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Chen X, Kaiser CM. AP profiling resolves co-translational folding pathway and chaperone interactions in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555749. [PMID: 37693575 PMCID: PMC10491307 DOI: 10.1101/2023.09.01.555749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Natural proteins have evolved to fold robustly along specific pathways. Folding begins during synthesis, guided by interactions of the nascent protein with the ribosome and molecular chaperones. However, the timing and progression of co-translational folding remain largely elusive, in part because the process is difficult to measure in the natural environment of the cytosol. We developed a high-throughput method to quantify co-translational folding in live cells that we term Arrest Peptide profiling (AP profiling). We employed AP profiling to delineate co-translational folding for a set of GTPase domains with very similar structures, defining how topology shapes folding pathways. Genetic ablation of major nascent chain-binding chaperones resulted in localized folding changes that suggest how functional redundancies among chaperones are achieved by distinct interactions with the nascent protein. Collectively, our studies provide a window into cellular folding pathways of complex proteins and pave the way for systematic studies on nascent protein folding at unprecedented resolution and throughput.
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Affiliation(s)
- Xiuqi Chen
- CMDB Graduate Program, Johns Hopkins University, Baltimore, MD, United States
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
- Present address: Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Christian M. Kaiser
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, United States
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2
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Rong Y, Jensen SI, Lindorff-Larsen K, Nielsen AT. Folding of heterologous proteins in bacterial cell factories: Cellular mechanisms and engineering strategies. Biotechnol Adv 2023; 63:108079. [PMID: 36528238 DOI: 10.1016/j.biotechadv.2022.108079] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 11/20/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022]
Abstract
The expression of correctly folded and functional heterologous proteins is important in many biotechnological production processes, whether it is enzymes, biopharmaceuticals or biosynthetic pathways for production of sustainable chemicals. For industrial applications, bacterial platform organisms, such as E. coli, are still broadly used due to the availability of tools and proven suitability at industrial scale. However, expression of heterologous proteins in these organisms can result in protein aggregation and low amounts of functional protein. This review provides an overview of the cellular mechanisms that can influence protein folding and expression, such as co-translational folding and assembly, chaperone binding, as well as protein quality control, across different model organisms. The knowledge of these mechanisms is then linked to different experimental methods that have been applied in order to improve functional heterologous protein folding, such as codon optimization, fusion tagging, chaperone co-production, as well as strain and protein engineering strategies.
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Affiliation(s)
- Yixin Rong
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Sheila Ingemann Jensen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200 Copenhagen N, Denmark
| | - Alex Toftgaard Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
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3
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Protein folding in vitro and in the cell: From a solitary journey to a team effort. Biophys Chem 2022; 287:106821. [PMID: 35667131 PMCID: PMC9636488 DOI: 10.1016/j.bpc.2022.106821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 04/18/2022] [Accepted: 04/21/2022] [Indexed: 12/22/2022]
Abstract
Correct protein folding is essential for the health and function of living organisms. Yet, it is not well understood how unfolded proteins reach their native state and avoid aggregation, especially within the cellular milieu. Some proteins, especially small, single-domain and apparent two-state folders, successfully attain their native state upon dilution from denaturant. Yet, many more proteins undergo misfolding and aggregation during this process, in a concentration-dependent fashion. Once formed, native and aggregated states are often kinetically trapped relative to each other. Hence, the early stages of protein life are absolutely critical for proper kinetic channeling to the folded state and for long-term solubility and function. This review summarizes current knowledge on protein folding/aggregation mechanisms in buffered solution and within the bacterial cell, highlighting early stages. Remarkably, teamwork between nascent chain, ribosome, trigger factor and Hsp70 molecular chaperones enables all proteins to overcome aggregation propensities and reach a long-lived bioactive state.
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4
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Miyake M, Sobajima M, Kurahashi K, Shigenaga A, Denda M, Otaka A, Saio T, Sakane N, Kosako H, Oyadomari S. Identification of an endoplasmic reticulum proteostasis modulator that enhances insulin production in pancreatic β cells. Cell Chem Biol 2022; 29:996-1009.e9. [PMID: 35143772 DOI: 10.1016/j.chembiol.2022.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 11/11/2021] [Accepted: 01/06/2022] [Indexed: 12/13/2022]
Abstract
Perturbation of endoplasmic reticulum (ER) proteostasis is associated with impairment of cellular function in diverse diseases, especially the function of pancreatic β cells in type 2 diabetes. Restoration of ER proteostasis by small molecules shows therapeutic promise for type 2 diabetes. Here, using cell-based screening, we report identification of a chemical chaperone-like small molecule, KM04794, that alleviates ER stress. KM04794 prevented protein aggregation and cell death caused by ER stressors and a mutant insulin protein. We also found that this compound increased intracellular and secreted insulin levels in pancreatic β cells. Chemical biology and biochemical approaches revealed that the compound accumulated in the ER and interacted directly with the ER molecular chaperone BiP. Our data show that this corrector of ER proteostasis can enhance insulin storage and pancreatic β cell function.
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Affiliation(s)
- Masato Miyake
- Division of Molecular Biology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan; Department of Molecular Research, Diabetes Therapeutics and Research Center, Tokushima University, Tokushima, Japan; Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan.
| | - Mitsuaki Sobajima
- Division of Molecular Biology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan; Department of Molecular Research, Diabetes Therapeutics and Research Center, Tokushima University, Tokushima, Japan
| | - Kiyoe Kurahashi
- Division of Molecular Biology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan; Department of Molecular Research, Diabetes Therapeutics and Research Center, Tokushima University, Tokushima, Japan; Department of Hematology, Endocrinology and Metabolism, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Akira Shigenaga
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima, Japan; Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Hiroshima, Japan
| | - Masaya Denda
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima, Japan
| | - Akira Otaka
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima, Japan
| | - Tomohide Saio
- Division of Molecular Life Science, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan; Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Naoki Sakane
- Pharmaceutical Frontier Research Laboratories, JT Inc., Yokohama, Japan
| | - Hidetaka Kosako
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Seiichi Oyadomari
- Division of Molecular Biology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan; Department of Molecular Research, Diabetes Therapeutics and Research Center, Tokushima University, Tokushima, Japan; Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan.
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5
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Macošek J, Mas G, Hiller S. Redefining Molecular Chaperones as Chaotropes. Front Mol Biosci 2021; 8:683132. [PMID: 34195228 PMCID: PMC8237284 DOI: 10.3389/fmolb.2021.683132] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/20/2021] [Indexed: 01/27/2023] Open
Abstract
Molecular chaperones are the key instruments of bacterial protein homeostasis. Chaperones not only facilitate folding of client proteins, but also transport them, prevent their aggregation, dissolve aggregates and resolve misfolded states. Despite this seemingly large variety, single chaperones can perform several of these functions even on multiple different clients, thus suggesting a single biophysical mechanism underlying. Numerous recently elucidated structures of bacterial chaperone–client complexes show that dynamic interactions between chaperones and their client proteins stabilize conformationally flexible non-native client states, which results in client protein denaturation. Based on these findings, we propose chaotropicity as a suitable biophysical concept to rationalize the generic activity of chaperones. We discuss the consequences of applying this concept in the context of ATP-dependent and -independent chaperones and their functional regulation.
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6
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Fatima K, Naqvi F, Younas H. A Review: Molecular Chaperone-mediated Folding, Unfolding and Disaggregation of Expressed Recombinant Proteins. Cell Biochem Biophys 2021; 79:153-174. [PMID: 33634426 DOI: 10.1007/s12013-021-00970-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 02/01/2021] [Indexed: 12/26/2022]
Abstract
The advancements in biotechnology over time have led to an increase in the demand of pure, soluble and functionally active proteins. Recombinant protein production has thus been employed to obtain high expression of purified proteins in bulk. E. coli is considered as the most desirable host for recombinant protein production due to its inexpensive and fast cultivation, simple nutritional requirements and known genetics. Despite all these benefits, recombinant protein production often comes with drawbacks, such as, the most common being the formation of inclusion bodies due to improper protein folding. Consequently, this can lead to the loss of the structure-function relationship of a protein. Apart from various strategies, one major strategy to resolve this issue is the use of molecular chaperones that act as folding modulators for proteins. Molecular chaperones assist newly synthesized, aggregated or misfolded proteins to fold into their native conformations. Chaperones have been widely used to improve the expression of various proteins which are otherwise difficult to produce in E. coli. Here, we discuss the structure, function, and role of major E. coli molecular chaperones in recombinant technology such as trigger factor, GroEL, DnaK and ClpB.
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Affiliation(s)
- Komal Fatima
- Department of Biochemistry, Kinnaird College for Women, Lahore, Punjab, Pakistan
| | - Fatima Naqvi
- Department of Biochemistry, Kinnaird College for Women, Lahore, Punjab, Pakistan
| | - Hooria Younas
- Department of Biochemistry, Kinnaird College for Women, Lahore, Punjab, Pakistan.
