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Wanninger S, Asadiatouei P, Bohlen J, Salem CB, Tinnefeld P, Ploetz E, Lamb DC. Deep-LASI: deep-learning assisted, single-molecule imaging analysis of multi-color DNA origami structures. Nat Commun 2023; 14:6564. [PMID: 37848439 PMCID: PMC10582187 DOI: 10.1038/s41467-023-42272-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 10/05/2023] [Indexed: 10/19/2023] Open
Abstract
Single-molecule experiments have changed the way we explore the physical world, yet data analysis remains time-consuming and prone to human bias. Here, we introduce Deep-LASI (Deep-Learning Assisted Single-molecule Imaging analysis), a software suite powered by deep neural networks to rapidly analyze single-, two- and three-color single-molecule data, especially from single-molecule Förster Resonance Energy Transfer (smFRET) experiments. Deep-LASI automatically sorts recorded traces, determines FRET correction factors and classifies the state transitions of dynamic traces all in ~20-100 ms per trajectory. We benchmarked Deep-LASI using ground truth simulations as well as experimental data analyzed manually by an expert user and compared the results with a conventional Hidden Markov Model analysis. We illustrate the capabilities of the technique using a highly tunable L-shaped DNA origami structure and use Deep-LASI to perform titrations, analyze protein conformational dynamics and demonstrate its versatility for analyzing both total internal reflection fluorescence microscopy and confocal smFRET data.
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Affiliation(s)
- Simon Wanninger
- Department of Chemistry and Center for NanoScience (CeNS) Ludwig-Maximilians-Universität München Butenandtstr. 5-13, 81377, Munich, Germany
| | - Pooyeh Asadiatouei
- Department of Chemistry and Center for NanoScience (CeNS) Ludwig-Maximilians-Universität München Butenandtstr. 5-13, 81377, Munich, Germany
| | - Johann Bohlen
- Department of Chemistry and Center for NanoScience (CeNS) Ludwig-Maximilians-Universität München Butenandtstr. 5-13, 81377, Munich, Germany
| | - Clemens-Bässem Salem
- Department of Chemistry and Center for NanoScience (CeNS) Ludwig-Maximilians-Universität München Butenandtstr. 5-13, 81377, Munich, Germany
| | - Philip Tinnefeld
- Department of Chemistry and Center for NanoScience (CeNS) Ludwig-Maximilians-Universität München Butenandtstr. 5-13, 81377, Munich, Germany
| | - Evelyn Ploetz
- Department of Chemistry and Center for NanoScience (CeNS) Ludwig-Maximilians-Universität München Butenandtstr. 5-13, 81377, Munich, Germany.
| | - Don C Lamb
- Department of Chemistry and Center for NanoScience (CeNS) Ludwig-Maximilians-Universität München Butenandtstr. 5-13, 81377, Munich, Germany.
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2
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Song J, Steidle L, Steymans I, Singh J, Sanner A, Böttinger L, Winter D, Becker T. The mitochondrial Hsp70 controls the assembly of the F 1F O-ATP synthase. Nat Commun 2023; 14:39. [PMID: 36596815 PMCID: PMC9810599 DOI: 10.1038/s41467-022-35720-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 12/20/2022] [Indexed: 01/04/2023] Open
Abstract
The mitochondrial F1FO-ATP synthase produces the bulk of cellular ATP. The soluble F1 domain contains the catalytic head that is linked via the central stalk and the peripheral stalk to the membrane embedded rotor of the FO domain. The assembly of the F1 domain and its linkage to the peripheral stalk is poorly understood. Here we show a dual function of the mitochondrial Hsp70 (mtHsp70) in the formation of the ATP synthase. First, it cooperates with the assembly factors Atp11 and Atp12 to form the F1 domain of the ATP synthase. Second, the chaperone transfers Atp5 into the assembly line to link the catalytic head with the peripheral stalk. Inactivation of mtHsp70 leads to integration of assembly-defective Atp5 variants into the mature complex, reflecting a quality control function of the chaperone. Thus, mtHsp70 acts as an assembly and quality control factor in the biogenesis of the F1FO-ATP synthase.
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Affiliation(s)
- Jiyao Song
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany.,Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Liesa Steidle
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Isabelle Steymans
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Jasjot Singh
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Anne Sanner
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Lena Böttinger
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dominic Winter
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Thomas Becker
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany.
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3
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Marszalek J, Craig EA, Tomiczek B. J-Domain Proteins Orchestrate the Multifunctionality of Hsp70s in Mitochondria: Insights from Mechanistic and Evolutionary Analyses. Subcell Biochem 2023; 101:293-318. [PMID: 36520311 DOI: 10.1007/978-3-031-14740-1_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Mitochondrial J-domain protein (JDP) co-chaperones orchestrate the function of their Hsp70 chaperone partner(s) in critical organellar processes that are essential for cell function. These include folding, refolding, and import of mitochondrial proteins, maintenance of mitochondrial DNA, and biogenesis of iron-sulfur cluster(s) (FeS), prosthetic groups needed for function of mitochondrial and cytosolic proteins. Consistent with the organelle's endosymbiotic origin, mitochondrial Hsp70 and the JDPs' functioning in protein folding and FeS biogenesis clearly descended from bacteria, while the origin of the JDP involved in protein import is less evident. Regardless of their origin, all mitochondrial JDP/Hsp70 systems evolved unique features that allowed them to perform mitochondria-specific functions. Their modes of functional diversification and specialization illustrate the versatility of JDP/Hsp70 systems and inform our understanding of system functioning in other cellular compartments.
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Affiliation(s)
- Jaroslaw Marszalek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland.
| | - Elizabeth A Craig
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Bartlomiej Tomiczek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
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Conformational dynamics of the Hsp70 chaperone throughout key steps of its ATPase cycle. Proc Natl Acad Sci U S A 2022; 119:e2123238119. [PMID: 36409905 PMCID: PMC9889847 DOI: 10.1073/pnas.2123238119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The 70 kDa heat shock proteins (Hsp70s) are highly versatile molecular chaperones that assist in a wide variety of protein-folding processes. They exert their functions by continuously cycling between states of low and high affinity for client polypeptides, driven by ATP-binding and hydrolysis. This cycling is tuned by cochaperones and clients. Although structures for the high and low client affinity conformations of Hsp70 and Hsp70 domains in complex with various cochaperones and peptide clients are available, it is unclear how structural rearrangements in the presence of cochaperones and clients are orchestrated in space and time. Here, we report insights into the conformational dynamics of the prokaryotic model Hsp70 DnaK throughout its adenosine-5'-triphosphate hydrolysis (ATPase) cycle using proximity-induced fluorescence quenching. Our data suggest that ATP and cochaperone-induced structural rearrangements in DnaK occur in a sequential manner and resolve hitherto unpredicted cochaperone and client-induced structural rearrangements. Peptides induce large conformational changes in DnaK·ATP prior to ATP hydrolysis, whereas a protein client induces significantly smaller changes but is much more effective in stimulating ATP hydrolysis. Analysis of the enthalpies of activation for the ATP-induced opening of the DnaK lid in the presence of clients indicates that the lid does not exert an enthalpic pulling force onto bound clients, suggesting entropic pulling as a major mechanism for client unfolding. Our data reveal important insights into the mechanics, allostery, and dynamics of Hsp70 chaperones. We established a methodology for understanding the link between dynamics and function, Hsp70 diversity, and activity modulation.
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5
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Kim H, Moon S, Ham S, Lee K, Römling U, Lee C. Cytoplasmic molecular chaperones in Pseudomonas species. J Microbiol 2022; 60:1049-1060. [PMID: 36318358 DOI: 10.1007/s12275-022-2425-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/20/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Pseudomonas is widespread in various environmental and host niches. To promote rejuvenation, cellular protein homeostasis must be finely tuned in response to diverse stresses, such as extremely high and low temperatures, oxidative stress, and desiccation, which can result in protein homeostasis imbalance. Molecular chaperones function as key components that aid protein folding and prevent protein denaturation. Pseudomonas, an ecologically important bacterial genus, includes human and plant pathogens as well as growth-promoting symbionts and species useful for bioremediation. In this review, we focus on protein quality control systems, particularly molecular chaperones, in ecologically diverse species of Pseudomonas, including the opportunistic human pathogen Pseudomonas aeruginosa, the plant pathogen Pseudomonas syringae, the soil species Pseudomonas putida, and the psychrophilic Pseudomonas antarctica.
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Affiliation(s)
- Hyunhee Kim
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Seongjoon Moon
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Soojeong Ham
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Kihyun Lee
- CJ Bioscience, Seoul, 04527, Republic of Korea
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Changhan Lee
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea.
