1
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Zhao S, Feng H, Jiang D, Yang K, Wang ST, Zhang YX, Wang Y, Liu H, Guo C, Tang TS. ER Ca 2+ overload activates the IRE1α signaling and promotes cell survival. Cell Biosci 2023; 13:123. [PMID: 37400935 DOI: 10.1186/s13578-023-01062-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/26/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND Maintaining homeostasis of Ca2+ stores in the endoplasmic reticulum (ER) is crucial for proper Ca2+ signaling and key cellular functions. Although Ca2+ depletion has been known to cause ER stress which in turn activates the unfolded protein response (UPR), how UPR sensors/transducers respond to excess Ca2+ when ER stores are overloaded remain largely unclear. RESULTS Here, we report for the first time that overloading of ER Ca2+ can directly sensitize the IRE1α-XBP1 axis. The overloaded ER Ca2+ in TMCO1-deficient cells can cause BiP dissociation from IRE1α, promote the dimerization and stability of the IRE1α protein, and boost IRE1α activation. Intriguingly, attenuation of the over-activated IRE1α-XBP1s signaling by a IRE1α inhibitor can cause a significant cell death in TMCO1-deficient cells. CONCLUSIONS Our data establish a causal link between excess Ca2+ in ER stores and the selective activation of IRE1α-XBP1 axis, underscoring an unexpected role of overload of ER Ca2+ in IRE1α activation and in preventing cell death.
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Affiliation(s)
- Song Zhao
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Haiping Feng
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dongfang Jiang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Keyan Yang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Si-Tong Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yu-Xin Zhang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yun Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hongmei Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China.
| | - Caixia Guo
- Beijing Institute of Genomics, Chinese Academy of Sciences/China National Center for Bioinformation, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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2
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Perera LA, Hattersley AT, Harding HP, Wakeling MN, Flanagan SE, Mohsina I, Raza J, Gardham A, Ron D, De Franco E. Infancy-onset diabetes caused by de-regulated AMPylation of the human endoplasmic reticulum chaperone BiP. EMBO Mol Med 2023; 15:e16491. [PMID: 36704923 PMCID: PMC9994480 DOI: 10.15252/emmm.202216491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 12/08/2022] [Accepted: 12/09/2022] [Indexed: 01/28/2023] Open
Abstract
Dysfunction of the endoplasmic reticulum (ER) in insulin-producing beta cells results in cell loss and diabetes mellitus. Here we report on five individuals from three different consanguineous families with infancy-onset diabetes mellitus and severe neurodevelopmental delay caused by a homozygous p.(Arg371Ser) mutation in FICD. The FICD gene encodes a bifunctional Fic domain-containing enzyme that regulates the ER Hsp70 chaperone, BiP, via catalysis of two antagonistic reactions: inhibitory AMPylation and stimulatory deAMPylation of BiP. Arg371 is a conserved residue in the Fic domain active site. The FICDR371S mutation partially compromises BiP AMPylation in vitro but eliminates all detectable deAMPylation activity. Overexpression of FICDR371S or knock-in of the mutation at the FICD locus of stressed CHO cells results in inappropriately elevated levels of AMPylated BiP and compromised secretion. These findings, guided by human genetics, highlight the destructive consequences of de-regulated BiP AMPylation and raise the prospect of tuning FICD's antagonistic activities towards therapeutic ends.
