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  1. Artikel ; Online: Role of the

    Jarrett, Clayton O / Leung, Jacqueline M / Motoshi, Suzuki / Sturdevant, Daniel E / Zhang, Yixiang / Hoyt, Forrest H / Hinnebusch, B Joseph

    mBio

    2024  , Seite(n) e0012424

    Abstract: Transmission of : Importance: Yersinia ... ...

    Abstract Transmission of
    Importance: Yersinia pestis
    Sprache Englisch
    Erscheinungsdatum 2024-05-09
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ZDB-ID 2557172-2
    ISSN 2150-7511 ; 2161-2129
    ISSN (online) 2150-7511
    ISSN 2161-2129
    DOI 10.1128/mbio.00124-24
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  2. Artikel ; Online: Scanning Electron Microscopy.

    Fischer, Elizabeth R / Hansen, Bryan T / Nair, Vinod / Hoyt, Forrest H / Schwartz, Cindi L / Dorward, David W

    Current protocols

    2024  Band 4, Heft 5, Seite(n) e1034

    Abstract: Scanning electron microscopy (SEM) remains distinct in its ability to allow topographical visualization of structures. Key elements to consider for successful examination of biological specimens include appropriate preparative and imaging techniques. ... ...

    Abstract Scanning electron microscopy (SEM) remains distinct in its ability to allow topographical visualization of structures. Key elements to consider for successful examination of biological specimens include appropriate preparative and imaging techniques. Chemical processing induces structural artifacts during specimen preparation, and several factors need to be considered when selecting fixation protocols to reduce these effects while retaining structures of interest. Particular care for proper dehydration of specimens is essential to minimize shrinkage and is necessary for placement under the high-vacuum environment required for routine operation of standard SEMs. Choice of substrate for mounting and coating specimens can reduce artifacts known as charging, and a basic understanding of microscope settings can optimize parameters to achieve desired results. This article describes fundamental techniques and tips for routine specimen preparation for a variety of biological specimens, preservation of labile or fragile structures, immune-labeling strategies, and microscope imaging parameters for optimal examination by SEM. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Chemical preparative techniques for preservation of biological specimens for examination by SEM Alternate Protocol 1: Practical considerations for the preparation of soft tissues Alternate Protocol 2: Removal of debris from the exoskeleton of invertebrates Alternate Protocol 3: Fixation of colonies grown on agar plates Alternate Protocol 4: Stabilization of polysaccharide structures with alcian blue and lysine Alternate Protocol 5: Preparation of non-adherent particulates in solution for SEM Support Protocol 1: Application of thin layer of adhesive on substrate to improve adherence Support Protocol 2: Poly-L-lysine coating specimen substrates for improved adherence Support Protocol 3: Microwave processing of biological specimens for examination by SEM Basic Protocol 2: Critical point drying of specimens Alternate Protocol 6: Chemical alternative to critical point drying Basic Protocol 3: Sputter coating Alternate Protocol 7: Improved bulk conductivity through "OTOTO" Basic Protocol 4: Immune-labeling strategies Alternate Protocol 8: Immune-labeling internal antigens with small gold probes Alternate protocol 9: Quantum dot or fluoronanogold preparations for correlative techniques Basic Protocol 5: Exposure of internal structures by mechanical fracturing Basic Protocol 6: Exposure of internal structures of tissues by fracturing with liquid nitrogen Basic Protocol 7: Anaglyph production from stereo pairs to produce 3D images.
    Mesh-Begriff(e) Microscopy, Electron, Scanning/methods ; Specimen Handling/methods ; Animals
    Sprache Englisch
    Erscheinungsdatum 2024-05-08
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 2691-1299
    ISSN (online) 2691-1299
    DOI 10.1002/cpz1.1034
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  3. Artikel ; Online: Pathogenic prion structures at high resolution.

