1
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Cobos SN, Janani C, Cruz G, Rana N, Son E, Frederic R, Paredes Casado J, Khan M, Bennett SA, Torrente MP. [PRION +] States Are Associated with Specific Histone H3 Post-Translational Modification Changes. Pathogens 2022; 11:pathogens11121436. [PMID: 36558770 PMCID: PMC9786042 DOI: 10.3390/pathogens11121436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 11/30/2022] Open
Abstract
Prions are proteins able to take on alternative conformations and propagate them in a self-templating process. In Saccharomyces cerevisiae, prions enable heritable responses to environmental conditions through bet-hedging mechanisms. Hence, [PRION+] states may serve as an atypical form of epigenetic control, producing heritable phenotypic change via protein folding. However, the connections between prion states and the epigenome remain unknown. Do [PRION+] states link to canonical epigenetic channels, such as histone post-translational modifications? Here, we map out the histone H3 modification landscape in the context of the [SWI+] and [PIN+] prion states. [SWI+] is propagated by Swi1, a subunit of the SWI/SNF chromatin remodeling complex, while [PIN+] is propagated by Rnq1, a protein of unknown function. We find [SWI+] yeast display decreases in the levels of H3K36me2 and H3K56ac compared to [swi-] yeast. In contrast, decreases in H3K4me3, H3K36me2, H3K36me3 and H3K79me3 are connected to the [PIN+] state. Curing of the prion state by treatment with guanidine hydrochloride restored histone PTM to [prion-] state levels. We find histone PTMs in the [PRION+] state do not match those in loss-of-function models. Our findings shed light into the link between prion states and histone modifications, revealing novel insight into prion function in yeast.
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Affiliation(s)
- Samantha N. Cobos
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
| | - Chaim Janani
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
| | - Gabriel Cruz
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
| | - Navin Rana
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
| | - Elizaveta Son
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
| | - Rania Frederic
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
| | | | - Maliha Khan
- Biology Department, Brooklyn College, Brooklyn, NY 11210, USA
| | - Seth A. Bennett
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
- Graduate Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - Mariana P. Torrente
- Chemistry Department, Brooklyn College, Brooklyn, NY 11210, USA
- Ph.D. Programs in Chemistry, Biochemistry, and Biology, The Graduate Center of the City University of New York, New York, NY 10016, USA
- Correspondence:
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2
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Nan H, Chen H, Tuite MF, Xu X. A viral expression factor behaves as a prion. Nat Commun 2019; 10:359. [PMID: 30664652 PMCID: PMC6341119 DOI: 10.1038/s41467-018-08180-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 12/20/2018] [Indexed: 02/07/2023] Open
Abstract
Prions are proteins that can fold into multiple conformations some of which are self-propagating. Such prion-forming proteins have been found in animal, plant, fungal and bacterial species, but have not yet been identified in viruses. Here we report that LEF-10, a baculovirus-encoded protein, behaves as a prion. Full-length LEF-10 or its candidate prion-forming domain (cPrD) can functionally replace the PrD of Sup35, a widely studied prion-forming protein from yeast, displaying a [PSI+]-like phenotype. Furthermore, we observe that high multiplicity of infection can induce the conversion of LEF-10 into an aggregated state in virus-infected cells, resulting in the inhibition of viral late gene expression. Our findings extend the knowledge of current prion proteins from cellular organisms to non-cellular life forms and provide evidence to support the hypothesis that prion-forming proteins are a widespread phenomenon in nature.
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Affiliation(s)
- Hao Nan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China
| | - Hongying Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China
| | - Mick F Tuite
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK
| | - Xiaodong Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China.