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6
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Zhao F, Zou MH. Role of the Mitochondrial Protein Import Machinery and Protein Processing in Heart Disease. Front Cardiovasc Med 2021; 8:749756. [PMID: 34651031 PMCID: PMC8505727 DOI: 10.3389/fcvm.2021.749756] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondria are essential organelles for cellular energy production, metabolic homeostasis, calcium homeostasis, cell proliferation, and apoptosis. About 99% of mammalian mitochondrial proteins are encoded by the nuclear genome, synthesized as precursors in the cytosol, and imported into mitochondria by mitochondrial protein import machinery. Mitochondrial protein import systems function not only as independent units for protein translocation, but also are deeply integrated into a functional network of mitochondrial bioenergetics, protein quality control, mitochondrial dynamics and morphology, and interaction with other organelles. Mitochondrial protein import deficiency is linked to various diseases, including cardiovascular disease. In this review, we describe an emerging class of protein or genetic variations of components of the mitochondrial import machinery involved in heart disease. The major protein import pathways, including the presequence pathway (TIM23 pathway), the carrier pathway (TIM22 pathway), and the mitochondrial intermembrane space import and assembly machinery, related translocases, proteinases, and chaperones, are discussed here. This review highlights the importance of mitochondrial import machinery in heart disease, which deserves considerable attention, and further studies are urgently needed. Ultimately, this knowledge may be critical for the development of therapeutic strategies in heart disease.
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Affiliation(s)
- Fujie Zhao
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
| | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
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7
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Schneider MM, Gautam S, Herling TW, Andrzejewska E, Krainer G, Miller AM, Trinkaus VA, Peter QAE, Ruggeri FS, Vendruscolo M, Bracher A, Dobson CM, Hartl FU, Knowles TPJ. The Hsc70 disaggregation machinery removes monomer units directly from α-synuclein fibril ends. Nat Commun 2021; 12:5999. [PMID: 34650037 PMCID: PMC8516981 DOI: 10.1038/s41467-021-25966-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 08/25/2021] [Indexed: 02/02/2023] Open
Abstract
Molecular chaperones contribute to the maintenance of cellular protein homoeostasis through assisting de novo protein folding and preventing amyloid formation. Chaperones of the Hsp70 family can further disaggregate otherwise irreversible aggregate species such as α-synuclein fibrils, which accumulate in Parkinson's disease. However, the mechanisms and kinetics of this key functionality are only partially understood. Here, we combine microfluidic measurements with chemical kinetics to study α-synuclein disaggregation. We show that Hsc70 together with its co-chaperones DnaJB1 and Apg2 can completely reverse α-synuclein aggregation back to its soluble monomeric state. This reaction proceeds through first-order kinetics where monomer units are removed directly from the fibril ends with little contribution from intermediate fibril fragmentation steps. These findings extend our mechanistic understanding of the role of chaperones in the suppression of amyloid proliferation and in aggregate clearance, and inform on possibilities and limitations of this strategy in the development of therapeutics against synucleinopathies.
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Affiliation(s)
- Matthias M. Schneider
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Saurabh Gautam
- grid.418615.f0000 0004 0491 845XDepartment of Cellular Biochemistry, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany ,Present Address: ViraTherapeutics GmbH, 6063 Rum, Austria
| | - Therese W. Herling
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Ewa Andrzejewska
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Georg Krainer
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Alyssa M. Miller
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Victoria A. Trinkaus
- grid.418615.f0000 0004 0491 845XDepartment of Cellular Biochemistry, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany ,grid.452617.3Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Quentin A. E. Peter
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Francesco Simone Ruggeri
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Michele Vendruscolo
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Andreas Bracher
- grid.418615.f0000 0004 0491 845XDepartment of Cellular Biochemistry, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Christopher M. Dobson
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - F. Ulrich Hartl
- grid.418615.f0000 0004 0491 845XDepartment of Cellular Biochemistry, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany ,grid.452617.3Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Tuomas P. J. Knowles
- grid.5335.00000000121885934Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK ,grid.5335.00000000121885934Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Road, Cambridge, CB3 0HE UK
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8
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Comparative analysis of the coordinated motion of Hsp70s from different organelles observed by single-molecule three-color FRET. Proc Natl Acad Sci U S A 2021; 118:2025578118. [PMID: 34389669 DOI: 10.1073/pnas.2025578118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Cellular function depends on the correct folding of proteins inside the cell. Heat-shock proteins 70 (Hsp70s), being among the first molecular chaperones binding to nascently translated proteins, aid in protein folding and transport. They undergo large, coordinated intra- and interdomain structural rearrangements mediated by allosteric interactions. Here, we applied a three-color single-molecule Förster resonance energy transfer (FRET) combined with three-color photon distribution analysis to compare the conformational cycle of the Hsp70 chaperones DnaK, Ssc1, and BiP. By capturing three distances simultaneously, we can identify coordinated structural changes during the functional cycle. Besides the known conformations of the Hsp70s with docked domains and open lid and undocked domains with closed lid, we observed additional intermediate conformations and distance broadening, suggesting flexibility of the Hsp70s in adopting the states in a coordinated fashion. Interestingly, the difference of this distance broadening varied between DnaK, Ssc1, and BiP. Study of their conformational cycle in the presence of substrate peptide and nucleotide exchange factors strengthened the observation of additional conformational intermediates, with BiP showing coordinated changes more clearly compared to DnaK and Ssc1. Additionally, DnaK and BiP were found to differ in their selectivity for nucleotide analogs, suggesting variability in the recognition mechanism of their nucleotide-binding domains for the different nucleotides. By using three-color FRET, we overcome the limitations of the usual single-distance approach in single-molecule FRET, allowing us to characterize the conformational space of proteins in higher detail.
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9
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Biddle JW, Gunawardena J. Reversal symmetries for cyclic paths away from thermodynamic equilibrium. Phys Rev E 2020; 101:062125. [PMID: 32688527 DOI: 10.1103/physreve.101.062125] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 04/21/2020] [Indexed: 11/07/2022]
Abstract
If a system is at thermodynamic equilibrium, an observer cannot tell whether a film of it is being played forward or in reverse: any transition will occur with the same frequency in the forward as in the reverse direction. However, if expenditure of energy changes the rate of even a single transition to yield a nonequilibrium steady state, such time-reversal symmetry undergoes a widespread breakdown, far beyond the point at which the energy is expended. An explosion of interdependency also arises, with steady-state probabilities of system states depending in a complicated manner on the rate of every transition in the system. Nevertheless, in the midst of this global nonequilibrium complexity, we find that cyclic paths have reversibility properties that remain local, and which can exhibit symmetry, no matter how far the system is from thermodynamic equilibrium. Specifically, given any cycle of reversible transitions, the ratio of the frequencies with which the cycle occurs in one direction versus the other is determined, in the long-time limit, only by the thermodynamic force on the cycle itself, without requiring knowledge of transition rates elsewhere in the system. In particular, if there is no net energy expenditure on the cycle, then, over long times, the cycle occurrence frequencies are the same in either direction.
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Affiliation(s)
- John W Biddle
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States
| | - Jeremy Gunawardena
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States
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10
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Tomiczek B, Delewski W, Nierzwicki L, Stolarska M, Grochowina I, Schilke B, Dutkiewicz R, Uzarska MA, Ciesielski SJ, Czub J, Craig EA, Marszalek J. Two-step mechanism of J-domain action in driving Hsp70 function. PLoS Comput Biol 2020; 16:e1007913. [PMID: 32479549 PMCID: PMC7289447 DOI: 10.1371/journal.pcbi.1007913] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 06/11/2020] [Accepted: 04/28/2020] [Indexed: 12/02/2022] Open
Abstract
J-domain proteins (JDPs), obligatory Hsp70 cochaperones, play critical roles in protein homeostasis. They promote key allosteric transitions that stabilize Hsp70 interaction with substrate polypeptides upon hydrolysis of its bound ATP. Although a recent crystal structure revealed the physical mode of interaction between a J-domain and an Hsp70, the structural and dynamic consequences of J-domain action once bound and how Hsp70s discriminate among its multiple JDP partners remain enigmatic. We combined free energy simulations, biochemical assays and evolutionary analyses to address these issues. Our results indicate that the invariant aspartate of the J-domain perturbs a conserved intramolecular Hsp70 network of contacts that crosses domains. This perturbation leads to destabilization of the domain-domain interface—thereby promoting the allosteric transition that triggers ATP hydrolysis. While this mechanistic step is driven by conserved residues, evolutionarily variable residues are key to initial JDP/Hsp70 recognition—via electrostatic interactions between oppositely charged surfaces. We speculate that these variable residues allow an Hsp70 to discriminate amongst JDP partners, as many of them have coevolved. Together, our data points to a two-step mode of J-domain action, a recognition stage followed by a mechanistic stage. It is well appreciated that Hsp70-based systems are the most versatile among molecular chaperones—functioning in all cell types and in all subcellular compartments. Via cyclic binding to protein substrates, Hsp70s facilitate their folding, trafficking, degradation and ability to interact with other proteins. Hsp70 function, however, depends on transient interaction with J-domain protein cochaperones that not only deliver substrates, but also activate the structural changes needed for efficient Hsp70 binding to substrate. But how J-domain proteins mechanistically function to drive these changes and how an Hsp70 discriminates among multiple J-domain partners have remained challenging central questions. Here, by using a combination of computational, evolutionary and experimental approaches, we provide evidence for a two-step mechanism. The initial recognition step involves variable residues that allow fine tuning of both the specificity and strength of J-domain protein interaction with Hsp70. The second, that is the mechanistic step, involves conserved residues that act to disrupt a conserved network of intramolecular interactions within Hsp70, thus ensuring robust activation of the structural changes necessary for effective substrate binding. We suggest that our findings are likely applicable to most Hsp70 systems.
