquine Treatment Of Arpe-19 Cells Leads To Lysosome Dilation And Intracellular Lipid Accumulation: Possible Implications Of Lysosomal Dysfunction In Macular Degeneration, Patrick M. Chen, Zoë J. Gombart, Jeff W. Chen

Dartmouth Scholarship

Age-related macular degeneration (AMD) is the leading cause of vision loss in elderly people over 60. The pathogenesis is still unclear. It has been suggested that lysosomal stress may lead to drusen formation, a biomarker of AMD. In this study, ARPE-19 cells were treated with chloroquine to inhibit lysosomal function. Chloroquine-treated ARPE-19 cells demonstrate a marked increase in vacuolation and dense intracellular debris. These are identified as chloroquine-dilated lysosomes and lipid bodies with LAMP-2 and LipidTOX co-localization, respectively. Dilation is an indicator of lysosomal dysfunction. Chloroquine disrupts uptake of exogenously applied rhodamine-labeled dextran by these cells. This suggests a disruption …


Rho Activation Of Mdia Formins Is Modulated By An Interaction With Inverted Formin 2 (Inf2), Hua Sun, Johannes S. Schlondorff, Elizabeth J. Brown, Henry N. Higgs, Martin R. Pollak Feb 2011

Rho Activation Of Mdia Formins Is Modulated By An Interaction With Inverted Formin 2 (Inf2), Hua Sun, Johannes S. Schlondorff, Elizabeth J. Brown, Henry N. Higgs, Martin R. Pollak

Dartmouth Scholarship

Inverted formin 2 (INF2) encodes a member of the diaphanous subfamily of formin proteins. Mutations in INF2 cause human kidney disease characterized by focal and segmental glomerulosclerosis. Disease-causing mutations occur only in the diaphanous inhibitory domain (DID), suggesting specific roles for this domain in the pathogenesis of disease. In a yeast two-hybrid screen, we identified the diaphanous autoregulatory domains (DADs) of the mammalian diaphanous-related formins (mDias) mDia1, mDia2, and mDia 3 as INF2_DID-interacting partners. The mDias are Rho family effectors that regulate actin dynamics. We confirmed in vitro INF2_DID/mDia_DAD binding by biochemical assays, confirmed the in vivo interaction of these …


Structure Of Vibrio Cholerae Toxt Reveals A Mechanism For Fatty Acid Regulation Of Virulence Genes, Michael J. Lowden, Karen Skorupski, Maria Pellegrini, Michael G. Chiorazzo, Ronald K. Taylor, F. Jon Kull Feb 2010

Structure Of Vibrio Cholerae Toxt Reveals A Mechanism For Fatty Acid Regulation Of Virulence Genes, Michael J. Lowden, Karen Skorupski, Maria Pellegrini, Michael G. Chiorazzo, Ronald K. Taylor, F. Jon Kull

Dartmouth Scholarship

Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. In order for V. cholerae to cause disease, it must produce two virulence factors, the toxin-coregulated pilus (TCP) and cholera toxin (CT), whose expression is controlled by a transcriptional cascade culminating with the expression of the AraC-family regulator, ToxT. We have solved the 1.9 A resolution crystal structure of ToxT, which reveals folds in the N- and C-terminal domains that share a number of features in common with AraC, MarA, and Rob as well as the unexpected presence of a buried 16-carbon fatty acid, cis-palmitoleate. The finding that …


Prion Protein Glycosylation Is Not Required For Strain-Specific Neurotropism, Justin R. Piro, Brent T. Harris, Koren Nishina, Claudio Soto, Rodrigo Morales, Judy R. Rees, Surachai Supattapone Jun 2009

Prion Protein Glycosylation Is Not Required For Strain-Specific Neurotropism, Justin R. Piro, Brent T. Harris, Koren Nishina, Claudio Soto, Rodrigo Morales, Judy R. Rees, Surachai Supattapone

Dartmouth Scholarship

In this study, we tested the hypothesis that the glycosylation of the pathogenic isoform of the prion protein (PrPSc) might encode the selective neurotropism of prion strains. We prepared unglycosylated cellular prion protein (PrPC) substrate molecules from normal mouse brain by treatment with PNGase F and used reconstituted serial protein cyclic misfolding amplification reactions to produce RML and 301C mouse prions containing unglycosylated PrPSc molecules. Both RML- and 301C-derived prions containing unglycosylated PrPSc molecules were infectious to wild-type mice, and neuropathological analysis showed that mice inoculated with these samples maintained strain-specific patterns of PrP …


Retinoid X Receptor And Peroxisome Proliferator-Activated Receptor-Gamma Agonists Cooperate To Inhibit Matrix Metalloproteinase Gene Expression, Peter S. Burrage, Adam C. Schmucker, Yanqing Ren, Michael B. Sporn, Constance E. Brinckerhoff Dec 2008

Retinoid X Receptor And Peroxisome Proliferator-Activated Receptor-Gamma Agonists Cooperate To Inhibit Matrix Metalloproteinase Gene Expression, Peter S. Burrage, Adam C. Schmucker, Yanqing Ren, Michael B. Sporn, Constance E. Brinckerhoff

Dartmouth Scholarship

We recently described the ability of retinoid X receptor (RXR) ligand LG100268 (LG268) to inhibit interleukin-1-beta (IL-1-β)-driven matrix metalloproteinase-1 (MMP-1) and MMP-13 gene expression in SW-1353 chondrosarcoma cells. Other investigators have demonstrated similar effects in chondrocytes treated with rosiglitazone, a ligand for peroxisome proliferator-activated receptor-gamma (PPARγ), for which RXR is an obligate dimerization partner. The goals of this study were to evaluate the inhibition of IL-1--induced expression of MMP-1andMMP-13 by combinatorial treatment with RXR and PPAR  ligands and to investigate the molecular mechanisms of this inhibition.