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Affiliation(s)
- Luke A Perera
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
- Present address:
The Francis Crick InstituteLondonUK
| | - Andrew T Hattersley
- Institute of Biomedical and Clinical Science, College of Medicine and HealthUniversity of ExeterExeterUK
| | - Heather P Harding
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Matthew N Wakeling
- Institute of Biomedical and Clinical Science, College of Medicine and HealthUniversity of ExeterExeterUK
| | - Sarah E Flanagan
- Institute of Biomedical and Clinical Science, College of Medicine and HealthUniversity of ExeterExeterUK
| | - Ibrahim Mohsina
- Department of Endocrine and DiabetesNational Institute of Child HealthKarachiPakistan
| | - Jamal Raza
- Department of Endocrine and DiabetesNational Institute of Child HealthKarachiPakistan
| | | | - David Ron
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Elisa De Franco
- Institute of Biomedical and Clinical Science, College of Medicine and HealthUniversity of ExeterExeterUK
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3
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Chaperone-Dependent Mechanisms as a Pharmacological Target for Neuroprotection. Int J Mol Sci 2023; 24:ijms24010823. [PMID: 36614266 PMCID: PMC9820882 DOI: 10.3390/ijms24010823] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 01/05/2023] Open
Abstract
Modern pharmacotherapy of neurodegenerative diseases is predominantly symptomatic and does not allow vicious circles causing disease development to break. Protein misfolding is considered the most important pathogenetic factor of neurodegenerative diseases. Physiological mechanisms related to the function of chaperones, which contribute to the restoration of native conformation of functionally important proteins, evolved evolutionarily. These mechanisms can be considered promising for pharmacological regulation. Therefore, the aim of this review was to analyze the mechanisms of endoplasmic reticulum stress (ER stress) and unfolded protein response (UPR) in the pathogenesis of neurodegenerative diseases. Data on BiP and Sigma1R chaperones in clinical and experimental studies of Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease are presented. The possibility of neuroprotective effect dependent on Sigma1R ligand activation in these diseases is also demonstrated. The interaction between Sigma1R and BiP-associated signaling in the neuroprotection is discussed. The performed analysis suggests the feasibility of pharmacological regulation of chaperone function, possibility of ligand activation of Sigma1R in order to achieve a neuroprotective effect, and the need for further studies of the conjugation of cellular mechanisms controlled by Sigma1R and BiP chaperones.
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4
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Melnyk A, Lang S, Sicking M, Zimmermann R, Jung M. Co-chaperones of the Human Endoplasmic Reticulum: An Update. Subcell Biochem 2023; 101:247-291. [PMID: 36520310 DOI: 10.1007/978-3-031-14740-1_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In mammalian cells, the rough endoplasmic reticulum (ER) plays central roles in the biogenesis of extracellular plus organellar proteins and in various signal transduction pathways. For these reasons, the ER comprises molecular chaperones, which are involved in import, folding, assembly, export, plus degradation of polypeptides, and signal transduction components, such as calcium channels, calcium pumps, and UPR transducers plus adenine nucleotide carriers/exchangers in the ER membrane. The calcium- and ATP-dependent ER lumenal Hsp70, termed immunoglobulin heavy-chain-binding protein or BiP, is the central player in all these activities and involves up to nine different Hsp40-type co-chaperones, i.e., ER membrane integrated as well as ER lumenal J-domain proteins, termed ERj or ERdj proteins, two nucleotide exchange factors or NEFs (Grp170 and Sil1), and NEF-antagonists, such as MANF. Here we summarize the current knowledge on the ER-resident BiP/ERj chaperone network and focus on the interaction of BiP with the polypeptide-conducting and calcium-permeable Sec61 channel of the ER membrane as an example for BiP action and how its functional cycle is linked to ER protein import and various calcium-dependent signal transduction pathways.
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Affiliation(s)
- Armin Melnyk
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
| | - Sven Lang
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
| | - Mark Sicking
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
| | - Richard Zimmermann
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany.
| | - Martin Jung
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
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5
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Kapelanski-Lamoureux A, Chen Z, Gao ZH, Deng R, Lazaris A, Lebeaupin C, Giles L, Malhotra J, Yong J, Zou C, de Jong YP, Metrakos P, Herzog RW, Kaufman RJ. Ectopic clotting factor VIII expression and misfolding in hepatocytes as a cause for hepatocellular carcinoma. Mol Ther 2022; 30:3542-3551. [PMID: 36242517 PMCID: PMC9734080 DOI: 10.1016/j.ymthe.2022.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/12/2022] [Indexed: 11/07/2022] Open
Abstract
Hemophilia A gene therapy targets hepatocytes to express B domain deleted (BDD) clotting factor VIII (FVIII) to permit viral encapsidation. Since BDD is prone to misfolding in the endoplasmic reticulum (ER) and ER protein misfolding in hepatocytes followed by high-fat diet (HFD) can cause hepatocellular carcinoma (HCC), we studied how FVIII misfolding impacts HCC development using hepatocyte DNA delivery to express three proteins from the same parental vector: (1) well-folded cytosolic dihydrofolate reductase (DHFR); (2) BDD-FVIII, which is prone to misfolding in the ER; and (3) N6-FVIII, which folds more efficiently than BDD-FVIII. One week after DNA delivery, when FVIII expression was undetectable, mice were fed HFD for 65 weeks. Remarkably, all mice that received BDD-FVIII vector developed liver tumors, whereas only 58% of mice that received N6 and no mice that received DHFR vector developed liver tumors, suggesting that the degree of protein misfolding in the ER increases predisposition to HCC in the context of an HFD and in the absence of viral transduction. Our findings raise concerns of ectopic BDD-FVIII expression in hepatocytes in the clinic, which poses risks independent of viral vector integration. Limited expression per hepatocyte and/or use of proteins that avoid misfolding may enhance safety.
