51
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Allosteric landscapes of eukaryotic cytoplasmic Hsp70s are shaped by evolutionary tuning of key interfaces. Proc Natl Acad Sci U S A 2018; 115:11970-11975. [PMID: 30397123 DOI: 10.1073/pnas.1811105115] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The 70-kDa heat shock proteins (Hsp70s) are molecular chaperones that perform a wide range of critical cellular functions. They assist in the folding of newly synthesized proteins, facilitate assembly of specific protein complexes, shepherd proteins across membranes, and prevent protein misfolding and aggregation. Hsp70s perform these functions by a conserved mechanism that relies on allosteric cycles of nucleotide-modulated binding and release of client proteins. Current models for Hsp70 allostery have come from extensive study of the bacterial Hsp70, DnaK. Extending our understanding to eukaryotic Hsp70s is extremely important not only in providing a likely common mechanistic framework but also because of their central roles in cellular physiology. In this study, we examined the allosteric behaviors of the eukaryotic cytoplasmic Hsp70s, HspA1 and Hsc70, and found significant differences from that of DnaK. We found that HspA1 and Hsc70 favor a state in which the nucleotide-binding domain (NBD) and substrate-binding domain (SBD) are intimately docked significantly more as compared to DnaK. Past work established that the NBD-SBD interface and the helical lid-β-SBD interface govern the allosteric landscape of DnaK. Here, we identified sites on these interfaces that differ between eukaryotic cytoplasmic Hsp70s and DnaK. Our mutational analysis has revealed key evolutionary variations that account for the population shifts between the docked and undocked conformations. These results underline the tunability of Hsp70 functions by modulation of allosteric interfaces through evolutionary diversification and also suggest sites where the binding of small-molecule modulators could influence Hsp70 function.
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52
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Oroz J, Chang BJ, Wysoczanski P, Lee CT, Pérez-Lara Á, Chakraborty P, Hofele RV, Baker JD, Blair LJ, Biernat J, Urlaub H, Mandelkow E, Dickey CA, Zweckstetter M. Structure and pro-toxic mechanism of the human Hsp90/PPIase/Tau complex. Nat Commun 2018; 9:4532. [PMID: 30382094 PMCID: PMC6208366 DOI: 10.1038/s41467-018-06880-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/03/2018] [Indexed: 02/01/2023] Open
Abstract
The molecular chaperone Hsp90 is critical for the maintenance of cellular homeostasis and represents a promising drug target. Despite increasing knowledge on the structure of Hsp90, the molecular basis of substrate recognition and pro-folding by Hsp90/co-chaperone complexes remains unknown. Here, we report the solution structures of human full-length Hsp90 in complex with the PPIase FKBP51, as well as the 280 kDa Hsp90/FKBP51 complex bound to the Alzheimer’s disease-related protein Tau. We reveal that the FKBP51/Hsp90 complex, which synergizes to promote toxic Tau oligomers in vivo, is highly dynamic and stabilizes the extended conformation of the Hsp90 dimer resulting in decreased Hsp90 ATPase activity. Within the ternary Hsp90/FKBP51/Tau complex, Hsp90 serves as a scaffold that traps the PPIase and nucleates multiple conformations of Tau’s proline-rich region next to the PPIase catalytic pocket in a phosphorylation-dependent manner. Our study defines a conceptual model for dynamic Hsp90/co-chaperone/client recognition. The chaperone Hsp90 plays a key role in maintaining cellular homeostasis. Here the authors provide structural insights into substrate recognition and the pro-folding mechanism of Hsp90/co-chaperone complexes by studying the complex of Hsp90 with its co-chaperone FKBP51 and the substrate Tau bound Hsp90/FKBP51 ternary complex using a NMR based integrative approach.