    Caughey, Byron / Standke, Heidi G / Artikis, Efrosini / Hoyt, Forrest / Kraus, Allison

    PLoS pathogens

    2022  Band 18, Heft 6, Seite(n) e1010594

    Mesh-Begriff(e) Humans ; PrPSc Proteins/chemistry ; Prion Diseases ; Prions/chemistry
    Chemische Substanzen PrPSc Proteins ; Prions
    Sprache Englisch
    Erscheinungsdatum 2022-06-30
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Intramural
    ZDB-ID 2205412-1
    ISSN 1553-7374 ; 1553-7374
    ISSN (online) 1553-7374
    ISSN 1553-7374
    DOI 10.1371/journal.ppat.1010594
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  4. Artikel ; Online: Replication of Coxiella burnetii in a Lysosome-Like Vacuole Does Not Require Lysosomal Hydrolases.

    Miller, Heather E / Hoyt, Forrest H / Heinzen, Robert A

    Infection and immunity

    2019  Band 87, Heft 11

    Abstract: ... Coxiella ... ...

    Abstract Coxiella burnetii
    Mesh-Begriff(e) Amino Acids/administration & dosage ; Amino Acids/pharmacology ; Cathepsin D ; Cell Proliferation ; Cholesterol/metabolism ; Coxiella burnetii ; Culture Media ; HeLa Cells ; Humans ; Hydrogen-Ion Concentration ; Hydrolases/metabolism ; Lysosomes ; Macrolides/pharmacology ; Microbial Viability
    Chemische Substanzen Amino Acids ; Culture Media ; Macrolides ; bafilomycin A1 (88899-55-2) ; Cholesterol (97C5T2UQ7J) ; Hydrolases (EC 3.-) ; Cathepsin D (EC 3.4.23.5)
    Sprache Englisch
    Erscheinungsdatum 2019-10-18
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, N.I.H., Intramural
    ZDB-ID 218698-6
    ISSN 1098-5522 ; 0019-9567
    ISSN (online) 1098-5522
    ISSN 0019-9567
    DOI 10.1128/IAI.00493-19
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  5. Artikel: Disruption of the Golgi Apparatus and Contribution of the Endoplasmic Reticulum to the SARS-CoV-2 Replication Complex

    Hackstadt, Ted / Chiramel, Abhilash I. / Hoyt, Forrest H. / Williamson, Brandi N. / Dooley, Cheryl A. / Beare, Paul A. / de Wit, Emmie / Best, Sonja M. / Fischer, Elizabeth R.

    Viruses. 2021 Sept. 09, v. 13, no. 9

    2021  

    Abstract: A variety of immunolabeling procedures for both light and electron microscopy were used to examine the cellular origins of the host membranes supporting the SARS-CoV-2 replication complex. The endoplasmic reticulum has long been implicated as a source of ...

    Abstract A variety of immunolabeling procedures for both light and electron microscopy were used to examine the cellular origins of the host membranes supporting the SARS-CoV-2 replication complex. The endoplasmic reticulum has long been implicated as a source of membrane for the coronavirus replication organelle. Using dsRNA as a marker for sites of viral RNA synthesis, we provide additional evidence supporting ER as a prominent source of membrane. In addition, we observed a rapid fragmentation of the Golgi apparatus which is visible by 6 h and complete by 12 h post-infection. Golgi derived lipid appears to be incorporated into the replication organelle although protein markers are dispersed throughout the infected cell. The mechanism of Golgi disruption is undefined, but chemical disruption of the Golgi apparatus by brefeldin A is inhibitory to viral replication. A search for an individual SARS-CoV-2 protein responsible for this activity identified at least five viral proteins, M, S, E, Orf6, and nsp3, that induced Golgi fragmentation when expressed in eukaryotic cells. Each of these proteins, as well as nsp4, also caused visible changes to ER structure as shown by correlative light and electron microscopy (CLEM). Collectively, these results imply that specific disruption of the Golgi apparatus is a critical component of coronavirus replication.
    Schlagwörter Golgi apparatus ; Severe acute respiratory syndrome coronavirus 2 ; brefeldin A ; electron microscopy ; endoplasmic reticulum ; lipids ; virus replication
    Sprache Englisch
    Erscheinungsverlauf 2021-0909
    Erscheinungsort Multidisciplinary Digital Publishing Institute
    Dokumenttyp Artikel
    ZDB-ID 2516098-9
    ISSN 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v13091798
    Datenquelle NAL Katalog (AGRICOLA)