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Affiliation(s)
- Audrey Kapelanski-Lamoureux
- Department of Anatomy and Cell Biology, McGill University, Cancer Research Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Zhouji Chen
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, SBP Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Zu-Hua Gao
- Department of Pathology and Oncology, McGill University Health Centre, Montreal, QC H4A 3J1, Canada,Cancer Research Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Ruishu Deng
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, SBP Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Anthoula Lazaris
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Cynthia Lebeaupin
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, SBP Medical Discovery Institute, La Jolla, CA 92037, USA,Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lisa Giles
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI 48109, USA
| | - Jyoti Malhotra
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI 48109, USA
| | - Jing Yong
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, SBP Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Chenhui Zou
- Division of Gastroenterology and Hepatology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Ype P. de Jong
- Division of Gastroenterology and Hepatology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Peter Metrakos
- Department of Surgery, McGill University; Cancer Research Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Roland W. Herzog
- Herman B Wells Center for Pediatric Research, Indiana University, Indianapolis, IN 46202, USA
| | - Randal J. Kaufman
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, SBP Medical Discovery Institute, La Jolla, CA 92037, USA,Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI 48109, USA,Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA,Howard Hughes Medical Institute, University of Michigan Medical Center, Ann Arbor, MI 48109, USA,Corresponding author: Randal J. Kaufman, Degenerative Diseases Program, SBP Medical Discovery Institute, La Jolla, CA 92037, USA.
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6
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Amankwah YS, Collins P, Fleifil Y, Unruh E, Ruiz Márquez KJ, Vitou K, Kravats AN. Grp94 works upstream of BiP in protein remodeling under heat stress. J Mol Biol 2022; 434:167762. [PMID: 35905823 DOI: 10.1016/j.jmb.2022.167762] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/28/2022] [Accepted: 07/21/2022] [Indexed: 10/16/2022]
Abstract
Hsp90 and Hsp70 are highly conserved molecular chaperones that promote the proper folding and activation of substrate proteins that are often referred to as clients. The two chaperones functionally collaborate to fold specific clients in an ATP-dependent manner. In eukaryotic cytosol, initial client folding is done by Hsp70 and its co-chaperones, followed by a direct transfer of client refolding intermediates to Hsp90 for final client processing. However, the mechanistic details of collaboration of organelle specific Hsp70 and Hsp90 are lacking. This work investigates the collaboration of the endoplasmic reticulum (ER) Hsp70 and Hsp90, BiP and Grp94 respectively, in protein remodeling using in vitro refolding assays. We show that under milder denaturation conditions, BiP collaborates with its co-chaperones to refold misfolded proteins in an ATP-dependent manner. Grp94 does not play a major role in this refolding reaction. However, under stronger denaturation conditions that favor aggregation, Grp94 works in an ATP-independent manner to bind and hold misfolded clients in a folding competent state for subsequent remodeling by the BiP system. We also show that the collaboration of Grp94 and BiP is not simply a reversal of the eukaryotic refolding mechanism since a direct interaction of Grp94 and BiP is not required for client transfer. Instead, ATP binding but not hydrolysis by Grp94 facilitates the release of the bound client, which is then picked up by the BiP system for subsequent refolding in a Grp94-independent manner.
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Affiliation(s)
- Yaa S Amankwah
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056
| | - Preston Collins
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056
| | - Yasmeen Fleifil
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056
| | - Erin Unruh
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056
| | | | - Katherine Vitou
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056
| | - Andrea N Kravats
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056.
