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Shatov VM, Muranova LK, Zamotina MA, Sluchanko NN, Gusev NB. α-Crystallin Domains of Five Human Small Heat Shock Proteins (sHsps) Differ in Dimer Stabilities and Ability to Incorporate Themselves into Oligomers of Full-Length sHsps. Int J Mol Sci 2023; 24:ijms24021085. [PMID: 36674601 PMCID: PMC9860685 DOI: 10.3390/ijms24021085] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/19/2022] [Accepted: 12/23/2022] [Indexed: 01/08/2023] Open
Abstract
The α-crystallin domain (ACD) is the hallmark of a diverse family of small heat shock proteins (sHsps). We investigated some of the ACD properties of five human sHsps as well as their interactions with different full-length sHsps. According to size-exclusion chromatography, at high concentrations, the ACDs of HspB1 (B1ACD), HspB5 (B5ACD) and HspB6 (B6ACD) formed dimers of different stabilities, which, upon dilution, dissociated to monomers to different degrees. Upon dilution, the B1ACD dimers possessed the highest stabilities, and those of B6ACD had the lowest. In striking contrast, the ACDs of HspB7 (B7ACD) and HspB8 (B8ACD) formed monomers in the same concentration range, which indicated the compromised stabilities of their dimer interfaces. B1ACD, B5ACD and B6ACD transiently interacted with full-length HspB1 and HspB5, which are known to form large oligomers, and modulated their oligomerization behavior. The small oligomers formed by the 3D mutant of HspB1 (mimicking phosphorylation at Ser15, Ser78 and Ser82) effectively interacted with B1ACD, B5ACD and B6ACD, incorporating these α-crystallin domains into their structures. The inherently dimeric full-length HspB6 readily formed heterooligomeric complexes with B1ACD and B5ACD. In sharp contrast to the abovementioned ACDs, B7ACD and B8ACD were unable to interact with full-length HspB1, the 3D mutant of HspB1, HspB5 or HspB6. Thus, their high sequence homology notwithstanding, B7ACD and B8ACD differ from the other three ACDs in their inability to form dimers and interact with the full-length small heat shock proteins. Having conservative primary structures and being apparently similar, the ACDs of the different sHsps differ in terms of their dimer stabilities, which can influence the heterooligomerization preferences of sHsps.
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Affiliation(s)
- Vladislav M. Shatov
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119234, Russia
| | - Lydia K. Muranova
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119234, Russia
| | - Maria A. Zamotina
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119234, Russia
| | - Nikolai N. Sluchanko
- A.N. Bach Institute of Biochemistry, Federal Research Center “Fundamentals of Biotechnology”, Russian Academy of Sciences, Moscow 119071, Russia
| | - Nikolai B. Gusev
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119234, Russia
- Correspondence: ; Tel.: +7-495-939-2747
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2
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The Role of Small Heat Shock Proteins in Protein Misfolding Associated Motoneuron Diseases. Int J Mol Sci 2022; 23:ijms231911759. [PMID: 36233058 PMCID: PMC9569637 DOI: 10.3390/ijms231911759] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
Motoneuron diseases (MNDs) are neurodegenerative conditions associated with death of upper and/or lower motoneurons (MNs). Proteostasis alteration is a pathogenic mechanism involved in many MNDs and is due to the excessive presence of misfolded and aggregated proteins. Protein misfolding may be the product of gene mutations, or due to defects in the translation process, or to stress agents; all these conditions may alter the native conformation of proteins making them prone to aggregate. Alternatively, mutations in members of the protein quality control (PQC) system may determine a loss of function of the proteostasis network. This causes an impairment in the capability to handle and remove aberrant or damaged proteins. The PQC system consists of the degradative pathways, which are the autophagy and the proteasome, and a network of chaperones and co-chaperones. Among these components, Heat Shock Protein 70 represents the main factor in substrate triage to folding, refolding, or degradation, and it is assisted in this task by a subclass of the chaperone network, the small heat shock protein (sHSPs/HSPBs) family. HSPBs take part in proteostasis by bridging misfolded and aggregated proteins to the HSP70 machinery and to the degradative pathways, facilitating refolding or clearance of the potentially toxic proteins. Because of its activity against proteostasis alteration, the chaperone system plays a relevant role in the protection against proteotoxicity in MNDs. Here, we discuss the role of HSPBs in MNDs and which HSPBs may represent a valid target for therapeutic purposes.