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  6. Artikel: High-resolution structure and strain comparison of infectious mammalian prions

    Kraus, Allison / Hoyt, Forrest / Schwartz, Cindi L. / Hansen, Bryan / Artikis, Efrosini / Hughson, Andrew G. / Raymond, Gregory J. / Race, Brent / Baron, Gerald S. / Caughey, Byron

    Molecular cell. 2021 Nov. 04, v. 81, no. 21

    2021  

    Abstract: Within the extensive range of self-propagating pathologic protein aggregates of mammals, prions are the most clearly infectious (e.g., ∼10⁹ lethal doses per milligram). The structures of such lethal assemblies of PrP molecules have been poorly understood. ...

    Abstract Within the extensive range of self-propagating pathologic protein aggregates of mammals, prions are the most clearly infectious (e.g., ∼10⁹ lethal doses per milligram). The structures of such lethal assemblies of PrP molecules have been poorly understood. Here we report a near-atomic core structure of a brain-derived, fully infectious prion (263K strain). Cryo-electron microscopy showed amyloid fibrils assembled with parallel in-register intermolecular β sheets. Each monomer provides one rung of the ordered fibril core, with N-linked glycans and glycolipid anchors projecting outward. Thus, single monomers form the templating surface for incoming monomers at fibril ends, where prion growth occurs. Comparison to another prion strain (aRML) revealed major differences in fibril morphology but, like 263K, an asymmetric fibril cross-section without paired protofilaments. These findings provide structural insights into prion propagation, strains, species barriers, and membrane pathogenesis. This structure also helps frame considerations of factors influencing the relative transmissibility of other pathologic amyloids.
    Schlagwörter amyloid ; cryo-electron microscopy ; glycolipids ; mammals ; pathogenesis ; polysaccharides ; prions
    Sprache Englisch
    Erscheinungsverlauf 2021-1104
    Umfang p. 4540-4551.e6.
    Erscheinungsort Elsevier Inc.
    Dokumenttyp Artikel
    ZDB-ID 1415236-8
    ISSN 1097-4164 ; 1097-2765
    ISSN (online) 1097-4164
    ISSN 1097-2765
    DOI 10.1016/j.molcel.2021.08.011
    Datenquelle NAL Katalog (AGRICOLA)

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  7. Artikel ; Online: Cryo-EM structure of anchorless RML prion reveals variations in shared motifs between distinct strains.

    Hoyt, Forrest / Standke, Heidi G / Artikis, Efrosini / Schwartz, Cindi L / Hansen, Bryan / Li, Kunpeng / Hughson, Andrew G / Manca, Matteo / Thomas, Olivia R / Raymond, Gregory J / Race, Brent / Baron, Gerald S / Caughey, Byron / Kraus, Allison

    Nature communications

    2022  Band 13, Heft 1, Seite(n) 4005

    Abstract: Little is known about the structural basis of prion strains. Here we provide a high (3.0 Å) resolution cryo-electron microscopy-based structure of infectious brain-derived fibrils of the mouse anchorless RML scrapie strain which, like the recently ... ...