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7
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Virolainen MS, Søltoft CL, Pedersen PA, Ellgaard L. Production of an Active, Human Membrane Protein in Saccharomyces cerevisiae: Full-Length FICD. Int J Mol Sci 2022; 23:ijms23052458. [PMID: 35269596 PMCID: PMC8910494 DOI: 10.3390/ijms23052458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 12/10/2022] Open
Abstract
The human Fic domain-containing protein (FICD) is a type II endoplasmic reticulum (ER) membrane protein that is important for the maintenance of ER proteostasis. Structural and in vitro biochemical characterisation of FICD AMPylase and deAMPylase activity have been restricted to the soluble ER-luminal domain produced in Escherichia coli. Information about potentially important features, such as structural motifs, modulator binding sites or other regulatory elements, is therefore missing for the approximately 100 N-terminal residues including the transmembrane region of FICD. Expressing and purifying the required quantity and quality of membrane proteins is demanding because of the low yields and poor stability often observed. Here, we produce full-length FICD by combining a Saccharomyces cerevisiae-based platform with green fluorescent protein (GFP) tagging to optimise the conditions for expression, solubilisation and purification. We subsequently employ these conditions to purify milligram quantities of His-tagged FICD per litre of culture, and show that the purified, detergent-solubilised membrane protein is an active deAMPylating enzyme. Our work provides a straightforward methodology for producing not only full-length FICD, but also other membrane proteins in S. cerevisiae for structural and biochemical characterisation.
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Affiliation(s)
- Minttu S. Virolainen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark; (M.S.V.); (C.L.S.)
| | - Cecilie L. Søltoft
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark; (M.S.V.); (C.L.S.)
| | - Per A. Pedersen
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2200 Copenhagen, Denmark
- Correspondence: (P.A.P.); (L.E.)
| | - Lars Ellgaard
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark; (M.S.V.); (C.L.S.)
- Correspondence: (P.A.P.); (L.E.)
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8
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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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9
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Li H, Sun S. Protein Aggregation in the ER: Calm behind the Storm. Cells 2021; 10:cells10123337. [PMID: 34943844 PMCID: PMC8699410 DOI: 10.3390/cells10123337] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 02/06/2023] Open
Abstract
As one of the largest organelles in eukaryotic cells, the endoplasmic reticulum (ER) plays a vital role in the synthesis, folding, and assembly of secretory and membrane proteins. To maintain its homeostasis, the ER is equipped with an elaborate network of protein folding chaperones and multiple quality control pathways whose cooperative actions safeguard the fidelity of protein biogenesis. However, due to genetic abnormalities, the error-prone nature of protein folding and assembly, and/or defects or limited capacities of the protein quality control systems, nascent proteins may become misfolded and fail to exit the ER. If not cleared efficiently, the progressive accumulation of misfolded proteins within the ER may result in the formation of toxic protein aggregates, leading to the so-called “ER storage diseases”. In this review, we first summarize our current understanding of the protein folding and quality control networks in the ER, including chaperones, unfolded protein response (UPR), ER-associated protein degradation (ERAD), and ER-selective autophagy (ER-phagy). We then survey recent research progress on a few ER storage diseases, with a focus on the role of ER quality control in the disease etiology, followed by a discussion on outstanding questions and emerging concepts in the field.
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Affiliation(s)
- Haisen Li
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA;
| | - Shengyi Sun
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA;
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI 48201, USA
- Correspondence:
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10
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Pick T, Beck A, Gamayun I, Schwarz Y, Schirra C, Jung M, Krause E, Niemeyer BA, Zimmermann R, Lang S, Anken EV, Cavalié A. Remodelling of Ca 2+ homeostasis is linked to enlarged endoplasmic reticulum in secretory cells. Cell Calcium 2021; 99:102473. [PMID: 34560367 DOI: 10.1016/j.ceca.2021.102473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 08/27/2021] [Accepted: 09/08/2021] [Indexed: 11/30/2022]
Abstract
The endoplasmic reticulum (ER) is extensively remodelled during the development of professional secretory cells to cope with high protein production. Since ER is the principal Ca2+ store in the cell, we characterised the Ca2+ homeostasis in NALM-6 and RPMI 8226 cells, which are commonly used as human pre-B and antibody secreting plasma cell models, respectively. Expression levels of Sec61 translocons and the corresponding Sec61-mediated Ca2+ leak from ER, Ca2+ storage capacity and store-operated Ca2+ entry were significantly enlarged in the secretory RPMI 8226 cell line. Using an immunoglobulin M heavy chain producing HeLa cell model, we found that the enlarged Ca2+ storage capacity and Ca2+ leak from ER are linked to ER expansion. Our data delineates a developmental remodelling of Ca2+ homeostasis in professional secretory cells in which a high Sec61-mediated Ca2+ leak and, thus, a high Ca2+ turnover in the ER is backed up by enhanced store-operated Ca2+ entry.
