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GroEL—A Versatile Chaperone for Engineering and a Plethora of Applications. Biomolecules 2022; 12:biom12050607. [PMID: 35625535 PMCID: PMC9138447 DOI: 10.3390/biom12050607] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 12/16/2022] Open
Abstract
Chaperones play a vital role in the life of cells by facilitating the correct folding of other proteins and maintaining them in a functional state, being themselves, as a rule, more stable than the rest of cell proteins. Their functional properties naturally tempt investigators to actively adapt them for biotechnology needs. This review will mostly focus on the applications found for the bacterial chaperonin GroE and its counterparts from other organisms, in biotechnology or for research purposes, both in their engineered or intact versions.
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Yamamoto H, Fukui N, Adachi M, Saiki E, Yamasaki A, Matsumura R, Kuroyanagi D, Hongo K, Mizobata T, Kawata Y. Human Molecular Chaperone Hsp60 and Its Apical Domain Suppress Amyloid Fibril Formation of α-Synuclein. Int J Mol Sci 2019; 21:ijms21010047. [PMID: 31861692 PMCID: PMC6982183 DOI: 10.3390/ijms21010047] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 01/14/2023] Open
Abstract
Heat shock proteins play roles in assisting other proteins to fold correctly and in preventing the aggregation and accumulation of proteins in misfolded conformations. However, the process of aging significantly degrades this ability to maintain protein homeostasis. Consequently, proteins with incorrect conformations are prone to aggregate and accumulate in cells, and this aberrant aggregation of misfolded proteins may trigger various neurodegenerative diseases, such as Parkinson's disease. Here, we investigated the possibilities of suppressing α-synuclein aggregation by using a mutant form of human chaperonin Hsp60, and a derivative of the isolated apical domain of Hsp60 (Hsp60 AD(Cys)). In vitro measurements were used to detect the effects of chaperonin on amyloid fibril formation, and interactions between Hsp60 proteins and α-synuclein were probed by quartz crystal microbalance analysis. The ability of Hsp60 AD(Cys) to suppress α-synuclein intracellular aggregation and cytotoxicity was also demonstrated. We show that Hsp60 mutant and Hsp60 AD(Cys) both effectively suppress α-synuclein amyloid fibril formation, and also demonstrate for the first time the ability of Hsp60 AD(Cys) to function as a mini-chaperone inside cells. These results highlight the possibility of using Hsp60 AD as a method of prevention and treatment of neurodegenerative diseases.
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Affiliation(s)
- Hanae Yamamoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; (H.Y.); (N.F.); (D.K.); (K.H.)
| | - Naoya Fukui
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; (H.Y.); (N.F.); (D.K.); (K.H.)
| | - Mayuka Adachi
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Koyama-Minami, Tottori 680-8552, Japan; (M.A.); (A.Y.); (R.M.)
| | - Eiichi Saiki
- Department of Chemistry and Biotechnology, Faculty of Engineering, Tottori University, Koyama-Minami, Tottori 680-8552, Japan;
| | - Anna Yamasaki
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Koyama-Minami, Tottori 680-8552, Japan; (M.A.); (A.Y.); (R.M.)
| | - Rio Matsumura
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Koyama-Minami, Tottori 680-8552, Japan; (M.A.); (A.Y.); (R.M.)
| | - Daichi Kuroyanagi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; (H.Y.); (N.F.); (D.K.); (K.H.)
| | - Kunihiro Hongo
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; (H.Y.); (N.F.); (D.K.); (K.H.)
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Koyama-Minami, Tottori 680-8552, Japan; (M.A.); (A.Y.); (R.M.)
- Department of Chemistry and Biotechnology, Faculty of Engineering, Tottori University, Koyama-Minami, Tottori 680-8552, Japan;
- Center for Research on Green Sustainable Chemistry, Koyama-Minami, Tottori University, Tottori 680-8552, Japan
| | - Tomohiro Mizobata
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; (H.Y.); (N.F.); (D.K.); (K.H.)
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Koyama-Minami, Tottori 680-8552, Japan; (M.A.); (A.Y.); (R.M.)
- Department of Chemistry and Biotechnology, Faculty of Engineering, Tottori University, Koyama-Minami, Tottori 680-8552, Japan;
- Center for Research on Green Sustainable Chemistry, Koyama-Minami, Tottori University, Tottori 680-8552, Japan
| | - Yasushi Kawata
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; (H.Y.); (N.F.); (D.K.); (K.H.)
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Koyama-Minami, Tottori 680-8552, Japan; (M.A.); (A.Y.); (R.M.)
