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  1. Article ; Online: Conformational diversity in purified prions produced in vitro.

    Walsh, Daniel J / Schwind, Abigail M / Noble, Geoffrey P / Supattapone, Surachai

    PLoS pathogens

    2023  Volume 19, Issue 1, Page(s) e1011083

    Abstract: Prion diseases are caused by misfolding of either wild-type or mutant forms of the prion protein (PrP) into self-propagating, pathogenic conformers, collectively termed PrPSc. Both wild-type and mutant PrPSc molecules exhibit conformational diversity in ... ...

    Abstract Prion diseases are caused by misfolding of either wild-type or mutant forms of the prion protein (PrP) into self-propagating, pathogenic conformers, collectively termed PrPSc. Both wild-type and mutant PrPSc molecules exhibit conformational diversity in vivo, but purified prions generated by the serial protein misfolding cyclic amplification (sPMCA) technique do not display this same diversity in vitro. This discrepancy has left a gap in our understanding of how conformational diversity arises at the molecular level in both types of prions. Here, we use continuous shaking instead of sPMCA to generate conformationally diverse purified prions in vitro. Using this approach, we show for the first time that wild type prions initially seeded by different native strains can propagate as metastable PrPSc conformers with distinguishable strain properties in purified reactions containing a single active cofactor. Propagation of these metastable PrPSc conformers requires appropriate shaking conditions, and changes in these conditions cause all the different PrPSc conformers to converge irreversibly into the same single conformer as that produced in sPMCA reactions. We also use continuous shaking to show that two mutant PrP molecules with different pathogenic point mutations (D177N and E199K) adopt distinguishable PrPSc conformations in reactions containing pure protein substrate without cofactors. Unlike wild-type prions, the conformations of mutant prions appear to be dictated by substrate sequence rather than seed conformation. Overall, our studies using purified substrates in shaking reactions show that wild-type and mutant prions use fundamentally different mechanisms to generate conformational diversity at the molecular level.
    MeSH term(s) Humans ; Prions/metabolism ; Prion Diseases/metabolism ; Prion Proteins ; Molecular Conformation
    Chemical Substances Prions ; Prion Proteins
    Language English
    Publishing date 2023-01-10
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2205412-1
    ISSN 1553-7374 ; 1553-7374
    ISSN (online) 1553-7374
    ISSN 1553-7374
    DOI 10.1371/journal.ppat.1011083
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Anti-NMDAR encephalitis in a patient with Crohn disease receiving adalimumab.

    Noble, Geoffrey P / Lancaster, Eric

    Neurology(R) neuroimmunology & neuroinflammation

    2018  Volume 5, Issue 5, Page(s) e476

    Language English
    Publishing date 2018-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2767740-0
    ISSN 2332-7812
    ISSN 2332-7812
    DOI 10.1212/NXI.0000000000000476
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Dissociation of recombinant prion autocatalysis from infectivity.

    Noble, Geoffrey P / Supattapone, Surachai

    Prion

    2015  Volume 9, Issue 6, Page(s) 405–411

    Abstract: Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only ... ...

    Abstract Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication--that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and non-infectious pair of autocatalytic recombinant PrP conformers derived from the same initial prion strain. (1) We identified restricted, C-terminal structural differences between these 2 conformers and provided evidence that these relatively subtle differences prevent the non-infectious conformer from templating the conversion of native PrP(C) substrates containing a glycosylphosphatidylinositol (GPI) anchor. (1) In this article we discuss a model, consistent with these findings, in which recombinant PrP, lacking post-translational modifications and associated folding constraints, is capable of adopting a wide variety of autocatalytic conformations. Only a subset of these recombinant conformers can be adopted by post-translationally modified native PrP(C), and this subset represents the recombinant conformers with high specific infectivity. We examine this model's implications for the generation of highly infectious recombinant prions and the protein-only hypothesis of prion replication.
    MeSH term(s) Animals ; PrPC Proteins/genetics ; PrPC Proteins/metabolism ; PrPSc Proteins/genetics ; PrPSc Proteins/metabolism ; Prions/genetics ; Prions/metabolism ; Protein Processing, Post-Translational/genetics ; Recombinant Proteins/genetics ; Recombinant Proteins/metabolism
    Chemical Substances PrPC Proteins ; PrPSc Proteins ; Prions ; Recombinant Proteins
    Language English
    Publishing date 2015
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ISSN 1933-690X
    ISSN (online) 1933-690X
    DOI 10.1080/19336896.2015.1123843
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Interallelic Transcriptional Enhancement as an in Vivo Measure of Transvection in Drosophila melanogaster.

