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Wegrzyn RD, Appiah GD, Morfino R, Milford SR, Walker AT, Ernst ET, Darrow WW, Li SL, Robison K, MacCannell D, Dai D, Girinathan BP, Hicks AL, Cosca B, Woronoff G, Plocik AM, Simen BB, Moriarty L, Guagliardo SAJ, Cetron MS, Friedman CR. Early Detection of Severe Acute Respiratory Syndrome Coronavirus 2 Variants Using Traveler-based Genomic Surveillance at 4 US Airports, September 2021-January 2022. Clin Infect Dis 2022; 76:e540-e543. [PMID: 35686436 PMCID: PMC9214179 DOI: 10.1093/cid/ciac461] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/28/2022] [Accepted: 06/02/2022] [Indexed: 11/25/2022] Open
Abstract
We enrolled arriving international air travelers in a severe acute respiratory syndrome coronavirus 2 genomic surveillance program. We used molecular testing of pooled nasal swabs and sequenced positive samples for sublineage. Traveler-based surveillance provided early-warning variant detection, reporting the first US Omicron BA.2 and BA.3 in North America.
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Affiliation(s)
- Renee D Wegrzyn
- Correspondence: C. R. Friedman, Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Mailstop: H16-4, Atlanta, GA 30333 ()
| | - Grace D Appiah
- Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | | | - Allison Taylor Walker
- Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | | | | | | | - Duncan MacCannell
- Office of Advanced Molecular Detection, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Dongjuan Dai
- Ginkgo Bioworks, Inc, Boston, Massachusetts, USA
| | | | | | - Bryan Cosca
- Ginkgo Bioworks, Inc, Boston, Massachusetts, USA
| | | | | | | | - Leah Moriarty
- Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sarah Anne J Guagliardo
- Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Martin S Cetron
- Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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2
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Phelan R, Baumgartner B, Brand S, Brister E, Burgiel SW, Charo RA, Coche I, Cofrancesco A, Delborne JA, Edwards O, Fisher JP, Gaywood M, Gordon DR, Howald G, Hunter ME, Kareiva P, Mankad A, Marvier M, Moseby K, Newhouse AE, Novak BJ, Ohrstrom G, Olson S, Palmer MJ, Palumbi S, Patterson N, Pedrono M, Pelegri F, Rohwer Y, Ryder OA, Saah JR, Scheller RM, Seddon PJ, Shaffer HB, Shapiro B, Sweeney M, Tercek MR, Thizy D, Tilt W, Weber M, Wegrzyn RD, Whitelaw B, Winkler M, Wodak J, Zimring M, Robbins P. Intended consequences statement. Conservat Sci and Prac 2021. [DOI: 10.1111/csp2.371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
| | | | | | - Evelyn Brister
- Rochester Institute of Technology Rochester New York USA
| | | | - R. Alta Charo
- University of Wisconsin‐Madison Madison Wisconsin USA
| | | | - Al Cofrancesco
- U.S. Army Corps of Engineers, Engineer Research and Development Center Vicksburg Mississippi USA
| | - Jason A. Delborne
- Genetic Engineering and Society Center North Carolina State University Raleigh North Carolina USA
| | - Owain Edwards
- Commonwealth Scientific and Industrial Research Organisation Floreat Western Australia Australia
| | | | | | - Doria R. Gordon
- Environmental Defense Fund Washington District of Columbia USA
| | - Gregg Howald
- Advanced Conservation Strategies Williamsburg Virginia USA
| | - Margaret E. Hunter
- U.S. Geological Survey, Wetland and Aquatic Research Center Gainesville Florida USA
| | | | - Aditi Mankad
- Commonwealth Scientific and Industrial Research Organisation Floreat Western Australia Australia
| | - Michelle Marvier
- Department of Environmental Studies and Sciences Santa Clara University Santa Clara California USA
| | | | - Andrew E. Newhouse
- State University of New York, College of Environmental Science and Forestry Syracuse New York USA
| | | | | | - Steven Olson
- Association of Zoos and Aquariums Silver Spring Maryland USA
| | | | - Stephen Palumbi
- Hopkins Marine Station Stanford University Pacific Grove California USA
| | - Neil Patterson
- State University of New York College of Environmental Science and Forestry Center for Native Peoples & the Environment Syracuse New York USA
| | - Miguel Pedrono
- French Agricultural Research Centre for International Development (CIRAD, UMR ASTRE) Montpellier France
| | - Francisco Pelegri
- Laboratory of Genetics University of Wisconsin‐Madison Madison Wisconsin USA
| | - Yasha Rohwer
- Oregon Institute of Technology Klamath Falls Oregon USA
| | | | | | - Robert M. Scheller
- Department of Forestry and Environmental Resources North Carolina State University Raleigh North Carolina USA