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7
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Koubek J, Schmitt J, Galmozzi CV, Kramer G. Mechanisms of Cotranslational Protein Maturation in Bacteria. Front Mol Biosci 2021; 8:689755. [PMID: 34113653 PMCID: PMC8185961 DOI: 10.3389/fmolb.2021.689755] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/10/2021] [Indexed: 01/05/2023] Open
Abstract
Growing cells invest a significant part of their biosynthetic capacity into the production of proteins. To become functional, newly-synthesized proteins must be N-terminally processed, folded and often translocated to other cellular compartments. A general strategy is to integrate these protein maturation processes with translation, by cotranslationally engaging processing enzymes, chaperones and targeting factors with the nascent polypeptide. Precise coordination of all factors involved is critical for the efficiency and accuracy of protein synthesis and cellular homeostasis. This review provides an overview of the current knowledge on cotranslational protein maturation, with a focus on the production of cytosolic proteins in bacteria. We describe the role of the ribosome and the chaperone network in protein folding and how the dynamic interplay of all cotranslationally acting factors guides the sequence of cotranslational events. Finally, we discuss recent data demonstrating the coupling of protein synthesis with the assembly of protein complexes and end with a brief discussion of outstanding questions and emerging concepts in the field of cotranslational protein maturation.
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Affiliation(s)
- Jiří Koubek
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Jaro Schmitt
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Carla Veronica Galmozzi
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
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8
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Jiang C, Wynne M, Huber D. How Quality Control Systems AID Sec-Dependent Protein Translocation. Front Mol Biosci 2021; 8:669376. [PMID: 33928127 PMCID: PMC8076867 DOI: 10.3389/fmolb.2021.669376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/17/2021] [Indexed: 02/01/2023] Open
Abstract
The evolutionarily conserved Sec machinery is responsible for transporting proteins across the cytoplasmic membrane. Protein substrates of the Sec machinery must be in an unfolded conformation in order to be translocated across (or inserted into) the cytoplasmic membrane. In bacteria, the requirement for unfolded proteins is strict: substrate proteins that fold (or misfold) prematurely in the cytoplasm prior to translocation become irreversibly trapped in the cytoplasm. Partially folded Sec substrate proteins and stalled ribosomes containing nascent Sec substrates can also inhibit translocation by blocking (i.e., “jamming”) the membrane-embedded Sec machinery. To avoid these issues, bacteria have evolved a complex network of quality control systems to ensure that Sec substrate proteins do not fold in the cytoplasm. This quality control network can be broken into three branches, for which we have defined the acronym “AID”: (i) avoidance of cytoplasmic intermediates through cotranslationally channeling newly synthesized Sec substrates to the Sec machinery; (ii) inhibition of folding Sec substrate proteins that transiently reside in the cytoplasm by molecular chaperones and the requirement for posttranslational modifications; (iii) destruction of products that could potentially inhibit translocation. In addition, several stress response pathways help to restore protein-folding homeostasis when environmental conditions that inhibit translocation overcome the AID quality control systems.
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Affiliation(s)
- Chen Jiang
- School of Biosciences and the Institute for Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Max Wynne
- School of Biosciences and the Institute for Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Damon Huber
- School of Biosciences and the Institute for Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
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9
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Choudhury M, Dhara A, Kumar M. Trigger Factor in Association with the ClpP1P2 Heterocomplex of Leptospira Promotes Protease/Peptidase Activity. ACS OMEGA 2021; 6:1400-1409. [PMID: 33490799 PMCID: PMC7818586 DOI: 10.1021/acsomega.0c05057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/28/2020] [Indexed: 05/07/2023]
Abstract
The genomic analysis of Leptospira reveals a trigger factor (TF) encoding gene (tig) to be colocalized along with the clpP1 and clpX. The TF is a crouching dragon-like protein known to be a ribosome-associated chaperone that is involved in cotranslational protein folding in bacteria in an ATP-independent mode. In Leptospira, tig is localized upstream of the clpP1 with a short (4 bp) overlap. In the present study, we document the distinctive role of Leptospira TF (LinTF) in the caseinolytic protease (ClpP) system. The recombinant LinTF (rLinTF) was found to improve the peptidase or protease activity of the ClpP1P2 heterocomplex and ClpXP1P2 complex, respectively, on model substrates. In addition, on supplementation of rLinTF to rClpP1P2 bound to its physiological ATPase chaperone ClpX or the antibiotic analogue acyldepsipeptide (ADEP), an augmentation in the activity of ClpP1P2 was observed. These studies underscore the novel role of LinTF in aiding the caseinolytic protease activity of Leptospira. Supplementation of rLinTF to a peptidase assay of rClpP1P2 conditionally in the presence of a salt (sodium citrate) with high Hofmeister strength led us to speculate that rLinTF may have a role in the assembly of multimeric proteins. The deletion of one of the arms (arm-2) of the LinTF structure from the carboxy terminal domain indicated a reduction in its capacity to stimulate rClpP1P2 activity. Thus, the C-terminal domain of LinTF may have a role in the assembly of multimeric ClpP protein, leading to enhancement of ClpP activity.
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Affiliation(s)
| | | | - Manish Kumar
- . Phone: +91-361-258-2230. Fax: +91-361-258-2249
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10
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Jia M, Wu B, Yang Z, Chen C, Zhao M, Hou X, Niu X, Jin C, Hu Y. Conformational Dynamics of the Periplasmic Chaperone SurA. Biochemistry 2020; 59:3235-3246. [PMID: 32786408 DOI: 10.1021/acs.biochem.0c00507] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The periplasmic protein SurA is the primary chaperone involved in the biogenesis of bacterial outer membrane proteins and is a potential antibacterial drug target. The three-dimensional structure of SurA can be divided into three parts, a core module formed by the N- and C-terminal regions and two peptidyl-prolyl isomerase (PPIase) domains, P1 and P2. Despite the determination of the structures of several SurA-peptide complexes, the functional mechanism of this chaperone remains elusive and the roles of the two PPIase domains are yet unclear. Herein, we characterize the conformational dynamics of SurA by using solution nuclear magnetic resonance and single-molecule fluorescence resonance energy transfer methods. We demonstrate a "closed-to-open" structural transition of the P1 domain that is correlated with both chaperone activity and peptide binding and show that the flexible P2 domain can also occupy conformations that closely contact the NC core module. Our results offer a structural basis for the counteracting roles of the two PPIase domains in regulating the SurA chaperone activity.
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Affiliation(s)
- Moye Jia
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Bo Wu
- School of Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing 100084, China
| | - Ziyu Yang
- Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.,MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Chunlai Chen
- School of Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing 100084, China
| | - Meiping Zhao
- Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.,MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xianhui Hou
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiaogang Niu
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Changwen Jin
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.,Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Yunfei Hu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for Optoelectronics, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, CAS, Wuhan 430071, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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11
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Rein T. Peptidylprolylisomerases, Protein Folders, or Scaffolders? The Example of FKBP51 and FKBP52. Bioessays 2020; 42:e1900250. [DOI: 10.1002/bies.201900250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/12/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Theo Rein
- Department of Translational Science in Psychiatry, MunichMax Planck Institute of Psychiatry Munich 80804 Germany
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12
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Structural insights into the complex of trigger factor chaperone and ribosomal protein S7 from Mycobacterium tuberculosis. Biochem Biophys Res Commun 2019; 512:838-844. [PMID: 30928093 DOI: 10.1016/j.bbrc.2019.03.166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 12/20/2022]
Abstract
Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), has threaten human health for thousands years. The chaperone trigger factor (TF) of Mtb (mtbTF), a ribosome-associated molecule, plays important roles in co-translational nascent chain folding and post-translational protein assembly. However, due to lack of structural information, the dynamic regulatory mechanism of mtbTF remains barely investigated. Herein we report the structural basis of the complex of TF and ribosomal protein S7 (mtbS7) from Mtb. The mtbTF-mtbS7 complex was obtained with high purity and homogeneity in vitro. MtbTF bound with mtbS7 in a Kd value of 1.433 μM, and formed a complex with mtbS7 at 1:2 M ratios as shown by isothermal titration calorimetry. In addition, the crystal structure of mtbS7 was solved to a resolution at 1.8 Å, which was composed of six α-helices and two β-strands. Moreover, the molecular envelopes of mtbTF and mtbTF-mtbS7 complex were built and consisted with these homologous structures by small-angle X-ray scattering method. Our current findings might provide structural basis for understanding the molecular mechanism of TF in protein folding and the regulation of ribosomal assembly in Mtb.
