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Bellanger T, Weidmann S. Is the lipochaperone activity of sHSP a key to the stress response encoded in its primary sequence? Cell Stress Chaperones 2023; 28:21-33. [PMID: 36367671 PMCID: PMC9877275 DOI: 10.1007/s12192-022-01308-7] [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: 09/07/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 11/13/2022] Open
Abstract
Several strategies have been put in place by organisms to adapt to their environment. One of these strategies is the production of stress proteins such as sHSPs, which have been widely described over the last 30 years for their role as molecular chaperones. Some sHSPs have, in addition, the particularity to exert a lipochaperone role by interacting with membrane lipids to maintain an optimal membrane fluidity. However, the mechanisms involved in this sHSP-lipid interaction remain poorly understood and described rather sporadically in the literature. This review gathers the information concerning the structure and function of these proteins available in the literature in order to highlight the mechanism involved in this interaction. In addition, analysis of primary sequence data of sHSPs available in database shows that sHSPs can interact with lipids via certain amino acid residues present on some β sheets of these proteins. These residues could have a key role in the structure and/or oligomerization dynamics of sHPSs, which is certainly essential for interaction with membrane lipids and consequently for maintaining optimal cell membrane fluidity.
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Affiliation(s)
- Tiffany Bellanger
- Univ. Bourgogne Franche-comté, AgroSup Dijon, PAM UMR A 02.102, Dijon, France
| | - Stéphanie Weidmann
- Univ. Bourgogne Franche-comté, AgroSup Dijon, PAM UMR A 02.102, Dijon, France
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2
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Nordquist EB, Clerico EM, Chen J, Gierasch LM. Computationally-Aided Modeling of Hsp70-Client Interactions: Past, Present, and Future. J Phys Chem B 2022; 126:6780-6791. [PMID: 36040440 PMCID: PMC10309085 DOI: 10.1021/acs.jpcb.2c03806] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hsp70 molecular chaperones play central roles in maintaining a healthy cellular proteome. Hsp70s function by binding to short peptide sequences in incompletely folded client proteins, thus preventing them from misfolding and/or aggregating, and in many cases holding them in a state that is competent for subsequent processes like translocation across membranes. There is considerable interest in predicting the sites where Hsp70s may bind their clients, as the ability to do so sheds light on the cellular functions of the chaperone. In addition, the capacity of the Hsp70 chaperone family to bind to a broad array of clients and to identify accessible sequences that enable discrimination of those that are folded from those that are not fully folded, which is essential to their cellular roles, is a fascinating puzzle in molecular recognition. In this article we discuss efforts to harness computational modeling with input from experimental data to develop a predictive understanding of the promiscuous yet selective binding of Hsp70 molecular chaperones to accessible sequences within their client proteins. We trace how an increasing understanding of the complexities of Hsp70-client interactions has led computational modeling to new underlying assumptions and design features. We describe the trend from purely data-driven analysis toward increased reliance on physics-based modeling that deeply integrates structural information and sequence-based functional data with physics-based binding energies. Notably, new experimental insights are adding to our understanding of the molecular origins of "selective promiscuity" in substrate binding by Hsp70 chaperones and challenging the underlying assumptions and design used in earlier predictive models. Taking the new experimental findings together with exciting progress in computational modeling of protein structures leads us to foresee a bright future for a predictive understanding of selective-yet-promiscuous binding exploited by Hsp70 molecular chaperones; the resulting new insights will also apply to substrate binding by other chaperones and by signaling proteins.
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Affiliation(s)
- Erik B. Nordquist
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts, 01003, United States
| | - Eugenia M. Clerico
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts, 01003, United States
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts, 01003, United States
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts, 01003, United States
| | - Lila M. Gierasch
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts, 01003, United States
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts, 01003, United States
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3
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Lampros M, Vlachos N, Voulgaris S, Alexiou GA. The Role of Hsp27 in Chemotherapy Resistance. Biomedicines 2022; 10:897. [PMID: 35453647 PMCID: PMC9028095 DOI: 10.3390/biomedicines10040897] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/05/2022] [Accepted: 04/09/2022] [Indexed: 01/27/2023] Open
Abstract
Heat shock protein (Hsp)-27 is a small-sized, ATP-independent, chaperone molecule that is overexpressed under conditions of cellular stress such as oxidative stress and heat shock, and protects proteins from unfolding, thus facilitating proteostasis and cellular survival. Despite its protective role in normal cell physiology, Hsp27 overexpression in various cancer cell lines is implicated in tumor initiation, progression, and metastasis through various mechanisms, including modulation of the SWH pathway, inhibition of apoptosis, promotion of EMT, adaptation of CSCs in the tumor microenvironment and induction of angiogenesis. Investigation of the role of Hsp27 in the resistance of various cancer cell types against doxorubicin, herceptin/trastuzumab, gemcitabine, 5-FU, temozolomide, and paclitaxel suggested that Hsp27 overexpression promotes cancer cell survival against the above-mentioned chemotherapeutic agents. Conversely, Hsp27 inhibition increased the efficacy of those chemotherapy drugs, both in vitro and in vivo. Although numerous signaling pathways and molecular mechanisms were implicated in that chemotherapy resistance, Hsp27 most commonly contributed to the upregulation of Akt/mTOR signaling cascade and inactivation of p53, thus inhibiting the chemotherapy-mediated induction of apoptosis. Blockage of Hsp27 could enhance the cytotoxic effect of well-established chemotherapeutic drugs, especially in difficult-to-treat cancer types, ultimately improving patients' outcomes.