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3
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Upadhyay A, Mishra A. Amyloids of multiple species: are they helpful in survival? Biol Rev Camb Philos Soc 2018; 93:1363-1386. [DOI: 10.1111/brv.12399] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 01/13/2018] [Accepted: 01/18/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Arun Upadhyay
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan 342011 India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan 342011 India
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4
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Feng Z, Hu X, Jiang Z, Song H, Ashraf MA. The recognition of multi-class protein folds by adding average chemical shifts of secondary structure elements. Saudi J Biol Sci 2016; 23:189-97. [PMID: 26980999 PMCID: PMC4778582 DOI: 10.1016/j.sjbs.2015.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/08/2015] [Accepted: 10/12/2015] [Indexed: 11/28/2022] Open
Abstract
The recognition of protein folds is an important step in the prediction of protein structure and function. Recently, an increasing number of researchers have sought to improve the methods for protein fold recognition. Following the construction of a dataset consisting of 27 protein fold classes by Ding and Dubchak in 2001, prediction algorithms, parameters and the construction of new datasets have improved for the prediction of protein folds. In this study, we reorganized a dataset consisting of 76-fold classes constructed by Liu et al. and used the values of the increment of diversity, average chemical shifts of secondary structure elements and secondary structure motifs as feature parameters in the recognition of multi-class protein folds. With the combined feature vector as the input parameter for the Random Forests algorithm and ensemble classification strategy, we propose a novel method to identify the 76 protein fold classes. The overall accuracy of the test dataset using an independent test was 66.69%; when the training and test sets were combined, with 5-fold cross-validation, the overall accuracy was 73.43%. This method was further used to predict the test dataset and the corresponding structural classification of the first 27-protein fold class dataset, resulting in overall accuracies of 79.66% and 93.40%, respectively. Moreover, when the training set and test sets were combined, the accuracy using 5-fold cross-validation was 81.21%. Additionally, this approach resulted in improved prediction results using the 27-protein fold class dataset constructed by Ding and Dubchak.
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Affiliation(s)
- Zhenxing Feng
- Department of Sciences, Inner Mongolia University of Technology, Hohhot, China
| | - Xiuzhen Hu
- Department of Sciences, Inner Mongolia University of Technology, Hohhot, China
| | - Zhuo Jiang
- Department of Sciences, Inner Mongolia University of Technology, Hohhot, China
| | - Hangyu Song
- Department of Sciences, Inner Mongolia University of Technology, Hohhot, China
| | - Muhammad Aqeel Ashraf
- Water Research Unit, Faculty of Science and Natural Resources, University Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia
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5
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Abstract
Specific conformations of signaling proteins can serve as “signals” in signal transduction by being recognized by receptors.
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Affiliation(s)
- Peter Tompa
- VIB Structural Biology Research Center (SBRC)
- Brussels
- Belgium
- Vrije Universiteit Brussel
- Brussels
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6
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Feng Z, Hu X. Recognition of 27-class protein folds by adding the interaction of segments and motif information. BIOMED RESEARCH INTERNATIONAL 2014; 2014:262850. [PMID: 25136571 PMCID: PMC4127253 DOI: 10.1155/2014/262850] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 06/28/2014] [Indexed: 01/31/2023]
Abstract
The recognition of protein folds is an important step for the prediction of protein structure and function. After the recognition of 27-class protein folds in 2001 by Ding and Dubchak, prediction algorithms, prediction parameters, and new datasets for the prediction of protein folds have been improved. However, the influences of interactions from predicted secondary structure segments and motif information on protein folding have not been considered. Therefore, the recognition of 27-class protein folds with the interaction of segments and motif information is very important. Based on the 27-class folds dataset built by Liu et al., amino acid composition, the interactions of secondary structure segments, motif frequency, and predicted secondary structure information were extracted. Using the Random Forest algorithm and the ensemble classification strategy, 27-class protein folds and corresponding structural classification were identified by independent test. The overall accuracy of the testing set and structural classification measured up to 78.38% and 92.55%, respectively. When the training set and testing set were combined, the overall accuracy by 5-fold cross validation was 81.16%. In order to compare with the results of previous researchers, the method above was tested on Ding and Dubchak's dataset which has been widely used by many previous researchers, and an improved overall accuracy 70.24% was obtained.