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Vallejo DD, Rojas Ramírez C, Parson KF, Han Y, Gadkari VV, Ruotolo BT. Mass Spectrometry Methods for Measuring Protein Stability. Chem Rev 2022; 122:7690-7719. [PMID: 35316030 DOI: 10.1021/acs.chemrev.1c00857] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mass spectrometry is a central technology in the life sciences, providing our most comprehensive account of the molecular inventory of the cell. In parallel with developments in mass spectrometry technologies targeting such assessments of cellular composition, mass spectrometry tools have emerged as versatile probes of biomolecular stability. In this review, we cover recent advancements in this branch of mass spectrometry that target proteins, a centrally important class of macromolecules that accounts for most biochemical functions and drug targets. Our efforts cover tools such as hydrogen-deuterium exchange, chemical cross-linking, ion mobility, collision induced unfolding, and other techniques capable of stability assessments on a proteomic scale. In addition, we focus on a range of application areas where mass spectrometry-driven protein stability measurements have made notable impacts, including studies of membrane proteins, heat shock proteins, amyloidogenic proteins, and biotherapeutics. We conclude by briefly discussing the future of this vibrant and fast-moving area of research.
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Affiliation(s)
- Daniel D Vallejo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Carolina Rojas Ramírez
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kristine F Parson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yilin Han
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Varun V Gadkari
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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4
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Tedesco B, Cristofani R, Ferrari V, Cozzi M, Rusmini P, Casarotto E, Chierichetti M, Mina F, Galbiati M, Piccolella M, Crippa V, Poletti A. Insights on Human Small Heat Shock Proteins and Their Alterations in Diseases. Front Mol Biosci 2022; 9:842149. [PMID: 35281256 PMCID: PMC8913478 DOI: 10.3389/fmolb.2022.842149] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
The family of the human small Heat Shock Proteins (HSPBs) consists of ten members of chaperones (HSPB1-HSPB10), characterized by a low molecular weight and capable of dimerization and oligomerization forming large homo- or hetero-complexes. All HSPBs possess a highly conserved centrally located α-crystallin domain and poorly conserved N- and C-terminal domains. The main feature of HSPBs is to exert cytoprotective functions by preserving proteostasis, assuring the structural maintenance of the cytoskeleton and acting in response to cellular stresses and apoptosis. HSPBs take part in cell homeostasis by acting as holdases, which is the ability to interact with a substrate preventing its aggregation. In addition, HSPBs cooperate in substrates refolding driven by other chaperones or, alternatively, promote substrate routing to degradation. Notably, while some HSPBs are ubiquitously expressed, others show peculiar tissue-specific expression. Cardiac muscle, skeletal muscle and neurons show high expression levels for a wide variety of HSPBs. Indeed, most of the mutations identified in HSPBs are associated to cardiomyopathies, myopathies, and motor neuropathies. Instead, mutations in HSPB4 and HSPB5, which are also expressed in lens, have been associated with cataract. Mutations of HSPBs family members encompass base substitutions, insertions, and deletions, resulting in single amino acid substitutions or in the generation of truncated or elongated proteins. This review will provide an updated overview of disease-related mutations in HSPBs focusing on the structural and biochemical effects of mutations and their functional consequences.
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Affiliation(s)
- B. Tedesco
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - R. Cristofani
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - V. Ferrari
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - M. Cozzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - P. Rusmini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - E. Casarotto
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - M. Chierichetti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - F. Mina
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - M. Galbiati
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - M. Piccolella
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - V. Crippa
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - A. Poletti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
- *Correspondence: A. Poletti,
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Gonçalves CC, Sharon I, Schmeing TM, Ramos CHI, Young JC. The chaperone HSPB1 prepares protein aggregates for resolubilization by HSP70. Sci Rep 2021; 11:17139. [PMID: 34429462 PMCID: PMC8384840 DOI: 10.1038/s41598-021-96518-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 08/11/2021] [Indexed: 01/22/2023] Open
Abstract
In human cells under stress conditions, misfolded polypeptides can form potentially cytotoxic insoluble aggregates. To eliminate aggregates, the HSP70 chaperone machinery extracts and resolubilizes polypeptides for triage to refolding or degradation. Yeast and bacterial chaperones of the small heat-shock protein (sHSP) family can bind substrates at early stages of misfolding, during the aggregation process. The co-aggregated sHSPs then facilitate downstream disaggregation by HSP70. Because it is unknown whether a human sHSP has this activity, we investigated the disaggregation role of human HSPB1. HSPB1 co-aggregated with unfolded protein substrates, firefly luciferase and mammalian lactate dehydrogenase. The co-aggregates formed with HSPB1 were smaller and more regularly shaped than those formed in its absence. Importantly, co-aggregation promoted the efficient disaggregation and refolding of the substrates, led by HSP70. HSPB1 itself was also extracted during disaggregation, and its homo-oligomerization ability was not required. Therefore, we propose that a human sHSP is an integral part of the chaperone network for protein disaggregation.