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Affiliation(s)
| | | | | | - George A. Alexiou
- Department of Neurosurgery, University Hospital of Ioannina, St. Niarhou Avenue, 45500 Ioannina, Greece; (M.L.); (N.V.); (S.V.)
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4
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Roy M, Bhakta K, Bhowmick A, Gupta S, Ghosh A, Ghosh A. Archaeal Hsp14 drives substrate shuttling between small heat shock proteins and thermosome: insights into a novel substrate transfer pathway. FEBS J 2021; 289:1080-1104. [PMID: 34637594 DOI: 10.1111/febs.16226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/26/2021] [Accepted: 10/11/2021] [Indexed: 12/25/2022]
Abstract
Heat shock proteins maintain protein homeostasis and facilitate the survival of an organism under stress. Archaeal heat shock machinery usually consists of only sHsps, Hsp70, and Hsp60. Moreover, Hsp70 is absent in thermophilic and hyperthermophilic archaea. In the absence of Hsp70, how aggregating protein substrates are transferred to Hsp60 for refolding remains elusive. Here, we investigated the crosstalk in the heat shock response pathway of thermoacidophilic crenarchaeon Sulfolobus acidocaldarius. In the present study, we biophysically and biochemically characterized one of the small heat shock proteins, Hsp14, of S. acidocaldarius. Moreover, we investigated its ability to interact with Hsp20 and Hsp60 to facilitate the substrate proteins' folding under stress conditions. Like Hsp20, we demonstrated that the dimer is the active form of Hsp14, and it forms an oligomeric storage form at a higher temperature. More importantly, the dynamics of the Hsp14 oligomer are maintained by rapid subunit exchange between the dimeric states, and the rate of subunit exchange increases with increasing temperature. We also tested the ability of Hsp14 to form hetero-oligomers via subunit exchange with Hsp20. We observed hetero-oligomer formation only at higher temperatures (50 °C-70 °C). Furthermore, experiments were performed to investigate the interaction between small heat shock proteins and Hsp60. We demonstrated an enthalpy-driven direct physical interaction between Hsp14 and Hsp60. Our results revealed that Hsp14 could transfer sHsp-captured substrate proteins to Hsp60, which then refolds them back to their active form.
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Affiliation(s)
- Mousam Roy
- Department of Biochemistry, Bose Institute, Kolkata, India
| | - Koustav Bhakta
- Department of Biochemistry, Bose Institute, Kolkata, India
| | | | | | - Anupama Ghosh
- Division of Plant Biology, Bose Institute, Kolkata, India
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5
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Fürsch J, Voormann C, Kammer KM, Stengel F. Structural Probing of Hsp26 Activation and Client Binding by Quantitative Cross-Linking Mass Spectrometry. Anal Chem 2021; 93:13226-13234. [PMID: 34542282 DOI: 10.1021/acs.analchem.1c02282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Small heat-shock proteins (sHSPs) are important members of the cellular stress response in all species. Their best-described function is the binding of early unfolding states and the resulting prevention of protein aggregation. Many sHSPs exist as a polydisperse composition of oligomers, which undergoes changes in subunit composition, folding status, and relative distribution upon heat activation. To date, only an incomplete picture of the mechanism of sHSP activation exists; in particular, the molecular basis of how sHSPs bind client proteins and mediate client specificity is not fully understood. In this study, we have applied cross-linking mass spectrometry (XL-MS) to obtain detailed structural information on sHSP activation and client binding for yeast Hsp26. Our cross-linking data reveals the middle domain of Hsp26 as a client-independent interface in multiple Hsp26::client complexes and indicates that client specificity is likely mediated via additional binding sites within its α-crystallin domain and C-terminal extension. Our quantitative XL-MS data underpins the middle domain as the main driver of heat-induced activation and client binding but shows that global rearrangements spanning all domains of Hsp26 take place simultaneously. We also investigated a Hsp26::client complex in the presence of Ssa1 (Hsp70) and Ydj1(Hsp40) at the initial stage of refolding and observe that the interaction between refolding chaperones is altered by the presence of a client protein, pointing to a mechanism where the interaction of Ydj1 with the HSP::client complex initiates the assembly of the active refolding machinery.
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Affiliation(s)
- Julius Fürsch
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Carsten Voormann
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Kai-Michael Kammer
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Florian Stengel
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
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6
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Structural basis of substrate recognition and thermal protection by a small heat shock protein. Nat Commun 2021; 12:3007. [PMID: 34021140 PMCID: PMC8140096 DOI: 10.1038/s41467-021-23338-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 04/23/2021] [Indexed: 12/12/2022] Open
Abstract
Small heat shock proteins (sHsps) bind unfolding proteins, thereby playing a pivotal role in the maintenance of proteostasis in virtually all living organisms. Structural elucidation of sHsp-substrate complexes has been hampered by the transient and heterogeneous nature of their interactions, and the precise mechanisms underlying substrate recognition, promiscuity, and chaperone activity of sHsps remain unclear. Here we show the formation of a stable complex between Arabidopsis thaliana plastid sHsp, Hsp21, and its natural substrate 1-deoxy-D-xylulose 5-phosphate synthase (DXPS) under heat stress, and report cryo-electron microscopy structures of Hsp21, DXPS and Hsp21-DXPS complex at near-atomic resolution. Monomeric Hsp21 binds across the dimer interface of DXPS and engages in multivalent interactions by recognizing highly dynamic structural elements in DXPS. Hsp21 partly unfolds its central α-crystallin domain to facilitate binding of DXPS, which preserves a native-like structure. This mode of interaction suggests a mechanism of sHsps anti-aggregation activity towards a broad range of substrates.