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Affiliation(s)
- Zhenxing Feng
- Department of Sciences, Inner Mongolia University of Technology, Hohhot, China
| | - Xiuzhen Hu
- Department of Sciences, Inner Mongolia University of Technology, Hohhot, China
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7
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Sabaté R, Villar-Piqué A, Espargaró A, Ventura S. Temperature Dependence of the Aggregation Kinetics of Sup35 and Ure2p Yeast Prions. Biomacromolecules 2011; 13:474-83. [DOI: 10.1021/bm201527m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Raimon Sabaté
- Institut de Biotecnologia
i de Biomedicina and Departament
de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona),
Spain
| | - Anna Villar-Piqué
- Institut de Biotecnologia
i de Biomedicina and Departament
de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona),
Spain
| | - Alba Espargaró
- Institut de Biotecnologia
i de Biomedicina and Departament
de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona),
Spain
| | - Salvador Ventura
- Institut de Biotecnologia
i de Biomedicina and Departament
de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona),
Spain
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8
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Kumar A, John L, Maity S, Manchanda M, Sharma A, Saini N, Chakraborty K, Sengupta S. Converging evidence of mitochondrial dysfunction in a yeast model of homocysteine metabolism imbalance. J Biol Chem 2011; 286:21779-95. [PMID: 21504896 DOI: 10.1074/jbc.m111.228072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
An elevated level of homocysteine, a thiol amino acid, is associated with various complex disorders. The cellular effects of homocysteine and its precursors S-adenosylhomocysteine (AdoHcy) and S-adenosylmethionine (AdoMet) are, however, poorly understood. We used Saccharomyces cerevisiae as a model to understand the basis of pathogenicity induced by homocysteine and its precursors. Both homocysteine and AdoHcy but not AdoMet inhibited the growth of the str4Δ strain (which lacks the enzyme that converts homocysteine to cystathionine-mimicking vascular cells). Addition of AdoMet abrogated the inhibitory effect of AdoHcy but not that of homocysteine indicating that an increase in the AdoMet/AdoHcy ratio is sufficient to overcome the AdoHcy-mediated growth defect but not that of homocysteine. Also, the transcriptomic profile of AdoHcy and homocysteine showed gross dissimilarity based on gene enrichment analysis. Furthermore, compared with homocysteine, AdoHcy treatment caused a higher level of oxidative stress in the cells. However, unlike a previously reported response in wild type (Kumar, A., John, L., Alam, M. M., Gupta, A., Sharma, G., Pillai, B., and Sengupta, S. (2006) Biochem. J. 396, 61-69), the str4Δ strain did not exhibit an endoplasmic reticulum stress response. This suggests that homocysteine induces varied response depending on the flux of homocysteine metabolism. We also observed altered expression of mitochondrial genes, defective membrane potential, and fragmentation of the mitochondrial network together with the increased expression of fission genes indicating that the imbalance in homocysteine metabolism has a major effect on mitochondrial functions. Furthermore, treatment of cells with homocysteine or AdoHcy resulted in apoptosis as revealed by annexin V staining and TUNEL assay. Cumulatively, our results suggest that elevated levels of homocysteine lead to mitochondrial dysfunction, which could potentially initiate pro-apoptotic pathways, and this could be one of the mechanisms underlying homocysteine-induced pathogenicity.
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Affiliation(s)
- Arun Kumar
- Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research, Mall Road, Delhi-110007, India
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9
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Abdelwahid E, Rolland S, Teng X, Conradt B, Hardwick JM, White K. Mitochondrial involvement in cell death of non-mammalian eukaryotes. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1813:597-607. [PMID: 20950655 PMCID: PMC3033473 DOI: 10.1016/j.bbamcr.2010.10.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 09/29/2010] [Accepted: 10/04/2010] [Indexed: 12/28/2022]
Abstract
Although mitochondria are essential organelles for long-term survival of eukaryotic cells, recent discoveries in biochemistry and genetics have advanced our understanding of the requirements for mitochondria in cell death. Much of what we understand about cell death is based on the identification of conserved cell death genes in Drosophila melanogaster and Caenorhabditis elegans. However, the role of mitochondria in cell death in these models has been much less clear. Considering the active role that mitochondria play in apoptosis in mammalian cells, the mitochondrial contribution to cell death in non-mammalian systems has been an area of active investigation. In this article, we review the current research on this topic in three non-mammalian models, C. elegans, Drosophila, and Saccharomyces cerevisiae. In addition, we discuss how non-mammalian models have provided important insight into the mechanisms of human disease as they relate to the mitochondrial pathway of cell death. The unique perspective derived from each of these model systems provides a more complete understanding of mitochondria in programmed cell death. This article is part of a Special Issue entitled Mitochondria: the deadly organelle.
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Affiliation(s)
- Eltyeb Abdelwahid
- Cutaneous Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA
| | - Stephane Rolland
- Department of Genetics, Norris Cotton Cancer Center, Dartmouth Medical School, Hanover, NH 03755, USA
| | - Xinchen Teng
- Departments of Molecular Microbiology and Immunology, and Pharmacology and Molecular Sciences, Johns Hopkins University, Schools of Public Health and Medicine, Baltimore, MD 21205, USA
| | - Barbara Conradt
- Department of Genetics, Norris Cotton Cancer Center, Dartmouth Medical School, Hanover, NH 03755, USA
| | - J. Marie Hardwick
- Departments of Molecular Microbiology and Immunology, and Pharmacology and Molecular Sciences, Johns Hopkins University, Schools of Public Health and Medicine, Baltimore, MD 21205, USA
| | - Kristin White
- Cutaneous Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA
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10
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Abstract
Organismal aging and longevity are influenced by many complex interacting factors. Epigenetics has recently emerged as another possible determinant of aging. Here, we review some of the epigenetic pathways that contribute to cellular senescence and age-associated phenotypes. Strategies aimed to reverse age-linked epigenetic alterations may lead to the development of new therapeutic interventions to delay or alleviate some of the most debilitating age-associated diseases.