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Affiliation(s)
- Bartlomiej Tomiczek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Wojciech Delewski
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Lukasz Nierzwicki
- Department of Physical Chemistry, Gdansk University of Technology, Gdansk, Poland
| | - Milena Stolarska
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Igor Grochowina
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Brenda Schilke
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Rafal Dutkiewicz
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Marta A. Uzarska
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Szymon J. Ciesielski
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jacek Czub
- Department of Physical Chemistry, Gdansk University of Technology, Gdansk, Poland
- * E-mail: (JC); (EAC); (JM)
| | - Elizabeth A. Craig
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail: (JC); (EAC); (JM)
| | - Jaroslaw Marszalek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail: (JC); (EAC); (JM)
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11
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How to get to the other side of the mitochondrial inner membrane – the protein import motor. Biol Chem 2020; 401:723-736. [DOI: 10.1515/hsz-2020-0106] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/25/2020] [Indexed: 12/13/2022]
Abstract
AbstractBiogenesis of mitochondria relies on import of more than 1000 different proteins from the cytosol. Approximately 70% of these proteins follow the presequence pathway – they are synthesized with cleavable N-terminal extensions called presequences and reach the final place of their function within the organelle with the help of the TOM and TIM23 complexes in the outer and inner membranes, respectively. The translocation of proteins along the presequence pathway is powered by the import motor of the TIM23 complex. The import motor of the TIM23 complex is localized at the matrix face of the inner membrane and is likely the most complicated Hsp70-based system identified to date. How it converts the energy of ATP hydrolysis into unidirectional translocation of proteins into mitochondria remains one of the biggest mysteries of this translocation pathway. Here, the knowns and the unknowns of the mitochondrial protein import motor are discussed.
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12
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Kinetics of the conformational cycle of Hsp70 reveals the importance of the dynamic and heterogeneous nature of Hsp70 for its function. Proc Natl Acad Sci U S A 2020; 117:7814-7823. [PMID: 32198203 PMCID: PMC7148561 DOI: 10.1073/pnas.1914376117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Heat shock protein 70 kDa (Hsp70) plays a central role in maintaining protein homeostasis. It cooperates with cochaperone Hsp40, which stimulates Hsp70 ATPase activity and presents protein substrates to Hsp70 to assist refolding. The mechanism by which Hsp40 regulates the intramolecular and intermolecular changes of Hsp70 is still largely unknown. Here, by bulk and single-molecule FRET, we report the conformational dynamics of Hsp70 and its regulation by Hsp40 as well as the kinetics of the multistep Hsp70–Hsp40 functional cycle. We show that Hsp40 modulates the conformations of ATP-bound Hsp70 to a domain-undocked ATPase-stimulated state, and facilitates the formation of a heterotetrameric Hsp70–Hsp40 complex. Our findings provide insights into the functional mechanism of this core chaperone machinery. Hsp70 is a conserved molecular chaperone that plays an indispensable role in regulating protein folding, translocation, and degradation. The conformational dynamics of Hsp70 and its regulation by cochaperones are vital to its function. Using bulk and single-molecule fluorescence resonance energy transfer (smFRET) techniques, we studied the interdomain conformational distribution of human stress-inducible Hsp70A1 and the kinetics of conformational changes induced by nucleotide and the Hsp40 cochaperone Hdj1. We found that the conformations between and within the nucleotide- and substrate-binding domains show heterogeneity. The conformational distribution in the ATP-bound state can be induced by Hdj1 to form an “ADP-like” undocked conformation, which is an ATPase-stimulated state. Kinetic measurements indicate that Hdj1 binds to monomeric Hsp70 as the first step, then induces undocking of the two domains and closing of the substrate-binding cleft. Dimeric Hdj1 then facilitates dimerization of Hsp70 and formation of a heterotetrameric Hsp70–Hsp40 complex. Our results provide a kinetic view of the conformational cycle of Hsp70 and reveal the importance of the dynamic nature of Hsp70 for its function.
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13
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Pfanner N, Warscheid B, Wiedemann N. Mitochondrial proteins: from biogenesis to functional networks. Nat Rev Mol Cell Biol 2020; 20:267-284. [PMID: 30626975 DOI: 10.1038/s41580-018-0092-0] [Citation(s) in RCA: 508] [Impact Index Per Article: 127.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mitochondria are essential for the viability of eukaryotic cells as they perform crucial functions in bioenergetics, metabolism and signalling and have been associated with numerous diseases. Recent functional and proteomic studies have revealed the remarkable complexity of mitochondrial protein organization. Protein machineries with diverse functions such as protein translocation, respiration, metabolite transport, protein quality control and the control of membrane architecture interact with each other in dynamic networks. In this Review, we discuss the emerging role of the mitochondrial protein import machinery as a key organizer of these mitochondrial protein networks. The preprotein translocases that reside on the mitochondrial membranes not only function during organelle biogenesis to deliver newly synthesized proteins to their final mitochondrial destination but also cooperate with numerous other mitochondrial protein complexes that perform a wide range of functions. Moreover, these protein networks form membrane contact sites, for example, with the endoplasmic reticulum, that are key for integration of mitochondria with cellular function, and defects in protein import can lead to diseases.
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Affiliation(s)
- Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany. .,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
| | - Bettina Warscheid
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,Institute of Biology II, Biochemistry - Functional Proteomics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany. .,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
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14
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Imamoglu R, Balchin D, Hayer-Hartl M, Hartl FU. Bacterial Hsp70 resolves misfolded states and accelerates productive folding of a multi-domain protein. Nat Commun 2020; 11:365. [PMID: 31953415 PMCID: PMC6969021 DOI: 10.1038/s41467-019-14245-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 12/17/2019] [Indexed: 11/09/2022] Open
Abstract
The ATP-dependent Hsp70 chaperones (DnaK in E. coli) mediate protein folding in cooperation with J proteins and nucleotide exchange factors (E. coli DnaJ and GrpE, respectively). The Hsp70 system prevents protein aggregation and increases folding yields. Whether it also enhances the rate of folding remains unclear. Here we show that DnaK/DnaJ/GrpE accelerate the folding of the multi-domain protein firefly luciferase (FLuc) ~20-fold over the rate of spontaneous folding measured in the absence of aggregation. Analysis by single-pair FRET and hydrogen/deuterium exchange identified inter-domain misfolding as the cause of slow folding. DnaK binding expands the misfolded region and thereby resolves the kinetically-trapped intermediates, with folding occurring upon GrpE-mediated release. In each round of release DnaK commits a fraction of FLuc to fast folding, circumventing misfolding. We suggest that by resolving misfolding and accelerating productive folding, the bacterial Hsp70 system can maintain proteins in their native states under otherwise denaturing stress conditions.
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Affiliation(s)
- Rahmi Imamoglu
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, Martinsried, Germany
| | - David Balchin
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, Martinsried, Germany.
| | - Manajit Hayer-Hartl
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, Martinsried, Germany.
| | - F Ulrich Hartl
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, Martinsried, Germany.
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15
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Velasco L, Dublang L, Moro F, Muga A. The Complex Phosphorylation Patterns that Regulate the Activity of Hsp70 and Its Cochaperones. Int J Mol Sci 2019; 20:ijms20174122. [PMID: 31450862 PMCID: PMC6747476 DOI: 10.3390/ijms20174122] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 12/26/2022] Open
Abstract
Proteins must fold into their native structure and maintain it during their lifespan to display the desired activity. To ensure proper folding and stability, and avoid generation of misfolded conformations that can be potentially cytotoxic, cells synthesize a wide variety of molecular chaperones that assist folding of other proteins and avoid their aggregation, which unfortunately is unavoidable under acute stress conditions. A protein machinery in metazoa, composed of representatives of the Hsp70, Hsp40, and Hsp110 chaperone families, can reactivate protein aggregates. We revised herein the phosphorylation sites found so far in members of these chaperone families and the functional consequences associated with some of them. We also discuss how phosphorylation might regulate the chaperone activity and the interaction of human Hsp70 with its accessory and client proteins. Finally, we present the information that would be necessary to decrypt the effect that post-translational modifications, and especially phosphorylation, could have on the biological activity of the Hsp70 system, known as the “chaperone code”.