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Affiliation(s)
- Javier Oroz
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Straße 3a, 37075, Göttingen, Germany.,Instituto de Química-Física Rocasolano, IQFR-CSIC, Serrano 119, 28006, Madrid, Spain
| | - Bliss J Chang
- Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Piotr Wysoczanski
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Straße 3a, 37075, Göttingen, Germany.,Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Chung-Tien Lee
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Ángel Pérez-Lara
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Pijush Chakraborty
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Straße 3a, 37075, Göttingen, Germany
| | - Romina V Hofele
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Jeremy D Baker
- Department of Molecular Medicine, Morsani College of Medicine, USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, 33613, USA
| | - Laura J Blair
- Department of Molecular Medicine, Morsani College of Medicine, USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, 33613, USA
| | - Jacek Biernat
- DZNE, CAESAR Research Center, Ludwig-Erhard-Alle 2, 53175, Bonn, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Eckhard Mandelkow
- DZNE, CAESAR Research Center, Ludwig-Erhard-Alle 2, 53175, Bonn, Germany
| | - Chad A Dickey
- Department of Molecular Medicine, Morsani College of Medicine, USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, 33613, USA
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Straße 3a, 37075, Göttingen, Germany. .,Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany.
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53
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Fuxreiter M. Fold or not to fold upon binding - does it really matter? Curr Opin Struct Biol 2018; 54:19-25. [PMID: 30340123 DOI: 10.1016/j.sbi.2018.09.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 12/14/2022]
Abstract
Protein interactions are usually determined by well-defined contact patterns. In this scenario, structuring of the interface is a prerequisite, which takes place prior or coupled to binding. Recent data, however, indicate plasticity of the templated folding pathway as well as considerable variations: polymorphism or dynamics in the bound-state. Conformational fluctuations in both cases are modulated by non-native, transient contacts, which complement suboptimal binding motifs to improve affinity. Here I discuss both templated folding and fuzzy binding mechanisms and propose a uniform scheme.
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Affiliation(s)
- Monika Fuxreiter
- MTA-DE Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Hungary.
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54
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Gopalan AB, Yuwen T, Kay LE, Vallurupalli P. A methyl 1H double quantum CPMG experiment to study protein conformational exchange. JOURNAL OF BIOMOLECULAR NMR 2018; 72:79-91. [PMID: 30276607 DOI: 10.1007/s10858-018-0208-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/01/2018] [Indexed: 05/24/2023]
Abstract
Protein conformational changes play crucial roles in enabling function. The Carr-Purcell-Meiboom-Gill (CPMG) experiment forms the basis for studying such dynamics when they involve the interconversion between highly populated and sparsely formed states, the latter having lifetimes ranging from ~ 0.5 to ~ 5 ms. Among the suite of experiments that have been developed are those that exploit methyl group probes by recording methyl 1H single quantum (Tugarinov and Kay in J Am Chem Soc 129:9514-9521, 2007) and triple quantum (Yuwen et al. in Angew Chem Int Ed Engl 55:11490-11494, 2016) relaxation dispersion profiles. Here we build upon these by developing a third experiment in which methyl 1H double quantum coherences evolve during a CPMG relaxation element. By fitting single, double, and triple quantum datasets, akin to recording the single quantum dataset at static magnetic fields of Bo, 2Bo and 3Bo, we show that accurate exchange values can be obtained even in cases where exchange rates exceed 10,000 s-1. The utility of the double quantum experiment is demonstrated with a pair of cavity mutants of T4 lysozyme (T4L) with ground and excited states interchanged and with exchange rates differing by fourfold (~ 900 s-1 and ~ 3600 s-1), as well as with a fast-folding domain where the unfolded state lifetime is ~ 80 µs.
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Affiliation(s)
- Anusha B Gopalan
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Tairan Yuwen
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.
| | - Pramodh Vallurupalli
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India.