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13
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Rohr M, Ries F, Herkt C, Gotsmann VL, Westrich LD, Gries K, Trösch R, Christmann J, Chaux-Jukic F, Jung M, Zimmer D, Mühlhaus T, Sommer F, Schroda M, Keller S, Möhlmann T, Willmund F. The Role of Plastidic Trigger Factor Serving Protein Biogenesis in Green Algae and Land Plants. PLANT PHYSIOLOGY 2019; 179:1093-1110. [PMID: 30651302 PMCID: PMC6393800 DOI: 10.1104/pp.18.01252] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 01/07/2019] [Indexed: 05/07/2023]
Abstract
Biochemical processes in chloroplasts are important for virtually all life forms. Tight regulation of protein homeostasis and the coordinated assembly of protein complexes, composed of both imported and locally synthesized subunits, are vital to plastid functionality. Protein biogenesis requires the action of cotranslationally acting molecular chaperones. One such chaperone is trigger factor (TF), which is known to cotranslationally bind most newly synthesized proteins in bacteria, thereby assisting their correct folding and maturation. However, how these processes are regulated in chloroplasts remains poorly understood. We report here functional investigation of chloroplast-localized TF (TIG1) in the green alga (Chlamydomonas reinhardtii) and the vascular land plant Arabidopsis (Arabidopsis thaliana). We show that chloroplastic TIG1 evolved as a specialized chaperone. Unlike other plastidic chaperones that are functionally interchangeable with their prokaryotic counterpart, TIG1 was not able to complement the broadly acting ortholog in Escherichia coli. Whereas general chaperone properties such as the prevention of aggregates or substrate recognition seems to be conserved between bacterial and plastidic TFs, plant TIG1s differed by associating with only a relatively small population of translating ribosomes. Furthermore, a reduction of plastidic TIG1 levels leads to deregulated protein biogenesis at the expense of increased translation, thereby disrupting the chloroplast energy household. This suggests a central role of TIG1 in protein biogenesis in the chloroplast.
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Affiliation(s)
- Marina Rohr
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Fabian Ries
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Claudia Herkt
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Vincent Leon Gotsmann
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Lisa Désirée Westrich
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Karin Gries
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Raphael Trösch
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Jens Christmann
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | | | - Martin Jung
- Medical Biochemistry and Molecular Biology, Building 44, Saarland University, 66421 Homburg, Germany
| | - David Zimmer
- Computational Systems Biology, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Timo Mühlhaus
- Computational Systems Biology, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Frederik Sommer
- Molecular Biotechnology and Systems Biology, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Sandro Keller
- Molecular Biophysics, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
| | - Torsten Möhlmann
- Plant Physiology, University of Kaiserslautern, Paul-Ehrlich Strasse 22, 67663 Kaiserslautern, Germany
| | - Felix Willmund
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Strasse 23, 67663 Kaiserslautern, Germany
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14
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Granzyme B Disrupts Central Metabolism and Protein Synthesis in Bacteria to Promote an Immune Cell Death Program. Cell 2017; 171:1125-1137.e11. [PMID: 29107333 DOI: 10.1016/j.cell.2017.10.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 08/23/2017] [Accepted: 09/30/2017] [Indexed: 01/17/2023]
Abstract
Human cytotoxic lymphocytes kill intracellular microbes. The cytotoxic granule granzyme proteases released by cytotoxic lymphocytes trigger oxidative bacterial death by disrupting electron transport, generating superoxide anion and inactivating bacterial oxidative defenses. However, they also cause non-oxidative cell death because anaerobic bacteria are also killed. Here, we use differential proteomics to identify granzyme B substrates in three unrelated bacteria: Escherichia coli, Listeria monocytogenes, and Mycobacteria tuberculosis. Granzyme B cleaves a highly conserved set of proteins in all three bacteria, which function in vital biosynthetic and metabolic pathways that are critical for bacterial survival under diverse environmental conditions. Key proteins required for protein synthesis, folding, and degradation are also substrates, including multiple aminoacyl tRNA synthetases, ribosomal proteins, protein chaperones, and the Clp system. Because killer cells use a multipronged strategy to target vital pathways, bacteria may not easily become resistant to killer cell attack.
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Sorokina I, Mushegian A. Rotational restriction of nascent peptides as an essential element of co-translational protein folding: possible molecular players and structural consequences. Biol Direct 2017; 12:14. [PMID: 28569180 PMCID: PMC5452302 DOI: 10.1186/s13062-017-0186-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/23/2017] [Indexed: 12/13/2022] Open
Abstract
Background A basic tenet of protein science is that all information about the spatial structure of proteins is present in their sequences. Nonetheless, many proteins fail to attain native structure upon experimental denaturation and refolding in vitro, raising the question of the specific role of cellular machinery in protein folding in vivo. Recently, we hypothesized that energy-dependent twisting of the protein backbone is an unappreciated essential factor guiding the protein folding process in vivo. Torque force may be applied by the ribosome co-translationally, and when accompanied by simultaneous restriction of the rotational mobility of the distal part of the growing chain, the resulting tension in the protein backbone would facilitate the formation of local secondary structure and direct the folding process. Results Our model of the early stages of protein folding in vivo postulates that the free motion of both terminal regions of the protein during its synthesis and maturation is restricted. The long-known but unexplained phenomenon of statistical overrepresentation of protein termini on the surfaces of the protein structures may be an indication of the backbone twist-based folding mechanism; sustained maintenance of a twist requires that both ends of the protein chain are anchored in space, and if the ends are released only after the majority of folding is complete, they are much more likely to remain on the surface of the molecule. We identified the molecular components that are likely to play a role in the twisting of the nascent protein chain and in the anchoring of its N-terminus. The twist may be induced at the C-terminus of the nascent polypeptide by the peptidyltransferase center of the ribosome. Several ribosome-associated proteins, including the trigger factor in bacteria and the nascent polypeptide-associated complex in archaea and eukaryotes, may restrict the rotational mobility of the N-proximal regions of the peptides. Conclusions Many experimental observations are consistent with the hypothesis of co-translational twisting of the protein backbone. Several molecular players in this hypothetical mechanism of protein folding can be suggested. In addition, the new view of protein folding in vivo opens the possibility of novel potential drug targets to combat human protein folding diseases. Reviewers This article was reviewed by Lakshminarayan Iyer and István Simon. Electronic supplementary material The online version of this article (doi:10.1186/s13062-017-0186-1) contains supplementary material, which is available to authorized users.
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Fan D, Zhou Q, Liu C, Zhang J. Functional characterization of the Helicobacter pylori chaperone protein HP0795. Microbiol Res 2016; 193:11-19. [PMID: 27825478 DOI: 10.1016/j.micres.2016.08.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/09/2016] [Accepted: 08/20/2016] [Indexed: 12/12/2022]
Abstract
Trigger factor (TF) is one of the multiple bacterial chaperone proteins interacting with nascent peptides and facilitating their folding in bacteria. While TF is well-characterized in E. coli, HP0795, a TF-like homologue gene identified earlier in the pathogenic Helicobacter pylori (H. pylori), has not been studied biochemically to date. To characterize its function as a chaperone, we performed 3D-modeling, cross-linking and in vitro enzyme assays to HP0795 in vitro. Our results show that HP0795 possesses peptidyl prolyl cis-trans isomerase activity and exhibits a dimeric structure in solution. In addition, stable expression of HP0795 in a series of well-characterized E. coli chaperone-deficient strains rescued the growth defects in these mutants. Furthermore, we showed that the presence of HP0795 greatly reduced protein aggregation caused by deficiencies of chaperones in these strains. In contrast to other chaperone genes in H. pylori, gene expression of HP0795 displays little induction under acidic pH conditions. Together, our results suggest that HP0795 is a constitutively expressed TF-like protein of the prokaryotic chaperone family that may not play a major role in acid response. Given the pathogenic properties of H. pylori, our insights might provide new avenues for potential future medical intervention for H. pylori-related conditions.
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Affiliation(s)
- Dongjie Fan
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Qiming Zhou
- School of Life Science and Technology, Harbin Institute of Technology, 2 Yikuang Street, Harbin, 150080, China; Beijing CapitalBio MedLab, 88 D2, Branch Six Street, Economic and Technological Development Zone, Beijing 101111, China
| | - Chuanpeng Liu
- School of Life Science and Technology, Harbin Institute of Technology, 2 Yikuang Street, Harbin, 150080, China
| | - Jianzhong Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
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17
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Global profiling of SRP interaction with nascent polypeptides. Nature 2016; 536:219-23. [PMID: 27487212 DOI: 10.1038/nature19070] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 06/29/2016] [Indexed: 12/23/2022]
Abstract
Signal recognition particle (SRP) is a universally conserved protein-RNA complex that mediates co-translational protein translocation and membrane insertion by targeting translating ribosomes to membrane translocons. The existence of parallel co- and post-translational transport pathways, however, raises the question of the cellular substrate pool of SRP and the molecular basis of substrate selection. Here we determine the binding sites of bacterial SRP within the nascent proteome of Escherichia coli at amino acid resolution, by sequencing messenger RNA footprints of ribosome-nascent-chain complexes associated with SRP. SRP, on the basis of its strong preference for hydrophobic transmembrane domains (TMDs), constitutes a compartment-specific targeting factor for nascent inner membrane proteins (IMPs) that efficiently excludes signal-sequence-containing precursors of periplasmic and outer membrane proteins. SRP associates with hydrophobic TMDs enriched in consecutive stretches of hydrophobic and bulky aromatic amino acids immediately on their emergence from the ribosomal exit tunnel. By contrast with current models, N-terminal TMDs are frequently skipped and TMDs internal to the polypeptide sequence are selectively recognized. Furthermore, SRP binds several TMDs in many multi-spanning membrane proteins, suggesting cycles of SRP-mediated membrane targeting. SRP-mediated targeting is not accompanied by a transient slowdown of translation and is not influenced by the ribosome-associated chaperone trigger factor (TF), which has a distinct substrate pool and acts at different stages during translation. Overall, our proteome-wide data set of SRP-binding sites reveals the underlying principles of pathway decisions for nascent chains in bacteria, with SRP acting as the dominant triaging factor, sufficient to separate IMPs from substrates of the SecA-SecB post-translational translocation and TF-assisted cytosolic protein folding pathways.