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Affiliation(s)
- Ursula Muñoz-Najar
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02903, USA.
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11
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Bodenmiller B, Wanka S, Kraft C, Urban J, Campbell D, Pedrioli PG, Gerrits B, Picotti P, Lam H, Vitek O, Brusniak MY, Roschitzki B, Zhang C, Shokat KM, Schlapbach R, Colman-Lerner A, Nolan GP, Nesvizhskii AI, Peter M, Loewith R, von Mering C, Aebersold R. Phosphoproteomic analysis reveals interconnected system-wide responses to perturbations of kinases and phosphatases in yeast. Sci Signal 2010; 3:rs4. [PMID: 21177495 PMCID: PMC3072779 DOI: 10.1126/scisignal.2001182] [Citation(s) in RCA: 243] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The phosphorylation and dephosphorylation of proteins by kinases and phosphatases constitute an essential regulatory network in eukaryotic cells. This network supports the flow of information from sensors through signaling systems to effector molecules and ultimately drives the phenotype and function of cells, tissues, and organisms. Dysregulation of this process has severe consequences and is one of the main factors in the emergence and progression of diseases, including cancer. Thus, major efforts have been invested in developing specific inhibitors that modulate the activity of individual kinases or phosphatases; however, it has been difficult to assess how such pharmacological interventions would affect the cellular signaling network as a whole. Here, we used label-free, quantitative phosphoproteomics in a systematically perturbed model organism (Saccharomyces cerevisiae) to determine the relationships between 97 kinases, 27 phosphatases, and more than 1000 phosphoproteins. We identified 8814 regulated phosphorylation events, describing the first system-wide protein phosphorylation network in vivo. Our results show that, at steady state, inactivation of most kinases and phosphatases affected large parts of the phosphorylation-modulated signal transduction machinery-and not only the immediate downstream targets. The observed cellular growth phenotype was often well maintained despite the perturbations, arguing for considerable robustness in the system. Our results serve to constrain future models of cellular signaling and reinforce the idea that simple linear representations of signaling pathways might be insufficient for drug development and for describing organismal homeostasis.
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Affiliation(s)
- Bernd Bodenmiller
- Institute of Molecular Systems Biology, ETH Zurich, 8093 Zurich, Switzerland
- Zurich PhD Program in Molecular Life Sciences, 8057 Zurich, Switzerland
| | - Stefanie Wanka
- Zurich PhD Program in Molecular Life Sciences, 8057 Zurich, Switzerland
- Institute of Molecular Life Sciences and Swiss Institute of Bioinformatics, University of Zurich, 8057 Zurich, Switzerland
| | - Claudine Kraft
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Jörg Urban
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
| | | | | | - Bertran Gerrits
- Functional Genomics Center Zurich, University Zurich and ETH Zurich, 8057 Zurich, Switzerland
| | - Paola Picotti
- Institute of Molecular Systems Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Henry Lam
- Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Olga Vitek
- Departments of Statistics and Computer Science, Purdue University, West Lafayette, IN 47107, USA
| | | | - Bernd Roschitzki
- Functional Genomics Center Zurich, University Zurich and ETH Zurich, 8057 Zurich, Switzerland
| | - Chao Zhang
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158–2280, USA
| | - Kevan M. Shokat
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158–2280, USA
| | - Ralph Schlapbach
- Functional Genomics Center Zurich, University Zurich and ETH Zurich, 8057 Zurich, Switzerland
| | - Alejandro Colman-Lerner
- Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, C1428EHA Buenos Aires, Argentina
| | - Garry P. Nolan
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | - Matthias Peter
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Robbie Loewith
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
| | - Christian von Mering
- Institute of Molecular Life Sciences and Swiss Institute of Bioinformatics, University of Zurich, 8057 Zurich, Switzerland
| | - Ruedi Aebersold
- Institute of Molecular Systems Biology, ETH Zurich, 8093 Zurich, Switzerland
- Institute for Systems Biology, Seattle, WA 98103, USA
- Faculty of Science, University of Zurich, 8057 Zurich, Switzerland
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12
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Khurana V, Lindquist S. Modelling neurodegeneration in Saccharomyces cerevisiae: why cook with baker's yeast? Nat Rev Neurosci 2010; 11:436-49. [PMID: 20424620 DOI: 10.1038/nrn2809] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In ageing populations, neurodegenerative diseases increase in prevalence, exacting an enormous toll on individuals and their communities. Multiple complementary experimental approaches are needed to elucidate the mechanisms underlying these complex diseases and to develop novel therapeutics. Here, we describe why the budding yeast Saccharomyces cerevisiae has a unique role in the neurodegeneration armamentarium. As the best-understood and most readily analysed eukaryotic organism, S. cerevisiae is delivering mechanistic insights into cell-autonomous mechanisms of neurodegeneration at an interactome-wide scale.