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55
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Bignon C, Troilo F, Gianni S, Longhi S. Partner-Mediated Polymorphism of an Intrinsically Disordered Protein. J Mol Biol 2018; 430:2493-2507. [DOI: 10.1016/j.jmb.2017.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/16/2017] [Accepted: 11/19/2017] [Indexed: 10/18/2022]
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56
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Saio T, Kawagoe S, Ishimori K, Kalodimos CG. Oligomerization of a molecular chaperone modulates its activity. eLife 2018; 7:35731. [PMID: 29714686 PMCID: PMC5988418 DOI: 10.7554/elife.35731] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 04/30/2018] [Indexed: 11/13/2022] Open
Abstract
Molecular chaperones alter the folding properties of cellular proteins via mechanisms that are not well understood. Here, we show that Trigger Factor (TF), an ATP-independent chaperone, exerts strikingly contrasting effects on the folding of non-native proteins as it transitions between a monomeric and a dimeric state. We used NMR spectroscopy to determine the atomic resolution structure of the 100 kDa dimeric TF. The structural data show that some of the substrate-binding sites are buried in the dimeric interface, explaining the lower affinity for protein substrates of the dimeric compared to the monomeric TF. Surprisingly, the dimeric TF associates faster with proteins and it exhibits stronger anti-aggregation and holdase activity than the monomeric TF. The structural data show that the dimer assembles in a way that substrate-binding sites in the two subunits form a large contiguous surface inside a cavity, thus accounting for the observed accelerated association with unfolded proteins. Our results demonstrate how the activity of a chaperone can be modulated to provide distinct functional outcomes in the cell.
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Affiliation(s)
- Tomohide Saio
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan.,Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Soichiro Kawagoe
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Koichiro Ishimori
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan.,Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Charalampos G Kalodimos
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, United States
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57
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Morán Luengo T, Kityk R, Mayer MP, Rüdiger SGD. Hsp90 Breaks the Deadlock of the Hsp70 Chaperone System. Mol Cell 2018; 70:545-552.e9. [PMID: 29706537 DOI: 10.1016/j.molcel.2018.03.028] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/17/2018] [Accepted: 03/23/2018] [Indexed: 10/17/2022]
Abstract
Protein folding in the cell requires ATP-driven chaperone machines such as the conserved Hsp70 and Hsp90. It is enigmatic how these machines fold proteins. Here, we show that Hsp90 takes a key role in protein folding by breaking an Hsp70-inflicted folding block, empowering protein clients to fold on their own. At physiological concentrations, Hsp70 stalls productive folding by binding hydrophobic, core-forming segments. Hsp90 breaks this deadlock and restarts folding. Remarkably, neither Hsp70 nor Hsp90 alters the folding rate despite ensuring high folding yields. In fact, ATP-dependent chaperoning is restricted to the early folding phase. Thus, the Hsp70-Hsp90 cascade does not fold proteins, but instead prepares them for spontaneous, productive folding. This stop-start mechanism is conserved from bacteria to man, assigning also a general function to bacterial Hsp90, HtpG. We speculate that the decreasing hydrophobicity along the Hsp70-Hsp90 cascade may be crucial for enabling spontaneous folding.
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Affiliation(s)
- Tania Morán Luengo
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands; Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Roman Kityk
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
| | - Stefan G D Rüdiger
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands; Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
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58
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He L, Hiller S. Common Patterns in Chaperone Interactions with a Native Client Protein. Angew Chem Int Ed Engl 2018; 57:5921-5924. [PMID: 29498447 DOI: 10.1002/anie.201713064] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/31/2018] [Indexed: 11/08/2022]
Abstract
Many molecular chaperones are promiscuous and interact with a wide range of unfolded, quasi-native, and native client proteins. The mechanisms by which chaperones interact with the highly diverse structures of native clients thus remain puzzling. In this work, we investigate at the atomic level how three ATP-independent chaperones interact with a β-sheet-rich protein, the Fyn SH3 domain. The results reveal that the chaperone Spy recognizes the locally frustrated surface of the client Fyn SH3 and that the interaction is transient and highly dynamic, leaving the chaperone-interacting surface on Fyn SH3 solvent accessible. The two alternative molecular chaperones SurA and Skp recognize the same locally frustrated surface of the Fyn SH3 domain. These results indicate dynamic recognition of frustrated segments as a common mechanism underlying the chaperone-native client interaction, which also provides a basis for chaperone promiscuousness.