- Department of Chemistry and Biotechnology, Faculty of Engineering, Tottori University, Koyama-Minami, Tottori 680-8552, Japan;
- Center for Research on Green Sustainable Chemistry, Koyama-Minami, Tottori University, Tottori 680-8552, Japan
- Correspondence: ; Tel.: +81-857-31-5787
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Miyawaki S, Uemura Y, Hongo K, Kawata Y, Mizobata T. Acid-denatured small heat shock protein HdeA from Escherichia coli forms reversible fibrils with an atypical secondary structure. J Biol Chem 2018; 294:1590-1601. [PMID: 30530490 DOI: 10.1074/jbc.ra118.005611] [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] [Received: 08/28/2018] [Revised: 12/06/2018] [Indexed: 12/13/2022] Open
Abstract
The periplasmic small heat shock protein HdeA from Escherichia coli is inactive under normal growth conditions (at pH 7) and activated only when E. coli cells are subjected to a sudden decrease in pH, converting HdeA into an acid-denatured active state. Here, using in vitro fibrillation assays, transmission EM, atomic-force microscopy, and CD analyses, we found that when HdeA is active as a molecular chaperone, it is also capable of forming inactive aggregates that, at first glance, resemble amyloid fibrils. We noted that the molecular chaperone activity of HdeA takes precedence over fibrillogenesis under acidic conditions, as the presence of denatured substrate protein was sufficient to suppress HdeA fibril formation. Further experiments suggested that the secondary structure of HdeA fibrils deviates somewhat from typical amyloid fibrils and contains α-helices. Strikingly, HdeA fibrils that formed at pH 2 were immediately resolubilized by a simple shift to pH 7 and from there could regain molecular chaperone activity upon a return to pH 1. HdeA, therefore, provides an unusual example of a "reversible" form of protein fibrillation with an atypical secondary structure composition. The competition between active assistance of denatured polypeptides (its "molecular chaperone" activity) and the formation of inactive fibrillary deposits (its "fibrillogenic" activity) provides a unique opportunity to probe the relationship among protein function, structure, and aggregation in detail.
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Affiliation(s)
- Shiori Miyawaki
- Graduate School of Sustainability Science, Tottori University, Tottori 680-8552, Japan
| | - Yumi Uemura
- Department of Engineering, Tottori University, Tottori 680-8552, Japan
| | - Kunihiro Hongo
- Graduate School of Sustainability Science, Tottori University, Tottori 680-8552, Japan; Department of Engineering, Tottori University, Tottori 680-8552, Japan; Center for Research on Green Sustainable Chemistry, Tottori University, Tottori 680-8552, Japan
| | - Yasushi Kawata
- Graduate School of Sustainability Science, Tottori University, Tottori 680-8552, Japan; Department of Engineering, Tottori University, Tottori 680-8552, Japan; Center for Research on Green Sustainable Chemistry, Tottori University, Tottori 680-8552, Japan
| | - Tomohiro Mizobata
- Graduate School of Sustainability Science, Tottori University, Tottori 680-8552, Japan; Department of Engineering, Tottori University, Tottori 680-8552, Japan; Center for Research on Green Sustainable Chemistry, Tottori University, Tottori 680-8552, Japan.
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Mizobata T, Kawata Y. The versatile mutational "repertoire" of Escherichia coli GroEL, a multidomain chaperonin nanomachine. Biophys Rev 2017; 10:631-640. [PMID: 29181744 DOI: 10.1007/s12551-017-0332-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/05/2017] [Indexed: 12/14/2022] Open
Abstract
The bacterial chaperonins are highly sophisticated molecular nanomachines, controlled by the hydrolysis of ATP to dynamically trap and remove from the environment unstable protein molecules that are susceptible to denaturation and aggregation. Chaperonins also act to assist in the refolding of these unstable proteins, providing a means by which these proteins may return in active form to the complex environment of the cell. The Escherichia coli GroE chaperonin system is one of the largest protein supramolecular complexes known, whose quaternary structure is required for segregating aggregation-prone proteins. Over the course of more than two decades of research on GroE, it has become accepted that GroE, more specifically the GroEL subunit, is a "high-tolerance" molecular system, capable of accommodating numerous mutations, while retaining its molecular integrity. In some cases, a given site of mutation was revealed to be absolutely required for GroEL function, providing hints regarding the network of signals and triggers that propel this unique system. In other instances, however, a mutation has produced a more delicate response, altering only part of, or in some cases, only a single facet of, the molecular mechanism, and these mutants have often provided invaluable hints on the extent of the complexity underlying chaperonin-assisted protein folding. In this review, we highlight some examples of the latter type of GroEL mutants which compose the unique "mutational repertoire" of GroEL and touch upon the important clues that each mutant provided to the overall effort to elucidate the details of GroE action.