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Affiliation(s)
- Tillman Pick
- Experimental and Clinical Pharmacology and Toxicology, Pre-clinical Center for Molecular Signalling (PZMS), Saarland University, 66421 Homburg, Germany.
| | - Andreas Beck
- Experimental and Clinical Pharmacology and Toxicology, Pre-clinical Center for Molecular Signalling (PZMS), Saarland University, 66421 Homburg, Germany
| | - Igor Gamayun
- Experimental and Clinical Pharmacology and Toxicology, Pre-clinical Center for Molecular Signalling (PZMS), Saarland University, 66421 Homburg, Germany
| | - Yvonne Schwarz
- Molecular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, 66421 Homburg, Germany
| | - Claudia Schirra
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, 66421 Homburg, Germany
| | - Martin Jung
- Medical Biochemistry and Molecular Biology, Pre-clinical Centre for Molecular Signalling (PZMS), Saarland University, 66421 Homburg, Germany
| | - Elmar Krause
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, 66421 Homburg, Germany
| | - Barbara A Niemeyer
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, 66421 Homburg, Germany
| | - Richard Zimmermann
- Medical Biochemistry and Molecular Biology, Pre-clinical Centre for Molecular Signalling (PZMS), Saarland University, 66421 Homburg, Germany
| | - Sven Lang
- Medical Biochemistry and Molecular Biology, Pre-clinical Centre for Molecular Signalling (PZMS), Saarland University, 66421 Homburg, Germany
| | - Eelco van Anken
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute and Università Vita-Salute San Raffaele, Milan, Italy
| | - Adolfo Cavalié
- Experimental and Clinical Pharmacology and Toxicology, Pre-clinical Center for Molecular Signalling (PZMS), Saarland University, 66421 Homburg, Germany.
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11
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Maubach G, Lim MCC, Sokolova O, Backert S, Meyer TF, Naumann M. TIFA has dual functions in Helicobacter pylori-induced classical and alternative NF-κB pathways. EMBO Rep 2021; 22:e52878. [PMID: 34328245 PMCID: PMC8419686 DOI: 10.15252/embr.202152878] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 11/21/2022] Open
Abstract
Helicobacter pylori infection constitutes one of the major risk factors for the development of gastric diseases including gastric cancer. The activation of nuclear factor‐kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) via classical and alternative pathways is a hallmark of H. pylori infection leading to inflammation in gastric epithelial cells. Tumor necrosis factor receptor‐associated factor (TRAF)‐interacting protein with forkhead‐associated domain (TIFA) was previously suggested to trigger classical NF‐κB activation, but its role in alternative NF‐κB activation remains unexplored. Here, we identify TRAF6 and TRAF2 as binding partners of TIFA, contributing to the formation of TIFAsomes upon H. pylori infection. Importantly, the TIFA/TRAF6 interaction enables binding of TGFβ‐activated kinase 1 (TAK1), leading to the activation of classical NF‐κB signaling, while the TIFA/TRAF2 interaction causes the transient displacement of cellular inhibitor of apoptosis 1 (cIAP1) from TRAF2, and proteasomal degradation of cIAP1, to facilitate the activation of the alternative NF‐κB pathway. Our findings therefore establish a dual function of TIFA in the activation of classical and alternative NF‐κB signaling in H. pylori‐infected gastric epithelial cells.