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Affiliation(s)
- Conrado C Gonçalves
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Room 900, Montreal, QC, H3G 1Y6, Canada
| | - Itai Sharon
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Room 457, Montreal, QC, H3G 0B1, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Room 457, Montreal, QC, H3G 0B1, Canada
| | - Carlos H I Ramos
- Institute of Chemistry, University of Campinas (UNICAMP), Campinas, SP, 13083-970, Brazil
| | - Jason C Young
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Room 900, Montreal, QC, H3G 1Y6, Canada.
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6
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Shatov VM, Strelkov SV, Gusev NB. The Heterooligomerization of Human Small Heat Shock Proteins Is Controlled by Conserved Motif Located in the N-Terminal Domain. Int J Mol Sci 2020; 21:ijms21124248. [PMID: 32549212 PMCID: PMC7352286 DOI: 10.3390/ijms21124248] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/07/2020] [Accepted: 06/12/2020] [Indexed: 01/18/2023] Open
Abstract
Ubiquitously expressed human small heat shock proteins (sHsps) HspB1, HspB5, HspB6 and HspB8 contain a conserved motif (S/G)RLFD in their N-terminal domain. For each of them, we prepared mutants with a replacement of the conserved R by A (R/A mutants) and a complete deletion of the pentapeptide (Δ mutants) and analyzed their heterooligomerization with other wild-type (WT) human sHsps. We found that WT HspB1 and HspB5 formed heterooligomers with HspB6 only upon heating. In contrast, both HspB1 mutants interacted with WT HspB6 even at low temperature. HspB1/HspB6 heterooligomers revealed a broad size distribution with equimolar ratio suggestive of heterodimers as building blocks, while HspB5/HspB6 heterooligomers had an approximate 2:1 ratio. In contrast, R/A or Δ mutants of HspB6, when mixed with either HspB1 or HspB5, resulted in heterooligomers with a highly variable molar ratio and a decreased HspB6 incorporation. No heterooligomerization of HspB8 or its mutants with either HspB1 or HspB5 could be detected. Finally, R/A or Δ mutations had no effect on heterooligomerization of HspB1 and HspB5 as analyzed by ion exchange chromatography. We conclude that the conserved N-terminal motif plays an important role in heterooligomer formation, as especially pronounced in HspB6 lacking the C-terminal IXI motif.
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Affiliation(s)
- Vladislav M. Shatov
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119991, Russian;
| | - Sergei V. Strelkov
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium;
| | - Nikolai B. Gusev
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119991, Russian;
- Correspondence:
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7
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Muranova LK, Sudnitsyna MV, Gusev NB. αB-Crystallin Phosphorylation: Advances and Problems. BIOCHEMISTRY (MOSCOW) 2018; 83:1196-1206. [DOI: 10.1134/s000629791810005x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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8
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The Role of the Arginine in the Conserved N-Terminal Domain RLFDQxFG Motif of Human Small Heat Shock Proteins HspB1, HspB4, HspB5, HspB6, and HspB8. Int J Mol Sci 2018; 19:ijms19072112. [PMID: 30036999 PMCID: PMC6073470 DOI: 10.3390/ijms19072112] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/14/2018] [Accepted: 07/17/2018] [Indexed: 11/17/2022] Open
Abstract
Although the N-terminal domain of vertebrate small heat shock proteins (sHsp) is poorly conserved, it contains a core motif preserved in many members of the sHsp family. The role of this RLFDQxFG motif remains elusive. We analyzed the specific role of the first arginine residue of this conserved octet sequence in five human sHsps (HspB1, HspB4, HspB5, HspB6, and HspB8). Substitution of this arginine with an alanine induced changes in thermal stability and/or intrinsic fluorescence of the related HspB1 and HspB8, but yielded only modest changes in the same biophysical properties of HspB4, HspB5, and HspB6 which together belong to another clade of vertebrate sHsps. Removal of the positively charged Arg side chain resulted in destabilization of the large oligomers of HspB1 and formation of smaller size oligomers of HspB5. The mutation induced only minor changes in the structure of HspB4 and HspB6. In contrast, the mutation in HspB8 was accompanied by shifting the equilibrium from dimers towards the formation of larger oligomers. We conclude that the RLFDQxFG motif plays distinct roles in the structure of several sHsp orthologs. This role correlates with the evolutionary relationship of the respective sHsps, but ultimately, it reflects the sequence context of this motif.