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18
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Regulation by a chaperone improves substrate selectivity during cotranslational protein targeting. Proc Natl Acad Sci U S A 2015; 112:E3169-78. [PMID: 26056263 DOI: 10.1073/pnas.1422594112] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ribosome exit site is a crowded environment where numerous factors contact nascent polypeptides to influence their folding, localization, and quality control. Timely and accurate selection of nascent polypeptides into the correct pathway is essential for proper protein biogenesis. To understand how this is accomplished, we probe the mechanism by which nascent polypeptides are accurately sorted between the major cotranslational chaperone trigger factor (TF) and the essential cotranslational targeting machinery, signal recognition particle (SRP). We show that TF regulates SRP function at three distinct stages, including binding of the translating ribosome, membrane targeting via recruitment of the SRP receptor, and rejection of ribosome-bound nascent polypeptides beyond a critical length. Together, these mechanisms enhance the specificity of substrate selection into both pathways. Our results reveal a multilayered mechanism of molecular interplay at the ribosome exit site, and provide a conceptual framework to understand how proteins are selected among distinct biogenesis machineries in this crowded environment.
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19
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Rathore YS, Dhoke RR, Badmalia M, Sagar A, Ashish. SAXS data based global shape analysis of trigger factor (TF) proteins from E. coli, V. cholerae, and P. frigidicola: resolving the debate on the nature of monomeric and dimeric forms. J Phys Chem B 2015; 119:6101-12. [PMID: 25950744 DOI: 10.1021/acs.jpcb.5b00759] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dimerization of bacterial chaperone trigger factor (TF) is an inherent protein concentration based property which available biophysical characterization and crystal structures have kept debatable. We acquired small-angle X-ray scattering (SAXS) intensity data from different TF homologues from Escherichia coli (ECTF), Vibrio cholerae (VCTF), and Psychrobacter frigidicola (PFTF) while varying each protein concentration. We found that ECTF and VCTF adopt a compact dimeric shape at higher concentrations which did not resemble the "back-to-back" conformation reported earlier for ECTF from crystallography (PDB ID: 1W26 ). In contrast, PFTF remained monomeric throughout the concentration range 2-90 μM displaying a multimodal open extended conformation. OLIGOMER analysis showed that both the ECTF and VCTF remained completely monomeric at lower concentrations (2-11 μM), while, at higher concentrations (60-90 μM), they adopted a dimeric form. Interestingly, the equilibrium existed in the medium concentration range (>11 and <60 μM), which correlates with the physiological concentration (40-50 μM) of TF in cell cytoplasm. Additionally, circular dichroism data revealed that solution structures of ECTF and VCTF contain predominantly α-helical content, while PFTF contains 310-helical content.
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Affiliation(s)
| | - Reema R Dhoke
- CSIR-Institute of Microbial Technology, Chandigarh, India
| | | | - Amin Sagar
- CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Ashish
- CSIR-Institute of Microbial Technology, Chandigarh, India
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20
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Godin-Roulling A, Schmidpeter PAM, Schmid FX, Feller G. Functional adaptations of the bacterial chaperone trigger factor to extreme environmental temperatures. Environ Microbiol 2015; 17:2407-20. [PMID: 25389111 DOI: 10.1111/1462-2920.12707] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 01/26/2023]
Abstract
Trigger factor (TF) is the first molecular chaperone interacting cotranslationally with virtually all nascent polypeptides synthesized by the ribosome in bacteria. Thermal adaptation of chaperone function was investigated in TFs from the Antarctic psychrophile Pseudoalteromonas haloplanktis, the mesophile Escherichia coli and the hyperthermophile Thermotoga maritima. This series covers nearly all temperatures encountered by bacteria. Although structurally homologous, these TFs display strikingly distinct properties that are related to the bacterial environmental temperature. The hyperthermophilic TF strongly binds model proteins during their folding and protects them from heat-induced misfolding and aggregation. It decreases the folding rate and counteracts the fast folding rate imposed by high temperature. It also functions as a carrier of partially folded proteins for delivery to downstream chaperones ensuring final maturation. By contrast, the psychrophilic TF displays weak chaperone activities, showing that these functions are less important in cold conditions because protein folding, misfolding and aggregation are slowed down at low temperature. It efficiently catalyses prolyl isomerization at low temperature as a result of its increased cellular concentration rather than from an improved activity. Some chaperone properties of the mesophilic TF possibly reflect its function as a cold shock protein in E. coli.
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Affiliation(s)
- Amandine Godin-Roulling
- Laboratory of Biochemistry, Centre for Protein Engineering, University of Liège, Liège, B-4000, Belgium
| | - Philipp A M Schmidpeter
- Laboratorium für Biochemie, Bayreuther Zentrum für Molekulare Biowissenschaften, Universität Bayreuth, Bayreuth, D-95447, Germany
| | - Franz X Schmid
- Laboratorium für Biochemie, Bayreuther Zentrum für Molekulare Biowissenschaften, Universität Bayreuth, Bayreuth, D-95447, Germany
| | - Georges Feller
- Laboratory of Biochemistry, Centre for Protein Engineering, University of Liège, Liège, B-4000, Belgium
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21
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Shi Y, Shinjo M, Zhou JM, Kihara H. Structural stability of E. coli trigger factor studied by synchrotron small-angle X-ray scattering. Biophys Chem 2014; 195:1-7. [PMID: 25133354 DOI: 10.1016/j.bpc.2014.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 07/16/2014] [Accepted: 07/16/2014] [Indexed: 11/17/2022]
Abstract
Solution small-angle X-ray scattering (SAXS) is an effective technique for quantitatively measuring the compactness and shape of proteins. We use SAXS to study the structural characteristics and unfolding transitions induced by urea for full length Escherichia coli trigger factor (TF) and a series of truncation mutants, obtaining and comparing the radiuses of gyration (Rg), the distance-distribution function (P(r) function) and integrated intensity of TF variants in native and unfolding states. The C-terminal 72-residue truncated mutant TF360 exhibited dramatic structural differences and reduced stability compared with the whole TF molecule, while the N-domain truncated mutant MC maintained its compact structure with reduced stability. These results indicate that the C-terminal region of TF plays an important role in the structural and conformational stabilities of the TF molecule, while the N-domain is relatively independent.
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Affiliation(s)
- Yi Shi
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road, Zhangjiang Hi-Tech Park, Pudong, Shanghai 201210, China.
| | - Masaji Shinjo
- Department of Physics, Kansai Medical University, 2-5-1, Shin-Machi, Hirakata 573-1010, Japan
| | - Jun-Mei Zhou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Hiroshi Kihara
- Department of Physics, Kansai Medical University, 2-5-1, Shin-Machi, Hirakata 573-1010, Japan.
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22
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Saio T, Guan X, Rossi P, Economou A, Kalodimos CG. Structural basis for protein antiaggregation activity of the trigger factor chaperone. Science 2014; 344:1250494. [PMID: 24812405 DOI: 10.1126/science.1250494] [Citation(s) in RCA: 213] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Molecular chaperones prevent aggregation and misfolding of proteins, but scarcity of structural data has impeded an understanding of the recognition and antiaggregation mechanisms. We report the solution structure, dynamics, and energetics of three trigger factor (TF) chaperone molecules in complex with alkaline phosphatase (PhoA) captured in the unfolded state. Our data show that TF uses multiple sites to bind to several regions of the PhoA substrate protein primarily through hydrophobic contacts. Nuclear magnetic resonance (NMR) relaxation experiments show that TF interacts with PhoA in a highly dynamic fashion, but as the number and length of the PhoA regions engaged by TF increase, a more stable complex gradually emerges. Multivalent binding keeps the substrate protein in an extended, unfolded conformation. The results show how molecular chaperones recognize unfolded polypeptides and, by acting as unfoldases and holdases, prevent the aggregation and premature (mis)folding of unfolded proteins.
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Affiliation(s)
- Tomohide Saio
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
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23
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Mattoo RUH, Goloubinoff P. Molecular chaperones are nanomachines that catalytically unfold misfolded and alternatively folded proteins. Cell Mol Life Sci 2014; 71:3311-25. [PMID: 24760129 PMCID: PMC4131146 DOI: 10.1007/s00018-014-1627-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 01/01/2023]
Abstract
By virtue of their general ability to bind (hold) translocating or unfolding polypeptides otherwise doomed to aggregate, molecular chaperones are commonly dubbed “holdases”. Yet, chaperones also carry physiological functions that do not necessitate prevention of aggregation, such as altering the native states of proteins, as in the disassembly of SNARE complexes and clathrin coats. To carry such physiological functions, major members of the Hsp70, Hsp110, Hsp100, and Hsp60/CCT chaperone families act as catalytic unfolding enzymes or unfoldases that drive iterative cycles of protein binding, unfolding/pulling, and release. One unfoldase chaperone may thus successively convert many misfolded or alternatively folded polypeptide substrates into transiently unfolded intermediates, which, once released, can spontaneously refold into low-affinity native products. Whereas during stress, a large excess of non-catalytic chaperones in holding mode may optimally prevent protein aggregation, after the stress, catalytic disaggregases and unfoldases may act as nanomachines that use the energy of ATP hydrolysis to repair proteins with compromised conformations. Thus, holding and catalytic unfolding chaperones can act as primary cellular defenses against the formation of early misfolded and aggregated proteotoxic conformers in order to avert or retard the onset of degenerative protein conformational diseases.