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Affiliation(s)
- Lorea Velasco
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain
| | - Leire Dublang
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain
| | - Fernando Moro
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
| | - Arturo Muga
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
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16
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Barth A, Voith von Voithenberg L, Lamb DC. Quantitative Single-Molecule Three-Color Förster Resonance Energy Transfer by Photon Distribution Analysis. J Phys Chem B 2019; 123:6901-6916. [PMID: 31117611 DOI: 10.1021/acs.jpcb.9b02967] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Single-molecule Förster resonance energy transfer (FRET) is a powerful tool to study conformational dynamics of biomolecules. Using solution-based single-pair FRET by burst analysis, conformational heterogeneities and fluctuations of fluorescently labeled proteins or nucleic acids can be studied by monitoring a single distance at a time. Three-color FRET is sensitive to three distances simultaneously and can thus elucidate complex coordinated motions within single molecules. While three-color FRET has been applied on the single-molecule level before, a detailed quantitative description of the obtained FRET efficiency distributions is still missing. Direct interpretation of three-color FRET data is additionally complicated by an increased shot noise contribution when converting photon counts to FRET efficiencies. However, to address the question of coordinated motion, it is of special interest to extract information about the underlying distance heterogeneity, which is not easily extracted from the FRET efficiency histograms directly. Here, we present three-color photon distribution analysis (3C-PDA), a method to extract distributions of interdye distances from three-color FRET measurements. We present a model for diffusion-based three-color FRET experiments and apply Bayesian inference to extract information about the physically relevant distance heterogeneity in the sample. The approach is verified using simulated data sets and experimentally applied to triple-labeled DNA duplexes. Finally, three-color FRET experiments on the Hsp70 chaperone BiP reveal conformational coordinated changes between individual domains. The possibility to address the co-occurrence of intramolecular distances makes 3C-PDA a powerful method to study the coordination of domain motions within biomolecules undergoing conformational dynamics.
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Affiliation(s)
- Anders Barth
- Department of Chemistry, Center for Integrated Protein Science Munich, Nanosystems Initiative Munich and Center for Nanoscience , Ludwig-Maximilians-Universität München , Butenandtstr. 5-13 , 81377 Munich , Germany
| | - Lena Voith von Voithenberg
- Department of Chemistry, Center for Integrated Protein Science Munich, Nanosystems Initiative Munich and Center for Nanoscience , Ludwig-Maximilians-Universität München , Butenandtstr. 5-13 , 81377 Munich , Germany
| | - Don C Lamb
- Department of Chemistry, Center for Integrated Protein Science Munich, Nanosystems Initiative Munich and Center for Nanoscience , Ludwig-Maximilians-Universität München , Butenandtstr. 5-13 , 81377 Munich , Germany
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17
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Dahiya V, Buchner J. Functional principles and regulation of molecular chaperones. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 114:1-60. [PMID: 30635079 DOI: 10.1016/bs.apcsb.2018.10.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To be able to perform their biological function, a protein needs to be correctly folded into its three dimensional structure. The protein folding process is spontaneous and does not require the input of energy. However, in the crowded cellular environment where there is high risk of inter-molecular interactions that may lead to protein molecules sticking to each other, hence forming aggregates, protein folding is assisted. Cells have evolved robust machinery called molecular chaperones to deal with the protein folding problem and to maintain proteins in their functional state. Molecular chaperones promote efficient folding of newly synthesized proteins, prevent their aggregation and ensure protein homeostasis in cells. There are different classes of molecular chaperones functioning in a complex interplay. In this review, we discuss the principal characteristics of different classes of molecular chaperones, their structure-function relationships, their mode of regulation and their involvement in human disorders.
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Affiliation(s)
- Vinay Dahiya
- Center for Integrated Protein Science Munich CIPSM at the Department Chemie, Technische Universität München, Garching, Germany
| | - Johannes Buchner
- Center for Integrated Protein Science Munich CIPSM at the Department Chemie, Technische Universität München, Garching, Germany.
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18
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Genest O, Wickner S, Doyle SM. Hsp90 and Hsp70 chaperones: Collaborators in protein remodeling. J Biol Chem 2018; 294:2109-2120. [PMID: 30401745 DOI: 10.1074/jbc.rev118.002806] [Citation(s) in RCA: 180] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Heat shock proteins 90 (Hsp90) and 70 (Hsp70) are two families of highly conserved ATP-dependent molecular chaperones that fold and remodel proteins. Both are important components of the cellular machinery involved in protein homeostasis and participate in nearly every cellular process. Although Hsp90 and Hsp70 each carry out some chaperone activities independently, they collaborate in other cellular remodeling reactions. In eukaryotes, both Hsp90 and Hsp70 function with numerous Hsp90 and Hsp70 co-chaperones. In contrast, bacterial Hsp90 and Hsp70 are less complex; Hsp90 acts independently of co-chaperones, and Hsp70 uses two co-chaperones. In this review, we focus on recent progress toward understanding the basic mechanisms of Hsp90-mediated protein remodeling and the collaboration between Hsp90 and Hsp70, with an emphasis on bacterial chaperones. We describe the structure and conformational dynamics of these chaperones and their interactions with each other and with client proteins. The physiological roles of Hsp90 in Escherichia coli and other bacteria are also discussed. We anticipate that the information gained from exploring the mechanism of the bacterial chaperone system will provide the groundwork for understanding the more complex eukaryotic Hsp90 system and its modulation by Hsp90 co-chaperones.
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Affiliation(s)
- Olivier Genest
- From the Aix Marseille Univ, CNRS, Laboratoire de Bioénergétique et Ingénierie des Protéines, 13402 Marseille, France and
| | - Sue Wickner
- the Laboratory of Molecular Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Shannon M Doyle
- the Laboratory of Molecular Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892
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19
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Johnston CL, Marzano NR, van Oijen AM, Ecroyd H. Using Single-Molecule Approaches to Understand the Molecular Mechanisms of Heat-Shock Protein Chaperone Function. J Mol Biol 2018; 430:4525-4546. [PMID: 29787765 DOI: 10.1016/j.jmb.2018.05.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/11/2018] [Accepted: 05/13/2018] [Indexed: 02/01/2023]
Abstract
The heat-shock proteins (Hsp) are a family of molecular chaperones, which collectively form a network that is critical for the maintenance of protein homeostasis. Traditional ensemble-based measurements have provided a wealth of knowledge on the function of individual Hsps and the Hsp network; however, such techniques are limited in their ability to resolve the heterogeneous, dynamic and transient interactions that molecular chaperones make with their client proteins. Single-molecule techniques have emerged as a powerful tool to study dynamic biological systems, as they enable rare and transient populations to be identified that would usually be masked in ensemble measurements. Thus, single-molecule techniques are particularly amenable for the study of Hsps and have begun to be used to reveal novel mechanistic details of their function. In this review, we discuss the current understanding of the chaperone action of Hsps and how gaps in the field can be addressed using single-molecule methods. Specifically, this review focuses on the ATP-independent small Hsps and the broader Hsp network and describes how these dynamic systems are amenable to single-molecule techniques.
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Affiliation(s)
- Caitlin L Johnston
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Nicholas R Marzano
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Antoine M van Oijen
- School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
| | - Heath Ecroyd
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
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20
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Voith von Voithenberg L, Lamb DC. Single Pair Förster Resonance Energy Transfer: A Versatile Tool To Investigate Protein Conformational Dynamics. Bioessays 2018; 40. [DOI: 10.1002/bies.201700078] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 12/05/2017] [Indexed: 01/23/2023]
Affiliation(s)
- Lena Voith von Voithenberg
- Department Chemie; Center for Nanoscience (CeNS); Center for Integrated Protein Science Munich (CIPSM); Nanosystem Initiative Munich (NIM); Ludwig-Maximilians-Universität München; Butenandtstr. 5-13 81377 München Germany
- BIOSS Centre for Signalling Studies; Schänzlestr. 18 79104 Freiburg Germany
| | - Don C. Lamb
- Department Chemie; Center for Nanoscience (CeNS); Center for Integrated Protein Science Munich (CIPSM); Nanosystem Initiative Munich (NIM); Ludwig-Maximilians-Universität München; Butenandtstr. 5-13 81377 München Germany
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21
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Wieteska L, Shahidi S, Zhuravleva A. Allosteric fine-tuning of the conformational equilibrium poises the chaperone BiP for post-translational regulation. eLife 2017; 6:29430. [PMID: 29064369 PMCID: PMC5655141 DOI: 10.7554/elife.29430] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/01/2017] [Indexed: 12/12/2022] Open
Abstract
BiP is the only Hsp70 chaperone in the endoplasmic reticulum (ER) and similar to other Hsp70s, its activity relies on nucleotide- and substrate-controllable docking and undocking of its nucleotide-binding domain (NBD) and substrate-binding domain (SBD). However, little is known of specific features of the BiP conformational landscape that tune BiP to its unique tasks and the ER environment. We present methyl NMR analysis of the BiP chaperone cycle that reveals surprising conformational heterogeneity of ATP-bound BiP that distinguishes BiP from its bacterial homologue DnaK. This unusual poise enables gradual post-translational regulation of the BiP chaperone cycle and its chaperone activity by subtle local perturbations at SBD allosteric 'hotspots'. In particular, BiP inactivation by AMPylation of its SBD does not disturb Hsp70 inter-domain allostery and preserves BiP structure. Instead it relies on a redistribution of the BiP conformational ensemble and stabilization the domain-docked conformation in presence of ADP and ATP.