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Affiliation(s)
- Gunter Maubach
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Michelle C C Lim
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Olga Sokolova
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Steffen Backert
- Division of Microbiology, Department of Biology, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Thomas F Meyer
- Department of Molecular Biology, Max-Planck Institute for Infection Biology, Berlin, Germany.,Laboratory of Infection Oncology, Institute of Clinical Molecular Biology, Christian Albrechts University of Kiel and University Hospital Schleswig Holstein, Kiel, Germany
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
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12
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Mayer MP. The Hsp70-Chaperone Machines in Bacteria. Front Mol Biosci 2021; 8:694012. [PMID: 34164436 PMCID: PMC8215388 DOI: 10.3389/fmolb.2021.694012] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/20/2021] [Indexed: 12/02/2022] Open
Abstract
The ATP-dependent Hsp70s are evolutionary conserved molecular chaperones that constitute central hubs of the cellular protein quality surveillance network. None of the other main chaperone families (Tig, GroELS, HtpG, IbpA/B, ClpB) have been assigned with a comparable range of functions. Through a multitude of functions Hsp70s are involved in many cellular control circuits for maintaining protein homeostasis and have been recognized as key factors for cell survival. Three mechanistic properties of Hsp70s are the basis for their high versatility. First, Hsp70s bind to short degenerate sequence motifs within their client proteins. Second, Hsp70 chaperones switch in a nucleotide-controlled manner between a state of low affinity for client proteins and a state of high affinity for clients. Third, Hsp70s are targeted to their clients by a large number of cochaperones of the J-domain protein (JDP) family and the lifetime of the Hsp70-client complex is regulated by nucleotide exchange factors (NEF). In this review I will discuss advances in the understanding of the molecular mechanism of the Hsp70 chaperone machinery focusing mostly on the bacterial Hsp70 DnaK and will compare the two other prokaryotic Hsp70s HscA and HscC with DnaK.
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Affiliation(s)
- Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, Heidelberg, Germany
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13
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Chatterjee BK, Truttmann MC. Fic and non-Fic AMPylases: protein AMPylation in metazoans. Open Biol 2021; 11:210009. [PMID: 33947243 PMCID: PMC8097203 DOI: 10.1098/rsob.210009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Protein AMPylation refers to the covalent attachment of an AMP moiety to the amino acid side chains of target proteins using ATP as nucleotide donor. This process is catalysed by dedicated AMP transferases, called AMPylases. Since this initial discovery, several research groups have identified AMPylation as a critical post-translational modification relevant to normal and pathological cell signalling in both bacteria and metazoans. Bacterial AMPylases are abundant enzymes that either regulate the function of endogenous bacterial proteins or are translocated into host cells to hijack host cell signalling processes. By contrast, only two classes of metazoan AMPylases have been identified so far: enzymes containing a conserved filamentation induced by cAMP (Fic) domain (Fic AMPylases), which primarily modify the ER-resident chaperone BiP, and SelO, a mitochondrial AMPylase involved in redox signalling. In this review, we compare and contrast bacterial and metazoan Fic and non-Fic AMPylases, and summarize recent technological and conceptual developments in the emerging field of AMPylation.
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Affiliation(s)
- Bhaskar K Chatterjee
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Matthias C Truttmann
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA.,Geriatrics Center, University of Michigan, Ann Arbor, MI 48109, USA
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14
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Specificity of AMPylation of the human chaperone BiP is mediated by TPR motifs of FICD. Nat Commun 2021; 12:2426. [PMID: 33893288 PMCID: PMC8065156 DOI: 10.1038/s41467-021-22596-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 03/18/2021] [Indexed: 02/02/2023] Open
Abstract
To adapt to fluctuating protein folding loads in the endoplasmic reticulum (ER), the Hsp70 chaperone BiP is reversibly modified with adenosine monophosphate (AMP) by the ER-resident Fic-enzyme FICD/HYPE. The structural basis for BiP binding and AMPylation by FICD has remained elusive due to the transient nature of the enzyme-substrate-complex. Here, we use thiol-reactive derivatives of the cosubstrate adenosine triphosphate (ATP) to covalently stabilize the transient FICD:BiP complex and determine its crystal structure. The complex reveals that the TPR-motifs of FICD bind specifically to the conserved hydrophobic linker of BiP and thus mediate specificity for the domain-docked conformation of BiP. Furthermore, we show that both AMPylation and deAMPylation of BiP are not directly regulated by the presence of unfolded proteins. Together, combining chemical biology, crystallography and biochemistry, our study provides structural insights into a key regulatory mechanism that safeguards ER homeostasis.