| | | | - H. Bradley Shaffer
- Department of Ecology and Evolutionary Biology and La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability University of California Los Angeles California USA
| | - Beth Shapiro
- Department of Ecology and Evolutionary Biology, and the Howard Hughes Medical Institute University of California Santa Cruz California USA
| | - Mike Sweeney
- The Nature Conservancy San Francisco California USA
| | | | | | | | | | | | - Bruce Whitelaw
- The Roslin Institute University of Edinburgh Midlothian UK
| | | | - Josh Wodak
- Institute for Culture and Society, Western Sydney University Parramatta New South Wales Australia
| | - Mark Zimring
- The Nature Conservancy San Francisco California USA
| | - Paul Robbins
- Nelson Institute for Environmental Studies University of Wisconsin‐Madison Madison Wisconsin USA
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3
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Wegrzyn RD, Lee AH, Jenkins AL, Stoddard CD, Cheever AE. Genome Editing: Insights from Chemical Biology to Support Safe and Transformative Therapeutic Applications. ACS Chem Biol 2018; 13:333-342. [PMID: 28992411 DOI: 10.1021/acschembio.7b00689] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Programmable nuclease-based genome editing technologies, including the clustered, regularly interspaced, short palindromic repeats (CRISPR)/Cas9 system, are becoming an essential component of many applications ranging from agriculture to medicine. However, fundamental limitations currently prevent the widespread, safe, and practical use of genome editors, especially for human disease interventions. These limitations include off-target effects, a lack of control over editing activity, suboptimal DNA repair outcomes, insufficient target conversion, and inadequate delivery performance. This perspective focuses on the potential for biological chemistry to address these limitations such that newly developed genome editing technologies can enable the broadest range of potential future applications. Equally important will be the development of these powerful technologies within a relevant ethical framework that emphasizes safety and responsible innovation.
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Affiliation(s)
- Renee D Wegrzyn
- Defense Advanced Research Projects Agency (DARPA) , 675 N. Randolph St., Arlington, Virginia 22203, United States
| | - Andrew H Lee
- Booz Allen Hamilton , 3811 Fairfax Dr. Suite 600, Arlington, Virginia 22203, United States
| | - Amy L Jenkins
- Schafer: A Belcan Company , 3811 Fairfax Dr., Arlington, Virginia 22203, United States
| | - Colby D Stoddard
- Quantitative Scientific Solutions , 4601 N. Fairfax Dr. Suite 1200, Arlington, Virginia 22203, United States
| | - Anne E Cheever
- Booz Allen Hamilton , 3811 Fairfax Dr. Suite 600, Arlington, Virginia 22203, United States
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4
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Nyborg AC, Moll JR, Wegrzyn RD, Havas D, Hutter-Paier B, Feuerstein GGZ, Rudolph AS. In vivo and ex vivo imaging of amyloid-β cascade aggregates with a Pronucleon™ peptide. J Alzheimers Dis 2013; 34:957-67. [PMID: 23321523 DOI: 10.3233/jad-122107] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Accumulation of amyloid-β (Aβ) cascade aggregates is considered a hallmark of Alzheimer's disease (AD). Current dogma holds that the appearance of Aβ oligomers and larger aggregates occur many years prior to plaque formation associated with the advanced and irreparable neurocognitive decline characteristic of AD. This premise is the impetus to identify these Aβ precursor structures prior to advanced plaque development. The Pronucleon™ technology platform is comprised of a novel series of engineered peptides that provide a unique readout when associated with beta-rich fiber and oligomeric Aβ. This technology has been applied to Ex Vivo tissue sections and In Vivo mouse models of AD to determine the potential utility of these synthetic peptides as potential imaging agents. In Ex Vivo studies, the Pronucleon™ peptide binds plaque like structures in brain sections obtained from transgenic mice overexpressing hAPP with both the human Swedish and London Aβ mutations. In Vivo, Pronucleon™ peptide administered peripherally can localize to the brain and label plaques throughout the brain in transgenic mice. Taken together, the data suggest that Pronucleon™ could provide a new imaging tool for Aβ cascade elements that precede advanced plaque and fibril formation, thereby advancing early diagnosis and treatment opportunities.