    Noble, Geoffrey P / Dolph, Patrick J / Supattapone, Surachai

    G3 (Bethesda, Md.)

    2016  Volume 6, Issue 10, Page(s) 3139–3148

    Abstract: Transvection-pairing-dependent interallelic regulation resulting from enhancer action in trans-occurs throughout the Drosophila melanogaster genome, likely as a result of the extensive somatic homolog pairing seen in Dipteran species. Recent studies of ... ...

    Abstract Transvection-pairing-dependent interallelic regulation resulting from enhancer action in trans-occurs throughout the Drosophila melanogaster genome, likely as a result of the extensive somatic homolog pairing seen in Dipteran species. Recent studies of transvection in Drosophila have demonstrated important qualitative differences between enhancer action in cis vs. in trans, as well as a modest synergistic effect of cis- and trans-acting enhancers on total tissue transcript levels at a given locus. In the present study, we identify a system in which cis- and trans-acting GAL4-UAS enhancer synergism has an unexpectedly large quantitative influence on gene expression, boosting total tissue transcript levels at least fourfold relative to those seen in the absence of transvection. We exploit this strong quantitative effect by using publicly available UAS-shRNA constructs from the TRiP library to assay candidate genes for transvection activity in vivo The results of the present study, which demonstrate that in trans activation by simple UAS enhancers can have large quantitative effects on gene expression in Drosophila, have important new implications for experimental design utilizing the GAL4-UAS system.
    MeSH term(s) Alleles ; Animals ; Animals, Genetically Modified ; Drosophila melanogaster/genetics ; Enhancer Elements, Genetic ; Epistasis, Genetic ; Gene Expression ; Gene Expression Regulation ; Gene Knockdown Techniques ; Prion Proteins/genetics ; Prion Proteins/metabolism ; RNA, Small Interfering/genetics ; Transcription, Genetic ; Transgenes
    Chemical Substances Prion Proteins ; RNA, Small Interfering
    Language English
    Publishing date 2016-10-13
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2629978-1
    ISSN 2160-1836 ; 2160-1836
    ISSN (online) 2160-1836
    ISSN 2160-1836
    DOI 10.1534/g3.116.032300
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Requirements for Mutant and Wild-Type Prion Protein Misfolding In Vitro

    Noble, Geoffrey P / Walsh Daniel J / Miller Michael B / Jackson Walker S / Supattapone Surachai

    Biochemistry. 2015 Feb. 10, v. 54, no. 5

    2015  

    Abstract: Misfolding of the prion protein (PrP) plays a central role in the pathogenesis of infectious, sporadic, and inherited prion diseases. Here we use a chemically defined prion propagation system to study misfolding of the pathogenic PrP mutant D177N in ... ...

    Abstract Misfolding of the prion protein (PrP) plays a central role in the pathogenesis of infectious, sporadic, and inherited prion diseases. Here we use a chemically defined prion propagation system to study misfolding of the pathogenic PrP mutant D177N in vitro. This mutation causes PrP to misfold spontaneously in the absence of cofactor molecules in a process dependent on time, temperature, pH, and intermittent sonication. Spontaneously misfolded mutant PrP is able to template its unique conformation onto wild-type PrP substrate in a process that requires a phospholipid activity distinct from that required for the propagation of infectious prions. Similar results were obtained with a second pathogenic PrP mutant, E199K, but not with the polymorphic substitution M128V. Moreover, wild-type PrP inhibits mutant PrP misfolding in a dose-dependent manner, and cofactor molecules can antagonize this effect. These studies suggest that interactions between mutant PrP, wild-type PrP, and other cellular factors may control the rate of PrP misfolding in inherited prion diseases.
    Keywords dose response ; mutants ; mutation ; pH ; pathogenesis ; phospholipids ; prion diseases ; prions ; protein folding ; temperature
    Language English
    Dates of publication 2015-0210
    Size p. 1180-1187.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 1108-3
    ISSN 1520-4995 ; 0006-2960
    ISSN (online) 1520-4995
    ISSN 0006-2960
    DOI 10.1021%2Fbi501495j
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: A Context-Dependent Role for the RNF146 Ubiquitin Ligase in Wingless/Wnt Signaling in