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15
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Adiponectin enhances the bioenergetics of cardiac myocytes via an AMPK- and succinate dehydrogenase-dependent mechanism. Cell Signal 2021; 78:109866. [PMID: 33271223 PMCID: PMC9619024 DOI: 10.1016/j.cellsig.2020.109866] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022]
Abstract
Adiponectin is one of the most abundant circulating hormones, which through adenosine monophosphate-activated protein kinase (AMPK), enhances fatty acid and glucose oxidation, and exerts a cardioprotective effect. However, its effects on cellular bioenergetics have not been explored. We have previously reported that 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR, an AMPK activator) enhances mitochondrial respiration through a succinate dehydrogenase (SDH or complex II)-dependent mechanism in cardiac myocytes, leading us to predict that Adiponectin would exert a similar effect via activating AMPK. Our results show that Adiponectin enhances basal mitochondrial oxygen consumption rate (OCR), ATP production, and spare respiratory capacity (SRC), which were all abolished by the knockdown of AMPKγ1, inhibition of SDH complex assembly, via the knockdown of the SDH assembly factor 1 (Sdhaf1), or inhibition of SDH activity. Additionally, Adiponectin alleviated hypoxia-induced reductions in OCR and ATP production, in a Sdhaf1-dependent manner, whereas overexpression of Sdhaf1 confirmed its sufficiency for mediating these effects. Importantly, the levels of holoenzyme SDH under the various conditions correlated with OCR. We also show that the effects of Adiponectin, AMPK, Sdhaf1, as well as, SDH complex assembly all required sirtuin 3 (Sirt3). In conclusion, Adiponectin potentiates mitochondrial bioenergetics via promoting SDH complex assembly in an AMPK-, Sdhaf1-, and Sirt3-dependent fashion in cardiac myocytes.
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16
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The Role of Endoplasmic Reticulum Chaperones in Protein Folding and Quality Control. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 59:27-50. [PMID: 34050861 DOI: 10.1007/978-3-030-67696-4_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Molecular chaperones assist the folding of nascent chains in the cell. Chaperones also aid in quality control decisions as persistent chaperone binding can help to sort terminal misfolded proteins for degradation. There are two major molecular chaperone families in the endoplasmic reticulum (ER) that assist proteins in reaching their native structure and evaluating the fidelity of the maturation process. The ER Hsp70 chaperone, BiP, supports adenine nucleotide-regulated binding to non-native proteins that possess exposed hydrophobic regions. In contrast, the carbohydrate-dependent chaperone system involving the membrane protein calnexin and its soluble paralogue calreticulin recognize a specific glycoform of an exposed hydrophilic protein modification for which the composition is controlled by a series of glycosidases and transferases. Here, we compare and contrast the properties, mechanisms of action and functions of these different chaperones systems that work in parallel, as well as together, to assist a large variety of substrates that traverse the eukaryotic secretory pathway.
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17
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Preissler S, Rato C, Yan Y, Perera LA, Czako A, Ron D. Calcium depletion challenges endoplasmic reticulum proteostasis by destabilising BiP-substrate complexes. eLife 2020; 9:62601. [PMID: 33295873 PMCID: PMC7758071 DOI: 10.7554/elife.62601] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022] Open
Abstract
The metazoan endoplasmic reticulum (ER) serves both as a hub for maturation of secreted proteins and as an intracellular calcium storage compartment, facilitating calcium-release-dependent cellular processes. ER calcium depletion robustly activates the unfolded protein response (UPR). However, it is unclear how fluctuations in ER calcium impact organellar proteostasis. Here, we report that calcium selectively affects the dynamics of the abundant metazoan ER Hsp70 chaperone BiP, by enhancing its affinity for ADP. In the calcium-replete ER, ADP rebinding to post-ATP hydrolysis BiP-substrate complexes competes with ATP binding during both spontaneous and co-chaperone-assisted nucleotide exchange, favouring substrate retention. Conversely, in the calcium-depleted ER, relative acceleration of ADP-to-ATP exchange favours substrate release. These findings explain the rapid dissociation of certain substrates from BiP observed in the calcium-depleted ER and suggest a mechanism for tuning ER quality control and coupling UPR activity to signals that mobilise ER calcium in secretory cells.