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9
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Klychnikov OI, Shamorkina TM, Weeks SD, van Leeuwen HC, Corver J, Drijfhout JW, van Veelen PA, Sluchanko NN, Strelkov SV, Hensbergen PJ. Discovery of a new Pro-Pro endopeptidase, PPEP-2, provides mechanistic insights into the differences in substrate specificity within the PPEP family. J Biol Chem 2018; 293:11154-11165. [PMID: 29794027 DOI: 10.1074/jbc.ra118.003244] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/22/2018] [Indexed: 12/20/2022] Open
Abstract
Pro-Pro endopeptidases (PPEPs) belong to a recently discovered family of proteases capable of hydrolyzing a Pro-Pro bond. The first member from the bacterial pathogen Clostridium difficile (PPEP-1) cleaves two C. difficile cell-surface proteins involved in adhesion, one of which is encoded by the gene adjacent to the ppep-1 gene. However, related PPEPs may exist in other bacteria and may shed light on substrate specificity in this enzyme family. Here, we report on the homolog of PPEP-1 in Paenibacillus alvei, which we denoted PPEP-2. We found that PPEP-2 is a secreted metalloprotease, which likewise cleaved a cell-surface protein encoded by an adjacent gene. However, the cleavage motif of PPEP-2, PLP↓PVP, is distinct from that of PPEP-1 (VNP↓PVP). As a result, an optimal substrate peptide for PPEP-2 was not cleaved by PPEP-1 and vice versa. To gain insight into the specificity mechanism of PPEP-2, we determined its crystal structure at 1.75 Å resolution and further confirmed the structure in solution using small-angle X-ray scattering (SAXS). We show that a four-amino-acid loop, which is distinct in PPEP-1 and -2 (GGST in PPEP-1 and SERV in PPEP-2), plays a crucial role in substrate specificity. A PPEP-2 variant, in which the four loop residues had been swapped for those from PPEP-1, displayed a shift in substrate specificity toward PPEP-1 substrates. Our results provide detailed insights into the PPEP-2 structure and the structural determinants of substrate specificity in this new family of PPEP proteases.
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Affiliation(s)
- Oleg I Klychnikov
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | | | - Stephen D Weeks
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | | | | | - Jan W Drijfhout
- Immunohematology and Blood Transfusion, Leiden University Medical Center, 2300 Leiden, The Netherlands
| | | | - Nikolai N Sluchanko
- the A. N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia, and.,the Department of Biophysics, Faculty of Biology, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sergei V Strelkov
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
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10
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Terminal Regions Confer Plasticity to the Tetrameric Assembly of Human HspB2 and HspB3. J Mol Biol 2018; 430:3297-3310. [PMID: 29969581 PMCID: PMC6119766 DOI: 10.1016/j.jmb.2018.06.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/22/2018] [Accepted: 06/26/2018] [Indexed: 01/17/2023]
Abstract
Heterogeneity in small heat shock proteins (sHsps) spans multiple spatiotemporal regimes-from fast fluctuations of part of the protein, to conformational variability of tertiary structure, plasticity of the interfaces, and polydispersity of the inter-converting, and co-assembling oligomers. This heterogeneity and dynamic nature of sHsps has significantly hindered their structural characterization. Atomic coordinates are particularly lacking for vertebrate sHsps, where most available structures are of extensively truncated homomers. sHsps play important roles in maintaining protein levels in the cell and therefore in organismal health and disease. HspB2 and HspB3 are vertebrate sHsps that are found co-assembled in neuromuscular cells, and variants thereof are associated with disease. Here, we present the structure of human HspB2/B3, which crystallized as a hetero-tetramer in a 3:1 ratio. In the HspB2/B3 tetramer, the four α-crystallin domains (ACDs) assemble into a flattened tetrahedron which is pierced by two non-intersecting approximate dyads. Assembly is mediated by flexible "nuts and bolts" involving IXI/V motifs from terminal regions filling ACD pockets. Parts of the N-terminal region bind in an unfolded conformation into the anti-parallel shared ACD dimer grooves. Tracts of the terminal regions are not resolved, most likely due to their disorder in the crystal lattice. This first structure of a full-length human sHsp heteromer reveals the heterogeneous interactions of the terminal regions and suggests a plasticity that is important for the cytoprotective functions of sHsps.