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Affiliation(s)
- Lukasz Wieteska
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Saeid Shahidi
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.,Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Anastasia Zhuravleva
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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22
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Sánchez-Rico C, Voith von Voithenberg L, Warner L, Lamb DC, Sattler M. Effects of Fluorophore Attachment on Protein Conformation and Dynamics Studied by spFRET and NMR Spectroscopy. Chemistry 2017; 23:14267-14277. [PMID: 28799205 DOI: 10.1002/chem.201702423] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Indexed: 12/28/2022]
Abstract
Fluorescence-based techniques are widely used to study biomolecular conformations, intra- and intermolecular interactions, and conformational dynamics of macromolecules. Especially for fluorescence-based single-molecule experiments, the choice of the fluorophore and labeling position are highly important. In this work, we studied the biophysical and structural effects that are associated with the conjugation of fluorophores to cysteines in the splicing factor U2AF65 by using single pair Förster resonance energy transfer (FRET) and nuclear magnetic resonance (NMR) spectroscopy. It is shown that certain acceptor fluorophores are advantageous depending on the experiments performed. The effects of dye attachment on the protein conformation were characterized using heteronuclear NMR experiments. The presence of hydrophobic and aromatic moieties in the fluorophores can significantly affect the conformation of the conjugated protein, presumably by transient interactions with the protein surface. Guidelines are provided for carefully choosing fluorophores, considering their photophysical properties and chemical features for the design of FRET experiments, and for minimizing artifacts.
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Affiliation(s)
- Carolina Sánchez-Rico
- Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.,Biomolecular NMR and Center for Integrated Protein Science Munich at Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85747, Garching, Germany
| | - Lena Voith von Voithenberg
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science, Nanosystems Initiative Munich and Centre for Nanoscience, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Lisa Warner
- Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.,Biomolecular NMR and Center for Integrated Protein Science Munich at Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85747, Garching, Germany
| | - Don C Lamb
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science, Nanosystems Initiative Munich and Centre for Nanoscience, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.,Biomolecular NMR and Center for Integrated Protein Science Munich at Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85747, Garching, Germany
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23
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Penkler D, Sensoy Ö, Atilgan C, Tastan Bishop Ö. Perturbation-Response Scanning Reveals Key Residues for Allosteric Control in Hsp70. J Chem Inf Model 2017; 57:1359-1374. [PMID: 28505454 DOI: 10.1021/acs.jcim.6b00775] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hsp70 molecular chaperones play an important role in maintaining cellular homeostasis, and are implicated in a wide array of cellular processes, including protein recovery from aggregates, cross-membrane protein translocation, and protein biogenesis. Hsp70 consists of two domains, a nucleotide binding domain (NBD) and a substrate binding domain (SBD), each of which communicates via an allosteric mechanism such that the protein interconverts between two functional states, an ATP-bound open conformation and an ADP-bound closed conformation. The exact mechanism for interstate conversion is not as yet fully understood. However, the ligand-bound states of the NBD and SBD as well as interactions with cochaperones such as DnaJ and nucleotide exchange factor are thought to play crucial regulatory roles. In this study, we apply the perturbation-response scanning (PRS) method in combination with molecular dynamics simulations as a computational tool for the identification of allosteric hot residues in the large multidomain Hsp70 protein. We find evidence in support of the hypothesis that substrate binding triggers ATP hydrolysis and that the ADP-substrate complex favors interstate conversion to the closed state. Furthermore, our data are in agreement with the proposal that there is an allosterically active intermediate state between the open and closed states and vice versa, as we find evidence that ATP binding to the closed structure and peptide binding to the open structure allosterically "activate" the respective complexes. We conclude our analysis by showing how our PRS data fit the current opinion on the Hsp70 conformational cycle and present several allosteric hot residues that may provide a platform for further studies to gain additional insight into Hsp70 allostery.
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Affiliation(s)
- David Penkler
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University , Grahamstown 6140, South Africa
| | - Özge Sensoy
- School of Engineering and Natural Sciences, Istanbul Medipol University , Beykoz 34810, Istanbul, Turkey
| | - Canan Atilgan
- Faculty of Engineering and Natural Sciences, Sabanci University , Tuzla 34956, Istanbul, Turkey
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University , Grahamstown 6140, South Africa
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24
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Lai AL, Clerico EM, Blackburn ME, Patel NA, Robinson CV, Borbat PP, Freed JH, Gierasch LM. Key features of an Hsp70 chaperone allosteric landscape revealed by ion-mobility native mass spectrometry and double electron-electron resonance. J Biol Chem 2017; 292:8773-8785. [PMID: 28428246 PMCID: PMC5448104 DOI: 10.1074/jbc.m116.770404] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 04/12/2017] [Indexed: 11/06/2022] Open
Abstract
Proteins are dynamic entities that populate conformational ensembles, and most functions of proteins depend on their dynamic character. Allostery, in particular, relies on ligand-modulated shifts in these conformational ensembles. Hsp70s are allosteric molecular chaperones with conformational landscapes that involve large rearrangements of their two domains (viz. the nucleotide-binding domain and substrate-binding domain) in response to adenine nucleotides and substrates. However, it remains unclear how the Hsp70 conformational ensemble is populated at each point of the allosteric cycle and how ligands control these populations. We have mapped the conformational species present under different ligand-binding conditions throughout the allosteric cycle of the Escherichia coli Hsp70 DnaK by two complementary methods, ion-mobility mass spectrometry and double electron-electron resonance. Our results obtained under biologically relevant ligand-bound conditions confirm the current picture derived from NMR and crystallographic data of domain docking upon ATP binding and undocking in response to ADP and substrate. Additionally, we find that the helical lid of DnaK is a highly dynamic unit of the structure in all ligand-bound states. Importantly, we demonstrate that DnaK populates a partially docked state in the presence of ATP and substrate and that this state represents an energy minimum on the DnaK allosteric landscape. Because Hsp70s are emerging as potential drug targets for many diseases, fully mapping an allosteric landscape of a molecular chaperone like DnaK will facilitate the development of small molecules that modulate Hsp70 function via allosteric mechanisms.