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Affiliation(s)
- Rayees U H Mattoo
- Department of Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
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24
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Kim YE, Hipp MS, Bracher A, Hayer-Hartl M, Hartl FU. Molecular chaperone functions in protein folding and proteostasis. Annu Rev Biochem 2013; 82:323-55. [PMID: 23746257 DOI: 10.1146/annurev-biochem-060208-092442] [Citation(s) in RCA: 981] [Impact Index Per Article: 89.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The biological functions of proteins are governed by their three-dimensional fold. Protein folding, maintenance of proteome integrity, and protein homeostasis (proteostasis) critically depend on a complex network of molecular chaperones. Disruption of proteostasis is implicated in aging and the pathogenesis of numerous degenerative diseases. In the cytosol, different classes of molecular chaperones cooperate in evolutionarily conserved folding pathways. Nascent polypeptides interact cotranslationally with a first set of chaperones, including trigger factor and the Hsp70 system, which prevent premature (mis)folding. Folding occurs upon controlled release of newly synthesized proteins from these factors or after transfer to downstream chaperones such as the chaperonins. Chaperonins are large, cylindrical complexes that provide a central compartment for a single protein chain to fold unimpaired by aggregation. This review focuses on recent advances in understanding the mechanisms of chaperone action in promoting and regulating protein folding and on the pathological consequences of protein misfolding and aggregation.
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Affiliation(s)
- Yujin E Kim
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
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25
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Singhal K, Vreede J, Mashaghi A, Tans SJ, Bolhuis PG. Hydrophobic collapse of trigger factor monomer in solution. PLoS One 2013; 8:e59683. [PMID: 23565160 PMCID: PMC3615003 DOI: 10.1371/journal.pone.0059683] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/16/2013] [Indexed: 11/30/2022] Open
Abstract
Trigger factor (TF) is a chaperone, found in bacterial cells and chloroplasts, that interacts with nascent polypeptide chains to suppress aggregation. While its crystal structure has been resolved, the solution structure and dynamics are largely unknown. We performed multiple molecular dynamics simulations on Trigger factor in solution, and show that its tertiary domains display collective motions hinged about inter-domain linkers with minimal or no loss in secondary structure. Moreover, we find that isolated TF typically adopts a collapsed state, with the formation of domain pairs. This collapse of TF in solution is induced by hydrophobic interactions and stabilised by hydrophilic contacts. To determine the nature of the domain interactions, we analysed the hydrophobicity of the domain surfaces by using the hydrophobic probe method of Acharya et al.[1], [2], as the standard hydrophobicity scales predictions are limited due to the complex environment. We find that the formation of domain pairs changes the hydrophobic map of TF, making the N-terminal and arm2 domain pair more hydrophilic and the head and arm1 domain pair more hydrophobic. These insights into the dynamics and interactions of the TF domains are important to eventually understand chaperone-substrate interactions and chaperone function.
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Affiliation(s)
- Kushagra Singhal
- van ‘t Hoff Institute of Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Jocelyne Vreede
- van ‘t Hoff Institute of Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Alireza Mashaghi
- Department of Systems Biophysics, FOM Institute AMOLF, Amsterdam, The Netherlands
| | - Sander J. Tans
- Department of Systems Biophysics, FOM Institute AMOLF, Amsterdam, The Netherlands
| | - Peter G. Bolhuis
- van ‘t Hoff Institute of Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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26
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Breaking on through to the other side: protein export through the bacterial Sec system. Biochem J 2013; 449:25-37. [PMID: 23216251 DOI: 10.1042/bj20121227] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
More than one-third of cellular proteomes traffic into and across membranes. Bacteria have invented several sophisticated secretion systems that guide various proteins to extracytoplasmic locations and in some cases inject them directly into hosts. Of these, the Sec system is ubiquitous, essential and by far the best understood. Secretory polypeptides are sorted from cytoplasmic ones initially due to characteristic signal peptides. Then they are targeted to the plasma membrane by chaperones/pilots. The translocase, a dynamic nanomachine, lies at the centre of this process and acts as a protein-conducting channel with a unique property; allowing both forward transfer of secretory proteins but also lateral release into the lipid bilayer with high fidelity and efficiency. This process, tightly orchestrated at the expense of energy, ensures fundamental cell processes such as membrane biogenesis, cell division, motility, nutrient uptake and environmental sensing. In the present review, we examine this fascinating process, summarizing current knowledge on the structure, function and mechanics of the Sec pathway.
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27
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Toffano-Nioche C, Nguyen AN, Kuchly C, Ott A, Gautheret D, Bouloc P, Jacq A. Transcriptomic profiling of the oyster pathogen Vibrio splendidus opens a window on the evolutionary dynamics of the small RNA repertoire in the Vibrio genus. RNA (NEW YORK, N.Y.) 2012; 18:2201-2219. [PMID: 23097430 PMCID: PMC3504672 DOI: 10.1261/rna.033324.112] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 09/08/2012] [Indexed: 06/01/2023]
Abstract
Work in recent years has led to the recognition of the importance of small regulatory RNAs (sRNAs) in bacterial regulation networks. New high-throughput sequencing technologies are paving the way to the exploration of an expanding sRNA world in nonmodel bacteria. In the Vibrio genus, compared to the enterobacteriaceae, still a limited number of sRNAs have been characterized, mostly in Vibrio cholerae, where they have been shown to be important for virulence, as well as in Vibrio harveyi. In addition, genome-wide approaches in V. cholerae have led to the discovery of hundreds of potential new sRNAs. Vibrio splendidus is an oyster pathogen that has been recently associated with massive mortality episodes in the French oyster growing industry. Here, we report the first RNA-seq study in a Vibrio outside of the V. cholerae species. We have uncovered hundreds of candidate regulatory RNAs, be it cis-regulatory elements, antisense RNAs, and trans-encoded sRNAs. Conservation studies showed the majority of them to be specific to V. splendidus. However, several novel sRNAs, previously unidentified, are also present in V. cholerae. Finally, we identified 28 trans sRNAs that are conserved in all the Vibrio genus species for which a complete genome sequence is available, possibly forming a Vibrio "sRNA core."
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Affiliation(s)
- Claire Toffano-Nioche
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, IFR115, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
| | - An N. Nguyen
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, IFR115, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
| | - Claire Kuchly
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, IFR115, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
| | - Alban Ott
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, IFR115, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
| | - Daniel Gautheret
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, IFR115, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
| | - Philippe Bouloc
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, IFR115, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
| | - Annick Jacq
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, IFR115, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
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28
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Bruel N, Castanié-Cornet MP, Cirinesi AM, Koningstein G, Georgopoulos C, Luirink J, Genevaux P. Hsp33 controls elongation factor-Tu stability and allows Escherichia coli growth in the absence of the major DnaK and trigger factor chaperones. J Biol Chem 2012; 287:44435-46. [PMID: 23148222 DOI: 10.1074/jbc.m112.418525] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Intracellular de novo protein folding is assisted by cellular networks of molecular chaperones. In Escherichia coli, cooperation between the chaperones trigger factor (TF) and DnaK is central to this process. Accordingly, the simultaneous deletion of both chaperone-encoding genes leads to severe growth and protein folding defects. Herein, we took advantage of such defective phenotypes to further elucidate the interactions of chaperone networks in vivo. We show that disruption of the TF/DnaK chaperone pathway is efficiently rescued by overexpression of the redox-regulated chaperone Hsp33. Consistent with this observation, the deletion of hslO, the Hsp33 structural gene, is no longer tolerated in the absence of the TF/DnaK pathway. However, in contrast with other chaperones like GroEL or SecB, suppression by Hsp33 was not attributed to its potential overlapping general chaperone function(s). Instead, we show that overexpressed Hsp33 specifically binds to elongation factor-Tu (EF-Tu) and targets it for degradation by the protease Lon. This synergistic action of Hsp33 and Lon was responsible for the rescue of bacterial growth in the absence of TF and DnaK, by presumably restoring the coupling between translation and the downstream folding capacity of the cell. In support of this hypothesis, we show that overexpression of the stress-responsive toxin HipA, which inhibits EF-Tu, also rescues bacterial growth and protein folding in the absence of TF and DnaK. The relevance for such a convergence of networks of chaperones and proteases acting directly on EF-Tu to modulate the intracellular rate of protein synthesis in response to protein aggregation is discussed.