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Erhardt M, Wegrzyn RD, Deuerling E. Extra N-terminal residues have a profound effect on the aggregation properties of the potential yeast prion protein Mca1. PLoS One 2010; 5:e9929. [PMID: 20360952 PMCID: PMC2847904 DOI: 10.1371/journal.pone.0009929] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 12/31/2009] [Indexed: 11/18/2022] Open
Abstract
The metacaspase Mca1 from Saccharomyces cerevisiae displays a Q/N-rich region at its N-terminus reminiscent of yeast prion proteins. In this study, we show that the ability of Mca1 to form insoluble aggregates is modulated by a peptide stretch preceding its putative prion-forming domain. Based on its genomic locus, three potential translational start sites of Mca1 can give rise to two slightly different long Mca1 proteins or a short version, Mca1451/453 and Mca1432, respectively, although under normal physiological conditions Mca1432 is the predominant form expressed. All Mca1 variants exhibit the Q/N-rich regions, while only the long variants Mca1451/453 share an extra stretch of 19 amino acids at their N-terminal end. Strikingly, only long versions of Mca1 but not Mca1432 revealed pronounced aggregation in vivo and displayed prion-like properties when fused to the C-terminal domain of Sup35 suggesting that the N-terminal peptide element promotes the conformational switch of Mca1 protein into an insoluble state. Transfer of the 19 N-terminal amino acid stretch of Mca1451 to the N-terminus of firefly luciferase resulted in increased aggregation of luciferase, suggesting a protein destabilizing function of the peptide element. We conclude that the aggregation propensity of the potential yeast prion protein Mca1 in vivo is strongly accelerated by a short peptide segment preceding its Q/N-rich region and we speculate that such a conformational switch might occur in vivo via the usage of alternative translational start sites.
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Affiliation(s)
- Marc Erhardt
- Molekulare Mikrobiologie, Fachbereich Biologie, Universität Konstanz, Konstanz, Germany
| | - Renee D. Wegrzyn
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Universität Heidelberg, Heidelberg, Germany
| | - Elke Deuerling
- Molekulare Mikrobiologie, Fachbereich Biologie, Universität Konstanz, Konstanz, Germany
- * E-mail:
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6
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Sadlish H, Rampelt H, Shorter J, Wegrzyn RD, Andréasson C, Lindquist S, Bukau B. Hsp110 chaperones regulate prion formation and propagation in S. cerevisiae by two discrete activities. PLoS One 2008; 3:e1763. [PMID: 18335038 PMCID: PMC2258148 DOI: 10.1371/journal.pone.0001763] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 02/07/2008] [Indexed: 11/18/2022] Open
Abstract
The cytosolic chaperone network of Saccharomyces cerevisiae is intimately associated with the emergence and maintenance of prion traits. Recently, the Hsp110 protein, Sse1, has been identified as a nucleotide exchange factor (NEF) for both cytosolic Hsp70 chaperone family members, Ssa1 and Ssb1. We have investigated the role of Sse1 in the de novo formation and propagation of [PSI(+)], the prion form of the translation termination factor, Sup35. As observed by others, we find that Sse1 is essential for efficient prion propagation. Our results suggest that the NEF activity is required for maintaining sufficient levels of substrate-free Ssa1. However, Sse1 exhibits an additional NEF-independent activity; it stimulates in vitro nucleation of Sup35NM, the prion domain of Sup35. We also observe that high levels of Sse1, but not of an unrelated NEF, very potently inhibit Hsp104-mediated curing of [PSI(+)]. Taken together, these results suggest a chaperone-like activity of Sse1 that assists in stabilization of early folding intermediates of the Sup35 prion conformation. This activity is not essential for prion formation under conditions of Sup35 overproduction, however, it may be relevant for spontaneous [PSI(+)] formation as well as for protection of the prion trait upon physiological Hsp104 induction.
