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Louros N, Schymkowitz J, Rousseau F. Mechanisms and pathology of protein misfolding and aggregation. Nat Rev Mol Cell Biol 2023; 24:912-933. [PMID: 37684425 DOI: 10.1038/s41580-023-00647-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2023] [Indexed: 09/10/2023]
Abstract
Despite advances in machine learning-based protein structure prediction, we are still far from fully understanding how proteins fold into their native conformation. The conventional notion that polypeptides fold spontaneously to their biologically active states has gradually been replaced by our understanding that cellular protein folding often requires context-dependent guidance from molecular chaperones in order to avoid misfolding. Misfolded proteins can aggregate into larger structures, such as amyloid fibrils, which perpetuate the misfolding process, creating a self-reinforcing cascade. A surge in amyloid fibril structures has deepened our comprehension of how a single polypeptide sequence can exhibit multiple amyloid conformations, known as polymorphism. The assembly of these polymorphs is not a random process but is influenced by the specific conditions and tissues in which they originate. This observation suggests that, similar to the folding of native proteins, the kinetics of pathological amyloid assembly are modulated by interactions specific to cells and tissues. Here, we review the current understanding of how intrinsic protein conformational propensities are modulated by physiological and pathological interactions in the cell to shape protein misfolding and aggregation pathology.
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Affiliation(s)
- Nikolaos Louros
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
| | - Frederic Rousseau
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
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2
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Reed AL, Mitchell W, Alexandrescu AT, Alder NN. Interactions of amyloidogenic proteins with mitochondrial protein import machinery in aging-related neurodegenerative diseases. Front Physiol 2023; 14:1263420. [PMID: 38028797 PMCID: PMC10652799 DOI: 10.3389/fphys.2023.1263420] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023] Open
Abstract
Most mitochondrial proteins are targeted to the organelle by N-terminal mitochondrial targeting sequences (MTSs, or "presequences") that are recognized by the import machinery and subsequently cleaved to yield the mature protein. MTSs do not have conserved amino acid compositions, but share common physicochemical properties, including the ability to form amphipathic α-helical structures enriched with basic and hydrophobic residues on alternating faces. The lack of strict sequence conservation implies that some polypeptides can be mistargeted to mitochondria, especially under cellular stress. The pathogenic accumulation of proteins within mitochondria is implicated in many aging-related neurodegenerative diseases, including Alzheimer's, Parkinson's, and Huntington's diseases. Mechanistically, these diseases may originate in part from mitochondrial interactions with amyloid-β precursor protein (APP) or its cleavage product amyloid-β (Aβ), α-synuclein (α-syn), and mutant forms of huntingtin (mHtt), respectively, that are mediated in part through their associations with the mitochondrial protein import machinery. Emerging evidence suggests that these amyloidogenic proteins may present cryptic targeting signals that act as MTS mimetics and can be recognized by mitochondrial import receptors and transported into different mitochondrial compartments. Accumulation of these mistargeted proteins could overwhelm the import machinery and its associated quality control mechanisms, thereby contributing to neurological disease progression. Alternatively, the uptake of amyloidogenic proteins into mitochondria may be part of a protein quality control mechanism for clearance of cytotoxic proteins. Here we review the pathomechanisms of these diseases as they relate to mitochondrial protein import and effects on mitochondrial function, what features of APP/Aβ, α-syn and mHtt make them suitable substrates for the import machinery, and how this information can be leveraged for the development of therapeutic interventions.
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Affiliation(s)
- Ashley L. Reed
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Wayne Mitchell
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Andrei T. Alexandrescu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Nathan N. Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
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3
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Gestaut D, Zhao Y, Park J, Ma B, Leitner A, Collier M, Pintilie G, Roh SH, Chiu W, Frydman J. Structural visualization of the tubulin folding pathway directed by human chaperonin TRiC/CCT. Cell 2022; 185:4770-4787.e20. [PMID: 36493755 PMCID: PMC9735246 DOI: 10.1016/j.cell.2022.11.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 09/01/2022] [Accepted: 11/14/2022] [Indexed: 12/13/2022]
Abstract
The ATP-dependent ring-shaped chaperonin TRiC/CCT is essential for cellular proteostasis. To uncover why some eukaryotic proteins can only fold with TRiC assistance, we reconstituted the folding of β-tubulin using human prefoldin and TRiC. We find unstructured β-tubulin is delivered by prefoldin to the open TRiC chamber followed by ATP-dependent chamber closure. Cryo-EM resolves four near-atomic-resolution structures containing progressively folded β-tubulin intermediates within the closed TRiC chamber, culminating in native tubulin. This substrate folding pathway appears closely guided by site-specific interactions with conserved regions in the TRiC chamber. Initial electrostatic interactions between the TRiC interior wall and both the folded tubulin N domain and its C-terminal E-hook tail establish the native substrate topology, thus enabling C-domain folding. Intrinsically disordered CCT C termini within the chamber promote subsequent folding of tubulin's core and middle domains and GTP-binding. Thus, TRiC's chamber provides chemical and topological directives that shape the folding landscape of its obligate substrates.