    Wang, Zhenghan / Tacchelly-Benites, Ofelia / Noble, Geoffrey P / Johnson, Megan K / Gagné, Jean-Philippe / Poirier, Guy G / Ahmed, Yashi

    Genetics

    2018  Volume 211, Issue 3, Page(s) 913–923

    Abstract: Aberrant activation of the Wnt signal transduction pathway triggers the development of colorectal cancer. The ADP-ribose polymerase Tankyrase (TNKS) mediates proteolysis of Axin-a negative regulator of Wnt signaling-and provides a promising therapeutic ... ...

    Abstract Aberrant activation of the Wnt signal transduction pathway triggers the development of colorectal cancer. The ADP-ribose polymerase Tankyrase (TNKS) mediates proteolysis of Axin-a negative regulator of Wnt signaling-and provides a promising therapeutic target for Wnt-driven diseases. Proteolysis of TNKS substrates is mediated through their ubiquitination by the poly-ADP-ribose (pADPr)-dependent RING-domain E3 ubiquitin ligase RNF146/Iduna. Like TNKS, RNF146 promotes Axin proteolysis and Wnt pathway activation in some cultured cell lines, but in contrast with TNKS, RNF146 is dispensable for Axin degradation in colorectal carcinoma cells. Thus, the contexts in which RNF146 is essential for TNKS-mediated Axin destabilization and Wnt signaling remain uncertain. Herein, we tested the requirement for RNF146 in TNKS-mediated Axin proteolysis and Wnt pathway activation in a range of
    MeSH term(s) Animals ; Axin Protein/metabolism ; Drosophila Proteins/genetics ; Drosophila Proteins/physiology ; Drosophila melanogaster ; Poly-ADP-Ribose Binding Proteins/genetics ; Poly-ADP-Ribose Binding Proteins/physiology ; Proteolysis ; Tankyrases/metabolism ; Wnt Signaling Pathway ; Wnt1 Protein/metabolism
    Chemical Substances Axin Protein ; Axn protein, Drosophila ; Drosophila Proteins ; Poly-ADP-Ribose Binding Proteins ; Rnf146 protein, Drosophila ; Wnt1 Protein ; wg protein, Drosophila ; Tankyrases (EC 2.4.2.30)
    Language English
    Publishing date 2018-12-28
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2167-2
    ISSN 1943-2631 ; 0016-6731
    ISSN (online) 1943-2631
    ISSN 0016-6731
    DOI 10.1534/genetics.118.301393
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Identification of a homology-independent linchpin domain controlling mouse and bank vole prion protein conversion.

    Burke, Cassandra M / Mark, Kenneth M K / Walsh, Daniel J / Noble, Geoffrey P / Steele, Alexander D / Diack, Abigail B / Manson, Jean C / Watts, Joel C / Supattapone, Surachai

    PLoS pathogens

    2020  Volume 16, Issue 9, Page(s) e1008875

    Abstract: Prions are unorthodox pathogens that cause fatal neurodegenerative diseases in humans and other mammals. Prion propagation occurs through the self-templating of the pathogenic conformer PrPSc, onto the cell-expressed conformer, PrPC. Here we study the ... ...