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Affiliation(s)
- Heather Sadlish
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Universität Heidelberg, Heidelberg, Germany
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7
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Ganusova EE, Ozolins LN, Bhagat S, Newnam GP, Wegrzyn RD, Sherman MY, Chernoff YO. Modulation of prion formation, aggregation, and toxicity by the actin cytoskeleton in yeast. Mol Cell Biol 2006; 26:617-29. [PMID: 16382152 PMCID: PMC1346895 DOI: 10.1128/mcb.26.2.617-629.2006] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Self-perpetuating protein aggregates transmit prion diseases in mammals and heritable traits in yeast. De novo prion formation can be induced by transient overproduction of the corresponding prion-forming protein or its prion domain. Here, we demonstrate that the yeast prion protein Sup35 interacts with various proteins of the actin cortical cytoskeleton that are involved in endocytosis. Sup35-derived aggregates, generated in the process of prion induction, are associated with the components of the endocytic/vacuolar pathway. Mutational alterations of the cortical actin cytoskeleton decrease aggregation of overproduced Sup35 and de novo prion induction and increase prion-related toxicity in yeast. Deletion of the gene coding for the actin assembly protein Sla2 is lethal in cells containing the prion isoforms of both Sup35 and Rnq1 proteins simultaneously. Our data are consistent with a model in which cytoskeletal structures provide a scaffold for generation of large aggregates, resembling mammalian aggresomes. These aggregates promote prion formation. Moreover, it appears that the actin cytoskeleton also plays a certain role in counteracting the toxicity of the overproduced potentially aggregating proteins.
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Affiliation(s)
- Elena E Ganusova
- School of Biology, Georgia Institute of Technology, M/C 0230, 310 Ferst Drive, Atlanta, Georgia 30332-0230, USA
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8
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Rauch T, Hundley HA, Pfund C, Wegrzyn RD, Walter W, Kramer G, Kim SY, Craig EA, Deuerling E. Dissecting functional similarities of ribosome-associated chaperones from Saccharomyces cerevisiae and Escherichia coli. Mol Microbiol 2005; 57:357-65. [PMID: 15978070 DOI: 10.1111/j.1365-2958.2005.04690.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ribosome-tethered chaperones that interact with nascent polypeptide chains have been identified in both prokaryotic and eukaryotic systems. However, these ribosome-associated chaperones share no sequence similarity: bacterial trigger factors (TF) form an independent protein family while the yeast machinery is Hsp70-based. The absence of any component of the yeast machinery results in slow growth at low temperatures and sensitivity to aminoglycoside protein synthesis inhibitors. After establishing that yeast ribosomal protein Rpl25 is able to recruit TF to ribosomes when expressed in place of its Escherichia coli homologue L23, the ribosomal TF tether, we tested whether such divergent ribosome-associated chaperones are functionally interchangeable. E. coli TF was expressed in yeast cells that lacked the endogenous ribosome-bound machinery. TF associated with yeast ribosomes, cross-linked to yeast nascent polypeptides and partially complemented the aminoglycoside sensitivity, demonstrating that ribosome-associated chaperones from divergent organisms share common functions, despite their lack of sequence similarity.
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Affiliation(s)
- Thomas Rauch
- Zentrum für Molekulare Biologie (ZMBH), Universität Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
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9
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Wegrzyn RD, Hofmann D, Merz F, Nikolay R, Rauch T, Graf C, Deuerling E. A conserved motif is prerequisite for the interaction of NAC with ribosomal protein L23 and nascent chains. J Biol Chem 2005; 281:2847-57. [PMID: 16316984 DOI: 10.1074/jbc.m511420200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In eukaryotes, newly synthesized proteins interact co-translationally with a multitude of different ribosome-bound factors and chaperones including the conserved heterodimeric nascent polypeptide-associated complex (NAC) and a Hsp40/70-based chaperone system. These factors are thought to play an important role in protein folding and targeting, yet their specific ribosomal localizations, which are prerequisite for their functions, remain elusive. This study describes the ribosomal localization of NAC and the molecular details by which NAC is able to contact the ribosome and gain access to nascent polypeptides. We identified a conserved RRK(X)nKK ribosome binding motif within the beta-subunit of NAC that is essential for the entire NAC complex to attach to ribosomes and allow for its interaction with nascent polypeptide chains. The motif localizes within a potential loop region between two predicted alpha-helices in the N terminus of betaNAC. This N-terminal betaNAC ribosome-binding domain was completely portable and sufficient to target an otherwise cytosolic protein to the ribosome. NAC modified with a UV-activatable cross-linker within its ribosome binding motif specifically cross-linked to L23 ribosomal protein family members at the exit site of the ribosome, providing the first evidence of NAC-L23 interaction in the context of the ribosome. Mutations of L23 reduced NAC ribosome binding in vivo and in vitro, whereas other eukaryotic ribosome-associated factors such as the Hsp70/40 chaperones Ssb or Zuotin were unaffected. We conclude that NAC employs a conserved ribosome binding domain to position itself on the L23 ribosomal protein adjacent to the nascent polypeptide exit site.