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Affiliation(s)
- Lichun He
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056, Basel, Switzerland
| | - Sebastian Hiller
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056, Basel, Switzerland
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59
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He L, Hiller S. Übereinstimmende Muster in Chaperon-Interaktionen mit einem nativen Klientenprotein. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201713064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lichun He
- Biozentrum; University of Basel; Klingelbergstraße 70 4056 Basel Schweiz
| | - Sebastian Hiller
- Biozentrum; University of Basel; Klingelbergstraße 70 4056 Basel Schweiz
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60
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Hiller S, Burmann BM. Chaperone-client complexes: A dynamic liaison. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 289:142-155. [PMID: 29544626 DOI: 10.1016/j.jmr.2017.12.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/08/2017] [Accepted: 12/10/2017] [Indexed: 06/08/2023]
Abstract
Living cells contain molecular chaperones that are organized in intricate networks to surveil protein homeostasis by avoiding polypeptide misfolding, aggregation, and the generation of toxic species. In addition, cellular chaperones also fulfill a multitude of alternative functionalities: transport of clients towards a target location, help them fold, unfold misfolded species, resolve aggregates, or deliver clients towards proteolysis machineries. Until recently, the only available source of atomic resolution information for virtually all chaperones were crystal structures of their client-free, apo-forms. These structures were unable to explain details of the functional mechanisms underlying chaperone-client interactions. The difficulties to crystallize chaperones in complexes with clients arise from their highly dynamic nature, making solution NMR spectroscopy the method of choice for their study. With the advent of advanced solution NMR techniques, in the past few years a substantial number of structural and functional studies on chaperone-client complexes have been resolved, allowing unique insight into the chaperone-client interaction. This review summarizes the recent insights provided by advanced high-resolution NMR-spectroscopy to understand chaperone-client interaction mechanisms at the atomic scale.
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Affiliation(s)
- Sebastian Hiller
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Björn M Burmann
- Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, University for Gothenburg, 405 30 Göteborg, Sweden.
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61
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Gopalan AB, Vallurupalli P. Measuring the signs of the methyl 1H chemical shift differences between major and 'invisible' minor protein conformational states using methyl 1H multi-quantum spectroscopy. JOURNAL OF BIOMOLECULAR NMR 2018; 70:187-202. [PMID: 29564579 DOI: 10.1007/s10858-018-0171-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 02/21/2018] [Indexed: 06/08/2023]
Abstract
Carr-Purcell-Meiboom-Gill (CPMG) type relaxation dispersion experiments are now routinely used to characterise protein conformational dynamics that occurs on the μs to millisecond (ms) timescale between a visible major state and 'invisible' minor states. The exchange rate(s) ([Formula: see text]), population(s) of the minor state(s) and the absolute value of the chemical shift difference [Formula: see text] (ppm) between different exchanging states can be extracted from the CPMG data. However the sign of [Formula: see text] that is required to reconstruct the spectrum of the 'invisible' minor state(s) cannot be obtained from CPMG data alone. Building upon the recently developed triple quantum (TQ) methyl [Formula: see text] CPMG experiment (Yuwen in Angew Chem 55:11490-11494, 2016) we have developed pulse sequences that use carbon detection to generate and evolve single quantum (SQ), double quantum (DQ) and TQ coherences from methyl protons in the indirect dimension to measure the chemical exchange-induced shifts of the SQ, DQ and TQ coherences from which the sign of [Formula: see text] is readily obtained for two state exchange. Further a combined analysis of the CPMG data and the difference in exchange induced shifts between the SQ and DQ resonances and between the SQ and TQ resonances improves the estimates of exchange parameters like the population of the minor state. We demonstrate the use of these experiments on two proteins undergoing exchange: (1) the ~ 18 kDa cavity mutant of T4 Lysozyme ([Formula: see text]) and (2) the [Formula: see text] kDa Peripheral Sub-unit Binding Domain (PSBD) from the acetyl transferase of Bacillus stearothermophilus ([Formula: see text]).