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Affiliation(s)
- Alex L Lai
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-2703
| | | | - Mandy E Blackburn
- the School of Environmental, Physical, and Applied Sciences, University of Central Missouri, Warrensburg, Missouri 64093, and
| | - Nisha A Patel
- the Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Carol V Robinson
- the Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Peter P Borbat
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-2703
| | - Jack H Freed
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-2703
| | - Lila M Gierasch
- the Departments of Biochemistry and Molecular Biology and .,Chemistry, University of Massachusetts, Amherst, Massachusetts 01003
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25
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Sundaramoorthy R, Hughes AL, Singh V, Wiechens N, Ryan DP, El-Mkami H, Petoukhov M, Svergun DI, Treutlein B, Quack S, Fischer M, Michaelis J, Böttcher B, Norman DG, Owen-Hughes T. Structural reorganization of the chromatin remodeling enzyme Chd1 upon engagement with nucleosomes. eLife 2017; 6. [PMID: 28332978 PMCID: PMC5391205 DOI: 10.7554/elife.22510] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/15/2017] [Indexed: 12/11/2022] Open
Abstract
The yeast Chd1 protein acts to position nucleosomes across genomes. Here, we model the structure of the Chd1 protein in solution and when bound to nucleosomes. In the apo state, the DNA-binding domain contacts the edge of the nucleosome while in the presence of the non-hydrolyzable ATP analog, ADP-beryllium fluoride, we observe additional interactions between the ATPase domain and the adjacent DNA gyre 1.5 helical turns from the dyad axis of symmetry. Binding in this conformation involves unravelling the outer turn of nucleosomal DNA and requires substantial reorientation of the DNA-binding domain with respect to the ATPase domains. The orientation of the DNA-binding domain is mediated by sequences in the N-terminus and mutations to this part of the protein have positive and negative effects on Chd1 activity. These observations indicate that the unfavorable alignment of C-terminal DNA-binding region in solution contributes to an auto-inhibited state. DOI:http://dx.doi.org/10.7554/eLife.22510.001
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Affiliation(s)
| | - Amanda L Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Vijender Singh
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Nicola Wiechens
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Daniel P Ryan
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Hassane El-Mkami
- School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
| | - Maxim Petoukhov
- Hamburg Outstation, European Molecular Biology Laboratory, Hamburg, Germany
| | - Dmitri I Svergun
- Hamburg Outstation, European Molecular Biology Laboratory, Hamburg, Germany
| | - Barbara Treutlein
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Salina Quack
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Monika Fischer
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Jens Michaelis
- Institute for Biophysics, Faculty of Natural Sciences, Ulm University, Ulm, Germany
| | - Bettina Böttcher
- Lehrstuhl für Biochemie, Rudolf-Virchow Zentrum, Universitat Würzburg, Würzburg, Germany
| | - David G Norman
- Nucleic Acids Structure Research Group, University of Dundee, Dundee, United Kingdom
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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26
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Stetz G, Verkhivker GM. Computational Analysis of Residue Interaction Networks and Coevolutionary Relationships in the Hsp70 Chaperones: A Community-Hopping Model of Allosteric Regulation and Communication. PLoS Comput Biol 2017; 13:e1005299. [PMID: 28095400 PMCID: PMC5240922 DOI: 10.1371/journal.pcbi.1005299] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 12/06/2016] [Indexed: 12/28/2022] Open
Abstract
Allosteric interactions in the Hsp70 proteins are linked with their regulatory mechanisms and cellular functions. Despite significant progress in structural and functional characterization of the Hsp70 proteins fundamental questions concerning modularity of the allosteric interaction networks and hierarchy of signaling pathways in the Hsp70 chaperones remained largely unexplored and poorly understood. In this work, we proposed an integrated computational strategy that combined atomistic and coarse-grained simulations with coevolutionary analysis and network modeling of the residue interactions. A novel aspect of this work is the incorporation of dynamic residue correlations and coevolutionary residue dependencies in the construction of allosteric interaction networks and signaling pathways. We found that functional sites involved in allosteric regulation of Hsp70 may be characterized by structural stability, proximity to global hinge centers and local structural environment that is enriched by highly coevolving flexible residues. These specific characteristics may be necessary for regulation of allosteric structural transitions and could distinguish regulatory sites from nonfunctional conserved residues. The observed confluence of dynamics correlations and coevolutionary residue couplings with global networking features may determine modular organization of allosteric interactions and dictate localization of key mediating sites. Community analysis of the residue interaction networks revealed that concerted rearrangements of local interacting modules at the inter-domain interface may be responsible for global structural changes and a population shift in the DnaK chaperone. The inter-domain communities in the Hsp70 structures harbor the majority of regulatory residues involved in allosteric signaling, suggesting that these sites could be integral to the network organization and coordination of structural changes. Using a network-based formalism of allostery, we introduced a community-hopping model of allosteric communication. Atomistic reconstruction of signaling pathways in the DnaK structures captured a direction-specific mechanism and molecular details of signal transmission that are fully consistent with the mutagenesis experiments. The results of our study reconciled structural and functional experiments from a network-centric perspective by showing that global properties of the residue interaction networks and coevolutionary signatures may be linked with specificity and diversity of allosteric regulation mechanisms. The diversity of allosteric mechanisms in the Hsp70 proteins could range from modulation of the inter-domain interactions and conformational dynamics to fine-tuning of the Hsp70 interactions with co-chaperones. The goal of this study is to present a systematic computational analysis of the dynamic and evolutionary factors underlying allosteric structural transformations of the Hsp70 proteins. We investigated the relationship between functional dynamics, residue coevolution, and network organization of residue interactions in the Hsp70 proteins. The results of this study revealed that conformational dynamics of the Hsp70 proteins may be linked with coevolutionary propensities and mutual information dependencies of the protein residues. Modularity and connectivity of allosteric interactions in the Hsp70 chaperones are coordinated by stable functional sites that feature unique coevolutionary signatures and high network centrality. The emergence of the inter-domain communities that are coordinated by functional centers and include highly coevolving residues could facilitate structural transitions through cooperative reorganization of the local interacting modules. We determined that the differences in the modularity of the residue interactions and organization of coevolutionary networks in DnaK may be associated with variations in their allosteric mechanisms. The network signatures of the DnaK structures are characteristic of a population-shift allostery that allows for coordinated structural rearrangements of local communities. A dislocation of mediating centers and insufficient coevolutionary coupling between functional regions may render a reduced cooperativity and promote a limited entropy-driven allostery in the Sse1 chaperone that occurs without structural changes. The results of this study showed that a network-centric framework and a community-hopping model of allosteric communication pathways may provide novel insights into molecular and evolutionary principles of allosteric regulation in the Hsp70 proteins.
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Affiliation(s)
- Gabrielle Stetz
- Graduate Program in Computational and Data Sciences, Schmid College of Science and Technology, Chapman University, Orange, California, United States of America
| | - Gennady M. Verkhivker
- Graduate Program in Computational and Data Sciences, Schmid College of Science and Technology, Chapman University, Orange, California, United States of America
- Chapman University School of Pharmacy, Irvine, California, United States of America
- * E-mail:
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Nicolaï A, Barakat F, Delarue P, Senet P. Fingerprints of Conformational States of Human Hsp70 at Sub-THz Frequencies. ACS OMEGA 2016; 1:1067-1074. [PMID: 30023501 PMCID: PMC6044683 DOI: 10.1021/acsomega.6b00157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 10/25/2016] [Indexed: 06/08/2023]
Abstract
Large multidomain proteins occur in different conformational states to function. Detection and monitoring of these different structural states are of crucial interest for understanding the mechanics of proteins. Using computational methods, we show that different protein conformational states of the two-domain 70 kDa human Heat-shock protein (hHsp70), with similar vibrational density of states, lead to remarkably different far-IR spectra at acoustical frequencies (ν < 300 GHz). We found that the slow damped motions of the positively charged residues of hHsp70 contribute the most to collective IR active modes at low frequencies (ν < 300 GHz). We predicted that different structural states and functional modes of large proteins, such as hHsp70, might be detected in the sub-THz frequency range by single-molecule spectroscopy similar to the recent extraordinary acoustic Raman spectroscopy (Wheaton S.; Nat. Photonics2015, 9, 68-72).
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Recognition of the 3' splice site RNA by the U2AF heterodimer involves a dynamic population shift. Proc Natl Acad Sci U S A 2016; 113:E7169-E7175. [PMID: 27799531 DOI: 10.1073/pnas.1605873113] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An essential early step in the assembly of human spliceosomes onto pre-mRNA involves the recognition of regulatory RNA cis elements in the 3' splice site by the U2 auxiliary factor (U2AF). The large (U2AF65) and small (U2AF35) subunits of the U2AF heterodimer contact the polypyrimidine tract (Py-tract) and the AG-dinucleotide, respectively. The tandem RNA recognition motif domains (RRM1,2) of U2AF65 adopt closed/inactive and open/active conformations in the free form and when bound to bona fide Py-tract RNA ligands. To investigate the molecular mechanism and dynamics of 3' splice site recognition by U2AF65 and the role of U2AF35 in the U2AF heterodimer, we have combined single-pair FRET and NMR experiments. In the absence of RNA, the RRM1,2 domain arrangement is highly dynamic on a submillisecond time scale, switching between closed and open conformations. The addition of Py-tract RNA ligands with increasing binding affinity (strength) gradually shifts the equilibrium toward an open conformation. Notably, the protein-RNA complex is rigid in the presence of a strong Py-tract but exhibits internal motion with weak Py-tracts. Surprisingly, the presence of U2AF35, whose UHM domain interacts with U2AF65 RRM1, increases the population of the open arrangement of U2AF65 RRM1,2 in the absence and presence of a weak Py-tract. These data indicate that the U2AF heterodimer promotes spliceosome assembly by a dynamic population shift toward the open conformation of U2AF65 to facilitate the recognition of weak Py-tracts at the 3' splice site. The structure and RNA binding of the heterodimer was unaffected by cancer-linked myelodysplastic syndrome mutants.
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29
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Alternative modes of client binding enable functional plasticity of Hsp70. Nature 2016; 539:448-451. [PMID: 27783598 DOI: 10.1038/nature20137] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/04/2016] [Indexed: 01/01/2023]
Abstract
The Hsp70 system is a central hub of chaperone activity in all domains of life. Hsp70 performs a plethora of tasks, including folding assistance, protection against aggregation, protein trafficking, and enzyme activity regulation, and interacts with non-folded chains, as well as near-native, misfolded, and aggregated proteins. Hsp70 is thought to achieve its many physiological roles by binding peptide segments that extend from these different protein conformers within a groove that can be covered by an ATP-driven helical lid. However, it has been difficult to test directly how Hsp70 interacts with protein substrates in different stages of folding and how it affects their structure. Moreover, recent indications of diverse lid conformations in Hsp70-substrate complexes raise the possibility of additional interaction mechanisms. Addressing these issues is technically challenging, given the conformational dynamics of both chaperone and client, the transient nature of their interaction, and the involvement of co-chaperones and the ATP hydrolysis cycle. Here, using optical tweezers, we show that the bacterial Hsp70 homologue (DnaK) binds and stabilizes not only extended peptide segments, but also partially folded and near-native protein structures. The Hsp70 lid and groove act synergistically when stabilizing folded structures: stabilization is abolished when the lid is truncated and less efficient when the groove is mutated. The diversity of binding modes has important consequences: Hsp70 can both stabilize and destabilize folded structures, in a nucleotide-regulated manner; like Hsp90 and GroEL, Hsp70 can affect the late stages of protein folding; and Hsp70 can suppress aggregation by protecting partially folded structures as well as unfolded protein chains. Overall, these findings in the DnaK system indicate an extension of the Hsp70 canonical model that potentially affects a wide range of physiological roles of the Hsp70 system.