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Affiliation(s)
- Renee D Wegrzyn
- Zentrum für Molekulare Biologie (ZMBH), Universität Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
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10
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Abstract
A central dogma in biology is the conversion of genetic information into active proteins. The biosynthesis of proteins by ribosomes and the subsequent folding of newly made proteins represent the last crucial steps in this process. To guarantee the correct folding of newly made proteins, a complex chaperone network is required in all cells. In concert with ongoing protein biosynthesis, ribosome-associated factors can interact directly with emerging nascent polypeptides to protect them from degradation or aggregation, to promote folding into their native structure, or to otherwise contribute to their folding program. Eukaryotic cells possess two major ribosome-associated systems, an Hsp70/Hsp40-based chaperone system and the functionally enigmatic NAC complex, whereas prokaryotes employ the Trigger Factor chaperone. Recent structural insights into Trigger Factor reveal an intricate cradle-like structure that, together with the exit site of the ribosome, forms a protected environment for the folding of newly synthesized proteins.
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Affiliation(s)
- R D Wegrzyn
- Zentrum für Molekulare Biologie, Universität Heidelberg, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany
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11
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Allen KD, Wegrzyn RD, Chernova TA, Müller S, Newnam GP, Winslett PA, Wittich KB, Wilkinson KD, Chernoff YO. Hsp70 chaperones as modulators of prion life cycle: novel effects of Ssa and Ssb on the Saccharomyces cerevisiae prion [PSI+]. Genetics 2004; 169:1227-42. [PMID: 15545639 PMCID: PMC1449557 DOI: 10.1534/genetics.104.037168] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
[PSI(+)] is a prion isoform of the yeast release factor Sup35. In some assays, the cytosolic chaperones Ssa1 and Ssb1/2 of the Hsp70 family were previously shown to exhibit "pro-[PSI(+)]" and "anti-[PSI(+)]" effects, respectively. Here, it is demonstrated for the first time that excess Ssa1 increases de novo formation of [PSI(+)] and that pro-[PSI(+)] effects of Ssa1 are shared by all other Ssa proteins. Experiments with chimeric constructs show that the peptide-binding domain is a major determinant of differences in the effects of Ssa and Ssb proteins on [PSI(+)]. Surprisingly, overproduction of either chaperone increases loss of [PSI(+)] when Sup35 is simultaneously overproduced. Excess Ssa increases both the average size of prion polymers and the proportion of monomeric Sup35 protein. Both in vivo and in vitro experiments uncover direct physical interactions between Sup35 and Hsp70 proteins. The proposed model postulates that Ssa stimulates prion formation and polymer growth by stabilizing misfolded proteins, which serve as substrates for prion conversion. In the case of very large prion aggregates, further increase in size may lead to the loss of prion activity. In contrast, Ssb either stimulates refolding into nonprion conformation or targets misfolded proteins for degradation, in this way counteracting prion formation and propagation.