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Affiliation(s)
- Nicolas Bruel
- Laboratoire de Microbiologie et Génétique Moléculaire (LMGM), Centre National de la Recherche Scientifique (CNRS) and Université Paul Sabatier, 31062 Toulouse, France
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Biology of the heat shock response and protein chaperones: budding yeast (Saccharomyces cerevisiae) as a model system. Microbiol Mol Biol Rev 2012; 76:115-58. [PMID: 22688810 DOI: 10.1128/mmbr.05018-11] [Citation(s) in RCA: 362] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The eukaryotic heat shock response is an ancient and highly conserved transcriptional program that results in the immediate synthesis of a battery of cytoprotective genes in the presence of thermal and other environmental stresses. Many of these genes encode molecular chaperones, powerful protein remodelers with the capacity to shield, fold, or unfold substrates in a context-dependent manner. The budding yeast Saccharomyces cerevisiae continues to be an invaluable model for driving the discovery of regulatory features of this fundamental stress response. In addition, budding yeast has been an outstanding model system to elucidate the cell biology of protein chaperones and their organization into functional networks. In this review, we evaluate our understanding of the multifaceted response to heat shock. In addition, the chaperone complement of the cytosol is compared to those of mitochondria and the endoplasmic reticulum, organelles with their own unique protein homeostasis milieus. Finally, we examine recent advances in the understanding of the roles of protein chaperones and the heat shock response in pathogenic fungi, which is being accelerated by the wealth of information gained for budding yeast.
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Hoffmann A, Becker AH, Zachmann-Brand B, Deuerling E, Bukau B, Kramer G. Concerted action of the ribosome and the associated chaperone trigger factor confines nascent polypeptide folding. Mol Cell 2012; 48:63-74. [PMID: 22921937 DOI: 10.1016/j.molcel.2012.07.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/17/2012] [Accepted: 07/16/2012] [Indexed: 01/13/2023]
Abstract
How nascent polypeptides emerging from ribosomes fold into functional structures is poorly understood. Here, we monitor disulfide bond formation, protease resistance, and enzymatic activity in nascent polypeptides to show that in close proximity to the ribosome, conformational space and kinetics of folding are restricted. Folding constraints decrease incrementally with distance from the ribosome surface. Upon ribosome binding, the chaperone Trigger Factor counters folding also of longer nascent chains, to extents varying between different chain segments. Trigger Factor even binds and unfolds pre-existing folded structures, the unfolding activity being limited by the thermodynamic stability of nascent chains. Folding retardation and unfolding activities are not shared by the DnaK chaperone assisting later folding steps. These ribosome- and Trigger Factor-specific activities together constitute an efficient mechanism to prevent or even revert premature folding, effectively limiting misfolded intermediates during protein synthesis.
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Affiliation(s)
- Anja Hoffmann
- Center for Molecular Biology of the University of Heidelberg, German Cancer Research Center, DKFZ-ZMBH Alliance, Heidelberg, Germany
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31
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Oh E, Becker AH, Sandikci A, Huber D, Chaba R, Gloge F, Nichols RJ, Typas A, Gross CA, Kramer G, Weissman JS, Bukau B. Selective ribosome profiling reveals the cotranslational chaperone action of trigger factor in vivo. Cell 2012; 147:1295-308. [PMID: 22153074 PMCID: PMC3277850 DOI: 10.1016/j.cell.2011.10.044] [Citation(s) in RCA: 326] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 08/10/2011] [Accepted: 10/18/2011] [Indexed: 11/29/2022]
Abstract
As nascent polypeptides exit ribosomes, they are engaged by a series of processing, targeting, and folding factors. Here, we present a selective ribosome profiling strategy that enables global monitoring of when these factors engage polypeptides in the complex cellular environment. Studies of the Escherichia coli chaperone trigger factor (TF) reveal that, though TF can interact with many polypeptides, β-barrel outer-membrane proteins are the most prominent substrates. Loss of TF leads to broad outer-membrane defects and premature, cotranslational protein translocation. Whereas in vitro studies suggested that TF is prebound to ribosomes waiting for polypeptides to emerge from the exit channel, we find that in vivo TF engages ribosomes only after ~100 amino acids are translated. Moreover, excess TF interferes with cotranslational removal of the N-terminal formyl methionine. Our studies support a triaging model in which proper protein biogenesis relies on the fine-tuned, sequential engagement of processing, targeting, and folding factors.
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Affiliation(s)
- Eugene Oh
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
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Maillard J, Genevaux P, Holliger C. Redundancy and specificity of multiple trigger factor chaperones in Desulfitobacteria. Microbiology (Reading) 2011; 157:2410-2421. [DOI: 10.1099/mic.0.050880-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ribosome-bound trigger factor (TF) chaperone assists folding of newly synthesized polypeptides and participates in the assembly of macromolecular complexes. In the present study we showed that multiple distinct TF paralogues are present in genomes of Desulfitobacteria, a bacterial genus known for its ability to grow using organohalide respiration. Two full-length TF chaperones and at least one truncated TF (lacking the N-terminal ribosome-binding domain) were identified, the latter being systematically linked to clusters of reductive dehalogenase genes encoding the key enzymes in organohalide respiration. Using a well-characterized heterologous chaperone-deficient Escherichia coli strain lacking both TF and DnaK chaperones, we demonstrated that all three TF chaperones were functional in vivo, as judged by their ability to partially suppress bacterial growth defects and protein aggregation in the absence of both major E. coli chaperones. Next, we found that the N-terminal truncated TF-like protein PceT functions as a dedicated chaperone for the cognate reductive dehalogenase PceA by solubilizing and stabilizing it in the heterologous system. Finally, we showed that PceT specifically interacts with the twin-arginine signal peptide of PceA. Taken together, our data define PceT (and more generally the new RdhT family) as a class of TF-like chaperones involved in the maturation of proteins secreted by the twin-arginine translocation pathway.
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Affiliation(s)
- Julien Maillard
- Laboratoire de Biotechnologie Environnementale (LBE), Institut d’Ingénierie de l’Environnement (IIE), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre National de la Recherche Scientifique (CNRS), Université Paul-Sabatier (UPS), Toulouse, France
| | - Christof Holliger
- Laboratoire de Biotechnologie Environnementale (LBE), Institut d’Ingénierie de l’Environnement (IIE), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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Mykytczuk NCS, Trevors JT, Foote SJ, Leduc LG, Ferroni GD, Twine SM. Proteomic insights into cold adaptation of psychrotrophic and mesophilic Acidithiobacillus ferrooxidans strains. Antonie Van Leeuwenhoek 2011; 100:259-77. [DOI: 10.1007/s10482-011-9584-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 04/29/2011] [Indexed: 11/29/2022]
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SecA interacts with ribosomes in order to facilitate posttranslational translocation in bacteria. Mol Cell 2011; 41:343-53. [PMID: 21292166 DOI: 10.1016/j.molcel.2010.12.028] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 08/06/2010] [Accepted: 12/10/2010] [Indexed: 11/21/2022]
Abstract
In Escherichia coli, translocation of exported proteins across the cytoplasmic membrane is dependent on the motor protein SecA and typically begins only after synthesis of the substrate has already been completed (i.e., posttranslationally). Thus, it has generally been assumed that the translocation machinery also recognizes its protein substrates posttranslationally. Here we report a specific interaction between SecA and the ribosome at a site near the polypeptide exit channel. This interaction is mediated by conserved motifs in SecA and ribosomal protein L23, and partial disruption of this interaction in vivo by introducing mutations into the genes encoding SecA or L23 affects the efficiency of translocation by the posttranslational pathway. Based on these findings, we propose that SecA could interact with its nascent substrates during translation in order to efficiently channel them into the "posttranslational" translocation pathway.
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Mogk A, Huber D, Bukau B. Integrating protein homeostasis strategies in prokaryotes. Cold Spring Harb Perspect Biol 2011; 3:cshperspect.a004366. [PMID: 21441580 DOI: 10.1101/cshperspect.a004366] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Bacterial cells are frequently exposed to dramatic fluctuations in their environment, which cause perturbation in protein homeostasis and lead to protein misfolding. Bacteria have therefore evolved powerful quality control networks consisting of chaperones and proteases that cooperate to monitor the folding states of proteins and to remove misfolded conformers through either refolding or degradation. The levels of the quality control components are adjusted to the folding state of the cellular proteome through the induction of compartment specific stress responses. In addition, the activities of several quality control components are directly controlled by these stresses, allowing for fast activation. Severe stress can, however, overcome the protective function of the proteostasis network leading to the formation of protein aggregates, which are sequestered at the cell poles. Protein aggregates are either solubilized by AAA+ chaperones or eliminated through cell division, allowing for the generation of damage-free daughter cells.
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Affiliation(s)
- Axel Mogk
- Zentrum für Molekulare Biologie Heidelberg, DKFZ-ZMBH Alliance, Universität Heidelberg, Heidelberg, Germany
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36
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Martinez-Hackert E, Hendrickson WA. Structural analysis of protein folding by the long-chain archaeal chaperone FKBP26. J Mol Biol 2011; 407:450-64. [PMID: 21262232 DOI: 10.1016/j.jmb.2011.01.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/05/2011] [Accepted: 01/12/2011] [Indexed: 11/17/2022]
Abstract
In the cell, protein folding is mediated by folding catalysts and chaperones. The two functions are often linked, especially when the catalytic module forms part of a multidomain protein, as in Methanococcus jannaschii peptidyl-prolyl cis/trans isomerase FKBP26. Here, we show that FKBP26 chaperone activity requires both a 50-residue insertion in the catalytic FKBP domain, also called 'Insert-in-Flap' or IF domain, and an 80-residue C-terminal domain. We determined FKBP26 structures from four crystal forms and analyzed chaperone domains in light of their ability to mediate protein-protein interactions. FKBP26 is a crescent-shaped homodimer. We reason that folding proteins are bound inside the large crescent cleft, thus enabling their access to inward-facing peptidyl-prolyl cis/trans isomerase catalytic sites and ipsilateral chaperone domain surfaces. As these chaperone surfaces participate extensively in crystal lattice contacts, we speculate that the observed lattice contacts reflect a proclivity for protein associations and represent substrate interactions by FKBP26 chaperone domains. Finally, we find that FKBP26 is an exceptionally flexible molecule, suggesting a mechanism for nonspecific substrate recognition.