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Affiliation(s)
- Vikram Khurana
- Department of Neurology, Brigham and Women's and Massachusetts General Hospitals, Harvard Medical School, Boston, Massachusetts, USA
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13
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Abstract
The elucidation of the precise molecular structure and dynamics of biological processes is the great work of biochemistry. From this, insights into the changes leading to process dysfunction or disease are derived, as well as the possible approaches to restore healthy function. Translating this information into effective and safe treatments for disease requires a coordinated interdisciplinary effort, a fusion of creativity and practicality, and a healthy dose of luck. Using several reviews in this volume as springboards, I discuss the broader issues of drug development, highlighting some recent successes and future directions. Such occurrences inspire awe but remain too rare for comfort.
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14
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Strawn LA, Lin CA, Tank EMH, Osman MM, Simpson SA, True HL. Mutants of the Paf1 complex alter phenotypic expression of the yeast prion [PSI+]. Mol Biol Cell 2009; 20:2229-41. [PMID: 19225160 DOI: 10.1091/mbc.e08-08-0813] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The yeast [PSI+] prion is an epigenetic modifier of translation termination fidelity that causes nonsense suppression. The prion [PSI+] forms when the translation termination factor Sup35p adopts a self-propagating conformation. The presence of the [PSI+] prion modulates survivability in a variety of growth conditions. Nonsense suppression is essential for many [PSI+]-mediated phenotypes, but many do not appear to be due to read-through of a single stop codon, but instead are multigenic traits. We hypothesized that other global mechanisms act in concert with [PSI+] to influence [PSI+]-mediated phenotypes. We have identified one such global regulator, the Paf1 complex (Paf1C). Paf1C is conserved in eukaryotes and has been implicated in several aspects of transcriptional and posttranscriptional regulation. Mutations in Ctr9p and other Paf1C components reduced [PSI+]-mediated nonsense suppression. The CTR9 deletion also alters nonsense suppression afforded by other genetic mutations but not always to the same extent as the effects on [PSI+]-mediated read-through. Our data suggest that the Paf1 complex influences mRNA translatability but not solely through changes in transcript stability or abundance. Finally, we demonstrate that the CTR9 deletion alters several [PSI+]-dependent phenotypes. This provides one example of how [PSI+] and genetic modifiers can interact to uncover and regulate phenotypic variability.
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Affiliation(s)
- Lisa A Strawn
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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15
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Renaut L, Bouayadi K, Kharrat H, Mondon P. A cytoplasmic protein-protein interaction detection method based on reporter translation. Anal Biochem 2009; 384:362-4. [PMID: 18977194 DOI: 10.1016/j.ab.2008.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 10/03/2008] [Accepted: 10/08/2008] [Indexed: 11/24/2022]
Abstract
One approach to drug discovery involves the targeting of abnormal protein-protein interactions that lead to pathology. We present a new technology allowing the detection of such interactions within the cytoplasm in a yeast-based system. The interaction detection is based on the sequestration of a translation termination factor involved in stop codon recognition. This sequestration inhibits the activity of the factor, thereby permitting the translation of a reporter gene harboring a premature stop codon. This novel cytoplasmic protein-protein interaction (CPPI) detection system should prove to be useful in the characterization of proteins as well as in partner identification, interaction mapping, and drug discovery applications.
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16
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Pettersson-Kastberg J, Aits S, Gustafsson L, Mossberg A, Storm P, Trulsson M, Persson F, Mok KH, Svanborg C. Can misfolded proteins be beneficial? The HAMLET case. Ann Med 2009; 41:162-76. [PMID: 18985467 DOI: 10.1080/07853890802502614] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
By changing the three-dimensional structure, a protein can attain new functions, distinct from those of the native protein. Amyloid-forming proteins are one example, in which conformational change may lead to fibril formation and, in many cases, neurodegenerative disease. We have proposed that partial unfolding provides a mechanism to generate new and useful functional variants from a given polypeptide chain. Here we present HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) as an example where partial unfolding and the incorporation of cofactor create a complex with new, beneficial properties. Native alpha-lactalbumin functions as a substrate specifier in lactose synthesis, but when partially unfolded the protein binds oleic acid and forms the tumoricidal HAMLET complex. When the properties of HAMLET were first described they were surprising, as protein folding intermediates and especially amyloid-forming protein intermediates had been regarded as toxic conformations, but since then structural studies have supported functional diversity arising from a change in fold. The properties of HAMLET suggest a mechanism of structure-function variation, which might help the limited number of human protein genes to generate sufficient structural diversity to meet the diverse functional demands of complex organisms.