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Affiliation(s)
- Kim D Allen
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, 30332-0363, USA
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12
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Kramer G, Rutkowska A, Wegrzyn RD, Patzelt H, Kurz TA, Merz F, Rauch T, Vorderwülbecke S, Deuerling E, Bukau B. Functional dissection of Escherichia coli trigger factor: unraveling the function of individual domains. J Bacteriol 2004; 186:3777-84. [PMID: 15175291 PMCID: PMC419933 DOI: 10.1128/jb.186.12.3777-3784.2004] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Escherichia coli, the ribosome-associated chaperone Trigger Factor (TF) promotes the folding of newly synthesized cytosolic proteins. TF is composed of three domains: an N-terminal domain (N), which mediates ribosome binding; a central domain (P), which has peptidyl-prolyl cis/trans isomerase activity and is involved in substrate binding in vitro; and a C-terminal domain (C) with unknown function. We investigated the contributions of individual domains (N, P, and C) or domain combinations (NP, PC, and NC) to the chaperone activity of TF in vivo and in vitro. All fragments comprising the N domain (N, NP, NC) complemented the synthetic lethality of Deltatig DeltadnaK in cells lacking TF and DnaK, prevented protein aggregation in these cells, and cross-linked to nascent polypeptides in vitro. However, DeltatigDeltadnaK cells expressing the N domain alone grew more slowly and showed less viability than DeltatigDeltadnaK cells synthesizing either NP, NC, or full-length TF, indicating beneficial contributions of the P and C domains to TF's chaperone activity. In an in vitro system with purified components, none of the TF fragments assisted the refolding of denatured d-glyceraldehyde-3-phosphate dehydrogenase in a manner comparable to that of wild-type TF, suggesting that the observed chaperone activity of TF fragments in vivo is dependent on their localization at the ribosome. These results indicate that the N domain, in addition to its function to promote binding to the ribosome, has a chaperone activity per se and is sufficient to substitute for TF in vivo.
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Affiliation(s)
- G Kramer
- Zentrum für Molekulare Biologie (ZMBH), Universität Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
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13
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Borchsenius AS, Wegrzyn RD, Newnam GP, Inge-Vechtomov SG, Chernoff YO. Yeast prion protein derivative defective in aggregate shearing and production of new 'seeds'. EMBO J 2001; 20:6683-91. [PMID: 11726504 PMCID: PMC125771 DOI: 10.1093/emboj/20.23.6683] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
According to the nucleated polymerization model, in vivo prion proliferation occurs via dissociation (shearing) of the huge prion polymers into smaller oligomeric 'seeds', initiating new rounds of prion replication. Here, we identify the deletion derivative of yeast prion protein Sup35 (Sup35-Delta22/69) that is specifically defective in aggregate shearing and 'seed' production. This derivative, [PSI+], previously thought to be unable to turn into a prion state, in fact retains the ability to form a prion ([PSI+](Delta22/69)) that can be maintained in selective conditions and transmitted by cytoplasmic infection (cytoduction), but which is mitotically unstable in non-selective conditions. MorePSI+](Delta22/69) retains its mitotic stability defect. The [PSI+](Delta22/69) cells contain more Sup35 protein in the insoluble fraction and form larger Sup35 aggregates compared with the conventional [PSI+] cells. Moderate excess of Hsp104 disaggregase increases transmission of the [PSI+](Delta22/69) prion, while excess Hsp70-Ssa chaperone antagonizes it, opposite to their effects on conventional [PSI+]. Our results shed light on the mechanisms determining the differences between transmissible prions and non-transmissible protein aggregates.
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Affiliation(s)
- Andrey S. Borchsenius
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0363, USA and Department of Genetics and Breeding, St Petersburg State University, St Petersburg, Russian Federation Corresponding author e-mail:
| | - Renee D. Wegrzyn
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0363, USA and Department of Genetics and Breeding, St Petersburg State University, St Petersburg, Russian Federation Corresponding author e-mail:
| | - Gary P. Newnam
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0363, USA and Department of Genetics and Breeding, St Petersburg State University, St Petersburg, Russian Federation Corresponding author e-mail:
| | - Sergey G. Inge-Vechtomov
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0363, USA and Department of Genetics and Breeding, St Petersburg State University, St Petersburg, Russian Federation Corresponding author e-mail:
| | - Yury O. Chernoff
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0363, USA and Department of Genetics and Breeding, St Petersburg State University, St Petersburg, Russian Federation Corresponding author e-mail:
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14
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Borchsenius AS, Wegrzyn RD, Newnam GP, Inge-Vechtomov SG, Chernoff YO. Yeast prion protein derivative defective in aggregate shearing and production of new 'seeds'. EMBO J 2001; 20:6683-6691. [PMID: 11726504 DOI: 10.1093/emboj/20.23.6683.as] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
According to the nucleated polymerization model, in vivo prion proliferation occurs via dissociation (shearing) of the huge prion polymers into smaller oligomeric 'seeds', initiating new rounds of prion replication. Here, we identify the deletion derivative of yeast prion protein Sup35 (Sup35-Delta22/69) that is specifically defective in aggregate shearing and 'seed' production. This derivative, [PSI+], previously thought to be unable to turn into a prion state, in fact retains the ability to form a prion ([PSI+](Delta22/69)) that can be maintained in selective conditions and transmitted by cytoplasmic infection (cytoduction), but which is mitotically unstable in non-selective conditions. MorePSI+](Delta22/69) retains its mitotic stability defect. The [PSI+](Delta22/69) cells contain more Sup35 protein in the insoluble fraction and form larger Sup35 aggregates compared with the conventional [PSI+] cells. Moderate excess of Hsp104 disaggregase increases transmission of the [PSI+](Delta22/69) prion, while excess Hsp70-Ssa chaperone antagonizes it, opposite to their effects on conventional [PSI+]. Our results shed light on the mechanisms determining the differences between transmissible prions and non-transmissible protein aggregates.