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Affiliation(s)
- Tomohiro Mizobata
- Graduate School of Engineering and Graduate School of Medical Sciences, Tottori University, Tottori, 680-8552, Japan.
| | - Yasushi Kawata
- Graduate School of Engineering and Graduate School of Medical Sciences, Tottori University, Tottori, 680-8552, Japan.
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Fukui N, Araki K, Hongo K, Mizobata T, Kawata Y. Modulating the Effects of the Bacterial Chaperonin GroEL on Fibrillogenic Polypeptides through Modification of Domain Hinge Architecture. J Biol Chem 2016; 291:25217-25226. [PMID: 27742838 DOI: 10.1074/jbc.m116.751925] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/05/2016] [Indexed: 11/06/2022] Open
Abstract
The isolated apical domain of the Escherichia coli GroEL subunit displays the ability to suppress the irreversible fibrillation of numerous amyloid-forming polypeptides. In previous experiments, we have shown that mutating Gly-192 (located at hinge II that connects the apical domain and the intermediate domain) to a tryptophan results in an inactive chaperonin whose apical domain is disoriented. In this study, we have utilized this disruptive effect of Gly-192 mutation to our advantage, by substituting this residue with amino acid residues of varying van der Waals volumes with the intent to modulate the affinity of GroEL toward fibrillogenic peptides. The affinities of GroEL toward fibrillogenic polypeptides such as Aβ(1-40) (amyloid-β(1-40)) peptide and α-synuclein increased in accordance to the larger van der Waals volume of the substituent amino acid side chain in the G192X mutants. When we compared the effects of wild-type GroEL and selected GroEL G192X mutants on α-synuclein fibril formation, we found that the effects of the chaperonin on α-synuclein fibrillation were different; the wild-type chaperonin caused changes in both the initial lag phase and the rate of fibril extension, whereas the effects of the G192X mutants were more specific toward the nucleus-forming lag phase. The chaperonins also displayed differential effects on α-synuclein fibril morphology, suggesting that through mutation of Gly-192, we may induce changes to the intermolecular affinities between GroEL and α-synuclein, leading to more efficient fibril suppression, and in specific cases, modulation of fibril morphology.
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Affiliation(s)
- Naoya Fukui
- From the Department of Chemistry and Biotechnology, Graduate School of Engineering, and
| | - Kiho Araki
- From the Department of Chemistry and Biotechnology, Graduate School of Engineering, and
| | - Kunihiro Hongo
- From the Department of Chemistry and Biotechnology, Graduate School of Engineering, and.,the Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori 680-8552, Japan
| | - Tomohiro Mizobata
- From the Department of Chemistry and Biotechnology, Graduate School of Engineering, and.,the Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori 680-8552, Japan
| | - Yasushi Kawata
- From the Department of Chemistry and Biotechnology, Graduate School of Engineering, and .,the Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori 680-8552, Japan
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GroEL2 of Mycobacterium tuberculosis Reveals the Importance of Structural Pliability in Chaperonin Function. J Bacteriol 2015; 198:486-97. [PMID: 26553853 DOI: 10.1128/jb.00844-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 11/05/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Intracellular protein folding is mediated by molecular chaperones, the best studied among which are the chaperonins GroEL and GroES. Conformational changes and allosteric transitions between different metastable states are hallmarks of the chaperonin mechanism. These conformational transitions between three structural domains of GroEL are anchored at two hinges. Although hinges are known to be critical for mediating the communication between different domains of GroEL, the relative importance of hinges on GroEL oligomeric assembly, ATPase activity, conformational changes, and functional activity is not fully characterized. We have exploited the inability of Mycobacterium tuberculosis GroEL2 to functionally complement an Escherichia coli groEL mutant to address the importance of hinge residues in the GroEL mechanism. Various chimeras of M. tuberculosis GroEL2 and E. coli GroEL allowed us to understand the role of hinges and dissect the consequences of oligomerization and substrate binding capability on conformational transitions. The present study explains the concomitant conformational changes observed with GroEL hinge variants and is best supported by the normal mode analysis. IMPORTANCE Conformational changes and allosteric transitions are hallmarks of the chaperonin mechanism. We have exploited the inability of M. tuberculosis GroEL2 to functionally complement a strain of E. coli in which groEL expression is repressed to address the importance of hinges. The significance of conservation at the hinge regions stands out as a prominent feature of the GroEL mechanism in binding to GroES and substrate polypeptides. The hinge residues play a significant role in the chaperonin activity in vivo and in vitro.