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Affiliation(s)
- Anusha B Gopalan
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Pramodh Vallurupalli
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal Ranga Reddy District, Hyderabad, Telangana, 500107, India.
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62
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Fuxreiter M. Fuzziness in Protein Interactions-A Historical Perspective. J Mol Biol 2018; 430:2278-2287. [PMID: 29477337 DOI: 10.1016/j.jmb.2018.02.015] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/09/2018] [Accepted: 02/16/2018] [Indexed: 12/22/2022]
Abstract
The proposal that coupled folding to binding is not an obligatory mechanism for intrinsically disordered (ID) proteins was put forward 10 years ago. The notion of fuzziness implies that conformational heterogeneity can be maintained upon interactions of ID proteins, which has a functional impact either on regulated assembly or activity of the corresponding complexes. Here I review how the concept has evolved in the past decade, via increasing experimental data providing insights into the mechanisms, pathways and regulatory modes. The effects of structural diversity and transient contacts on protein assemblies have been collected and systematically analyzed (Fuzzy Complexes Database, http://protdyn-database.org). Fuzziness has also been exploited as a framework to decipher molecular organization of higher-order protein structures. Quantification of conformational heterogeneity opens exciting future perspectives for drug discovery from small molecule-ID protein interactions to supramolecular assemblies.
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Affiliation(s)
- Monika Fuxreiter
- MTA-DE Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary.
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63
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Sekhar A, Velyvis A, Zoltsman G, Rosenzweig R, Bouvignies G, Kay LE. Conserved conformational selection mechanism of Hsp70 chaperone-substrate interactions. eLife 2018; 7:32764. [PMID: 29460778 PMCID: PMC5819949 DOI: 10.7554/elife.32764] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/27/2017] [Indexed: 12/17/2022] Open
Abstract
Molecular recognition is integral to biological function and frequently involves preferred binding of a molecule to one of several exchanging ligand conformations in solution. In such a process the bound structure can be selected from the ensemble of interconverting ligands a priori (conformational selection, CS) or may form once the ligand is bound (induced fit, IF). Here we focus on the ubiquitous and conserved Hsp70 chaperone which oversees the integrity of the cellular proteome through its ATP-dependent interaction with client proteins. We directly quantify the flux along CS and IF pathways using solution NMR spectroscopy that exploits a methyl TROSY effect and selective isotope-labeling methodologies. Our measurements establish that both bacterial and human Hsp70 chaperones interact with clients by selecting the unfolded state from a pre-existing array of interconverting structures, suggesting a conserved mode of client recognition among Hsp70s and highlighting the importance of molecular dynamics in this recognition event. Proteins are the workhorses of a cell and are involved in almost all biological processes. Newly made proteins need to ‘fold’ into precise three-dimensional shapes in order to carry out their roles. However, proteins sometimes fold incorrectly or unfold. These protein forms are not able to work effectively and in some cases may even cause diseases. Chaperone proteins help other proteins to fold correctly and are found in living organisms ranging in complexity from bacteria to humans. There are many different types of chaperones that play different roles inside cells. One, called Hsp70, binds to proteins that are incorrectly folded to help them to mature into their correct structures. However, it was not clear whether Hsp70 can also associate with the mature, correctly folded form of the proteins. A technique called Nuclear Magnetic Resonance (NMR) spectroscopy can distinguish between mature, unfolded and chaperone-bound forms of the same protein. Sekhar et al. therefore used NMR to investigate which forms of a protein Hsp70 binds to. This revealed that both the bacterial and human versions of the Hsp70 chaperone interact only with unfolded proteins. The results presented by Sekhar et al. also explain why Hsp70 does not disrupt the routine workings of the cell: because it does not bind to mature forms of proteins. These observations extend our understanding of how chaperones assist in folding proteins, and fit into a broader research theme exploring how proteins recognize one another. It will now be interesting to see whether the same mechanism holds for more complex forms of proteins, such as aggregates, or larger protein structures with regions of both folded and unfolded elements.