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Affiliation(s)
- Daniel Gestaut
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Yanyan Zhao
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Junsun Park
- School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Boxue Ma
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Alexander Leitner
- Institute of Molecular Systems Biology, Dept of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Miranda Collier
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Grigore Pintilie
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Soung-Hun Roh
- School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea,Co-Corresponding authors: (lead contact), ,
| | - Wah Chiu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA,Co-Corresponding authors: (lead contact), ,
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, CA 94305, USA,Department of Genetics, Stanford University, Stanford, CA 94305, USA,Co-Corresponding authors: (lead contact), ,
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4
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Koculi E, Thirumalai D. Retardation of Folding Rates of Substrate Proteins in the Nanocage of GroEL. Biochemistry 2021; 60:460-464. [PMID: 33464880 DOI: 10.1021/acs.biochem.0c00903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Escherichia coli ATP-consuming chaperonin machinery, a complex between GroEL and GroES, has evolved to facilitate folding of substrate proteins (SPs) that cannot do so spontaneously. A series of kinetic experiments show that the SPs are encapsulated in the GroEL/ES nanocage for a short duration. If confinement of the SPs is the mechanism by which GroEL/ES facilitates folding, it follows that the assisted folding rate, relative to the bulk value, should always be enhanced. Here, we show that this is not the case for the folding of rhodanese in the presence of the full machinery of GroEL/ES and ATP. The assisted folding rate of rhodanese decreases. On the basis of our finding and those reported in other studies, we suggest that the ATP-consuming chaperonin machinery has evolved to optimize the product of the folding rate and the yield of the folded SPs on the biological time scale. Neither the rate nor the yield is separately maximized.
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Affiliation(s)
- Eda Koculi
- Department of Biology, Johns Hopkins University, 144 Mudd Hall, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - D Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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5
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Martinho MS, Nancarrow DJ, Lawrence TS, Beer DG, Ray D. Chaperones and Ubiquitin Ligases Balance Mutant p53 Protein Stability in Esophageal and Other Digestive Cancers. Cell Mol Gastroenterol Hepatol 2020; 11:449-464. [PMID: 33130332 PMCID: PMC7788241 DOI: 10.1016/j.jcmgh.2020.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/07/2020] [Accepted: 10/14/2020] [Indexed: 02/07/2023]
Abstract
The incidence of esophageal adenocarcinoma (EAC) and other gastrointestinal (GI) cancers have risen dramatically, thus defining the oncogenic drivers to develop effective therapies are necessary. Patients with Barrett's Esophagus (BE), have an elevated risk of developing EAC. Around 70%-80% of BE cases that progress to dysplasia and cancer have detectable TP53 mutations. Similarly, in other GI cancers higher rates of TP53 mutation are reported, which provide a significant survival advantage to dysplastic/cancer cells. Targeting molecular chaperones that mediate mutant p53 stability may effectively induce mutant p53 degradation and improve cancer outcomes. Statins can achieve this via disrupting the interaction between mutant p53 and the chaperone DNAJA1, promoting CHIP-mediated degradation of mutant p53, and statins are reported to significantly reduce the risk of BE progression to EAC. However, statins demonstrated sub-optimal efficacy depending on cancer types and TP53 mutation specificity. Besides the well-established role of MDM2 in p53 stability, we reported that individual isoforms of the E3 ubiquitin ligase GRAIL (RNF128) are critical, tissue-specific regulators of mutant p53 stability in BE progression to EAC, and targeting the interaction of mutant p53 with these isoforms may help mitigate EAC development. In this review, we discuss the critical ubiquitin-proteasome and chaperone regulation of mutant p53 stability in EAC and other GI cancers with future insights as to how to affect mutant p53 stability, further noting how the precise p53 mutation may influence the efficacy of treatment strategies and identifying necessary directions for further research in this field.