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7
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Lukinović V, Biggar KK. Deconvoluting complex protein interaction networks through reductionist strategies in peptide biochemistry: Modern approaches and research questions. Comp Biochem Physiol B Biochem Mol Biol 2021; 256:110616. [PMID: 34000427 DOI: 10.1016/j.cbpb.2021.110616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/06/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022]
Abstract
Following the decoding of the first human genome, researchers have vastly improved their understanding of cell biology and its regulation. As a result, it has become clear that it is not merely genetic information, but the aberrant changes in the functionality and connectivity of its encoded proteins that drive cell response to periods of stress and external cues. Therefore, proper utilization of refined methods that help to describe protein signalling or regulatory networks (i.e., functional connectivity), can help us understand how change in the signalling landscape effects the cell. However, given the vast complexity in 'how and when' proteins communicate or interact with each other, it is extremely difficult to define, characterize, and understand these interaction networks in a tangible manner. Herein lies the challenge of tackling the functional proteome; its regulation is encoded in multiple layers of interaction, chemical modification and cell compartmentalization. To address and refine simple research questions, modern reductionist strategies in protein biochemistry have successfully used peptide-based experiments; their summation helping to simplify the overall complexity of these protein interaction networks. In this way, peptides are powerful tools used in fundamental research that can be readily applied to comparative biochemical research. Understanding and defining how proteins interact is one of the key aspects towards understanding how the proteome functions. To date, reductionist peptide-based research has helped to address a wide range of proteome-related research questions, including the prediction of enzymes substrates, identification of posttranslational modifications, and the annotation of protein interaction partners. Peptide arrays have been used to identify the binding specificity of reader domains, which are able to recognise the posttranslational modifications; forming dynamic protein interactions that are dependent on modification state. Finally, representing one of the fastest growing classes of inhibitor molecules, peptides are now begin explored as "disruptors" of protein-protein interactions or enzyme activity. Collectively, this review will discuss the use of peptides, peptide arrays, peptide-oriented computational biochemistry as modern reductionist strategies in deconvoluting the functional proteome.
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Affiliation(s)
- Valentina Lukinović
- Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Kyle K Biggar
- Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada.
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8
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Lallier M, Marchandet L, Moukengue B, Charrier C, Baud’huin M, Verrecchia F, Ory B, Lamoureux F. Molecular Chaperones in Osteosarcoma: Diagnosis and Therapeutic Issues. Cells 2021; 10:cells10040754. [PMID: 33808130 PMCID: PMC8067202 DOI: 10.3390/cells10040754] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/12/2021] [Accepted: 03/25/2021] [Indexed: 12/16/2022] Open
Abstract
Osteosarcoma (OS) is the most common form of primary bone tumor affecting mainly children and young adults. Despite therapeutic progress, the 5-year survival rate is 70%, but it drops drastically to 30% for poor responders to therapies or for patients with metastases. Identifying new therapeutic targets is thus essential. Heat Shock Proteins (HSPs) are the main effectors of Heat Shock Response (HSR), the expression of which is induced by stressors. HSPs are a large family of proteins involved in the folding and maturation of other proteins in order to maintain proteostasis. HSP overexpression is observed in many cancers, including breast, prostate, colorectal, lung, and ovarian, as well as OS. In this article we reviewed the significant role played by HSPs in molecular mechanisms leading to OS development and progression. HSPs are directly involved in OS cell proliferation, apoptosis inhibition, migration, and drug resistance. We focused on HSP27, HSP60, HSP70 and HSP90 and summarized their potential clinical uses in OS as either biomarkers for diagnosis or therapeutic targets. Finally, based on different types of cancer, we consider the advantage of targeting heat shock factor 1 (HSF1), the major transcriptional regulator of HSPs in OS.
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Affiliation(s)
- Morgane Lallier
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
| | - Louise Marchandet
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
| | - Brice Moukengue
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
| | - Celine Charrier
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
| | - Marc Baud’huin
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
- CHU Nantes, 44035 Nantes, France
| | - Franck Verrecchia
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
| | - Benjamin Ory
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
| | - François Lamoureux
- UMR1238, Phy-OS, Sarcomes Osseux et Remodelage des Tissus Calcifiés, INSERM, Université de Nantes, 44035 Nantes, France; (M.L.); (L.M.); (B.M.); (C.C.); (M.B.); (F.V.); (B.O.)
- Correspondence:
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Proteinaceous Transformers: Structural and Functional Variability of Human sHsps. Int J Mol Sci 2020; 21:ijms21155448. [PMID: 32751672 PMCID: PMC7432308 DOI: 10.3390/ijms21155448] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/27/2020] [Accepted: 07/29/2020] [Indexed: 02/04/2023] Open
Abstract
The proteostasis network allows organisms to support and regulate the life cycle of proteins. Especially regarding stress, molecular chaperones represent the main players within this network. Small heat shock proteins (sHsps) are a diverse family of ATP-independent molecular chaperones acting as the first line of defense in many stress situations. Thereby, the promiscuous interaction of sHsps with substrate proteins results in complexes from which the substrates can be refolded by ATP-dependent chaperones. Particularly in vertebrates, sHsps are linked to a broad variety of diseases and are needed to maintain the refractive index of the eye lens. A striking key characteristic of sHsps is their existence in ensembles of oligomers with varying numbers of subunits. The respective dynamics of these molecules allow the exchange of subunits and the formation of hetero-oligomers. Additionally, these dynamics are closely linked to the chaperone activity of sHsps. In current models a shift in the equilibrium of the sHsp ensemble allows regulation of the chaperone activity, whereby smaller oligomers are commonly the more active species. Different triggers reversibly change the oligomer equilibrium and regulate the activity of sHsps. However, a finite availability of high-resolution structures of sHsps still limits a detailed mechanistic understanding of their dynamics and the correlating recognition of substrate proteins. Here we summarize recent advances in understanding the structural and functional relationships of human sHsps with a focus on the eye-lens αA- and αB-crystallins.