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Affiliation(s)
- Ashok Sekhar
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Algirdas Velyvis
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Guy Zoltsman
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Rina Rosenzweig
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada.,Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Guillaume Bouvignies
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Univ. Paris 06, CNRS, PSL Research University, Paris, France.,Sorbonne Universités, UPMC Univ. Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules, Paris, France
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada.,Hospital for Sick Children, Program in Molecular Medicine, University Avenue, Toronto, Canada
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64
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Sekhar A, Nagesh J, Rosenzweig R, Kay LE. Conformational heterogeneity in the Hsp70 chaperone-substrate ensemble identified from analysis of NMR-detected titration data. Protein Sci 2017; 26:2207-2220. [PMID: 28833766 DOI: 10.1002/pro.3276] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/17/2017] [Indexed: 01/06/2023]
Abstract
The Hsp70 chaperone system plays a critical role in cellular homeostasis by binding to client protein molecules. We have recently shown by methyl-TROSY NMR methods that the Escherichia coli Hsp70, DnaK, can form multiple bound complexes with a small client protein, hTRF1. In an effort to characterize the interactions further we report here the results of an NMR-based titration study of hTRF1 and DnaK, where both molecular components are monitored simultaneously, leading to a binding model. A central finding is the formation of a previously undetected 3:1 hTRF1-DnaK complex, suggesting that under heat shock conditions, DnaK might be able to protect cytosolic proteins whose net concentrations would exceed that of the chaperone. Moreover, these results provide new insight into the heterogeneous ensemble of complexes formed by DnaK chaperones and further emphasize the unique role of NMR spectroscopy in obtaining information about individual events in a complex binding scheme by exploiting a large number of probes that report uniquely on distinct binding processes.
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Affiliation(s)
- Ashok Sekhar
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Jayashree Nagesh
- Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Rina Rosenzweig
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Program in Molecular Medicine, 555 University Avenue, Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
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Wruck F, Avellaneda MJ, Koers EJ, Minde DP, Mayer MP, Kramer G, Mashaghi A, Tans SJ. Protein Folding Mediated by Trigger Factor and Hsp70: New Insights from Single-Molecule Approaches. J Mol Biol 2017; 430:438-449. [PMID: 28911846 DOI: 10.1016/j.jmb.2017.09.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/26/2017] [Accepted: 09/04/2017] [Indexed: 01/01/2023]
Abstract
Chaperones assist in protein folding, but what this common phrase means in concrete terms has remained surprisingly poorly understood. We can readily measure chaperone binding to unfolded proteins, but how they bind and affect proteins along folding trajectories has remained obscure. Here we review recent efforts by our labs and others that are beginning to pry into this issue, with a focus on the chaperones trigger factor and Hsp70. Single-molecule methods are central, as they allow the stepwise process of folding to be followed directly. First results have already revealed contrasts with long-standing paradigms: rather than acting only "early" by stabilizing unfolded chain segments, these chaperones can bind and stabilize partially folded structures as they grow to their native state. The findings suggest a fundamental redefinition of the protein folding problem and a more extensive functional repertoire of chaperones than previously assumed.
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Affiliation(s)
- Florian Wruck
- AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands
| | | | - Eline J Koers
- AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands
| | - David P Minde
- AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Alireza Mashaghi
- Leiden Academic Centre for Drug Research, Faculty of Mathematics and Natural Sciences, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands
| | - Sander J Tans
- AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands.
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