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Abstract
Co-chaperonins function together with chaperonins to mediate ATP-dependant protein folding in a variety of cellular compartments. GroEL and its co-chaperonin GroES are the only essential chaperones in Escherichia coli and are the archetypal members of this family of protein folding machines. The unique mechanism used by GroEL and GroES to drive protein folding is embedded in the complex architecture of double-ringed complexes, forming two central chambers that undergo structural rearrangements as part of the folding mechanism. GroES forms a lid over the chamber, and in doing so dislodges bound substrate into the chamber, thereby allowing non-native proteins to fold in isolation. GroES also modulates allosteric transitions of GroEL. A significant number of bacteria and eukaryotes house multiple chaperonin and co-chaperonin proteins, many of which have acquired additional intracellular and extracellular biological functions. In some instances co-chaperonins display contrasting functions to those of chaperonins. Human Hsp60 continues to play a key role in the pathogenesis of many human diseases, in particular autoimmune diseases and cancer. A greater understanding of the fascinating roles of both intracellular and extracellular Hsp10, in addition to its role as a co-chaperonin, on cellular processes will accelerate the development of techniques to treat diseases associated with the chaperonin family.
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Affiliation(s)
- Aileen Boshoff
- Biomedical Biotechnology Research Unit (BioBRU), Biotechnology Innovation Centre, Rhodes University, PO Box 94, 6140, Grahamstown, South Africa,
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Mizuta T, Ando K, Uemura T, Kawata Y, Mizobata T. Probing the dynamic process of encapsulation in Escherichia coli GroEL. PLoS One 2013; 8:e78135. [PMID: 24205127 PMCID: PMC3813556 DOI: 10.1371/journal.pone.0078135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/16/2013] [Indexed: 11/24/2022] Open
Abstract
Kinetic analyses of GroE-assisted folding provide a dynamic sequence of molecular events that underlie chaperonin function. We used stopped-flow analysis of various fluorescent GroEL mutants to obtain details regarding the sequence of events that transpire immediately after ATP binding to GroEL and GroEL with prebound unfolded proteins. Characterization of GroEL CP86, a circularly permuted GroEL with the polypeptide ends relocated to the vicinity of the ATP binding site, showed that GroES binding and protection of unfolded protein from solution is achieved surprisingly early in the functional cycle, and in spite of greatly reduced apical domain movement. Analysis of fluorescent GroEL SR-1 and GroEL D398A variants suggested that among other factors, the presence of two GroEL rings and a specific conformational rearrangement of Helix M in GroEL contribute significantly to the rapid release of unfolded protein from the GroEL apical domain.
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Affiliation(s)
- Toshifumi Mizuta
- Department of Biotechnology, Graduate School of Engineering, Tottori, Japan
| | - Kasumi Ando
- Department of Biotechnology, Graduate School of Engineering, Tottori, Japan
| | - Tatsuya Uemura
- Department of Biomedical Science, Graduate School of Medical Sciences, Tottori University, Tottori, Japan
| | - Yasushi Kawata
- Department of Biotechnology, Graduate School of Engineering, Tottori, Japan
- Department of Biomedical Science, Graduate School of Medical Sciences, Tottori University, Tottori, Japan
| | - Tomohiro Mizobata
- Department of Biotechnology, Graduate School of Engineering, Tottori, Japan
- Department of Biomedical Science, Graduate School of Medical Sciences, Tottori University, Tottori, Japan
- * E-mail:
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Kim KS, Lee JY, Kwon SY, Yang HJ, Choi EK, Shin MH, Ahn KS, Um JY, Lee JH, Jang HJ. Comparative transcriptomic analysis of the multi-targeted effects of the herbal extracts against Escherichia coli O157:H7. BIOCHIP JOURNAL 2012. [DOI: 10.1007/s13206-012-6410-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yamauchi S, Ueda Y, Matsumoto M, Inoue U, Hayashi H. Distinct features of protein folding by the GroEL system from a psychrophilic bacterium, Colwellia psychrerythraea 34H. Extremophiles 2012; 16:871-82. [PMID: 22996829 DOI: 10.1007/s00792-012-0483-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 09/09/2012] [Indexed: 01/28/2023]
Abstract
We investigated the protein folding mechanism of the GroEL system of a psychrophilic bacterium, Colwellia psychrerythraea 34H. The amount of mRNA of the groESL operon of C. psychrerythraea was increased about 6-fold after a temperature upshift from 8 to 18 °C for 30 min, suggesting that this temperature causes heat stress in this bacterium. A σ(32)-type promoter was found upstream of the groESL, suggesting that the C. psychrerythraea groESL is regulated by the σ(32) system, like the groESL in E. coli. The maximum ATPase and CTPase activities of CpGroEL were observed at 45 and 35 °C, respectively, which are much higher than the growth temperatures of C. psychrerythraea. We found that the refolding activity of the CpGroEL system in the presence of ATP is lower than that in the presence of CTP. This suggests that ATP is not the optimum energy source of the CpGroEL system. Analyses for the interaction of CpGroEL-CpGroES revealed that CTP could weaken this interaction, resulting in effective refolding function of the CpGroEL system. From these findings, we consider that the CpGroEL system possesses an energy-saving mechanism for avoiding excess consumption of ATP to ensure growth in a low-temperature environment.