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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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Haslbeck M, Weinkauf S, Buchner J. Small heat shock proteins: Simplicity meets complexity. J Biol Chem 2018; 294:2121-2132. [PMID: 30385502 DOI: 10.1074/jbc.rev118.002809] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Small heat shock proteins (sHsps) are a ubiquitous and ancient family of ATP-independent molecular chaperones. A key characteristic of sHsps is that they exist in ensembles of iso-energetic oligomeric species differing in size. This property arises from a unique mode of assembly involving several parts of the subunits in a flexible manner. Current evidence suggests that smaller oligomers are more active chaperones. Thus, a shift in the equilibrium of the sHsp ensemble allows regulating the chaperone activity. Different mechanisms have been identified that reversibly change the oligomer equilibrium. The promiscuous interaction with non-native proteins generates complexes that can form aggregate-like structures from which native proteins are restored by ATP-dependent chaperones such as Hsp70 family members. In recent years, this basic paradigm has been expanded, and new roles and new cofactors, as well as variations in structure and regulation of sHsps, have emerged.
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Affiliation(s)
- Martin Haslbeck
- From the Department of Chemie and Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85 748 Garching, Germany
| | - Sevil Weinkauf
- From the Department of Chemie and Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85 748 Garching, Germany
| | - Johannes Buchner
- From the Department of Chemie and Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85 748 Garching, Germany
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12
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Roy M, Gupta S, Patranabis S, Ghosh A. The oligomeric plasticity of Hsp20 of Sulfolobus acidocaldarius protects environment-induced protein aggregation and membrane destabilization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2549-2565. [PMID: 30293966 DOI: 10.1016/j.bbamem.2018.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/29/2018] [Accepted: 09/05/2018] [Indexed: 12/21/2022]
Abstract
Small heat shock proteins (sHsps) are a ubiquitous family of molecular chaperones that rescue misfolded proteins from irreversible aggregation during cellular stress. Many such sHsps exist as large polydisperse species in solution, and a rapid dynamic subunit exchange between oligomeric and dissociated forms modulates their function under a variety of stress conditions. Here, we investigated the structural and functional properties of Hsp20 from thermoacidophilic crenarchaeon Sulfolobus acidocaldarius. To provide a framework for investigating the structure-function relationship of Hsp20 and understanding its dynamic nature, we employed several biophysical and biochemical techniques. Our data suggested the existence of a ~24-mer of Hsp20 at room temperature (25 °C) and a higher oligomeric form at higher temperature (50 °C-70 °C) and lower pH (3.0-5.0). To our surprise, we identified a dimeric form of protein as the functional conformation in the presence of aggregating substrate proteins. The hydrophobic microenvironment mainly regulates the oligomeric plasticity of Hsp20, and it plays a key role in the protection of stress-induced protein aggregation. In Sulfolobus sp., Hsp20, despite being a non-secreted protein, has been reported to be present in secretory vesicles and it is still unclear whether it stabilizes substrate proteins or membrane lipids within the secreted vesicles. To address such an issue, we tested the ability of Hsp20 to interact with membrane lipids along with its ability to modulate membrane fluidity. Our data revealed that Hsp20 interacts with membrane lipids via a hydrophobic interaction and it lowers the propensity of in vitro phase transition of bacterial and archaeal lipids.
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Affiliation(s)
- Mousam Roy
- Department of Biochemistry, Bose Institute, Centenary Campus, P 1/12, C. I. T. Road, Scheme - VIIM, Kolkata 700054, West Bengal, India
| | - Sayandeep Gupta
- Department of Biochemistry, Bose Institute, Centenary Campus, P 1/12, C. I. T. Road, Scheme - VIIM, Kolkata 700054, West Bengal, India
| | - Somi Patranabis
- Department of Biochemistry, Bose Institute, Centenary Campus, P 1/12, C. I. T. Road, Scheme - VIIM, Kolkata 700054, West Bengal, India
| | - Abhrajyoti Ghosh
- Department of Biochemistry, Bose Institute, Centenary Campus, P 1/12, C. I. T. Road, Scheme - VIIM, Kolkata 700054, West Bengal, India.
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Lee J, Roberts JS, Atanasova KR, Chowdhury N, Yilmaz Ö. A novel kinase function of a nucleoside-diphosphate-kinase homologue in Porphyromonas gingivalis is critical in subversion of host cell apoptosis by targeting heat-shock protein 27. Cell Microbiol 2018; 20:e12825. [PMID: 29359393 PMCID: PMC5893355 DOI: 10.1111/cmi.12825] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 12/13/2022]
Abstract
We have previously shown that a homologue of a conserved nucleoside-diphosphate-kinase (Ndk) family of multifunctional enzymes and secreted molecule in Porphyromonas gingivalis can modulate select host molecular pathways including downregulation of reactive-oxygen-species generation to promote bacterial survival in human gingival epithelial cells (GECs). In this study, we describe a novel kinase function for bacterial effector, P. gingivalis-Ndk, in abrogating epithelial cell death by phosphorylating heat-shock protein 27 (HSP27) in GECs. Infection by P. gingivalis was recently suggested to increase phosphorylation of HSP27 in cancer-epithelial cells; however, the mechanism and biological significance of antiapoptotic phospho-HSP27 during infection has never been characterised. Interestingly, using glutathione S-transferase-rNdk pull-down analysed by mass spectrometry, we identified HSP27 in GECs as a strong binder of P. gingivalis-Ndk and further verified using confocal microscopy and ELISA. Therefore, we hypothesised P. gingivalis-Ndk can phosphorylate HSP27 for inhibition of apoptosis in GECs. We further employed P. gingivalis-Ndk protein constructs and an isogenic P. gingivalis-ndk-deficient-mutant strain for functional examination. P. gingivalis-infected GECs displayed significantly increased phospho-HSP27 compared with ndk-deficient-strain during 24 hr infection. Phospho-HSP27 was significantly increased by transfection of GFP-tagged-Ndk into uninfected-GECs, and in vitro phosphorylation assays revealed direct phosphorylation of HSP27 at serines 78 and 82 by P. gingivalis-Ndk. Depletion of HSP27 via siRNA significantly reversed resistance against staurosporine-mediated-apoptosis during infection. Transfection of recombinant P. gingivalis-Ndk protein into GECs substantially decreased staurosporine-induced-apoptosis. Finally, ndk-deficient-mutant strain was unable to inhibit staurosporine-induced Cytochrome C release/Caspase-9 activation. Thus, we show for the first time the phosphorylation of HSP27 by a bacterial effector-P. gingivalis-Ndk-and a novel function of Ndks that is directly involved in inhibition of host cell apoptosis and the subsequent bacterial survival.
