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  1. Article ; Online: Localized and efficient curli nucleation requires the chaperone-like amyloid assembly protein CsgF.

    Nenninger, Ashley A / Robinson, Lloyd S / Hultgren, Scott J

    Proceedings of the National Academy of Sciences of the United States of America

    2009  Volume 106, Issue 3, Page(s) 900–905

    Abstract: Elucidation of the early events in amyloidogenesis is key to understanding the pathology of, and developing therapies for, amyloid diseases. Critical informants about these early events are amyloid assembly proteins that facilitate the transition from ... ...

    Abstract Elucidation of the early events in amyloidogenesis is key to understanding the pathology of, and developing therapies for, amyloid diseases. Critical informants about these early events are amyloid assembly proteins that facilitate the transition from monomer to amyloid fiber. Curli are a functional amyloid whose in vivo polymerization requires a dedicated nucleator protein, CsgB, and an assembly protein, CsgF. Here we demonstrate that without CsgF, curli subunits are released from the cell into the media and are inefficiently polymerized, resulting in fewer and mislocalized curli fibers. CsgF is secreted to the cell surface, where it mediates the cell-association and protease-resistance of the CsgB nucleator, suggesting that CsgF is required for specific localization and/or chaperoning of CsgB for full nucleator activity. CsgF is thus critical to achieve localized and efficient nucleation of fiber subunits into functional, cell-associated amyloid.
    MeSH term(s) Amyloid/chemistry ; Amyloidosis/etiology ; Bacterial Proteins/analysis ; Bacterial Proteins/chemistry ; Bacterial Proteins/physiology ; Base Sequence ; Escherichia coli Proteins/metabolism ; Escherichia coli Proteins/physiology ; Lipoproteins/physiology ; Molecular Chaperones/physiology ; Molecular Sequence Data ; Protein Folding
    Chemical Substances Amyloid ; Bacterial Proteins ; CsgB protein, E coli ; CsgG protein, E coli ; Escherichia coli Proteins ; Lipoproteins ; Molecular Chaperones ; Crl protein, Bacteria (148349-72-8)
    Language English
    Publishing date 2009-01-08
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.0812143106
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 1148: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

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  2. Article: Localized and efficient curli nucleation requires the chaperone-like amyloid assembly protein CsgF

    Nenninger, Ashley A / Robinson, Lloyd S / Hultgren, Scott J

    Proceedings of the National Academy of Sciences of the United States of America. 2009 Jan. 20, v. 106, no. 3

    2009  

    Abstract: Elucidation of the early events in amyloidogenesis is key to understanding the pathology of, and developing therapies for, amyloid diseases. Critical informants about these early events are amyloid assembly proteins that facilitate the transition from ... ...

    Abstract Elucidation of the early events in amyloidogenesis is key to understanding the pathology of, and developing therapies for, amyloid diseases. Critical informants about these early events are amyloid assembly proteins that facilitate the transition from monomer to amyloid fiber. Curli are a functional amyloid whose in vivo polymerization requires a dedicated nucleator protein, CsgB, and an assembly protein, CsgF. Here we demonstrate that without CsgF, curli subunits are released from the cell into the media and are inefficiently polymerized, resulting in fewer and mislocalized curli fibers. CsgF is secreted to the cell surface, where it mediates the cell-association and protease-resistance of the CsgB nucleator, suggesting that CsgF is required for specific localization and/or chaperoning of CsgB for full nucleator activity. CsgF is thus critical to achieve localized and efficient nucleation of fiber subunits into functional, cell-associated amyloid.
    Keywords amyloid ; amyloidosis ; polymerization ; protein subunits
    Language English
    Dates of publication 2009-0120
    Size p. 900-905.
    Publishing place National Academy of Sciences
    Document type Article
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.0812143106
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Bonn / Germany

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  3. Article ; Online: CsgE is a curli secretion specificity factor that prevents amyloid fibre aggregation.

    Nenninger, Ashley A / Robinson, Lloyd S / Hammer, Neal D / Epstein, Elisabeth Ashman / Badtke, Matthew P / Hultgren, Scott J / Chapman, Matthew R

    Molecular microbiology

    2011  Volume 81, Issue 2, Page(s) 486–499

    Abstract: Curli are extracellular amyloid fibres produced by Escherichia coli that are critical for biofilm formation and adhesion to biotic and abiotic surfaces. CsgA and CsgB are the major and minor curli subunits, respectively, while CsgE, CsgF and CsgG direct ... ...