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Affiliation(s)
- May San Martinho
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan; Section of Thoracic Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Derek J Nancarrow
- Section of Thoracic Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Theodore S Lawrence
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - David G Beer
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan; Section of Thoracic Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Dipankar Ray
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
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6
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Ramakrishnan R, Houben B, Rousseau F, Schymkowitz J. Differential proteostatic regulation of insoluble and abundant proteins. Bioinformatics 2020; 35:4098-4107. [PMID: 30903148 PMCID: PMC6792106 DOI: 10.1093/bioinformatics/btz214] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/13/2019] [Accepted: 03/20/2019] [Indexed: 12/19/2022] Open
Abstract
Motivation Despite intense effort, it has been difficult to explain chaperone dependencies of proteins from sequence or structural properties. Results We constructed a database collecting all publicly available data of experimental chaperone interaction and dependency data for the Escherichia coli proteome, and enriched it with an extensive set of protein-specific as well as cell-context-dependent proteostatic parameters. Employing this new resource, we performed a comprehensive meta-analysis of the key determinants of chaperone interaction. Our study confirms that GroEL client proteins are biased toward insoluble proteins of low abundance, but for client proteins of the Trigger Factor/DnaK axis, we instead find that cellular parameters such as high protein abundance, translational efficiency and mRNA turnover are key determinants. We experimentally confirmed the finding that chaperone dependence is a function of translation rate and not protein-intrinsic parameters by tuning chaperone dependence of Green Fluorescent Protein (GFP) in E.coli by synonymous mutations only. The juxtaposition of both protein-intrinsic and cell-contextual chaperone triage mechanisms explains how the E.coli proteome achieves combining reliable production of abundant and conserved proteins, while also enabling the evolution of diverging metabolic functions. Availability and implementation The database will be made available via http://phdb.switchlab.org. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Reshmi Ramakrishnan
- Switch Laboratory, Center for Brain and Disease Research, VIB.,Department of Cellular and Molecular Medicine, KULeuven, Leuven Belgium
| | - Bert Houben
- Switch Laboratory, Center for Brain and Disease Research, VIB.,Department of Cellular and Molecular Medicine, KULeuven, Leuven Belgium
| | - Frederic Rousseau
- Switch Laboratory, Center for Brain and Disease Research, VIB.,Department of Cellular and Molecular Medicine, KULeuven, Leuven Belgium
| | - Joost Schymkowitz
- Switch Laboratory, Center for Brain and Disease Research, VIB.,Department of Cellular and Molecular Medicine, KULeuven, Leuven Belgium
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7
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Fan M, Rao T, Zacco E, Ahmed MT, Shukla A, Ojha A, Freeke J, Robinson CV, Benesch JL, Lund PA. The unusual mycobacterial chaperonins: evidence for in vivo oligomerization and specialization of function. Mol Microbiol 2012; 85:934-44. [PMID: 22834700 DOI: 10.1111/j.1365-2958.2012.08150.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The pathogen Mycobacterium tuberculosis expresses two chaperonins, one (Cpn60.1) dispensable and one (Cpn60.2) essential. These proteins have been reported not to form oligomers despite the fact that oligomerization of chaperonins is regarded as essential for their function. We show here that the Cpn60.2 homologue from Mycobacterium smegmatis also fails to oligomerize under standard conditions. However, we also show that the Cpn60.2 proteins from both organisms can replace the essential groEL gene of Escherichia coli, and that they can function with E. coli GroES cochaperonin, as well as with their cognate cochaperonin proteins, strongly implying that they form oligomers in vivo. We show that the Cpn60.1 proteins, but not the Cpn60.2 proteins, can complement for loss of the M. smegmatis cpn60.1 gene. We investigated the oligomerization of the Cpn60.2 proteins using analytical ultracentrifugation and mass spectroscopy. Both form monomers under standard conditions, but they form higher order oligomers in the presence of kosmotropes and ADP or ATP. Under these conditions, their ATPase activity is significantly enhanced. We conclude that the essential mycobacterial chaperonins, while unstable compared to many other bacterial chaperonins, do act as oligomers in vivo, and that there has been specialization of function of the mycobacterial chaperonins following gene duplication.