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Affiliation(s)
- Jungnam Lee
- Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Florida, USA
| | - JoAnn S Roberts
- Department of Oral Health Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | - Nityananda Chowdhury
- Department of Oral Health Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Özlem Yilmaz
- Department of Oral Health Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
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14
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Sakai G, Tokuda H, Yamamoto N, Matsushima-Nishiwaki R, Fujita K, Kawabata T, Kozawa O, Otsuka T. Association of HSP22 with mTOR in osteoblasts: regulation of TNF-α-stimulated IL-6 synthesis. FEBS Lett 2018. [PMID: 29532456 DOI: 10.1002/1873-3468.13028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Heat shock protein 22 (HSP22) is ubiquitously expressed in various types of cells including in osteoblasts. We previously reported that tumor necrosis factor (TNF)-α stimulates interleukin (IL)-6 synthesis via p44/p42 MAPK in osteoblast-like MC3T3-E1 cells and that mTOR/p70 S6 kinase (p70 S6K) negatively regulates the IL-6 synthesis. In this study, we investigated the involvement of HSP22 in TNF-α-stimulated-IL-6 synthesis and the underlying mechanism in MC3T3-E1 cells. HSP22 knockdown reduces TNF-α-stimulated release of IL-6. In addition, HSP22 knockdown strengthens TNF-α-induced phosphorylation of p70 S6K but suppresses that of p44/p42 MAPK. HSP22 coimmunoprecipitates with mTOR. HSP22 knockdown increases the basal levels of phosphorylated mTOR. These results strongly suggest that HSP22 interacts with mTOR and regulates TNF-α-induced IL-6 synthesis in osteoblasts.
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Affiliation(s)
- Go Sakai
- Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Japan.,Department of Pharmacology, Gifu University Graduate School of Medicine, Japan
| | - Haruhiko Tokuda
- Department of Pharmacology, Gifu University Graduate School of Medicine, Japan.,Department of Clinical Laboratory/Biobank of Medical Genome Center, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Naohiro Yamamoto
- Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Japan.,Department of Pharmacology, Gifu University Graduate School of Medicine, Japan
| | | | - Kazuhiko Fujita
- Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Japan.,Department of Pharmacology, Gifu University Graduate School of Medicine, Japan
| | - Tetsu Kawabata
- Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Japan.,Department of Pharmacology, Gifu University Graduate School of Medicine, Japan
| | - Osamu Kozawa
- Department of Pharmacology, Gifu University Graduate School of Medicine, Japan
| | - Takanobu Otsuka
- Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Japan
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15
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Targeting Heat Shock Proteins in Cancer: A Promising Therapeutic Approach. Int J Mol Sci 2017; 18:ijms18091978. [PMID: 28914774 PMCID: PMC5618627 DOI: 10.3390/ijms18091978] [Citation(s) in RCA: 312] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/01/2017] [Accepted: 09/05/2017] [Indexed: 12/12/2022] Open
Abstract
Heat shock proteins (HSPs) are a large family of chaperones that are involved in protein folding and maturation of a variety of "client" proteins protecting them from degradation, oxidative stress, hypoxia, and thermal stress. Hence, they are significant regulators of cellular proliferation, differentiation and strongly implicated in the molecular orchestration of cancer development and progression as many of their clients are well established oncoproteins in multiple tumor types. Interestingly, tumor cells are more HSP chaperonage-dependent than normal cells for proliferation and survival because the oncoproteins in cancer cells are often misfolded and require augmented chaperonage activity for correction. This led to the development of several inhibitors of HSP90 and other HSPs that have shown promise both preclinically and clinically in the treatment of cancer. In this article, we comprehensively review the roles of some of the important HSPs in cancer, and how targeting them could be efficacious, especially when traditional cancer therapies fail.