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Affiliation(s)
- Erik Martinez-Hackert
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
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37
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Kunzmann MH, Staub I, Böttcher T, Sieber SA. Protein reactivity of natural product-derived γ-butyrolactones. Biochemistry 2011; 50:910-6. [PMID: 21188974 DOI: 10.1021/bi101858g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The discovery of novel and unique target-drug pairs for the treatment of human diseases such as cancer and bacterial infections is an urgent goal of chemical and pharmaceutical sciences. Natural products represent an inspiring source of compounds for designing chemical biology methods with applications in target identification and characterization. Inspired by the huge structural diversity of γ-butyrolactones, which constitute up to 10% of all known compounds of natural origin, we extended the "activity-based protein profiling" (ABPP) target identification technology to this promising and so far unexplored natural compound class. We designed and synthesized a comprehensive set of natural product-derived γ-lactones and thiolactones that varied in protein reactivity. Several important bacterial enzymes that are involved in diverse cellular functions such as metabolism (dihydrolipoyl dehydrogenase and 6-phosphofructokinase), cell wall biosynthesis (MurA1 and MurA2), and protein folding (trigger factors) were obtained. Especially protein folding in bacteria could represent a novel strategy for antibiotic intervention and requires chemical tools for characterization and inhibition. Future studies that extend structural modifications to protein reactive α-methylene-γ-butyrolactone as well as to reversible binding γ-lactones and thiolactones will reveal if this premise holds true.
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Affiliation(s)
- Martin H Kunzmann
- Center for Integrated Protein Science Munich CIPSM, Department of Chemistry, Technische Universität München, Lichtenbergstrasse 4, 81377 Munich, Germany
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Lakshmipathy SK, Gupta R, Pinkert S, Etchells SA, Hartl FU. Versatility of trigger factor interactions with ribosome-nascent chain complexes. J Biol Chem 2010; 285:27911-23. [PMID: 20595383 DOI: 10.1074/jbc.m110.134163] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Trigger factor (TF) is the first molecular chaperone that interacts with nascent chains emerging from bacterial ribosomes. TF is a modular protein, consisting of an N-terminal ribosome binding domain, a PPIase domain, and a C-terminal domain, all of which participate in polypeptide binding. To directly monitor the interactions of TF with nascent polypeptide chains, TF variants were site-specifically labeled with an environmentally sensitive NBD fluorophore. We found a marked increase in TF-NBD fluorescence during translation of firefly luciferase (Luc) chains, which expose substantial regions of hydrophobicity, but not with nascent chains lacking extensive hydrophobic segments. TF remained associated with Luc nascent chains for 111 +/- 7 s, much longer than it remained bound to the ribosomes (t((1/2)) approximately 10-14 s). Thus, multiple TF molecules can bind per nascent chain during translation. The Escherichia coli cytosolic proteome was classified into predicted weak and strong interactors for TF, based on the occurrence of continuous hydrophobic segments in the primary sequence. The residence time of TF on the nascent chain generally correlated with the presence of hydrophobic regions and the capacity of nascent chains to bury hydrophobicity. Interestingly, TF bound the signal sequence of a secretory protein, pOmpA, but not the hydrophobic signal anchor sequence of the inner membrane protein FtsQ. On the other hand, proteins lacking linear hydrophobic segments also recruited TF, suggesting that TF can recognize hydrophobic surface features discontinuous in sequence. Moreover, TF retained significant affinity for the folded domain of the positively charged, ribosomal protein S7, indicative of an alternative mode of TF action. Thus, unlike other chaperones, TF appears to employ multiple mechanisms to interact with a wide range of substrate proteins.
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39
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Deuerling E, Bukau B. Chaperone-Assisted Folding of Newly Synthesized Proteins in the Cytosol. Crit Rev Biochem Mol Biol 2010; 39:261-77. [PMID: 15763705 DOI: 10.1080/10409230490892496] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The way in which a newly synthesized polypeptide chain folds into its unique three-dimensional structure remains one of the fundamental questions in molecular biology. Protein folding in the cell is a problematic process and, in many cases, requires the assistance of a network of molecular chaperones to support productive protein foldingin vivo. During protein biosynthesis, ribosome-associated chaperones guide the folding of the nascent polypeptide emerging from the ribosomal tunnel. In this review we summarize the basic principles of the protein-folding process and the involved chaperones, and focus on the role of ribosome-associated chaperones. Our discussion emphasizes the bacterial Trigger Factor, which is the best studied chaperone of this type. Recent advances have determined the atomic structure of the Trigger Factor, providing new, exciting insights into the role of ribosome-associated chaperones in co-translational protein folding.
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Affiliation(s)
- Elke Deuerling
- Zentrum für Molekulare Biologie Heidelberg, Universität Heidelberg, Heidelberg, Germany.
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40
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Hoffmann A, Bukau B, Kramer G. Structure and function of the molecular chaperone Trigger Factor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:650-61. [PMID: 20132842 DOI: 10.1016/j.bbamcr.2010.01.017] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 01/22/2010] [Indexed: 01/16/2023]
Abstract
Newly synthesized proteins often require the assistance of molecular chaperones to efficiently fold into functional three-dimensional structures. At first, ribosome-associated chaperones guide the initial folding steps and protect growing polypeptide chains from misfolding and aggregation. After that folding into the native structure may occur spontaneously or require support by additional chaperones which do not bind to the ribosome such as DnaK and GroEL. Here we review the current knowledge on the best-characterized ribosome-associated chaperone at present, the Escherichia coli Trigger Factor. We describe recent progress on structural and dynamic aspects of Trigger Factor's interactions with the ribosome and substrates and discuss how these interactions affect co-translational protein folding. In addition, we discuss the newly proposed ribosome-independent function of Trigger Factor as assembly factor of multi-subunit protein complexes. Finally, we cover the functional cooperation between Trigger Factor, DnaK and GroEL in folding of cytosolic proteins and the interplay between Trigger Factor and other ribosome-associated factors acting in enzymatic processing and translocation of nascent polypeptide chains.
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Affiliation(s)
- Anja Hoffmann
- Zentrum für Molekulare Biologie der Universität Heidelberg, Heidelberg, Germany
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41
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Promiscuous substrate recognition in folding and assembly activities of the trigger factor chaperone. Cell 2009; 138:923-34. [PMID: 19737520 DOI: 10.1016/j.cell.2009.07.044] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 03/28/2009] [Accepted: 07/31/2009] [Indexed: 11/22/2022]
Abstract
Trigger factor (TF) is a molecular chaperone that binds to bacterial ribosomes where it contacts emerging nascent chains, but TF is also abundant free in the cytosol where its activity is less well characterized. In vitro studies show that TF promotes protein refolding. We find here that ribosome-free TF stably associates with and rescues from misfolding a large repertoire of full-length proteins. We identify over 170 members of this cytosolic Escherichia coli TF substrate proteome, including ribosomal protein S7. We analyzed the biochemical properties of a TF:S7 complex from Thermotoga maritima and determined its crystal structure. Thereby, we obtained an atomic-level picture of a promiscuous chaperone in complex with a physiological substrate protein. The structure of the complex reveals the molecular basis of substrate recognition by TF, indicates how TF could accelerate protein folding, and suggests a role for TF in the biogenesis of protein complexes.
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42
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The ribosome as a platform for co-translational processing, folding and targeting of newly synthesized proteins. Nat Struct Mol Biol 2009; 16:589-97. [PMID: 19491936 DOI: 10.1038/nsmb.1614] [Citation(s) in RCA: 347] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The early events in the life of newly synthesized proteins in the cellular environment are remarkably complex. Concurrently with their synthesis by the ribosome, nascent polypeptides are subjected to enzymatic processing, chaperone-assisted folding or targeting to translocation pores at membranes. The ribosome itself has a key role in these different tasks and governs the interplay between the various factors involved. Indeed, the ribosome serves as a platform for the spatially and temporally regulated association of enzymes, targeting factors and chaperones that act upon the nascent polypeptides emerging from the exit tunnel. Furthermore, the ribosome provides opportunities to coordinate the protein-synthesis activity of its peptidyl transferase center with the protein targeting and folding processes. Here we review the early co-translational events involving the ribosome that guide cytosolic proteins to their native state.