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11
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Freilich R, Arhar T, Abrams JL, Gestwicki JE. Protein-Protein Interactions in the Molecular Chaperone Network. Acc Chem Res 2018; 51:940-949. [PMID: 29613769 DOI: 10.1021/acs.accounts.8b00036] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Molecular chaperones play a central role in protein homeostasis (a.k.a. proteostasis) by balancing protein folding, quality control, and turnover. To perform these diverse tasks, chaperones need the malleability to bind nearly any "client" protein and the fidelity to detect when it is misfolded. Remarkably, these activities are carried out by only ∼180 dedicated chaperones in humans. How do a relatively small number of chaperones maintain cellular and organismal proteostasis for an entire proteome? Furthermore, once a chaperone binds a client, how does it "decide" what to do with it? One clue comes from observations that individual chaperones engage in protein-protein interactions (PPIs)-both with each other and with their clients. These physical links coordinate multiple chaperones into organized, functional complexes and facilitate the "handoff" of clients between them. PPIs also link chaperones and their clients to other cellular pathways, such as those that mediate trafficking (e.g., cytoskeleton) and degradation (e.g., proteasome). The PPIs of the chaperone network have a wide range of affinity values (nanomolar to micromolar) and involve many distinct types of domain modules, such as J domains, zinc fingers, and tetratricopeptide repeats. Many of these motifs have the same binding surfaces on shared partners, such that members of one chaperone class often compete for the same interactions. Somehow, this collection of PPIs draws together chaperone families and creates multiprotein subnetworks that are able to make the "decisions" of protein quality control. The key to understanding chaperone-mediated proteostasis might be to understand how PPIs are regulated. This Account will discuss the efforts of our group and others to map, measure, and chemically perturb the PPIs within the molecular chaperone network. Structural biology methods, including X-ray crystallography, NMR spectroscopy, and electron microscopy, have all played important roles in visualizing the chaperone PPIs. Guided by these efforts and -omics approaches to measure PPIs, new advances in high-throughput chemical screening that are specially designed to account for the challenges of this system have emerged. Indeed, chemical biology has played a particularly important role in this effort, as molecules that either promote or inhibit specific PPIs have proven to be invaluable research probes in cells and animals. In addition, these molecules have provided leads for the potential treatment of protein misfolding diseases. One of the major products of this research field has been the identification of putative PPI drug targets within the chaperone network, which might be used to change chaperone "decisions" and rebalance proteostasis.
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Affiliation(s)
- Rebecca Freilich
- Department of Pharmaceutical Chemistry and The Institute for Neurodegenerative Disease, University of California—San Francisco, San Francisco, California 94158, United States
| | - Taylor Arhar
- Department of Pharmaceutical Chemistry and The Institute for Neurodegenerative Disease, University of California—San Francisco, San Francisco, California 94158, United States
| | - Jennifer L. Abrams
- Department of Pharmaceutical Chemistry and The Institute for Neurodegenerative Disease, University of California—San Francisco, San Francisco, California 94158, United States
| | - Jason E. Gestwicki
- Department of Pharmaceutical Chemistry and The Institute for Neurodegenerative Disease, University of California—San Francisco, San Francisco, California 94158, United States
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12
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Weeks SD, Muranova LK, Heirbaut M, Beelen S, Strelkov SV, Gusev NB. Characterization of human small heat shock protein HSPB1 α-crystallin domain localized mutants associated with hereditary motor neuron diseases. Sci Rep 2018; 8:688. [PMID: 29330367 PMCID: PMC5766566 DOI: 10.1038/s41598-017-18874-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 12/15/2017] [Indexed: 01/25/2023] Open
Abstract
Congenital mutations in human small heat shock protein HSPB1 (HSP27) have been linked to Charcot-Marie-Tooth disease, a commonly occurring peripheral neuropathy. Understanding the molecular mechanism of such mutations is indispensable towards developing future therapies for this currently incurable disorder. Here we describe the physico-chemical properties of the autosomal dominant HSPB1 mutants R127W, S135F and R136W. Despite having a nominal effect on thermal stability, the three mutations induce dramatic changes to quaternary structure. At high concentrations or under crowding conditions, the mutants form assemblies that are approximately two times larger than those formed by the wild-type protein. At low concentrations, the mutants have a higher propensity to dissociate into small oligomers, while the dissociation of R127W and R135F mutants is enhanced by MAPKAP kinase-2 mediated phosphorylation. Specific differences are observed in the ability to form hetero-oligomers with the homologue HSPB6 (HSP20). For wild-type HSPB1 this only occurs at or above physiological temperature, whereas the R127W and S135F mutants form hetero-oligomers with HSPB6 at 4 °C, and the R136W mutant fails to form hetero-oligomers. Combined, the results suggest that the disease-related mutations of HSPB1 modify its self-assembly and interaction with partner proteins thus affecting normal functioning of HSPB1 in the cell.
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Affiliation(s)
- Stephen D Weeks
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000, Leuven, Belgium.
| | - Lydia K Muranova
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, 119991, Russian Federation
| | - Michelle Heirbaut
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000, Leuven, Belgium
| | - Steven Beelen
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000, Leuven, Belgium
| | - Sergei V Strelkov
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000, Leuven, Belgium.
| | - Nikolai B Gusev
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, 119991, Russian Federation.