    Abstract Prions are unorthodox pathogens that cause fatal neurodegenerative diseases in humans and other mammals. Prion propagation occurs through the self-templating of the pathogenic conformer PrPSc, onto the cell-expressed conformer, PrPC. Here we study the conversion of PrPC to PrPSc using a recombinant mouse PrPSc conformer (mouse protein-only recPrPSc) as a unique tool that can convert bank vole but not mouse PrPC substrates in vitro. Thus, its templating ability is not dependent on sequence homology with the substrate. In the present study, we used chimeric bank vole/mouse PrPC substrates to systematically determine the domain that allows for conversion by Mo protein-only recPrPSc. Our results show that that either the presence of the bank vole amino acid residues E227 and S230 or the absence of the second N-linked glycan are sufficient to allow PrPC substrates to be converted by Mo protein-only recPrPSc and several native infectious prion strains. We propose that residues 227 and 230 and the second glycan are part of a C-terminal domain that acts as a linchpin for bank vole and mouse prion conversion.
    MeSH term(s) Animals ; Arvicolinae ; Brain/metabolism ; Brain/pathology ; Cricetinae ; Mesocricetus ; Mice ; Mice, Transgenic ; PrPC Proteins/genetics ; PrPC Proteins/metabolism ; PrPSc Proteins/genetics ; PrPSc Proteins/metabolism ; Prion Diseases/genetics ; Prion Diseases/metabolism ; Prion Diseases/pathology ; Protein Domains
    Chemical Substances PrPC Proteins ; PrPSc Proteins
    Language English
    Publishing date 2020-09-08
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2205412-1
    ISSN 1553-7374 ; 1553-7366
    ISSN (online) 1553-7374
    ISSN 1553-7366
    DOI 10.1371/journal.ppat.1008875
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Requirements for mutant and wild-type prion protein misfolding in vitro.

    Noble, Geoffrey P / Walsh, Daniel J / Miller, Michael B / Jackson, Walker S / Supattapone, Surachai

    Biochemistry

    2015  Volume 54, Issue 5, Page(s) 1180–1187

    Abstract: Misfolding of the prion protein (PrP) plays a central role in the pathogenesis of infectious, sporadic, and inherited prion diseases. Here we use a chemically defined prion propagation system to study misfolding of the pathogenic PrP mutant D177N in ... ...

    Abstract Misfolding of the prion protein (PrP) plays a central role in the pathogenesis of infectious, sporadic, and inherited prion diseases. Here we use a chemically defined prion propagation system to study misfolding of the pathogenic PrP mutant D177N in vitro. This mutation causes PrP to misfold spontaneously in the absence of cofactor molecules in a process dependent on time, temperature, pH, and intermittent sonication. Spontaneously misfolded mutant PrP is able to template its unique conformation onto wild-type PrP substrate in a process that requires a phospholipid activity distinct from that required for the propagation of infectious prions. Similar results were obtained with a second pathogenic PrP mutant, E199K, but not with the polymorphic substitution M128V. Moreover, wild-type PrP inhibits mutant PrP misfolding in a dose-dependent manner, and cofactor molecules can antagonize this effect. These studies suggest that interactions between mutant PrP, wild-type PrP, and other cellular factors may control the rate of PrP misfolding in inherited prion diseases.
    MeSH term(s) Amino Acid Substitution ; Animals ; Hot Temperature ; Hydrogen-Ion Concentration ; Mice ; Mutation, Missense ; Prion Diseases/genetics ; Prion Diseases/metabolism ; Prions/chemistry ; Prions/genetics ; Prions/metabolism ; Protein Folding
    Chemical Substances Prions
    Language English
    Publishing date 2015-02-10
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1108-3
    ISSN 1520-4995 ; 0006-2960
    ISSN (online) 1520-4995
    ISSN 0006-2960
    DOI 10.1021/bi501495j
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Non-reducing alkaline solubilization and rapid on-column refolding of recombinant prion protein.

    Walsh, Daniel J / Noble, Geoffrey P / Piro, Justin R / Supattapone, Surachai

    Preparative biochemistry & biotechnology

    2012  Volume 42, Issue 1, Page(s) 77–86

    Abstract: Mature prion protein (PrP) is a 208-residue polypeptide that contains a single disulfide bond. We report an alternative method to purify recombinant mouse PrP produced in Escherichia coli. Bacterial inclusion bodies were solubilized in a buffer ... ...