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Affiliation(s)
- MingQi Fan
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
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8
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Stefanopoulou M, Kokoschka M, Sheldrick WS, Wolters DA. Cell response of Escherichia coli
to cisplatin-induced stress. Proteomics 2011; 11:4174-88. [DOI: 10.1002/pmic.201100203] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 07/19/2011] [Accepted: 08/04/2011] [Indexed: 11/08/2022]
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9
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Sabate R, de Groot NS, Ventura S. Protein folding and aggregation in bacteria. Cell Mol Life Sci 2010; 67:2695-715. [PMID: 20358253 PMCID: PMC11115605 DOI: 10.1007/s00018-010-0344-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 02/19/2010] [Accepted: 03/05/2010] [Indexed: 01/31/2023]
Abstract
Proteins might experience many conformational changes and interactions during their lifetimes, from their synthesis at ribosomes to their controlled degradation. Because, in most cases, only folded proteins are functional, protein folding in bacteria is tightly controlled genetically, transcriptionally, and at the protein sequence level. In addition, important cellular machinery assists the folding of polypeptides to avoid misfolding and ensure the attainment of functional structures. When these redundant protective strategies are overcome, misfolded polypeptides are recruited into insoluble inclusion bodies. The protein embedded in these intracellular deposits might display different conformations including functional and beta-sheet-rich structures. The latter assemblies are similar to the amyloid fibrils characteristic of several human neurodegenerative diseases. Interestingly, bacteria exploit the same structural principles for functional properties such as adhesion or cytotoxicity. Overall, this review illustrates how prokaryotic organisms might provide the bedrock on which to understand the complexity of protein folding and aggregation in the cell.
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Affiliation(s)
- Raimon Sabate
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Natalia S. de Groot
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Salvador Ventura
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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10
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Rao T, Lund PA. Differential expression of the multiple chaperonins of Mycobacterium smegmatis. FEMS Microbiol Lett 2010; 310:24-31. [DOI: 10.1111/j.1574-6968.2010.02039.x] [Citation(s) in RCA: 22] [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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11
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Markossian KA, Golub NV, Chebotareva NA, Asryants RA, Naletova IN, Muronetz VI, Muranov KO, Kurganov BI. Comparative analysis of the effects of alpha-crystallin and GroEL on the kinetics of thermal aggregation of rabbit muscle glyceraldehyde-3-phosphate dehydrogenase. Protein J 2010; 29:11-25. [PMID: 19936900 DOI: 10.1007/s10930-009-9217-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Effects of alpha-crystallin and GroEL on the kinetics of thermal aggregation of rabbit muscle glyceraldehyde-3-phosphate dehydrogenase (GAPDH) have been studied using dynamic light scattering and analytical ultracentrifugation. The analysis of the initial parts of the dependences of the hydrodynamic radius of protein aggregates on time shows that in the presence of alpha-crystallin or GroEL the kinetic regime of GAPDH aggregation is changed from the regime of diffusion-limited cluster-cluster aggregation to the regime of reaction-limited cluster-cluster aggregation, wherein the sticking probability for the colliding particles becomes lower the unity. In contrast to alpha-crystallin, GroEL does not interfere with formation of the start aggregates which include denatured GAPDH molecules. On the basis of the analytical ultracentrifugation data the conclusion has been made that the products of dissociation of GAPDH and alpha-crystallin or GroEL play an important role in the interactions of GAPDH and chaperones at elevated temperatures.
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Affiliation(s)
- Kira A Markossian
- Bach Institute of Biochemistry, Russian Academy of Sciences, 119071, Moscow, Russia.
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12
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Kanno R, Koike-Takeshita A, Yokoyama K, Taguchi H, Mitsuoka K. Cryo-EM structure of the native GroEL-GroES complex from thermus thermophilus encapsulating substrate inside the cavity. Structure 2009; 17:287-93. [PMID: 19217399 DOI: 10.1016/j.str.2008.12.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Revised: 12/09/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
Abstract
The chaperonin GroEL interacts with various proteins, leading them to adopt their correct conformations with the aid of GroES and ATP. The actual mechanism is still being debated. In this study, by use of cryo-electron microscopy, we determined the solution structure of the Thermus thermophilus GroEL-GroES complex encapsulating its substrate proteins. We observed the averaged density of substrate proteins in the center of the GroEL-GroES cavity. The position of the averaged substrate density in the cavity suggested a repulsive interaction between a majority of the substrate proteins and the interior wall of the cavity, which is suitable for substrate release. In addition, we observed a distortion of the cis-GroEL ring, especially at the position near the substrate, which indicated that the interaction between the encapsulated proteins and the GroEL ring results in an adjustment in the cavity's shape to accommodate the substrate.