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16
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Haslbeck M, Vierling E. A first line of stress defense: small heat shock proteins and their function in protein homeostasis. J Mol Biol 2015; 427:1537-48. [PMID: 25681016 DOI: 10.1016/j.jmb.2015.02.002] [Citation(s) in RCA: 380] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 02/03/2015] [Accepted: 02/04/2015] [Indexed: 10/24/2022]
Abstract
Small heat shock proteins (sHsps) are virtually ubiquitous molecular chaperones that can prevent the irreversible aggregation of denaturing proteins. sHsps complex with a variety of non-native proteins in an ATP-independent manner and, in the context of the stress response, form a first line of defense against protein aggregation in order to maintain protein homeostasis. In vertebrates, they act to maintain the clarity of the eye lens, and in humans, sHsp mutations are linked to myopathies and neuropathies. Although found in all domains of life, sHsps are quite diverse and have evolved independently in metazoans, plants and fungi. sHsp monomers range in size from approximately 12 to 42kDa and are defined by a conserved β-sandwich α-crystallin domain, flanked by variable N- and C-terminal sequences. Most sHsps form large oligomeric ensembles with a broad distribution of different, sphere- or barrel-like oligomers, with the size and structure of the oligomers dictated by features of the N- and C-termini. The activity of sHsps is regulated by mechanisms that change the equilibrium distribution in tertiary features and/or quaternary structure of the sHsp ensembles. Cooperation and/or co-assembly between different sHsps in the same cellular compartment add an underexplored level of complexity to sHsp structure and function.
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Affiliation(s)
- Martin Haslbeck
- Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85 748 Garching, Germany.
| | - Elizabeth Vierling
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Life Science Laboratories, N329 240 Thatcher Road, Amherst, MA 01003-9364, USA.
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17
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18
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Katsogiannou M, Andrieu C, Rocchi P. Heat shock protein 27 phosphorylation state is associated with cancer progression. Front Genet 2014; 5:346. [PMID: 25339975 PMCID: PMC4186339 DOI: 10.3389/fgene.2014.00346] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 09/16/2014] [Indexed: 11/13/2022] Open
Abstract
Understanding the mechanisms that control stress-induced survival is critical to explain how tumors frequently resist to treatment and to improve current anti-cancer therapies. Cancer cells are able to cope with stress and escape drug toxicity by regulating heat shock proteins (Hsps) expression and function. Hsp27 (HSPB1), a member of the small Hsp family, represents one of the key players of many signaling pathways contributing to tumorigenicity, treatment resistance, and apoptosis inhibition. Hsp27 is overexpressed in many types of cancer and its functions are regulated by post-translational modifications, such as phosphorylation. Protein phosphorylation is the most widespread signaling mechanism in eukaryotic cells, and it is involved in all fundamental cellular processes. Aberrant phosphorylation of Hsp27 has been associated with cancer but the molecular mechanisms by which it is implicated in cancer development and progression remain undefined. This mini-review focuses on the role of phosphorylation in Hsp27 functions in cancer cells and its potential usefulness as therapeutic target in cancer.
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Affiliation(s)
- Maria Katsogiannou
- Institut National de la Santé et de la Recherche Médicale, Unités Mixtes de Recherche 1068, Centre de Recherche en Cancérologie de Marseille Marseille, France ; Institut Paoli-Calmettes Marseille, France ; Centre de Recherche en Cancérologie de Marseille, Institut National de la Santé et de la Recherche Médicale Unités Mixtes de Recherche 1068, Aix-Marseille Université Marseille, France ; Centre National de la Recherche Scientifique, Unités Mixtes de Recherche 7258, Centre de Recherche en Cancérologie de Marseille Marseille, France
| | - Claudia Andrieu
- Institut National de la Santé et de la Recherche Médicale, Unités Mixtes de Recherche 1068, Centre de Recherche en Cancérologie de Marseille Marseille, France ; Institut Paoli-Calmettes Marseille, France ; Centre de Recherche en Cancérologie de Marseille, Institut National de la Santé et de la Recherche Médicale Unités Mixtes de Recherche 1068, Aix-Marseille Université Marseille, France ; Centre National de la Recherche Scientifique, Unités Mixtes de Recherche 7258, Centre de Recherche en Cancérologie de Marseille Marseille, France
| | - Palma Rocchi
- Institut National de la Santé et de la Recherche Médicale, Unités Mixtes de Recherche 1068, Centre de Recherche en Cancérologie de Marseille Marseille, France ; Institut Paoli-Calmettes Marseille, France ; Centre de Recherche en Cancérologie de Marseille, Institut National de la Santé et de la Recherche Médicale Unités Mixtes de Recherche 1068, Aix-Marseille Université Marseille, France ; Centre National de la Recherche Scientifique, Unités Mixtes de Recherche 7258, Centre de Recherche en Cancérologie de Marseille Marseille, France
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19
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Guzzo J. Biotechnical applications of small heat shock proteins from bacteria. Int J Biochem Cell Biol 2012; 44:1698-705. [PMID: 22706478 DOI: 10.1016/j.biocel.2012.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 01/05/2023]
Abstract
The stress responses of most bacteria are thought to involve the upregulation of small heat shock proteins. We describe here some of the most pertinent aspects of small heat shock proteins, to highlight their potential for use in various applications. Bacterial species have between one and 13 genes encoding small heat shock proteins, the precise number depending on the species considered. Major efforts have recently been made to characterize the protein protection and membrane stabilization mechanisms involving small heat shock proteins in bacteria. These proteins seem to be involved in the acquisition of cellular heat tolerance. They could therefore potentially be used to maintain cell viability under unfavorable conditions, such as heat shock or chemical treatments. This review highlights the potential roles of applications of small heat shock proteins in stabilizing overproduced heterologous proteins in Escherichia coli, purified bacterial small heat shock proteins in protein biochip technology, proteomic analysis and food technology and the potential impact of these proteins on some diseases. This article is part of a Directed Issue entitled: Small HSPs in physiology and pathology.
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Affiliation(s)
- Jean Guzzo
- UMR A PAM Université de Bourgogne/Agrosup Dijon Equipe Valmis Institut Jules Guyot, 1 Rue Claude Ladrey, BP27877, 21078 Dijon, France.