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Affiliation(s)
- Jenny Pettersson-Kastberg
- Department of Microbiology, Immunology and Glycobiology (MIG), Institute of Laboratory Medicine, Lund University, Sölvegatan 23, Lund, Sweden
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17
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Abstract
The sequencing of the human genome promised the identification of disease-causing genes and, subsequently, therapies for those diseases. However, when identifying the genetic basis of a disease, it is not uncommon to discover an abnormal protein whose normal function is unknown. The genetic manipulations required to assign function to genes is often extremely difficult, if not impossible, in human cells. Model organisms have been used to facilitate understanding of gene function because of the ease of genetic manipulations and because many features of eukaryotic physiology have been conserved across phyla. Yeast is a simple eukaryote with a tractable genome, a short generation time, and a large network of researchers who have generated a vast arsenal of research tools. These traits make yeast ideally suited to help reveal the function of genes implicated in human disease.
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18
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Abstract
Highly repetitive sequence within proteins is an abundant feature yet is considered by some to be the protein equivalent of "junk DNA." Homopolymer sequences, the most highly repetitive of this group, are typically encoded by trinucleotide repeats at the DNA level. It is thought that many of these sequences are produced by a replicative slippage mechanism. Recent studies suggest that these highly mutable regions within proteins may allow for rapid morphological evolution emerging from the increased variability afforded by such coding structures. However, in a homopolymer, it is difficult to determine if the repeated amino acid is due to slippage at the DNA level or due to selection at the protein level. Here we develop and test a model to detect cases for which the homopolymer tract has clearly been selected for, with no evidence of slippage at the DNA level. The polyserine tract within the phosphatidylserine receptor protein is used as an excellent example of one such case.
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Affiliation(s)
- Melanie A Huntley
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
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19
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Outeiro TF, Giorgini F. Yeast as a drug discovery platform in Huntington's and Parkinson's diseases. Biotechnol J 2006; 1:258-69. [PMID: 16897706 DOI: 10.1002/biot.200500043] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The high degree of conservation of cellular and molecular processes between the budding yeast Saccharomyces cerevisiae and higher eukaryotes have made it a valuable system for numerous studies of the basic mechanisms behind devastating illnesses such as cancer, infectious disease, and neurodegenerative disorders. Several studies in yeast have already contributed to our basic understanding of cellular dysfunction in both Huntington's and Parkinson's disease. Functional genomics approaches currently being undertaken in yeast may lead to novel insights into the genes and pathways that modulate neuronal cell dysfunction and death in these diseases. In addition, the budding yeast constitutes a valuable system for identification of new drug targets, both via target-based and non-target-based drug screening. Importantly, yeast can be used as a cellular platform to analyze the cellular effects of candidate compounds, which is critical for the development of effective therapeutics. While the molecular mechanisms that underlie neurodegeneration will ultimately have to be tested in neuronal and animal models, there are several distinct advantages to using simple model organisms to elucidate fundamental aspects of protein aggregation, amyloid toxicity, and cellular dysfunction. Here, we review recent studies that have shown that amyloid formation by disease-causing proteins and many of the resulting cellular deficits can be faithfully recapitulated in yeast. In addition, we discuss new yeast-based techniques for screening candidate therapeutic compounds for Huntington's and Parkinson's diseases.