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Affiliation(s)
- Ryo Kanno
- Department of Biophysics, Faculty of Science, Kyoto University, Oiwake, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
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13
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Brackley KI, Grantham J. Activities of the chaperonin containing TCP-1 (CCT): implications for cell cycle progression and cytoskeletal organisation. Cell Stress Chaperones 2009; 14:23-31. [PMID: 18595008 PMCID: PMC2673901 DOI: 10.1007/s12192-008-0057-x] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 05/29/2008] [Indexed: 11/30/2022] Open
Abstract
The chaperonin containing TCP-1 (CCT) is required for the production of native actin and tubulin and numerous other proteins, several of which are involved in cell cycle progression. The mechanistic details of how CCT acts upon its folding substrates are intriguing: whilst actin and tubulin bind in a sequence-specific manner, it is possible that some proteins could use CCT as a more general binding interface. Therefore, how CCT accommodates the folding requirements of its substrates, some of which are produced in a cell cycle-specific manner, is of great interest. The reliance of folding substrates upon CCT for the adoption of their native structures results in CCT activity having far-reaching implications for a vast array of cellular processes. For example, the dependency of the major cytoskeletal proteins actin and tubulin upon CCT results in CCT activity being linked to any cellular process that depends on the integrity of the microfilament and microtubule-based cytoskeletal systems.
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Affiliation(s)
- Karen I. Brackley
- Department of Cell and Molecular Biology, Göteborgs Universitet, Medicinaregatan 9C, 40530 Göteborg, Sweden
| | - Julie Grantham
- Department of Cell and Molecular Biology, Göteborgs Universitet, Medicinaregatan 9C, 40530 Göteborg, Sweden
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14
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Komar AA. A pause for thought along the co-translational folding pathway. Trends Biochem Sci 2008; 34:16-24. [PMID: 18996013 DOI: 10.1016/j.tibs.2008.10.002] [Citation(s) in RCA: 250] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 10/09/2008] [Accepted: 10/13/2008] [Indexed: 11/26/2022]
Abstract
A unifying concept that combines the basic features governing self-organization of proteins into complex three-dimensional structures in vitro and in vivo is still lacking. Recent experimental results and theoretical in silico modeling studies provide evidence showing that mRNA might contain an additional layer of information, beyond the amino acid sequence, that fine-tunes in vivo protein folding, which is largely believed to start as a co-translational process. These findings indicate that translation kinetics might direct the co-translational folding pathway and that translational pausing at rare codons might provide a time delay to enable independent and sequential folding of the defined portions of the nascent polypeptide emerging from the ribosome.
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Affiliation(s)
- Anton A Komar
- Department of Biological, Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH 44115, USA.
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15
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Ellis RJ. Protein misassembly: macromolecular crowding and molecular chaperones. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 594:1-13. [PMID: 17205670 DOI: 10.1007/978-0-387-39975-1_1] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The generic tendency of proteins to misassemble into nonfunctional, and sometimes cytotoxic, structures poses a universal problem for all types of cell. This problem is exacerbated by the high total concentration of macromolecules found within most intracellular compartments but it is solved by the actions of molecular chaperones. This review discusses some of the basic evidence and key concepts relating to this conclusion.
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Affiliation(s)
- R John Ellis
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
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16
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Villebeck L, Persson M, Luan SL, Hammarström P, Lindgren M, Jonsson BH. Conformational rearrangements of tail-less complex polypeptide 1 (TCP-1) ring complex (TRiC)-bound actin. Biochemistry 2007; 46:5083-93. [PMID: 17417821 DOI: 10.1021/bi062093o] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mechanism of chaperonins is still under intense investigation. Earlier studies by others and us on the bacterial chaperonin GroEL points to an active role of chaperonins in unfolding the target protein during initial binding. Here, a natural eukaryotic chaperonin system [tail-less complex polypeptide 1 (TCP-1) ring complex (TRiC) and its target protein actin] was investigated to determine if the active participation of the chaperonin in the folding process is evolutionary-conserved. Using fluorescence resonance energy transfer (FRET) measurements on four distinct doubly fluorescein-labeled variants of actin, we have obtained a fairly detailed map of the structural rearrangements that occur during the TRiC-actin interaction. The results clearly show that TRiC has an active role in rearranging the bound actin molecule. The target is stretched as a consequence of binding to TRiC and further rearranged in a second step as a consequence of ATP binding; i.e., the mechanism of chaperonins is conserved during evolution.