    Abstract Little is known about the structural basis of prion strains. Here we provide a high (3.0 Å) resolution cryo-electron microscopy-based structure of infectious brain-derived fibrils of the mouse anchorless RML scrapie strain which, like the recently determined hamster 263K strain, has a parallel in-register β-sheet-based core. Several structural motifs are shared between these ex vivo prion strains, including an amino-proximal steric zipper and three β-arches. However, detailed comparisons reveal variations in these shared structural topologies and other features. Unlike 263K and wildtype RML prions, the anchorless RML prions lack glycophosphatidylinositol anchors and are severely deficient in N-linked glycans. Nonetheless, the similarity of our anchorless RML structure to one reported for wildtype RML prion fibrils in an accompanying paper indicates that these post-translational modifications do not substantially alter the amyloid core conformation. This work demonstrates both common and divergent structural features of prion strains at the near-atomic level.
    Mesh-Begriff(e) Amyloid ; Animals ; Brain/metabolism ; Cryoelectron Microscopy ; Mice ; Prions/metabolism ; Scrapie ; Sheep
    Chemische Substanzen Amyloid ; Prions
    Sprache Englisch
    Erscheinungsdatum 2022-07-13
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Intramural
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-022-30458-6
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  8. Artikel ; Online: Cryo-EM of prion strains from the same genotype of host identifies conformational determinants.

    Hoyt, Forrest / Alam, Parvez / Artikis, Efrosini / Schwartz, Cindi L / Hughson, Andrew G / Race, Brent / Baune, Chase / Raymond, Gregory J / Baron, Gerald S / Kraus, Allison / Caughey, Byron

    PLoS pathogens

    2022  Band 18, Heft 11, Seite(n) e1010947

    Abstract: Prion strains in a given type of mammalian host are distinguished by differences in clinical presentation, neuropathological lesions, survival time, and characteristics of the infecting prion protein (PrP) assemblies. Near-atomic structures of prions ... ...

    Abstract Prion strains in a given type of mammalian host are distinguished by differences in clinical presentation, neuropathological lesions, survival time, and characteristics of the infecting prion protein (PrP) assemblies. Near-atomic structures of prions from two host species with different PrP sequences have been determined but comparisons of distinct prion strains of the same amino acid sequence are needed to identify purely conformational determinants of prion strain characteristics. Here we report a 3.2 Å resolution cryogenic electron microscopy-based structure of the 22L prion strain purified from the brains of mice engineered to express only PrP lacking glycophosphatidylinositol anchors [anchorless (a) 22L]. Comparison of this near-atomic structure to our recently determined structure of the aRML strain propagated in the same inbred mouse reveals that these two mouse prion strains have distinct conformational templates for growth via incorporation of PrP molecules of the same sequence. Both a22L and aRML are assembled as stacks of PrP molecules forming parallel in-register intermolecular β-sheets and intervening loops, with single monomers spanning the ordered fibril core. Each monomer shares an N-terminal steric zipper, three major arches, and an overall V-shape, but the details of these and other conformational features differ markedly. Thus, variations in shared conformational motifs within a parallel in-register β-stack fibril architecture provide a structural basis for prion strain differentiation within a single host genotype.
    Mesh-Begriff(e) Animals ; Mice ; Cryoelectron Microscopy ; Genotype ; Prion Proteins/genetics ; Prions/metabolism ; Protein Conformation
    Chemische Substanzen Prion Proteins ; Prions
    Sprache Englisch
    Erscheinungsdatum 2022-11-07
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Intramural
    ZDB-ID 2205412-1
    ISSN 1553-7374 ; 1553-7374
    ISSN (online) 1553-7374
    ISSN 1553-7374
    DOI 10.1371/journal.ppat.1010947
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  9. Artikel ; Online: Disruption of the Golgi Apparatus and Contribution of the Endoplasmic Reticulum to the SARS-CoV-2 Replication Complex.

    Hackstadt, Ted / Chiramel, Abhilash I / Hoyt, Forrest H / Williamson, Brandi N / Dooley, Cheryl A / Beare, Paul A / de Wit, Emmie / Best, Sonja M / Fischer, Elizabeth R

    Viruses

    2021  Band 13, Heft 9

    Abstract: A variety of immunolabeling procedures for both light and electron microscopy were used to examine the cellular origins of the host membranes supporting the SARS-CoV-2 replication complex. The endoplasmic reticulum has long been implicated as a source of ...