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30
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Stetz G, Verkhivker GM. Probing Allosteric Inhibition Mechanisms of the Hsp70 Chaperone Proteins Using Molecular Dynamics Simulations and Analysis of the Residue Interaction Networks. J Chem Inf Model 2016; 56:1490-517. [DOI: 10.1021/acs.jcim.5b00755] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Gabrielle Stetz
- Graduate
Program in Computational and Data Sciences, Department of Computational
Sciences, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, California 92866, United States
| | - Gennady M. Verkhivker
- Graduate
Program in Computational and Data Sciences, Department of Computational
Sciences, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, California 92866, United States
- Chapman University School of Pharmacy, Irvine, California 92618, United States
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31
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Banerjee R, Jayaraj GG, Peter JJ, Kumar V, Mapa K. Monitoring conformational heterogeneity of the lid of DnaK substrate-binding domain during its chaperone cycle. FEBS J 2016; 283:2853-68. [PMID: 27248857 DOI: 10.1111/febs.13769] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 03/04/2016] [Accepted: 05/31/2016] [Indexed: 11/29/2022]
Abstract
DnaK or Hsp70 of Escherichia coli is a master regulator of the bacterial proteostasis network. Allosteric communication between the two functional domains of DnaK, the N-terminal nucleotide-binding domain (NBD) and the C-terminal substrate- or peptide-binding domain (SBD) regulate its activity. X-ray crystallography and NMR studies have provided snapshots of distinct conformations of Hsp70 proteins in various physiological states; however, the conformational heterogeneity and dynamics of allostery-driven Hsp70 activity remains underexplored. In this work, we employed single-molecule Förster resonance energy transfer (sm-FRET) measurements to capture distinct intradomain conformational states of a region within the DnaK-SBD known as the lid. Our data conclusively demonstrate prominent conformational heterogeneity of the DnaK lid in ADP-bound states; in contrast, the ATP-bound open conformations are homogeneous. Interestingly, a nonhydrolysable ATP analogue, AMP-PNP, imparts heterogeneity to the lid conformations mimicking the ADP-bound state. The cochaperone DnaJ confers ADP-like heterogeneous lid conformations to DnaK, although the presence of the cochaperone accelerates the substrate-binding rate by a hitherto unknown mechanism. Irrespective of the presence of DnaJ, binding of a peptide substrate to the DnaK-SBD leads to prominent lid closure. Lid closure is only partial upon binding to molten globule-like authentic cellular substrates, probably to accommodate non-native substrate proteins of varied structures.
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Affiliation(s)
- Rupa Banerjee
- Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Gopal Gunanathan Jayaraj
- Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSir), CSIR-CRRI, New Delhi, India
| | - Joshua Jebakumar Peter
- Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Vignesh Kumar
- Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSir), CSIR-CRRI, New Delhi, India
| | - Koyeli Mapa
- Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSir), CSIR-CRRI, New Delhi, India.,Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Greater Noida, India
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32
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Balchin D, Hayer-Hartl M, Hartl FU. In vivo aspects of protein folding and quality control. Science 2016; 353:aac4354. [DOI: 10.1126/science.aac4354] [Citation(s) in RCA: 832] [Impact Index Per Article: 104.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Most proteins must fold into unique three-dimensional structures to perform their biological functions. In the crowded cellular environment, newly synthesized proteins are at risk of misfolding and forming toxic aggregate species. To ensure efficient folding, different classes of molecular chaperones receive the nascent protein chain emerging from the ribosome and guide it along a productive folding pathway. Because proteins are structurally dynamic, constant surveillance of the proteome by an integrated network of chaperones and protein degradation machineries is required to maintain protein homeostasis (proteostasis). The capacity of this proteostasis network declines during aging, facilitating neurodegeneration and other chronic diseases associated with protein aggregation. Understanding the proteostasis network holds the promise of identifying targets for pharmacological intervention in these pathologies.
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33
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Alderson TR, Kim JH, Markley JL. Dynamical Structures of Hsp70 and Hsp70-Hsp40 Complexes. Structure 2016; 24:1014-30. [PMID: 27345933 DOI: 10.1016/j.str.2016.05.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/05/2016] [Accepted: 05/10/2016] [Indexed: 12/25/2022]
Abstract
Protein misfolding and aggregation are pathological events that place a significant amount of stress on the maintenance of protein homeostasis (proteostasis). For prevention and repair of protein misfolding and aggregation, cells are equipped with robust mechanisms that mainly rely on molecular chaperones. Two classes of molecular chaperones, heat shock protein 70 kDa (Hsp70) and Hsp40, recognize and bind to misfolded proteins, preventing their toxic biomolecular aggregation and enabling refolding or targeted degradation. Here, we review the current state of structural biology of Hsp70 and Hsp40-Hsp70 complexes and examine the link between their structures, dynamics, and functions. We highlight the power of nuclear magnetic resonance spectroscopy to untangle complex relationships behind molecular chaperones and their mechanism(s) of action.
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Affiliation(s)
- Thomas Reid Alderson
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3TA, UK; Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jin Hae Kim
- National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - John Lute Markley
- National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
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34
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Dancing through Life: Molecular Dynamics Simulations and Network-Centric Modeling of Allosteric Mechanisms in Hsp70 and Hsp110 Chaperone Proteins. PLoS One 2015; 10:e0143752. [PMID: 26619280 PMCID: PMC4664246 DOI: 10.1371/journal.pone.0143752] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/09/2015] [Indexed: 01/04/2023] Open
Abstract
Hsp70 and Hsp110 chaperones play an important role in regulating cellular processes that involve protein folding and stabilization, which are essential for the integrity of signaling networks. Although many aspects of allosteric regulatory mechanisms in Hsp70 and Hsp110 chaperones have been extensively studied and significantly advanced in recent experimental studies, the atomistic picture of signal propagation and energetics of dynamics-based communication still remain unresolved. In this work, we have combined molecular dynamics simulations and protein stability analysis of the chaperone structures with the network modeling of residue interaction networks to characterize molecular determinants of allosteric mechanisms. We have shown that allosteric mechanisms of Hsp70 and Hsp110 chaperones may be primarily determined by nucleotide-induced redistribution of local conformational ensembles in the inter-domain regions and the substrate binding domain. Conformational dynamics and energetics of the peptide substrate binding with the Hsp70 structures has been analyzed using free energy calculations, revealing allosteric hotspots that control negative cooperativity between regulatory sites. The results have indicated that cooperative interactions may promote a population-shift mechanism in Hsp70, in which functional residues are organized in a broad and robust allosteric network that can link the nucleotide-binding site and the substrate-binding regions. A smaller allosteric network in Hsp110 structures may elicit an entropy-driven allostery that occurs in the absence of global structural changes. We have found that global mediating residues with high network centrality may be organized in stable local communities that are indispensable for structural stability and efficient allosteric communications. The network-centric analysis of allosteric interactions has also established that centrality of functional residues could correlate with their sensitivity to mutations across diverse chaperone functions. This study reconciles a wide spectrum of structural and functional experiments by demonstrating how integration of molecular simulations and network-centric modeling may explain thermodynamic and mechanistic aspects of allosteric regulation in chaperones.
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35
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Needham PG, Patel HJ, Chiosis G, Thibodeau PH, Brodsky JL. Mutations in the Yeast Hsp70, Ssa1, at P417 Alter ATP Cycling, Interdomain Coupling, and Specific Chaperone Functions. J Mol Biol 2015; 427:2948-65. [PMID: 25913688 DOI: 10.1016/j.jmb.2015.04.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/08/2015] [Accepted: 04/17/2015] [Indexed: 01/05/2023]
Abstract
The major cytoplasmic Hsp70 chaperones in the yeast Saccharomyces cerevisiae are the Ssa proteins, and much of our understanding of Hsp70 biology has emerged from studying ssa mutant strains. For example, Ssa1 catalyzes multiple cellular functions, including protein transport and degradation, and to this end, the ssa1-45 mutant has proved invaluable. However, the biochemical defects associated with the corresponding Ssa1-45 protein (P417L) are unknown. Consequently, we characterized Ssa1 P417L, as well as a P417S variant, which corresponds to a mutation in the gene encoding the yeast mitochondrial Hsp70. We discovered that the P417L and P417S proteins exhibit accelerated ATPase activity that was similar to the Hsp40-stimulated rate of ATP hydrolysis of wild-type Ssa1. We also found that the mutant proteins were compromised for peptide binding. These data are consistent with defects in peptide-stimulated ATPase activity and with results from limited proteolysis experiments, which indicated that the mutants' substrate binding domains were highly vulnerable to digestion. Defects in the reactivation of heat-denatured luciferase were also evident. Correspondingly, yeast expressing P417L or P417S as the only copy of Ssa were temperature sensitive and exhibited defects in Ssa1-dependent protein translocation and misfolded protein degradation. Together, our studies suggest that the structure of the substrate binding domain is altered and that coupling between this domain and the nucleotide binding domain is disabled when the conserved P417 residue is mutated. Our data also provide new insights into the nature of the many cellular defects associated with the ssa1-45 allele.