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Affiliation(s)
- Laila Villebeck
- Division of Molecular Biotechnology, IFM, Linköping University, Linköping 58183, Sweden
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17
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18
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Abstract
A recent proteome analysis of protein folding inside cells of Escherichia coli predicts that only 84 of the approximately 2400 cytosolic proteins expressed in minimal media depend absolutely on the GroEL/GroES chaperone system to avoid aggregation. These proteins are enriched in alpha/beta domains and 13 are essential for growth.
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Affiliation(s)
- R John Ellis
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
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19
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Paschen SA, Waizenegger T, Stan T, Preuss M, Cyrklaff M, Hell K, Rapaport D, Neupert W. Evolutionary conservation of biogenesis of β-barrel membrane proteins. Nature 2003; 426:862-6. [PMID: 14685243 DOI: 10.1038/nature02208] [Citation(s) in RCA: 333] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2003] [Accepted: 10/30/2003] [Indexed: 11/08/2022]
Abstract
The outer membranes of mitochondria and chloroplasts are distinguished by the presence of beta-barrel membrane proteins. The outer membrane of Gram-negative bacteria also harbours beta-barrel proteins. In mitochondria these proteins fulfil a variety of functions such as transport of small molecules (porin/VDAC), translocation of proteins (Tom40) and regulation of mitochondrial morphology (Mdm10). These proteins are encoded by the nucleus, synthesized in the cytosol, targeted to mitochondria as chaperone-bound species, recognized by the translocase of the outer membrane, and then inserted into the outer membrane where they assemble into functional oligomers. Whereas some knowledge has been accumulated on the pathways of insertion of proteins that span cellular membranes with alpha-helical segments, very little is known about how beta-barrel proteins are integrated into lipid bilayers and assembled into oligomeric structures. Here we describe a protein complex that is essential for the topogenesis of mitochondrial outer membrane beta-barrel proteins (TOB). We present evidence that important elements of the topogenesis of beta-barrel membrane proteins have been conserved during the evolution of mitochondria from endosymbiotic bacterial ancestors.
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Affiliation(s)
- Stefan A Paschen
- Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5, D-81377 München, Germany
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20
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Affiliation(s)
- R John Ellis
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
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21
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Abstract
The GroEL/GroES chaperonin system acts as a passive anti-aggregation cage for refolding rubisco and rhodanese, and not as an active unfolding device. Refolding aconitase is too large to enter the cage but reversible binding to GroEL reduces its aggregration. Unexpectedly, confinement in the cage increases the rate of refolding of rubisco, but not rhodanese.
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Affiliation(s)
- R J Ellis
- Department of Biological Sciences, University of Warwick, CV4 7AL, Coventry, UK.
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22
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Abstract
The folding of most newly synthesized proteins in the cell requires the interaction of a variety of protein cofactors known as molecular chaperones. These molecules recognize and bind to nascent polypeptide chains and partially folded intermediates of proteins, preventing their aggregation and misfolding. There are several families of chaperones; those most involved in protein folding are the 40-kDa heat shock protein (HSP40; DnaJ), 60-kDa heat shock protein (HSP60; GroEL), and 70-kDa heat shock protein (HSP70; DnaK) families. The availability of high-resolution structures has facilitated a more detailed understanding of the complex chaperone machinery and mechanisms, including the ATP-dependent reaction cycles of the GroEL and HSP70 chaperones. For both of these chaperones, the binding of ATP triggers a critical conformational change leading to release of the bound substrate protein. Whereas the main role of the HSP70/HSP40 chaperone system is to minimize aggregation of newly synthesized proteins, the HSP60 chaperones also facilitate the actual folding process by providing a secluded environment for individual folding molecules and may also promote the unfolding and refolding of misfolded intermediates.