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Affiliation(s)
- Seiji Yamauchi
- Cell-Free Science and Technology Research Center, Ehime University, 3 Bunkyo-cho, Matsuyama, 790-8577, Japan.
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Tanabe M, Ishida R, Izuhara F, Komatsuda A, Wakui H, Sawada K, Otaka M, Nakamura N, Itoh H. The ATPase activity of molecular chaperone HSP60 is inhibited by immunosuppressant mizoribine. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ajmb.2012.22010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Reconstitution of the human chaperonin CCT by co-expression of the eight distinct subunits in mammalian cells. Protein Expr Purif 2011; 82:61-9. [PMID: 22133715 DOI: 10.1016/j.pep.2011.11.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/10/2011] [Accepted: 11/14/2011] [Indexed: 11/20/2022]
Abstract
The eukaryotic cytosolic chaperonin CCT (chaperonin-containing TCP-1) assists folding of newly synthesized polypeptides. The fully functional CCT is built from two identical rings, each composed of single copies of eight distinct subunits. To study the structure and function of the CCT complex and the role of each subunit, a rapid and efficient method for preparing a recombinant CCT complex is needed. In this work, we established an efficient expression and purification method to obtain human recombinant CCT. BHK-21 cells were infected with a vaccinia virus expressing T7 RNA polymerase and transfected with eight plasmids, each encoding any one of the eight CCT subunits in the T7 RNA polymerase promoter/terminator unit. The CCT1 subunit was engineered to carry a hexa-histidine tag or FLAG tag in the internal loop region. Three days later, cells were harvested for purification of the CCT complex through tag-dependent affinity chromatography and gel filtration. The purified recombinant CCT complexes were indistinguishable from the endogenous CCT purified from HeLa cells in terms of morphology and function. In conclusion, the co-expression system established in this study should be a simple and powerful tool for reconstitution of a large multi-subunit complex.
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Mizobata T, Uemura T, Isaji K, Hirayama T, Hongo K, Kawata Y. Probing the functional mechanism of Escherichia coli GroEL using circular permutation. PLoS One 2011; 6:e26462. [PMID: 22028884 PMCID: PMC3196576 DOI: 10.1371/journal.pone.0026462] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 09/27/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The Escherichia coli chaperonin GroEL subunit consists of three domains linked via two hinge regions, and each domain is responsible for a specific role in the functional mechanism. Here, we have used circular permutation to study the structural and functional characteristics of the GroEL subunit. METHODOLOGY/PRINCIPAL FINDINGS Three soluble, partially active mutants with polypeptide ends relocated into various positions of the apical domain of GroEL were isolated and studied. The basic functional hallmarks of GroEL (ATPase and chaperoning activities) were retained in all three mutants. Certain functional characteristics, such as basal ATPase activity and ATPase inhibition by the cochaperonin GroES, differed in the mutants while at the same time, the ability to facilitate the refolding of rhodanese was roughly equal. Stopped-flow fluorescence experiments using a fluorescent variant of the circularly permuted GroEL CP376 revealed that a specific kinetic transition that reflects movements of the apical domain was missing in this mutant. This mutant also displayed several characteristics that suggested that the apical domains were behaving in an uncoordinated fashion. CONCLUSIONS/SIGNIFICANCE The loss of apical domain coordination and a concomitant decrease in functional ability highlights the importance of certain conformational signals that are relayed through domain interlinks in GroEL. We propose that circular permutation is a very versatile tool to probe chaperonin structure and function.
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Affiliation(s)
- Tomohiro Mizobata
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan.
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