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Affiliation(s)
- Patrick G Needham
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | | | - Gabriela Chiosis
- Program in Molecular Pharmacology and Chemistry; Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
| | - Patrick H Thibodeau
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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36
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A Perspective on Transport of Proteins into Mitochondria: A Myriad of Open Questions. J Mol Biol 2015; 427:1135-58. [DOI: 10.1016/j.jmb.2015.02.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/30/2015] [Accepted: 02/02/2015] [Indexed: 11/22/2022]
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37
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Bonomi M, Pellarin R, Kim SJ, Russel D, Sundin BA, Riffle M, Jaschob D, Ramsden R, Davis TN, Muller EGD, Sali A. Determining protein complex structures based on a Bayesian model of in vivo Förster resonance energy transfer (FRET) data. Mol Cell Proteomics 2014; 13:2812-23. [PMID: 25139910 PMCID: PMC4223474 DOI: 10.1074/mcp.m114.040824] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 08/13/2014] [Indexed: 12/24/2022] Open
Abstract
The use of in vivo Förster resonance energy transfer (FRET) data to determine the molecular architecture of a protein complex in living cells is challenging due to data sparseness, sample heterogeneity, signal contributions from multiple donors and acceptors, unequal fluorophore brightness, photobleaching, flexibility of the linker connecting the fluorophore to the tagged protein, and spectral cross-talk. We addressed these challenges by using a Bayesian approach that produces the posterior probability of a model, given the input data. The posterior probability is defined as a function of the dependence of our FRET metric FRETR on a structure (forward model), a model of noise in the data, as well as prior information about the structure, relative populations of distinct states in the sample, forward model parameters, and data noise. The forward model was validated against kinetic Monte Carlo simulations and in vivo experimental data collected on nine systems of known structure. In addition, our Bayesian approach was validated by a benchmark of 16 protein complexes of known structure. Given the structures of each subunit of the complexes, models were computed from synthetic FRETR data with a distance root-mean-squared deviation error of 14 to 17 Å. The approach is implemented in the open-source Integrative Modeling Platform, allowing us to determine macromolecular structures through a combination of in vivo FRETR data and data from other sources, such as electron microscopy and chemical cross-linking.
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Affiliation(s)
- Massimiliano Bonomi
- From the ‡Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, California 94158; §Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom;
| | - Riccardo Pellarin
- From the ‡Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, California 94158
| | - Seung Joong Kim
- From the ‡Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, California 94158
| | - Daniel Russel
- From the ‡Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, California 94158
| | - Bryan A Sundin
- ‖Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Michael Riffle
- ‖Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Daniel Jaschob
- ‖Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Richard Ramsden
- ‖Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Trisha N Davis
- ‖Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Eric G D Muller
- ‖Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Andrej Sali
- From the ‡Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, California 94158;
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38
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Hartmann A, Krainer G, Schlierf M. Different fluorophore labeling strategies and designs affect millisecond kinetics of DNA hairpins. Molecules 2014; 19:13735-54. [PMID: 25255759 PMCID: PMC6271894 DOI: 10.3390/molecules190913735] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 08/21/2014] [Accepted: 08/26/2014] [Indexed: 11/18/2022] Open
Abstract
Changes in molecular conformations are one of the major driving forces of complex biological processes. Many studies based on single-molecule techniques have shed light on conformational dynamics and contributed to a better understanding of living matter. In particular, single-molecule FRET experiments have revealed unprecedented information at various time scales varying from milliseconds to seconds. The choice and the attachment of fluorophores is a pivotal requirement for single-molecule FRET experiments. One particularly well-studied millisecond conformational change is the opening and closing of DNA hairpin structures. In this study, we addressed the influence of base- and terminal-labeled fluorophores as well as the fluorophore DNA interactions on the extracted kinetic information of the DNA hairpin. Gibbs free energies varied from ∆G0 = −3.6 kJ/mol to ∆G0 = −0.2 kJ/mol for the identical DNA hairpin modifying only the labeling scheme and design of the DNA sample. In general, the base-labeled DNA hairpin is significantly destabilized compared to the terminal-labeled DNA hairpin and fluorophore DNA interactions additionally stabilize the closed state of the DNA hairpin. Careful controls and variations of fluorophore attachment chemistry are essential for a mostly undisturbed measurement of the underlying energy landscape of biomolecules.
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Affiliation(s)
- Andreas Hartmann
- B CUBE, Center for Molecular Bioengineering, Technische Universität Dresden, Dresden 01307, Germany.
| | - Georg Krainer
- B CUBE, Center for Molecular Bioengineering, Technische Universität Dresden, Dresden 01307, Germany.
| | - Michael Schlierf
- B CUBE, Center for Molecular Bioengineering, Technische Universität Dresden, Dresden 01307, Germany.
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39
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Amick J, Schlanger SE, Wachnowsky C, Moseng MA, Emerson CC, Dare M, Luo WI, Ithychanda SS, Nix JC, Cowan JA, Page RC, Misra S. Crystal structure of the nucleotide-binding domain of mortalin, the mitochondrial Hsp70 chaperone. Protein Sci 2014; 23:833-42. [PMID: 24687350 DOI: 10.1002/pro.2466] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 03/18/2014] [Indexed: 01/18/2023]
Abstract
Mortalin, a member of the Hsp70-family of molecular chaperones, functions in a variety of processes including mitochondrial protein import and quality control, Fe-S cluster protein biogenesis, mitochondrial homeostasis, and regulation of p53. Mortalin is implicated in regulation of apoptosis, cell stress response, neurodegeneration, and cancer and is a target of the antitumor compound MKT-077. Like other Hsp70-family members, Mortalin consists of a nucleotide-binding domain (NBD) and a substrate-binding domain. We determined the crystal structure of the NBD of human Mortalin at 2.8 Å resolution. Although the Mortalin nucleotide-binding pocket is highly conserved relative to other Hsp70 family members, we find that its nucleotide affinity is weaker than that of Hsc70. A Parkinson's disease-associated mutation is located on the Mortalin-NBD surface and may contribute to Mortalin aggregation. We present structure-based models for how the Mortalin-NBD may interact with the nucleotide exchange factor GrpEL1, with p53, and with MKT-077. Our structure may contribute to the understanding of disease-associated Mortalin mutations and to improved Mortalin-targeting antitumor compounds.
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Affiliation(s)
- Joseph Amick
- Department of Molecular Cardiology, The Cleveland Clinic, Cleveland, Ohio, 44195
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40
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Mayer MP. Hsp70 chaperone dynamics and molecular mechanism. Trends Biochem Sci 2013; 38:507-14. [PMID: 24012426 DOI: 10.1016/j.tibs.2013.08.001] [Citation(s) in RCA: 300] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 08/06/2013] [Accepted: 08/06/2013] [Indexed: 01/09/2023]
Abstract
The chaperone functions of heat shock protein (Hsp)70 involve an allosteric control mechanism between the nucleotide-binding domain (NBD) and polypeptide substrate-binding domain (SBD): ATP binding and hydrolysis regulates the affinity for polypeptides, and polypeptide binding accelerates ATP hydrolysis. These data suggest that Hsp70s exist in at least two conformational states. Although structural information on the conformation with high affinity for polypeptides has been available for several years, the conformation with an open polypeptide binding cleft was elucidated only recently. In addition, other biophysical studies have revealed a more dynamic picture of Hsp70s, shedding light on the molecular mechanism by which Hsp70s assist protein folding. In this review recent insights into the structure and mechanism of Hsp70s are discussed.
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Affiliation(s)
- Matthias P Mayer
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH-Alliance, Heidelberg, Germany.
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Mashaghi A, Kramer G, Lamb DC, Mayer MP, Tans SJ. Chaperone Action at the Single-Molecule Level. Chem Rev 2013; 114:660-76. [DOI: 10.1021/cr400326k] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Alireza Mashaghi
- AMOLF Institute, Science Park
104, 1098 XG Amsterdam, The Netherlands
| | - Günter Kramer
- Zentrum
für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Don C. Lamb
- Physical
Chemistry, Department of Chemistry, Munich Center for Integrated Protein
Science (CiPSM) and Center for Nanoscience, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Gerhard-Ertl-Building, 81377 Munich, Germany
| | - Matthias P. Mayer
- Zentrum
für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Sander J. Tans
- AMOLF Institute, Science Park
104, 1098 XG Amsterdam, The Netherlands
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