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20
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Acunzo J, Katsogiannou M, Rocchi P. Small heat shock proteins HSP27 (HspB1), αB-crystallin (HspB5) and HSP22 (HspB8) as regulators of cell death. Int J Biochem Cell Biol 2012; 44:1622-31. [PMID: 22521623 DOI: 10.1016/j.biocel.2012.04.002] [Citation(s) in RCA: 212] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 04/02/2012] [Accepted: 04/04/2012] [Indexed: 01/17/2023]
Abstract
Hsp27, αB-crystallin and HSP22 are ubiquitous small heat shock proteins (sHsp) whose expression is induced in response to a wide variety of unfavorable physiological and environmental conditions. These sHsp protect cells from otherwise lethal conditions mainly by their involvement in cell death pathways such as necrosis, apoptosis or autophagy. At a molecular level, the mechanisms accounting for sHsp functions in cell death are (1) prevention of denatured proteins aggregation, (2) regulation of caspase activity, (3) regulation of the intracellular redox state, (4) function in actin polymerization and cytoskeleton integrity and (5) proteasome-mediated degradation of selected proteins. In cancer cells, these sHsp are often overexpressed and associated with increased tumorigenicity, cancer cells metastatic potential and resistance to chemotherapy. Altogether, these properties suggest that Hsp27, αB-crystallin and Hsp22 are appropriate targets for modulating cell death pathways. In the present, we briefly review recent reports showing molecular evidence of cell death regulation by these sHsp and co-chaperones. This article is part of a Directed Issue entitled: Small HSPs in physiology and pathology.
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Affiliation(s)
- Julie Acunzo
- Centre de Recherche en Cancérologie de Marseille, UMR1068 Inserm, Institut Paoli-Calmette, Aix-Marseille Univ, Marseille, France
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21
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Healy EF, King PJ. A mechanism of action for small heat shock proteins. Biochem Biophys Res Commun 2012; 417:268-73. [DOI: 10.1016/j.bbrc.2011.11.098] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 11/18/2011] [Indexed: 11/24/2022]
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22
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Ahmed S, Mathews AS, Byeon N, Lavasanifar A, Kaur K. Peptide arrays for screening cancer specific peptides. Anal Chem 2011; 82:7533-41. [PMID: 20799711 DOI: 10.1021/ac1003085] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In this paper, we describe a novel method to screen peptides for specific recognition by cancer cells. Seventy peptides were synthesized on a cellulose membrane in an array format, and a direct method to study the peptide-whole cell interaction was developed. The relative binding affinity of the cells for different peptides with respect to a lead 12-mer p160 peptide, identified by phage display, was evaluated using the CyQUANT fluorescence of the bound cells. Screening allowed identification of at least five new peptides that displayed higher affinity (up to 3-fold) for MDA-MB-435 and MCF-7 human cancer cells compared to the p160 peptide. These peptides showed very little binding to the control (noncancerous) human umbilical vein endothelial cells (HUVECs). Three of these peptides were synthesized separately and labeled with fluorescein isothiocyanate (FITC) to study their uptake and interaction with the cancer and control cells using confocal laser scanning microscopy and flow cytometry. The results confirmed the high and specific affinity of an 11-mer peptide 11 (RGDPAYQGRFL) and a 10-mer peptide 18 (WXEAAYQRFL) for the cancer cells versus HUVECs. Peptide 11 binds different receptors on target cancer cells as its sequence contains multiple recognition motifs, whereas peptide 18 binds mainly to the putative p160 receptor. The peptide array-whole cell binding assay reported here is a complementary method to phage display for further screening and optimization of cancer targeting peptides for cancer therapy and diagnosis.
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Affiliation(s)
- Sahar Ahmed
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2N8, Canada
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23
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Ahrman E, Lambert W, Aquilina JA, Robinson CV, Emanuelsson CS. Chemical cross-linking of the chloroplast localized small heat-shock protein, Hsp21, and the model substrate citrate synthase. Protein Sci 2007; 16:1464-78. [PMID: 17567739 PMCID: PMC2206695 DOI: 10.1110/ps.072831607] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The molecular mechanism whereby the small heat-shock protein (sHsp) chaperones interact with and prevent aggregation of other proteins is not fully understood. We have characterized the sHsp-substrate protein interaction at normal and increased temperatures utilizing a model substrate protein, citrate synthase (CS), widely used in chaperone assays, and a dodecameric plant sHsp, Hsp21, by chemical cross-linking with 3,3'-Dithiobis[sulfosuccinimidylpropionate] (DTSSP) and mass spectrometric peptide mapping. In the absence of CS, the cross-linker captured Hsp21 in dodecameric form, even at increased temperature (47 degrees C). In the presence of equimolar amounts of CS, no Hsp21 dodecamer was captured, indicating a substrate-induced Hsp21 dodecamer dissociation by equimolar amounts of CS. Cross-linked Hsp21-Hsp21 dipeptides indicated an exposure of the Hsp21 C-terminal tails and substrate-binding sites normally covered by the C terminus. Cross-linked Hsp21-CS dipeptides mapped to several sites on the surface of the CS dimer, indicating that there are numerous weak and short-lived interactions between Hsp21 and CS, even at normal temperatures. The N-terminal arms especially interacted with a motif in the CS dimer, which is absent in thermostable forms of CS. The cross-linking data suggest that the presence of substrate rather than temperature influences the conformation of Hsp21.
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Affiliation(s)
- Emma Ahrman
- Department of Biochemistry, Lund University, Sweden.