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Vandebroek T, Vanhelmont T, Terwel D, Borghgraef P, Lemaire K, Snauwaert J, Wera S, Van Leuven F, Winderickx J. Identification and isolation of a hyperphosphorylated, conformationally changed intermediate of human protein tau expressed in yeast. Biochemistry 2005; 44:11466-75. [PMID: 16114883 DOI: 10.1021/bi0506775] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hyperphosphorylation and aggregation of protein tau are typical for neurodegenerative tauopathies, including Alzheimer's disease (AD). We demonstrate here that human tau expressed in yeast acquired pathological phosphoepitopes, assumed a pathological conformation, and formed aggregates. These processes were modulated by yeast kinases Mds1 and Pho85, orthologues of GSK-3beta and cdk5, respectively. Surprisingly, inactivation of Pho85 increased phosphorylation of tau-4R, concomitant with increased conformational change defined by antibody MC1 and a 40-fold increase in aggregation. Soluble protein tau, purified from yeast lacking PHO85, spontaneously and rapidly formed tau filaments in vitro. Further fractionation of tau by anion-exchange chromatography yielded a hyperphosphorylated monomeric subfraction, termed hP-tau/MC1, with slow electrophoretic mobility and enriched with all major epitopes, including MC1. Isolated hP-tau/MC1 vastly accelerated in vitro aggregation of wild-type tau-4R, demonstrating its functional capacity to initiate aggregation, as well as its structural stability. Combined, this novel yeast model recapitulates hyperphosphorylation, conformation, and aggregation of protein tau, provides insight in molecular changes crucial in tauopathies, offers a source for isolation of modified protein tau, and has potential for identification of modulating compounds and genes.
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Coughlan CM, Brodsky JL. Use of yeast as a model system to investigate protein conformational diseases. Mol Biotechnol 2005; 30:171-80. [PMID: 15920289 DOI: 10.1385/mb:30:2:171] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Protein conformational diseases arise when a cellular protein adopts an aberrant shape that either directly or indirectly alters the physiology of its host cell. Notable conformational diseases include cystic fibrosis, Huntington's disease, the prion-related diseases, Alzheimer's disease, and antitrypsin deficiency. In principle, the severity and progression of conformational diseases can be altered by cellular factors that recognize and attempt to ameliorate the harmful effects of the disease-causing, misshapen protein. To better define the mechanistic underpinnings of cellular factors that mediate quality control, and to understand why a single misfolded protein can impact cell viability, specific proteins that cause each of the diseases listed above have been expressed in a model eukaryote, the yeast Saccharomyces cerevisiae. In this review, we describe what has been learned from these studies, and speculate on future uses of yeast expression systems.
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22
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Freudenstein JV, Pickett KM, Simmons MP, Wenzel JW. From basepairs to birdsongs: phylogenetic data in the age of genomics. Cladistics 2005. [DOI: 10.1111/j.1096-0031.2003.tb00377.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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23
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Catharino S, Buchner J, Walter S. Characterization of oligomeric species in the fibrillization pathway of the yeast prion Ure2p. Biol Chem 2005; 386:633-41. [PMID: 16207084 DOI: 10.1515/bc.2005.074] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The [URE3] prion of Saccharomyces cerevisiae shares many features with mammalian prions and poly-glutamine related disorders and has become a model for studying amyloid diseases. The development of the [URE3] phenotype is thought to be caused by a structural switch in the Ure2p protein. In [URE3] cells, Ure2p is found predominantly in an aggregated state, while it is a soluble dimer in wild-type cells. In vitro, Ure2p forms fibrils with amyloid-like properties. Several studies suggest that the N-terminal domain of Ure2p is essential for prion formation. In this work, we investigated the fibril formation of Ure2p by isolating soluble oligomeric species, which are generated during fibrillization, and characterized them with respect to size and structure. Our data support the critical role of the N-terminal domain for fibril formation, as we observed fibrils in the presence of 5 M guanidinium chloride, conditions at which the C-terminal domain is completely unfolded. Based on fluorescence measurements, we conclude that the structure of the C-terminal domain is very similar in dimeric and fibrillar Ure2p. When studying the time course of fibrillization, we detected the formation of small, soluble oligomeric species during the early stages of the process. Their remarkable resistance against denaturants, their increased content of beta-structure, and their ability to 'seed' Ure2p fibrillization suggest that conversion to the amyloid-like conformation has already occurred. Thus, they likely represent critical intermediates in the fibrillization pathway of Ure2p.
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Affiliation(s)
- Silvia Catharino
- Fachbereich Chemie, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany
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24
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Abstract
Proteins associated with disease and development of the nervous system are thought to contain repetitive, simple sequences. However, genome-wide surveys for simple sequences within proteins have revealed that repetitive peptide sequences are the most frequent shared peptide segments among eukaryotic proteins, including those of Saccharomyces cerevisiae, which has few to no specialized developmental and neurological proteins. It is therefore of interest to determine if these specialized proteins have an excess of simple sequences when compared to other sets of compositionally similar proteins. We have determined the relative abundance of simple sequences within neurological proteins and find no excess of repetitive simple sequence within this class. In fact, polyglutamine repeats that are associated with many neurodegenerative diseases are no more abundant within neurological specialized proteins than within nonneurological collections of proteins. We also examined the codon composition of serine homopolymers to determine what forces may play a role in the evolution of extended homopolymers. Codon type homogeneity tends to be favored, suggesting replicative slippage instead of selection as the main force responsible for producing these homopolymers.