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43
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Fan DJ, Ding YW, Zhou JM. Structural rearrangements and the unfolding mechanism of a Trigger Factor mutant studied by multiple structural probes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:944-52. [DOI: 10.1016/j.bbapap.2009.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 03/10/2009] [Accepted: 03/16/2009] [Indexed: 10/21/2022]
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Erales J, Lignon S, Gontero B. CP12 from Chlamydomonas reinhardtii, a permanent specific "chaperone-like" protein of glyceraldehyde-3-phosphate dehydrogenase. J Biol Chem 2009; 284:12735-44. [PMID: 19287002 DOI: 10.1074/jbc.m808254200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A new role is reported for CP12, a highly unfolded and flexible protein, mainly known for its redox function with A(4) glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Both reduced and oxidized CP12 can prevent the in vitro thermal inactivation and aggregation of GAPDH from Chlamydomonas reinhardtii. This mechanism is thus not redox-dependent. The protection is specific to CP12, because other proteins, such as bovine serum albumin, thioredoxin, and a general chaperone, Hsp33, do not fully prevent denaturation of GAPDH. Furthermore, CP12 acts as a specific chaperone, since it does not protect other proteins, such as catalase, alcohol dehydrogenase, or lysozyme. The interaction between CP12 and GAPDH is necessary to prevent the aggregation and inactivation, since the mutant C66S that does not form any complex with GAPDH cannot accomplish this protection. Unlike the C66S mutant, the C23S mutant that lacks the N-terminal bridge is partially able to protect and to slow down the inactivation and aggregation. Tryptic digestion coupled to mass spectrometry confirmed that the S-loop of GAPDH is the interaction site with CP12. Thus, CP12 not only has a redox function but also behaves as a specific "chaperone-like protein" for GAPDH, although a stable and not transitory interaction is observed. This new function of CP12 may explain why it is also present in complexes involving A(2)B(2) GAPDHs that possess a regulatory C-terminal extension (GapB subunit) and therefore do not require CP12 to be redox-regulated.
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Affiliation(s)
- Jenny Erales
- Laboratoire d'Enzymologie de Complexes Supramoléculaires, UPR 9036, Bioénergétique et Ingénierie des Protéines, Marseille Cedex 20, France
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45
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Trigger factor from the psychrophilic bacterium Psychrobacter frigidicola is a monomeric chaperone. J Bacteriol 2008; 191:1162-8. [PMID: 19060145 DOI: 10.1128/jb.01137-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In eubacteria, trigger factor (TF) is the first chaperone to interact with newly synthesized polypeptides and assist their folding as they emerge from the ribosome. We report the first characterization of a TF from a psychrophilic organism. TF from Psychrobacter frigidicola (TF(Pf)) was cloned, produced in Escherichia coli, and purified. Strikingly, cross-linking and fluorescence anisotropy analyses revealed it to exist in solution as a monomer, unlike the well-characterized, dimeric E. coli TF (TF(Ec)). Moreover, TF(Pf) did not exhibit the downturn in reactivation of unfolded GAPDH (glyceraldehyde-3-phosphate dehydrogenase) that is observed with its E. coli counterpart, even at high TF/GAPDH molar ratios and revealed dramatically reduced retardation of membrane translocation by a model recombinant protein compared to the E. coli chaperone. TF(Pf) was also significantly more effective than TF(Ec) at increasing the yield of soluble and functional recombinant protein in a cell-free protein synthesis system, indicating that it is not dependent on downstream systems for its chaperoning activity. We propose that TF(Pf) differs from TF(Ec) in its quaternary structure and chaperone activity, and we discuss the potential significance of these differences in its native environment.
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46
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Schlünzen F, Wilson DN, Tian P, Harms JM, McInnes SJ, Hansen HAS, Albrecht R, Buerger J, Wilbanks SM, Fucini P. The binding mode of the trigger factor on the ribosome: implications for protein folding and SRP interaction. Structure 2008; 13:1685-94. [PMID: 16271892 DOI: 10.1016/j.str.2005.08.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 08/02/2005] [Accepted: 08/03/2005] [Indexed: 01/21/2023]
Abstract
This study presents the X-ray structure of the N-terminal binding domain of the D. radiodurans trigger factor (TF) in complex with the D. radiodurans large ribosomal subunit. At 3.35 A, a complete description of the interactions with ribosomal proteins L23, L29, and 23S rRNA are disclosed, many of which differ from those found previously for a heterologous bacterial-archaeal TF-ribosome complex. The beta hairpin loop of eubacterial L24, which is shorter in archaeal ribosomes, contacts the TF and severely diminishes the molecular cradle proposed to exist between the TF and ribosome. Bound to the ribosome, TF exposes a hydrophobic crevice large enough to accommodate the nascent polypeptide chain. Superimposition of the full-length TF and the signal-recognition particle (SRP) onto the complex shows that simultaneous cohabitation is possible, in agreement with biochemical data, and suggests a model for the interplay of TF, SRP, and the nascent chain during translation.
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Affiliation(s)
- Frank Schlünzen
- Max-Planck Institute for Molecular Genetics, Ihnestrasse 73, D-14195 Berlin, Germany.
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47
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Pandhal J, Snijders APL, Wright PC, Biggs CA. A cross-species quantitative proteomic study of salt adaptation in a halotolerant environmental isolate using15N metabolic labelling. Proteomics 2008; 8:2266-84. [PMID: 18452222 DOI: 10.1002/pmic.200700398] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jagroop Pandhal
- Biological and Environmental Systems Group, Department of Chemical and Process Engineering, University of Sheffield, Sheffield, UK
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48
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Merz F, Boehringer D, Schaffitzel C, Preissler S, Hoffmann A, Maier T, Rutkowska A, Lozza J, Ban N, Bukau B, Deuerling E. Molecular mechanism and structure of Trigger Factor bound to the translating ribosome. EMBO J 2008; 27:1622-32. [PMID: 18497744 DOI: 10.1038/emboj.2008.89] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 04/10/2008] [Indexed: 11/09/2022] Open
Abstract
Ribosome-associated chaperone Trigger Factor (TF) initiates folding of newly synthesized proteins in bacteria. Here, we pinpoint by site-specific crosslinking the sequence of molecular interactions of Escherichia coli TF and nascent chains during translation. Furthermore, we provide the first full-length structure of TF associated with ribosome-nascent chain complexes by using cryo-electron microscopy. In its active state, TF arches over the ribosomal exit tunnel accepting nascent chains in a protective void. The growing nascent chain initially follows a predefined path through the entire interior of TF in an unfolded conformation, and even after folding into a domain it remains accommodated inside the protective cavity of ribosome-bound TF. The adaptability to accept nascent chains of different length and folding states may explain how TF is able to assist co-translational folding of all kinds of nascent polypeptides during ongoing synthesis. Moreover, we suggest a model of how TF's chaperoning function can be coordinated with the co-translational processing and membrane targeting of nascent polypeptides by other ribosome-associated factors.
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Affiliation(s)
- Frieder Merz
- Zentrum für Molekulare Biologie Heidelberg, DKFZ-ZMBH Alliance, Universität Heidelberg, Heidelberg, Germany
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Thermal unfolding of Escherichia coli trigger factor studied by ultra-sensitive differential scanning calorimetry. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:1728-34. [PMID: 18539163 DOI: 10.1016/j.bbapap.2008.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Revised: 04/22/2008] [Accepted: 05/08/2008] [Indexed: 11/22/2022]
Abstract
Temperature-induced unfolding of Escherichia coli trigger factor (TF) and its domain truncation mutants, NM and MC, were studied by ultra-sensitive differential scanning calorimetry (UC-DSC). Detailed thermodynamic analysis showed that thermal induced unfolding of TF and MC involves population of dimeric intermediates. In contrast, the thermal unfolding of the NM mutant involves population of only monomeric states. Covalent cross-linking experiments confirmed the presence of dimeric intermediates during thermal unfolding of TF and MC. These data not only suggest that the dimeric form of TF is extremely resistant to thermal unfolding, but also provide further evidence that the C-terminal domain of TF plays a vital role in forming and stabilizing the dimeric structure of the TF molecule. Since TF is the first molecular chaperone that nascent polypeptides encounter in eubacteria, the stable dimeric intermediates of TF populated during thermal denaturation might be important in responding to stress damage to the cell, such as heat shock.
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Abstract
Guanidine induced equilibrium and kinetic folding of a variant of green fluorescent protein (F99S/M153T/V163A, GFPuv) was studied. Using manual mixing and stopped-flow techniques, we combined different probes, including tryptophan fluorescence, chromophore fluorescence and reactivity with DTNB, to trace the spontaneous and TF-assisted folding of guanidine denatured GFPuv. We found that both unfolding and refolding of GFPuv occurred in a stepwise manner and a stable intermediate was populated under equilibrium conditions. The thermodynamic parameters obtained show that the intermediate state of GFPuv is quite compact compared to the denatured state and most of the green fluorescence is retained in this state. By studying GFPuv folding assisted by TF and a number of TF mutants, we found that wild-type TF catalyzes proline isomerization and accelerates the folding rate at low TF concentrations, but retards GFPuv folding and decelerates the folding rate at high TF concentrations. This reflects the two activities of TF, as an enzyme and as a chaperone. A general mechanism of TF assisted protein folding is discussed.
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Affiliation(s)
- Jiang-Bi Xie
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
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