    Abstract Curli are extracellular amyloid fibres produced by Escherichia coli that are critical for biofilm formation and adhesion to biotic and abiotic surfaces. CsgA and CsgB are the major and minor curli subunits, respectively, while CsgE, CsgF and CsgG direct the extracellular localization and assembly of curli subunits into fibres. The secretion and stability of CsgA and CsgB are dependent on the outer membrane lipoprotein CsgG. Here, we identified functional interactions between CsgG and CsgE during curli secretion. We discovered that CsgG overexpression restored curli production to a csgE strain under curli-inducing conditions. In antibiotic sensitivity and protein secretion assays, CsgG expression alone allowed translocation of erythromycin and small periplasmic proteins across the outer membrane. Coexpression of CsgE with CsgG blocked non-specific protein and antibiotic passage across the outer membrane. However, CsgE did not block secretion of proteins containing a 22-amino-acid putative outer membrane secretion signal of CsgA (A22). Finally, using purified proteins, we found that CsgE prohibited the self-assembly of CsgA into amyloid fibres. Collectively, these data indicate that CsgE provides substrate specificity to the curli secretion pore CsgG, and acts directly on the secretion substrate CsgA to prevent premature subunit assembly.
    MeSH term(s) Bacterial Proteins/metabolism ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Escherichia coli Proteins/genetics ; Escherichia coli Proteins/metabolism ; Lipoproteins/genetics ; Lipoproteins/metabolism ; Membrane Transport Proteins/genetics ; Membrane Transport Proteins/metabolism ; Protein Binding ; Protein Denaturation ; Protein Interaction Mapping ; Protein Multimerization
    Chemical Substances Bacterial Proteins ; CsgB protein, E coli ; CsgE protein, E coli ; CsgG protein, E coli ; Escherichia coli Proteins ; Lipoproteins ; Membrane Transport Proteins ; csgA protein, E coli ; Crl protein, Bacteria (148349-72-8)
    Language English
    Publishing date 2011-06-07
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 619315-8
    ISSN 1365-2958 ; 0950-382X
    ISSN (online) 1365-2958
    ISSN 0950-382X
    DOI 10.1111/j.1365-2958.2011.07706.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2502: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
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    ab Jg. 2022: Lesesaal (EG)

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  4. Article: The pathogenic fungus Cryptococcus neoformans expresses two functional GDP-mannose transporters with distinct expression patterns and roles in capsule synthesis.

    Cottrell, Tricia R / Griffith, Cara L / Liu, Hong / Nenninger, Ashley A / Doering, Tamara L

    Eukaryotic cell

    2007  Volume 6, Issue 5, Page(s) 776–785

    Abstract: Cryptococcus neoformans is a fungal pathogen that is responsible for life-threatening disease, particularly in the context of compromised immunity. This organism makes extensive use of mannose in constructing its cell wall, glycoproteins, and glycolipids. ...

    Abstract Cryptococcus neoformans is a fungal pathogen that is responsible for life-threatening disease, particularly in the context of compromised immunity. This organism makes extensive use of mannose in constructing its cell wall, glycoproteins, and glycolipids. Mannose also comprises up to two-thirds of the main cryptococcal virulence factor, a polysaccharide capsule that surrounds the cell. The glycosyltransfer reactions that generate cellular carbohydrate structures usually require activated donors such as nucleotide sugars. GDP-mannose, the mannose donor, is produced in the cytosol by the sequential actions of phosphomannose isomerase, phosphomannomutase, and GDP-mannose pyrophosphorylase. However, most mannose-containing glycoconjugates are synthesized within intracellular organelles. This topological separation necessitates a specific transport mechanism to move this key precursor across biological membranes to the appropriate site for biosynthetic reactions. We have discovered two GDP-mannose transporters in C. neoformans, in contrast to the single such protein reported previously for other fungi. Biochemical studies of each protein expressed in Saccharomyces cerevisiae show that both are functional, with similar kinetics and substrate specificities. Microarray experiments indicate that the two proteins Gmt1 and Gmt2 are transcribed with distinct patterns of expression in response to variations in growth conditions. Additionally, deletion of the GMT1 gene yields cells with small capsules and a defect in capsule induction, while deletion of GMT2 does not alter the capsule. We suggest that C. neoformans produces two GDP-mannose transporters to satisfy its enormous need for mannose utilization in glycan synthesis. Furthermore, we propose that the two proteins have distinct biological roles. This is supported by the different expression patterns of GMT1 and GMT2 in response to environmental stimuli and the dissimilar phenotypes that result when each gene is deleted.
    MeSH term(s) Amino Acid Sequence ; Antigens, Fungal/biosynthesis ; Biological Transport ; Carrier Proteins/chemistry ; Carrier Proteins/metabolism ; Cryptococcus neoformans/cytology ; Cryptococcus neoformans/metabolism ; Gene Expression Regulation, Fungal ; Genetic Complementation Test ; Mannose/metabolism ; Molecular Sequence Data ; Mutation/genetics ; Saccharomyces cerevisiae ; Substrate Specificity
    Chemical Substances Antigens, Fungal ; Carrier Proteins ; GDP-mannose transporter ; Mannose (PHA4727WTP)
    Language English
    Publishing date 2007-05
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2077635-4
    ISSN 1535-9786 ; 1535-9778
    ISSN (online) 1535-9786
    ISSN 1535-9778
    DOI 10.1128/EC.00015-07
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 5779: Show issues Location:
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