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Affiliation(s)
- A L Fink
- Department of Chemistry and Biochemistry, The University of California, Santa Cruz, California, USA
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23
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Clark AC, Frieden C. The chaperonin GroEL binds to late-folding non-native conformations present in native Escherichia coli and murine dihydrofolate reductases. J Mol Biol 1999; 285:1777-88. [PMID: 9917411 DOI: 10.1006/jmbi.1998.2403] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dihydrofolate reductases from mouse (MuDHFR) or Escherichia coli (EcDHFR) are shown to refold via several intermediate forms, each of which can bind to the chaperonin GroEL. When stable complexes with GroEL are formed, they consist of late-folding intermediates. In addition, we find that late-folding intermediates that are present in the native enzyme bind to GroEL. For the E. coli and murine proteins, the extent of protein bound increases as the temperature is increased from 8 degreesC to 42 degreesC, at which temperature either protein is completely bound as the last (EcDHFR) or the last two (MuDHFR) folding intermediate(s). Thus for EcDHFR, the binding is transient at low temperature (<30 degreesC) and stable at high temperature (>35 degreesC). For MuDHFR, complex formation appears less temperature dependent. In general, the data demonstrate that the overall binding free energy for the interaction of GroEL with native DHFR is the sum of the free energy for the first step in DHFR unfolding, which is unfavorable, and the free energy of binding the non-native conformation, which is favorable. For EcDHFR, this results in an overall binding free energy that is unfavorable below 30 degreesC. Over the temperature range of 8 degreesC to 42 degreesC, GroEL binds MuDHFR more tightly than EcDHFR, due partially to a small free energy difference between two pre-existing non-native conformations of MuDHFR, resulting in binding to more than one folding intermediate.
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Affiliation(s)
- A C Clark
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA
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24
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Persson M, Hammarström P, Lindgren M, Jonsson BH, Svensson M, Carlsson U. EPR mapping of interactions between spin-labeled variants of human carbonic anhydrase II and GroEL: evidence for increased flexibility of the hydrophobic core by the interaction. Biochemistry 1999; 38:432-41. [PMID: 9890926 DOI: 10.1021/bi981442e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human carbonic anhydrase II (HCA II) interacts weakly with GroEL at room temperature. To further investigate this interaction we used electron paramagnetic resonance (EPR) spectroscopy to study HCA II cysteine mutants spin-labeled at selected positions. From our results it is evident that protein-protein interactions can be specifically mapped by site-directed spin-labeling and EPR measurements. HCA II needs to be unfolded to about the same extent as a GuHCl-induced molten-globule intermediate of the enzyme to interact with GroEL. The interaction with GroEL includes interactions with outer parts of the HCA II molecule, such as peripheral beta-strands and the N-terminal domain, which have previously been shown to be rather unstable. As a result of the interaction, the rigid and compact hydrophobic core exhibits higher flexibility than in the molten globule, which is likely to facilitate rearrangements of misfolded structure during the folding process. The degree of binding to GroEL and accompanying inactivation of the enzyme depend on the stability of the HCA II variant, and nonspecific hydrophobic interactions appear to be most important in stabilizing the GroEL-substrate complex.
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Affiliation(s)
- M Persson
- IFM-Department of Chemistry, Linköping University, Sweden
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25
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Affiliation(s)
- A C Clark
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110-3344, USA
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26
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Symmetry in the 2.25 MDa homomultimeric phosphoenolpyruvate synthase fromStaphylothermus marinus: Analyses of negatively stained preparations. Micron 1998. [DOI: 10.1016/s0968-4328(97)00069-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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27
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Affiliation(s)
- R J Ellis
- Department of Biological Sciences, University of Warwick, Coventry, UK.
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28
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Coyle JE, Jaeger J, Gross M, Robinson CV, Radford SE. Structural and mechanistic consequences of polypeptide binding by GroEL. FOLDING & DESIGN 1998; 2:R93-104. [PMID: 9427006 DOI: 10.1016/s1359-0278(97)00046-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The remarkable ability of the chaperonin GroEL to recognise a diverse range of non-native states of proteins constitutes one of the most fascinating molecular recognition events in protein chemistry. Recent structural studies have revealed a possible model for substrate binding by GroEL and a high-resolution image of the GroEL-GroES folding machinery has provided important new insights into our understanding of the mechanism of action of this chaperonin. Studies with a variety of model substrates reveal that the binding of substrate proteins to GroEL is not just a passive event, but can result in significant changes in the structure and stability of the bound polypeptide. The potential impact of this on the mechanism of chaperonin-assisted folding is not fully understood, but provides exciting scope for further experiment.
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Affiliation(s)
- J E Coyle
- School of Biochemistry and Molecular Biology, University of Leeds, UK
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29
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Affiliation(s)
- R J Ellis
- Department of Biological Sciences, University of Warwick, Coventry, United Kingdom.