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13
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Jovcevski B, Kelly MA, Aquilina JA, Benesch JLP, Ecroyd H. Evaluating the Effect of Phosphorylation on the Structure and Dynamics of Hsp27 Dimers by Means of Ion Mobility Mass Spectrometry. Anal Chem 2017; 89:13275-13282. [PMID: 29135234 DOI: 10.1021/acs.analchem.7b03328] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The quaternary structure and dynamics of the human small heat-shock protein Hsp27 are linked to its molecular chaperone function and influenced by post-translational modifications, including phosphorylation. Phosphorylation of Hsp27 promotes oligomer dissociation and can enhance chaperone activity. This study explored the impact of phosphorylation on the quaternary structure and dynamics of Hsp27. Using mutations that mimic phosphorylation, and ion mobility mass spectrometry, we show that successive substitutions result in an increase in the conformational heterogeneity of Hsp27 dimers. In contrast, we did not detect any changes in the structure of an Hsp27 12-mer, representative of larger Hsp27 oligomers. Our data suggest that oligomer dissociation and increased flexibility of the dimer contribute to the enhanced chaperone activity of phosphorylated Hsp27. Thus, post-translational modifications such as phosphorylation play a crucial role in modulating both the tertiary and quaternary structure of Hsp27, which is pivotal to its function as a key component of the proteostasis network in cells. Our data demonstrate the utility of ion mobility mass spectrometry for probing the structure and dynamics of heterogeneous proteins.
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Affiliation(s)
- Blagojce Jovcevski
- Illawarra Health and Medical Research Institute and School of Biological Sciences, University of Wollongong , Wollongong, New South Wales 2522, Australia
| | - Megan A Kelly
- Illawarra Health and Medical Research Institute and School of Biological Sciences, University of Wollongong , Wollongong, New South Wales 2522, Australia
| | - J Andrew Aquilina
- Illawarra Health and Medical Research Institute and School of Biological Sciences, University of Wollongong , Wollongong, New South Wales 2522, Australia
| | - Justin L P Benesch
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Heath Ecroyd
- Illawarra Health and Medical Research Institute and School of Biological Sciences, University of Wollongong , Wollongong, New South Wales 2522, Australia
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14
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Sudnitsyna MV, Gusev NB. Methylglyoxal and Small Heat Shock Proteins. BIOCHEMISTRY (MOSCOW) 2017; 82:751-759. [PMID: 28918740 DOI: 10.1134/s000629791707001x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Methylglyoxal is a highly reactive dicarbonyl compound formed during glucose metabolism and able to modify phospholipids, nucleic acids, and proteins belonging to the so-called dicarbonyl proteome. Small heat shock proteins participating in protection of the cell against different unfavorable conditions can be modified by methylglyoxal. The probability of methylglyoxal modification is increased in the case of distortion of glucose metabolism (diabetes), in the case of utilization of glycolysis as the main source of energy (malignancy), and/or at low rate of modified protein turnover. We have analyzed data on modification of small heat shock protein HspB1 in different tumors and under distortion of carbohydrate metabolism. Data on the effect of methylglyoxal modification on stability, chaperone-like activity, and antiapoptotic activity of HspB1 were analyzed. We discuss data on methylglyoxal modifications of lens α-crystallins. The mutual dependence and mutual effects of methylglyoxal modification and other posttranslational modifications of lens crystallins are analyzed. We conclude that although there is no doubt that the small heat shock proteins undergo methylglyoxal modification, the physiological significance of this process remains enigmatic, and new experimental approaches should be developed for understanding how this type of modification affects functioning of small heat shock proteins in the cell.
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Affiliation(s)
- M V Sudnitsyna
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia.
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15
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Carver JA, Grosas AB, Ecroyd H, Quinlan RA. The functional roles of the unstructured N- and C-terminal regions in αB-crystallin and other mammalian small heat-shock proteins. Cell Stress Chaperones 2017; 22:627-638. [PMID: 28391594 PMCID: PMC5465038 DOI: 10.1007/s12192-017-0789-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/06/2017] [Accepted: 03/16/2017] [Indexed: 01/18/2023] Open
Abstract
Small heat-shock proteins (sHsps), such as αB-crystallin, are one of the major classes of molecular chaperone proteins. In vivo, under conditions of cellular stress, sHsps are the principal defence proteins that prevent large-scale protein aggregation. Progress in determining the structure of sHsps has been significant recently, particularly in relation to the conserved, central and β-sheet structured α-crystallin domain (ACD). However, an understanding of the structure and functional roles of the N- and C-terminal flanking regions has proved elusive mainly because of their unstructured and dynamic nature. In this paper, we propose functional roles for both flanking regions, based around three properties: (i) they act in a localised crowding manner to regulate interactions with target proteins during chaperone action, (ii) they protect the ACD from deleterious amyloid fibril formation and (iii) the flexibility of these regions, particularly at the extreme C-terminus in mammalian sHsps, provides solubility for sHsps under chaperone and non-chaperone conditions. In the eye lens, these properties are highly relevant as the crystallin proteins, in particular the two sHsps αA- and αB-crystallin, are present at very high concentrations.