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24
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Sandhu N, Duus K, Jørgensen CS, Hansen PR, Bruun SW, Pedersen LØ, Højrup P, Houen G. Peptide binding specificity of the chaperone calreticulin. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:701-13. [PMID: 17499031 DOI: 10.1016/j.bbapap.2007.03.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 03/28/2007] [Accepted: 03/29/2007] [Indexed: 10/23/2022]
Abstract
Calreticulin is a molecular chaperone with specificity for polypeptides and N-linked monoglucosylated glycans. In order to determine the specificity of polypeptide binding, the interaction of calreticulin with polypeptides was investigated using synthetic peptides of different length and composition. A large set of available synthetic peptides (n=127) was tested for binding to calreticulin and the results analysed by multivariate data analysis. The parameter that correlated best with binding was hydrophobicity while beta-turn potential disfavoured binding. Only hydrophobic peptides longer than 5 amino acids showed binding and a clear correlation with hydrophobicity was demonstrated for oligomers of different hydrophobic amino acids. Insertion of hydrophilic amino acids in a hydrophobic sequence diminished or abolished binding. In conclusion our results show that calreticulin has a peptide-binding specificity for hydrophobic sequences and delineate the fine specificity of calreticulin for hydrophobic amino acid residues.
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Affiliation(s)
- Noreen Sandhu
- Department of Autoimmunology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen, Denmark
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25
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de Miguel N, Echeverria PC, Angel SO. Differential subcellular localization of members of the Toxoplasma gondii small heat shock protein family. EUKARYOTIC CELL 2006; 4:1990-7. [PMID: 16339717 PMCID: PMC1317493 DOI: 10.1128/ec.4.12.1990-1997.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The results of this study describe the identification and characterization of the Toxoplasma gondii alpha-crystallin/small heat shock protein (sHsp) family. By database (www.toxodb.org) search, five parasite sHsps (Hsp20, Hsp21, Hsp28, Hsp29, and the previously characterized Hsp30/Bag1) were identified. As expected, they share the homologous alpha-crystallin domain, which is the key characteristic of sHsps. However, the N-terminal segment of each protein contains unique characteristics in size and sequence. Most T. gondii sHsps are constitutively expressed in tachyzoites and fully differentiated bradyzoites, with the exception of Hsp30/Bag1. Interestingly, by subcellular localization we observed that T. gondii sHsps are located in different compartments. Hsp20 is located at the apical end of the cell, Hsp28 is located inside the mitochondrion, Hsp29 showed a membrane-associated labeling, and Hsp21 appeared throughout the cytosol of the parasites. These particular differences in the immunostaining patterns suggest that their targets and functions might be different.
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Affiliation(s)
- N de Miguel
- Laboratorio de Parasitología Molecular, IIB-INTECH, Camino Circunvalación Laguna Km6, C.C 164, 7130 Chascomús, Prov. Buenos Aires, Argentina
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26
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Haslbeck M, Franzmann T, Weinfurtner D, Buchner J. Some like it hot: the structure and function of small heat-shock proteins. Nat Struct Mol Biol 2005; 12:842-6. [PMID: 16205709 DOI: 10.1038/nsmb993] [Citation(s) in RCA: 605] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Small heat-shock proteins (sHsps) are a widespread and diverse class of molecular chaperones. Recent evidence suggests that they maintain protein homeostasis by binding proteins in non-native conformations, thereby preventing substrate aggregation. Some members of the sHsp family are inactive or only partially active under physiological conditions, and transition toward the active state is induced by specific triggers, such as elevated temperature. Release of substrate proteins bound to sHsps requires cooperation with ATP-dependent chaperones, suggesting that sHsps create a reservoir of non-native proteins for subsequent refolding.
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Affiliation(s)
- Martin Haslbeck
- Technische Universität München, Department Chemie, Lichtenbergstr. 4, 85747 Garching, Germany
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27
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Ghosh JG, Clark JI. Insights into the domains required for dimerization and assembly of human alphaB crystallin. Protein Sci 2005; 14:684-95. [PMID: 15722445 PMCID: PMC2279284 DOI: 10.1110/ps.041152805] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Protein pin array technology was used to identify subunit-subunit interaction sites in the small heat shock protein (sHSP) alphaB crystallin. Subunit-subunit interaction sites were defined as consensus sequences that interacted with both human alphaA crystallin and alphaB crystallin. The human alphaB crystallin protein pin array consisted of contiguous and overlapping peptides, eight amino acids in length, immobilized on pins that were in a 96-well ELISA plate format. The interaction of alphaB crystallin peptides with physiological partner proteins, alphaA crystallin and alphaB crystallin, was detected using antibodies and recorded using spectrophotometric absorbance. Five peptide sequences including 37LFPTSTSLSPFYLRPPSF54 in the N terminus, 75FSVNLDVK82)(beta3), 131LTITSSLS138 (beta8) and 141GVLTVNGP148 (beta9) that form beta strands in the conserved alpha crystallin core domain, and 155PERTIPITREEK166 in the C-terminal extension were identified as subunit-subunit interaction sites in human alphaB crystallin using the novel protein pin array assay. The subunit-subunit interaction sites were mapped to a three-dimensional (3D) homology model of wild-type human alphaB crystallin that was based on the crystal structure of wheat sHSP16.9 and Methanococcus jannaschi sHSP16.5 (Mj sHSP16.5). The subunit-subunit interaction sites identified and mapped onto the homology model were solvent-exposed and had variable secondary structures ranging from beta strands to random coils and short alpha helices. The subunit-subunit interaction sites formed a pattern of hydrophobic patches on the 3D surface of human alphaB crystallin.
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Affiliation(s)
- Joy G Ghosh
- Department of Biological Structure and Design, HSB G514, Box 357420, University of Washington, Seattle, WA 98195-7420, USA
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