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Affiliation(s)
- Melanie A Huntley
- Department of Biology, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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25
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Outeiro TF, Muchowski PJ. Molecular genetics approaches in yeast to study amyloid diseases. J Mol Neurosci 2004; 23:49-60. [PMID: 15126692 DOI: 10.1385/jmn:23:1-2:049] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2003] [Accepted: 06/15/2003] [Indexed: 11/11/2022]
Abstract
The occurrence of protein aggregates in ordered fibrillar structures known as amyloid, found inside and outside of brain cells, is a feature shared by many neurodegenerative disorders, including Alzheimer's, Parkinson's, and Huntington's diseases. Although the molecular mechanisms that underlie neurodegeneration will ultimately have to be tested in neuronal and animal models, there are several distinct advantages in using model organisms to elucidate fundamental aspects of protein aggregation, amyloid formation, and toxicity. Here, we review recent studies indicating that amyloid formation by disease-causing proteins can be faithfully recapitulated in simple yeast-based models in Saccharomyces cerevisiae. These studies have already contributed to our basic understanding of molecular chaperone function/dysfunction in Huntington's disease, and functional genomics approaches being undertaken currently will likely bear novel insights into the genes and pathways that modulate neuronal cell dysfunction and death in these devastating diseases. A final advantage of using yeast to study amyloid formation and toxicity is the ease and rapidity with which large-scale drug-screening efforts can be conducted in this model organism.
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26
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Ross CA, Poirier MA. Protein aggregation and neurodegenerative disease. Nat Med 2004; 10 Suppl:S10-7. [PMID: 15272267 DOI: 10.1038/nm1066] [Citation(s) in RCA: 2491] [Impact Index Per Article: 118.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Accepted: 05/20/2004] [Indexed: 01/26/2023]
Abstract
Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and prion diseases are increasingly being realized to have common cellular and molecular mechanisms including protein aggregation and inclusion body formation. The aggregates usually consist of fibers containing misfolded protein with a beta-sheet conformation, termed amyloid. There is partial but not perfect overlap among the cells in which abnormal proteins are deposited and the cells that degenerate. The most likely explanation is that inclusions and other visible protein aggregates represent an end stage of a molecular cascade of several steps, and that earlier steps in the cascade may be more directly tied to pathogenesis than the inclusions themselves. For several diseases, genetic variants assist in explaining the pathogenesis of the more common sporadic forms and developing mouse and other models. There is now increased understanding of the pathways involved in protein aggregation, and some recent clues have emerged as to the molecular mechanisms of cellular toxicity. These are leading to approaches toward rational therapeutics.
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Affiliation(s)
- Christopher A Ross
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Ross Research Building, Room 618, 720 Rutland Avenue, Baltimore, Maryland 21205, USA.
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Fändrich M, Forge V, Buder K, Kittler M, Dobson CM, Diekmann S. Myoglobin forms amyloid fibrils by association of unfolded polypeptide segments. Proc Natl Acad Sci U S A 2003; 100:15463-8. [PMID: 14665689 PMCID: PMC307590 DOI: 10.1073/pnas.0303758100] [Citation(s) in RCA: 228] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Observations that beta-sheet proteins form amyloid fibrils under at least partially denaturing conditions has raised questions as to whether these fibrils assemble by docking of preformed beta-structure or by association of unfolded polypeptide segments. By using alpha-helical protein apomyoglobin, we show that the ease of fibril assembly correlates with the extent of denaturation. By contrast, monomeric beta-sheet intermediates could not be observed under the conditions of fibril formation. These data suggest that amyloid fibril formation from apomyoglobin depends on disordered polypeptide segments and conditions that are selectively unfavorable to folding. However, it is inevitable that such conditions often stabilize protein folding intermediates.
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Affiliation(s)
- Marcus Fändrich
- Institut für Molekulare Biotechnologie, Beutenbergstrasse 11, D-07745 Jena, Germany.
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28
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Abstract
Can Drosophila models be engineered that accurately reflect Huntington's disease (HD) and other neurological diseases and can they contribute to the search for treatments and cures? A number of publications seem to provide a resounding yes to that question. Here we seek to review some of the salient features of these models.
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Affiliation(s)
- J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697-2300, USA.
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29
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Current Awareness. Yeast 2001. [DOI: 10.1002/yea.687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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