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Affiliation(s)
- John A Carver
- Research School of Chemistry, The Australian National University, Acton, ACT, 2601, Australia.
| | - Aidan B Grosas
- Research School of Chemistry, The Australian National University, Acton, ACT, 2601, Australia
| | - Heath Ecroyd
- School of Biological Sciences and the Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Roy A Quinlan
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK
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16
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Preis W, Bestehorn A, Buchner J, Haslbeck M. An alternative splice variant of human αA-crystallin modulates the oligomer ensemble and the chaperone activity of α-crystallins. Cell Stress Chaperones 2017; 22:541-552. [PMID: 28214988 PMCID: PMC5465031 DOI: 10.1007/s12192-017-0772-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/31/2017] [Accepted: 02/01/2017] [Indexed: 01/26/2023] Open
Abstract
In humans, ten genes encode small heat shock proteins with lens αA-crystallin and αB-crystallin representing two of the most prominent members. The canonical isoforms of αA-crystallin and αB-crystallin collaborate in the eye lens to prevent irreversible protein aggregation and preserve visual acuity. α-Crystallins form large polydisperse homo-oligomers and hetero-oligomers and as part of the proteostasis system bind substrate proteins in non-native conformations, thereby stabilizing them. Here, we analyzed a previously uncharacterized, alternative splice variant (isoform 2) of human αA-crystallin with an exchanged N-terminal sequence. This variant shows the characteristic α-crystallin secondary structure, exists on its own predominantly in a monomer-dimer equilibrium, and displays only low chaperone activity. However, the variant is able to integrate into higher order oligomers of canonical αA-crystallin and αB-crystallin as well as their hetero-oligomer. The presence of the variant leads to the formation of new types of higher order hetero-oligomers with an overall decreased number of subunits and enhanced chaperone activity. Thus, alternative mRNA splicing of human αA-crystallin leads to an additional, formerly not characterized αA-crystallin species which is able to modulate the properties of the canonical ensemble of α-crystallin oligomers.
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Affiliation(s)
- Waldemar Preis
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Annika Bestehorn
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Johannes Buchner
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Martin Haslbeck
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany.
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17
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Carra S, Alberti S, Arrigo PA, Benesch JL, Benjamin IJ, Boelens W, Bartelt-Kirbach B, Brundel BJJM, Buchner J, Bukau B, Carver JA, Ecroyd H, Emanuelsson C, Finet S, Golenhofen N, Goloubinoff P, Gusev N, Haslbeck M, Hightower LE, Kampinga HH, Klevit RE, Liberek K, Mchaourab HS, McMenimen KA, Poletti A, Quinlan R, Strelkov SV, Toth ME, Vierling E, Tanguay RM. The growing world of small heat shock proteins: from structure to functions. Cell Stress Chaperones 2017; 22:601-611. [PMID: 28364346 PMCID: PMC5465036 DOI: 10.1007/s12192-017-0787-8] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2017] [Indexed: 12/21/2022] Open
Abstract
Small heat shock proteins (sHSPs) are present in all kingdoms of life and play fundamental roles in cell biology. sHSPs are key components of the cellular protein quality control system, acting as the first line of defense against conditions that affect protein homeostasis and proteome stability, from bacteria to plants to humans. sHSPs have the ability to bind to a large subset of substrates and to maintain them in a state competent for refolding or clearance with the assistance of the HSP70 machinery. sHSPs participate in a number of biological processes, from the cell cycle, to cell differentiation, from adaptation to stressful conditions, to apoptosis, and, even, to the transformation of a cell into a malignant state. As a consequence, sHSP malfunction has been implicated in abnormal placental development and preterm deliveries, in the prognosis of several types of cancer, and in the development of neurological diseases. Moreover, mutations in the genes encoding several mammalian sHSPs result in neurological, muscular, or cardiac age-related diseases in humans. Loss of protein homeostasis due to protein aggregation is typical of many age-related neurodegenerative and neuromuscular diseases. In light of the role of sHSPs in the clearance of un/misfolded aggregation-prone substrates, pharmacological modulation of sHSP expression or function and rescue of defective sHSPs represent possible routes to alleviate or cure protein conformation diseases. Here, we report the latest news and views on sHSPs discussed by many of the world's experts in the sHSP field during a dedicated workshop organized in Italy (Bertinoro, CEUB, October 12-15, 2016).