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30
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Edenhofer F, Weiss S, Winnacker EL, Famulok M. Chemie und Molekularbiologie der übertragbaren spongiformen Encephalopathien. Angew Chem Int Ed Engl 1997. [DOI: 10.1002/ange.19971091604] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Persson M, Carlsson U, Bergenhem N. GroEL provides a folding pathway with lower apparent activation energy compared to spontaneous refolding of human carbonic anhydrase II. FEBS Lett 1997; 411:43-7. [PMID: 9247139 DOI: 10.1016/s0014-5793(97)00663-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The kinetics of the refolding of the enzyme, human carbonic anhydrase II (HCA II), at different temperatures, together with the Escherichia coli chaperonin GroEL, has been studied. The Arrhenius plots for the spontaneous, GroEL-assisted, and GroEL/ES-assisted refolding of HCA II show that the apparent activation energy (E(a)) is lower in the presence of the chaperonin GroEL alone than for the spontaneous reaction, whereas the apparent activation energy for the GroEL/ES-assisted reaction is almost the same as for the spontaneous reaction (85, 46, and 72 kJ/mol, for the spontaneous, GroEL, and GroEL/ES-assisted reactions, respectively).
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Affiliation(s)
- M Persson
- IFM/Department of Chemistry, Linköping University, Sweden
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32
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Frieden C, Clark AC. Protein folding: how the mechanism of GroEL action is defined by kinetics. Proc Natl Acad Sci U S A 1997; 94:5535-8. [PMID: 9159107 PMCID: PMC20813 DOI: 10.1073/pnas.94.11.5535] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/1997] [Indexed: 02/04/2023] Open
Abstract
We propose a mechanism for the role of the bacterial chaperonin GroEL in folding proteins. The principal assumptions of the mechanism are (i) that many unfolded proteins bind to GroEL because GroEL preferentially binds small unstructured regions of the substrate protein, (ii) that substrate protein within the cavity of GroEL folds by the same kinetic mechanism and rate processes as in bulk solution, (iii) that stable or transient complexes with GroEL during the folding process are defined by a kinetic partitioning between formation and dissociation of the complex and the rate of folding and unfolding of the protein, and (iv) that dissociation from the complex in early stages of folding may lead to aggregation but dissociation at a late stage leads to correct folding. The experimental conditions for refolding may play a role in defining the function of GroEL in the folding pathway. We propose that the role of GroES and MgATP, either binding or hydrolysis, is to regulate the association and dissociation processes rather than affecting the rate of folding.
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Affiliation(s)
- C Frieden
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
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33
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Abstract
Using stopped-flow fluorescence techniques, we have examined both the refolding and unfolding reactions of four structurally homologous dihydrofolate reductases (murine DHFR, wild-type E. coli DHFR, and two E. coli DHFR mutants) in the presence and absence of the molecular chaperonin GroEL. We show that GroEL binds the unfolded conformation of each DHFR with second order rate constants greater than 3 x 10(7) M(-1)s(-1) at 22 degrees C. Once bound to GroEL, the proteins refold with rate constants similar to those for folding in the absence of GroEL. The overall rate of formation of native enzyme is decreased by the stability of the complex between GroEL and the last folding intermediate. For wild-type E. coli DHFR, complex formation is transient while for the others, a stable complex is formed. The stable complexes are the same regardless of whether they are formed from the unfolded or folded DHFR. When complex formation is initiated from the native conformation, GroEL binds to a pre-existing non-native conformation, presumably a late folding intermediate, rather than to the native state, thus shifting the conformational equilibrium toward the non-native species by mass action. The model presented here for the interaction of these four proteins with GroEL quantitatively describes the difference between the formation of a transient complex and a stable complex as defined by the rate constants for release and rebinding to GroEL relative to the rate constant for the last folding step. Due to this kinetic partitioning, three different mechanisms can be proposed for the formation of stable complexes between GroEL and either murine DHFR or the two E. coli DHFR mutants. These data show that productive folding of GroEL-bound proteins can occur in the absence of nucleotides or the co-chaperonin GroES and suggest that transient complex formation may be the functional role of GroEL under normal conditions.
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Affiliation(s)
- A C Clark
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO 63110, USA
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34
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Affiliation(s)
- G M Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA
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35
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Abstract
The folding of many newly synthesized proteins in the cell depends on a set of conserved proteins known as molecular chaperones. These prevent the formation of misfolded protein structures, both under normal conditions and when cells are exposed to stresses such as high temperature. Significant progress has been made in the understanding of the ATP-dependent mechanisms used by the Hsp70 and chaperonin families of molecular chaperones, which can cooperate to assist in folding new polypeptide chains.
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Affiliation(s)
- F U Hartl
- Howard Hughes Medical Institute, Memorial Sloan-Kettering Cancer Center, New York 10021, USA
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