    Abstract Mature prion protein (PrP) is a 208-residue polypeptide that contains a single disulfide bond. We report an alternative method to purify recombinant mouse PrP produced in Escherichia coli. Bacterial inclusion bodies were solubilized in a buffer containing 2 M urea at pH 12.5. The solubilized protein was rapidly purified on a nickel affinity column without a chaotrope gradient, followed by ion-exchange chromatography. The yield and purity of PrP produced by this alternative approach was similar to that obtained using a conventional solubilization and on-column refolding protocol. Recombinant PrP produced using the non-reducing purification protocol is properly folded, as determined by circular dichroism, and a competent substrate for amyloid fibril formation, as determined by Thoflavin-T dye binding assays. In summary, this report describes a rapid method for producing properly folded recombinant PrP without reducing agents or a chaotrope gradient.
    MeSH term(s) Animals ; Chromatography, Gel/methods ; Chromatography, Ion Exchange/methods ; Circular Dichroism/methods ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Hydrogen-Ion Concentration ; Inclusion Bodies/chemistry ; Inclusion Bodies/metabolism ; Mice ; Prion Proteins ; Prions/chemistry ; Prions/genetics ; Prions/isolation & purification ; Prions/metabolism ; Protein Folding ; Recombinant Proteins/chemistry ; Recombinant Proteins/isolation & purification ; Recombinant Proteins/metabolism ; Solubility
    Chemical Substances Prion Proteins ; Prions ; Prnp protein, mouse ; Recombinant Proteins
    Language English
    Publishing date 2012-02-06
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1322522-4
    ISSN 1532-2297 ; 1082-6068
    ISSN (online) 1532-2297
    ISSN 1082-6068
    DOI 10.1080/10826068.2011.564256
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Complex distribution of EFL and EF-1α proteins in the green algal lineage

    Keeling Patrick J / Rogers Matthew B / Noble Geoffrey P

    BMC Evolutionary Biology, Vol 7, Iss 1, p

    2007  Volume 82

    Abstract: Abstract Background EFL (or elongation factor-like) is a member of the translation superfamily of GTPase proteins. It is restricted to eukaryotes, where it is found in a punctate distribution that is almost mutually exclusive with elongation factor-1 ... ...

    Abstract Abstract Background EFL (or elongation factor-like) is a member of the translation superfamily of GTPase proteins. It is restricted to eukaryotes, where it is found in a punctate distribution that is almost mutually exclusive with elongation factor-1 alpha (EF-1α). EF-1α is a core translation factor previously thought to be essential in eukaryotes, so its relationship to EFL has prompted the suggestion that EFL has spread by horizontal or lateral gene transfer (HGT or LGT) and replaced EF-1α multiple times. Among green algae, trebouxiophyceans and chlorophyceans have EFL, but the ulvophycean Acetabularia and the sister group to green algae, land plants, have EF-1α. This distribution singles out green algae as a particularly promising group to understand the origin of EFL and the effects of its presence on EF-1α. Results We have sampled all major lineages of green algae for both EFL and EF-1α. EFL is unexpectedly broad in its distribution, being found in all green algal lineages (chlorophyceans, trebouxiophyceans, ulvophyceans, prasinophyceans, and mesostigmatophyceans), except charophyceans and the genus Acetabularia . The presence of EFL in the genus Mesostigma and EF-1α in Acetabularia are of particular interest, since the opposite is true of all their closest relatives. The phylogeny of EFL is poorly resolved, but the Acetabularia EF-1α is clearly related to homologues from land plants and charophyceans, demonstrating that EF-1α was present in the common ancestor of the green lineage. Conclusion The distribution of EFL and EF-1α in the green lineage is not consistent with the phylogeny of the organisms, indicating a complex history of both genes. Overall, we suggest that after the introduction of EFL (in the ancestor of green algae or earlier), both genes co-existed in green algal genomes for some time before one or the other was lost on multiple occasions.
    Keywords Biology (General) ; QH301-705.5 ; Science ; Q ; DOAJ:Biology ; DOAJ:Biology and Life Sciences ; Evolution ; QH359-425
    Subject code 580 ; 420
    Language English
    Publishing date 2007-05-01T00:00:00Z
    Publisher BioMed Central
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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