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Affiliation(s)
- Serena Carra
- Department of Biomedical, Metabolic and Neural Sciences, and Centre for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via G. Campi 287, 41125 Modena, Italy
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Patrick A. Arrigo
- Université de Lyon, 69622 Lyon, France
- CNRS, UMR 5310, INSERM U1217, Institut NeuroMyoGène, Université Lyon 1, 69100 Villeurbanne, France
| | | | - Ivor J. Benjamin
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112-5650 USA
| | - Wilbert Boelens
- Biomolecular Chemistry, 284, Radboud University, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | | | - Bianca J. J. M. Brundel
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | | | - Bernd Bukau
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - John A. Carver
- The Research School of Chemistry, The Australian National University, Acton, ACT 2601 Australia
| | - Heath Ecroyd
- Illawara Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Cecilia Emanuelsson
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, 221 00 Lund, Sweden
| | - Stephanie Finet
- IMPMC UMR7590, CNRS, UPMC Paris 6, 4 place Jussieu, Paris, France
| | - Nikola Golenhofen
- Institute of Anatomy and Cell Biology, University of Ulm, 89081 Ulm, Germany
| | - Pierre Goloubinoff
- Department of Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Nikolai Gusev
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, 119991 Russia
| | | | - Lawrence E. Hightower
- Department of Molecular & Cell Biology, University of Connecticut, 91 North Eagleville Road, Storrs, CT 06269-3125 USA
| | - Harm H. Kampinga
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
| | - Rachel E. Klevit
- Department of Biochemistry, University of Washington, Seattle, WA 98195 USA
| | - Krzysztof Liberek
- Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and the Medical University of Gdańsk, Gdańsk, Poland
| | - Hassane S. Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232 USA
| | - Kathryn A. McMenimen
- Departments of Pathology, Biological Chemistry, and Medicinal Chemistry and the Life Sciences Institute, University of Michigan, Ann Arbor, MI USA
| | - Angelo Poletti
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Roy Quinlan
- Department of Biosciences and the Biophysical Sciences Institute, University of Durham, Durham, UK
| | - Sergei V. Strelkov
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Melinda E. Toth
- Laboratory of Animal Genetics and Molecular Neurobiology, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Elizabeth Vierling
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003 USA
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721 USA
| | - Robert M. Tanguay
- Laboratory of Cell & Developmental Genetics, IBIS, and Department of Molecular Biology, Medical Biochemistry and Pathology, Medical School, Université Laval, Québec (Qc), G1V 0A6 Canada
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18
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Heirbaut M, Lermyte F, Martin EM, Beelen S, Sobott F, Strelkov SV, Weeks SD. Specific sequences in the N-terminal domain of human small heat-shock protein HSPB6 dictate preferential hetero-oligomerization with the orthologue HSPB1. J Biol Chem 2017; 292:9944-9957. [PMID: 28487364 DOI: 10.1074/jbc.m116.773515] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/20/2017] [Indexed: 12/17/2022] Open
Abstract
Small heat-shock proteins (sHSPs) are a conserved group of molecular chaperones with important roles in cellular proteostasis. Although sHSPs are characterized by their small monomeric weight, they typically assemble into large polydisperse oligomers that vary in both size and shape but are principally composed of dimeric building blocks. These assemblies can include different sHSP orthologues, creating additional complexity that may affect chaperone activity. However, the structural and functional properties of such hetero-oligomers are poorly understood. We became interested in hetero-oligomer formation between human heat-shock protein family B (small) member 1 (HSPB1) and HSPB6, which are both highly expressed in skeletal muscle. When mixed in vitro, these two sHSPs form a polydisperse oligomer array composed solely of heterodimers, suggesting preferential association that is determined at the monomer level. Previously, we have shown that the sHSP N-terminal domains (NTDs), which have a high degree of intrinsic disorder, are essential for the biased formation. Here we employed iterative deletion mapping to elucidate how the NTD of HSPB6 influences its preferential association with HSPB1 and show that this region has multiple roles in this process. First, the highly conserved motif RLFDQXFG is necessary for subunit exchange among oligomers. Second, a site ∼20 residues downstream of this motif determines the size of the resultant hetero-oligomers. Third, a region unique to HSPB6 dictates the preferential formation of heterodimers. In conclusion, the disordered NTD of HSPB6 helps regulate the size and stability of hetero-oligomeric complexes, indicating that terminal sHSP regions define the assembly properties of these proteins.
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Affiliation(s)
- Michelle Heirbaut
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Frederik Lermyte
- the Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium, and
| | - Esther M Martin
- the Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium, and.,the Astbury Centre for Structural Molecular Biology and
| | - Steven Beelen
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Frank Sobott
- the Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium, and.,the Astbury Centre for Structural Molecular Biology and.,School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, United Kingdom
| | - Sergei V Strelkov
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium,
| | - Stephen D Weeks
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium,
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