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Affiliation(s)
- A S Borchsenius
- School of Biology and Institute for Bioengineering and Bioscience, Atlanta, GA 30332-0363, USA
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15
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Abstract
In vivo propagation of [PSI(+)], an aggregation-prone prion isoform of the yeast release factor Sup35 (eRF3), has previously been shown to require intermediate levels of the chaperone protein Hsp104. Here we perform a detailed study on the mechanism of prion loss after Hsp104 inactivation. Complete or partial inactivation of Hsp104 was achieved by the following approaches: deleting the HSP104 gene; modifying the HSP104 promoter that results in low level of its expression; and overexpressing the dominant-negative ATPase-inactive mutant HSP104 allele. In contrast to guanidine-HCl, an agent blocking prion proliferation, Hsp104 inactivation induced relatively rapid loss of [PSI(+)] and another candidate yeast prion, [PIN(+)]. Thus, the previously hypothesized mechanism of prion dilution in cell divisions due to the blocking of prion proliferation is not sufficient to explain the effect of Hsp104 inactivation. The [PSI(+)] response to increased levels of another chaperone, Hsp70-Ssa, depends on whether the Hsp104 activity is increased or decreased. A decrease of Hsp104 levels or activity is accompanied by a decrease in the number of Sup35(PSI+) aggregates and an increase in their size. This eventually leads to accumulation of huge agglomerates, apparently possessing reduced prion forming capability and representing dead ends of the prion replication cycle. Thus, our data confirm that the primary function of Hsp104 in prion propagation is to disassemble prion aggregates and generate the small prion seeds that initiate new rounds of prion propagation (possibly assisted by Hsp70-Ssa).
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Affiliation(s)
- R D Wegrzyn
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332-0363, USA
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16
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Abstract
[PSI(+)] is a prion (infectious protein) of Sup35p, a subunit of the Saccharomyces cerevisiae translation termination factor. We isolated a dominant allele, SSA1-21, of a gene encoding an Hsp70 chaperone that impairs [PSI(+)] mitotic stability and weakens allosuppression caused by [PSI(+)]. While [PSI(+)] stability is normal in strains lacking SSA1, SSA2, or both, SSA1-21 strains with a deletion of SSA2 cannot propagate [PSI(+)]. SSA1-21 [PSI(+)] strains are hypersensitive to curing of [PSI(+)] by guanidine-hydrochloride and partially cured of [PSI(+)] by rapid induction of the heat-shock response but not by growth at 37 degrees. The number of inheritable [PSI(+)] particles is significantly reduced in SSA1-21 cells. SSA1-21 effects on [PSI(+)] appear to be independent of Hsp104, another stress-inducible protein chaperone known to be involved in [PSI(+)] propagation. We propose that cytosolic Hsp70 is important for the formation of Sup35p polymers characteristic of [PSI(+)] from preexisting material and that Ssa1-21p both lacks and interferes with this activity. We further demonstrate that the negative effect of heat stress on [PSI(+)] phenotype directly correlates with solubility of Sup35p and find that in wild-type strains the presence of [PSI(+)] causes a stress that elevates basal expression of Hsp104 and SSA1.