    Abstract A variety of immunolabeling procedures for both light and electron microscopy were used to examine the cellular origins of the host membranes supporting the SARS-CoV-2 replication complex. The endoplasmic reticulum has long been implicated as a source of membrane for the coronavirus replication organelle. Using dsRNA as a marker for sites of viral RNA synthesis, we provide additional evidence supporting ER as a prominent source of membrane. In addition, we observed a rapid fragmentation of the Golgi apparatus which is visible by 6 h and complete by 12 h post-infection. Golgi derived lipid appears to be incorporated into the replication organelle although protein markers are dispersed throughout the infected cell. The mechanism of Golgi disruption is undefined, but chemical disruption of the Golgi apparatus by brefeldin A is inhibitory to viral replication. A search for an individual SARS-CoV-2 protein responsible for this activity identified at least five viral proteins, M, S, E, Orf6, and nsp3, that induced Golgi fragmentation when expressed in eukaryotic cells. Each of these proteins, as well as nsp4, also caused visible changes to ER structure as shown by correlative light and electron microscopy (CLEM). Collectively, these results imply that specific disruption of the Golgi apparatus is a critical component of coronavirus replication.
    Mesh-Begriff(e) Animals ; Chlorocebus aethiops ; Coronavirus M Proteins/physiology ; Coronavirus M Proteins/ultrastructure ; Endoplasmic Reticulum/ultrastructure ; Endoplasmic Reticulum/virology ; Golgi Apparatus/ultrastructure ; Golgi Apparatus/virology ; Humans ; Intracellular Membranes/ultrastructure ; Intracellular Membranes/virology ; Microscopy, Electron ; SARS-CoV-2/physiology ; SARS-CoV-2/ultrastructure ; Vero Cells ; Viral Structural Proteins/physiology ; Viral Structural Proteins/ultrastructure ; Virus Replication
    Chemische Substanzen Coronavirus M Proteins ; M protein, SARS-CoV ; Viral Structural Proteins
    Sprache Englisch
    Erscheinungsdatum 2021-09-09
    Erscheinungsland Switzerland
    Dokumenttyp Journal Article ; Research Support, N.I.H., Intramural
    ZDB-ID 2516098-9
    ISSN 1999-4915 ; 1999-4915
    ISSN (online) 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v13091798
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  10. Artikel ; Online: High-resolution structure and strain comparison of infectious mammalian prions.

    Kraus, Allison / Hoyt, Forrest / Schwartz, Cindi L / Hansen, Bryan / Artikis, Efrosini / Hughson, Andrew G / Raymond, Gregory J / Race, Brent / Baron, Gerald S / Caughey, Byron

    Molecular cell

    2021  Band 81, Heft 21, Seite(n) 4540–4551.e6

    Abstract: Within the extensive range of self-propagating pathologic protein aggregates of mammals, prions are the most clearly infectious (e.g., ∼ ... ...

    Abstract Within the extensive range of self-propagating pathologic protein aggregates of mammals, prions are the most clearly infectious (e.g., ∼10
    Mesh-Begriff(e) Amyloid/chemistry ; Animals ; Brain/metabolism ; Cryoelectron Microscopy/methods ; Glycolipids/chemistry ; Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; Mice ; Phenotype ; Polysaccharides/chemistry ; Prion Proteins/chemistry ; Prions/chemistry ; Prions/ultrastructure ; Protein Binding ; Protein Structure, Secondary ; Thermodynamics
    Chemische Substanzen Amyloid ; Glycolipids ; Polysaccharides ; Prion Proteins ; Prions
    Sprache Englisch
    Erscheinungsdatum 2021-08-25
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, N.I.H., Intramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1415236-8
    ISSN 1097-4164 ; 1097-2765
    ISSN (online) 1097-4164
    ISSN 1097-2765
    DOI 10.1016/j.molcel.2021.08.011
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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