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Affiliation(s)
- G Jung
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0851, USA
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Bailleul-Winslett PA, Newnam GP, Wegrzyn RD, Chernoff YO. An antiprion effect of the anticytoskeletal drug latrunculin A in yeast. Gene Expr 2000; 9:145-56. [PMID: 11243411 PMCID: PMC5964936 DOI: 10.3727/000000001783992650] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 09/07/2000] [Accepted: 09/18/2000] [Indexed: 11/24/2022]
Abstract
Prions are infectious aggregation-prone isoforms of the normal proteins, supposedly able to seed aggregation of the normal cellular counterparts. In vitro, prion proteins form amyloid fibers, resembling cytoskeletal structures. Yeast prion [PSI], which is a cytoplasmically inherited aggregated isoform of the translation termination factor Sup35p (eRF3), serves as a useful model for studying mechanisms of prion diseases and other amyloidoses. The previously described interaction between Sup35p and cytoskeletal assembly protein Sla1p points to the possible relationships between prions and cytoskeletal networks. Although the Sup35PSI+ aggregates do not colocalize with actin patches, we have shown that yeast cells are efficiently cured of the [PSI] prion by prolonged incubation with latrunculin A, a drug disrupting the actin cytoskeleton. On the other hand, treatments with sodium azide or cycloheximide, agents blocking yeast protein synthesis and cell proliferation but not disrupting the cytoskeleton, do not cause a significant loss of [PSI]. Moreover, simultaneous treatment with sodium azide or cycloheximide blocks [PSI] curing by latrunculin A, indicating that prion loss in the presence of latrunculin A requires a continuation of protein synthesis during cytoskeleton disruption. The sodium azide treatment also decreases the toxic effect of latrunculin A. Latrunculin A influences neither the levels of total cellular Sup35p nor the levels of chaperone proteins, such as Hsp104 and Hsp70, which were previously shown to affect [PSI]. This makes an indirect effect of latrunculin A on [PSI] via induction of Hsps unlikely. Fluorescence microscopy detects changes in the structure and/or localization of the Sup35PSI+ aggregates in latrunculin A-treated cells. We conclude that the stable maintenance of the [PSI] prion aggregates in the protein-synthesizing yeast cells partly depends on an intact actin cytoskeleton, suggesting that anticytoskeletal treatments could be used to counteract some aggregation-related disorders.
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Affiliation(s)
- Peggy A. Bailleul-Winslett
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, M/C 0363, Atlanta, GA 30332-0363
| | - Gary P. Newnam
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, M/C 0363, Atlanta, GA 30332-0363
| | - Renee D. Wegrzyn
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, M/C 0363, Atlanta, GA 30332-0363
| | - Yury O. Chernoff
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, M/C 0363, Atlanta, GA 30332-0363
- Address correspondence to Yury O. Chernoff, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332-0363. Tel: (404) 894-1157; Fax: (404) 894-0519, (404) 894-2291; E-mail:
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18
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Abstract
The maintenance of [PSI], a prion-like form of the yeast release factor Sup35, requires a specific concentration of the chaperone protein Hsp104: either deletion or overexpression of Hsp104 will cure cells of [PSI]. A major puzzle of these studies was that overexpression of Hsp104 alone, from a heterologous promoter, cures cells of [PSI] very efficiently, yet the natural induction of Hsp104 with heat shock, stationary-phase growth, or sporulation does not. These observations pointed to a mechanism for protecting the genetic information carried by the [PSI] element from vicissitudes of the environment. Here, we show that simultaneous overexpression of Ssa1, a protein of the Hsp70 family, protects [PSI] from curing by overexpression of Hsp104. Ssa1 protein belongs to the Ssa subfamily, members of which are normally induced with Hsp104 during heat shock, stationary-phase growth, and sporulation. At the molecular level, excess Ssa1 prevents a shift of Sup35 protein from the insoluble (prion) to the soluble (cellular) state in the presence of excess Hsp104. Overexpression of Ssa1 also increases nonsense suppression by [PSI] when Hsp104 is expressed at its normal level. In contrast, hsp104 deletion strains lose [PSI] even in the presence of overproduced Ssa1. Overproduction of the unrelated chaperone protein Hsp82 (Hsp90) neither cured [PSI] nor antagonized the [PSI]-curing effect of overproduced Hsp104. Our results suggest it is the interplay between Hsp104 and Hsp70 that allows the maintenance of [PSI] under natural growth conditions.
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Affiliation(s)
- G P Newnam
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0230, USA
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