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Affiliation(s)
- Steffen Preissler
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Claudia Rato
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Yahui Yan
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Luke A Perera
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Aron Czako
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - David Ron
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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18
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Poothong J, Pottekat A, Siirin M, Campos AR, Paton AW, Paton JC, Lagunas-Acosta J, Chen Z, Swift M, Volkmann N, Hanein D, Yong J, Kaufman RJ. Factor VIII exhibits chaperone-dependent and glucose-regulated reversible amyloid formation in the endoplasmic reticulum. Blood 2020; 135:1899-1911. [PMID: 32128578 PMCID: PMC7243144 DOI: 10.1182/blood.2019002867] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/13/2020] [Indexed: 12/14/2022] Open
Abstract
Hemophilia A, an X-linked bleeding disorder caused by deficiency of factor VIII (FVIII), is treated by protein replacement. Unfortunately, this regimen is costly due to the expense of producing recombinant FVIII as a consequence of its low-level secretion from mammalian host cells. FVIII expression activates the endoplasmic reticulum (ER) stress response, causes oxidative stress, and induces apoptosis. Importantly, little is known about the factors that cause protein misfolding and aggregation in metazoans. Here, we identified intrinsic and extrinsic factors that cause FVIII to form aggregates. We show that FVIII forms amyloid-like fibrils within the ER lumen upon increased FVIII synthesis or inhibition of glucose metabolism. Significantly, FVIII amyloids can be dissolved upon restoration of glucose metabolism to produce functional secreted FVIII. Two ER chaperone families and their cochaperones, immunoglobulin binding protein (BiP) and calnexin/calreticulin, promote FVIII solubility in the ER, where the former is also required for disaggregation. A short aggregation motif in the FVIII A1 domain (termed Aggron) is necessary and sufficient to seed β-sheet polymerization, and BiP binding to this Aggron prevents amyloidogenesis. Our findings provide novel insight into mechanisms that limit FVIII secretion and ER protein aggregation in general and have implication for ongoing hemophilia A gene-therapy clinical trials.
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Affiliation(s)
| | | | | | - Alexandre Rosa Campos
- Proteomics Core Facility, Sanford Burnham Prebys (SBP) Medical Discovery Institute, La Jolla, CA
| | - Adrienne W Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, Australia; and
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, Australia; and
| | | | | | - Mark Swift
- Immunity and Pathogenesis Program, SBP Medical Discovery Institute, La Jolla, CA
| | - Niels Volkmann
- Immunity and Pathogenesis Program, SBP Medical Discovery Institute, La Jolla, CA
| | - Dorit Hanein
- Immunity and Pathogenesis Program, SBP Medical Discovery Institute, La Jolla, CA
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19
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Arrieta A, Blackwood EA, Stauffer WT, Santo Domingo M, Bilal AS, Thuerauf DJ, Pentoney AN, Aivati C, Sarakki AV, Doroudgar S, Glembotski CC. Mesencephalic astrocyte-derived neurotrophic factor is an ER-resident chaperone that protects against reductive stress in the heart. J Biol Chem 2020; 295:7566-7583. [PMID: 32327487 DOI: 10.1074/jbc.ra120.013345] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/17/2020] [Indexed: 12/13/2022] Open
Abstract
We have previously demonstrated that ischemia/reperfusion (I/R) impairs endoplasmic reticulum (ER)-based protein folding in the heart and thereby activates an unfolded protein response sensor and effector, activated transcription factor 6α (ATF6). ATF6 then induces mesencephalic astrocyte-derived neurotrophic factor (MANF), an ER-resident protein with no known structural homologs and unclear ER function. To determine MANF's function in the heart in vivo, here we developed a cardiomyocyte-specific MANF-knockdown mouse model. MANF knockdown increased cardiac damage after I/R, which was reversed by AAV9-mediated ectopic MANF expression. Mechanistically, MANF knockdown in cultured neonatal rat ventricular myocytes (NRVMs) impaired protein folding in the ER and cardiomyocyte viability during simulated I/R. However, this was not due to MANF-mediated protection from reactive oxygen species generated during reperfusion. Because I/R impairs oxygen-dependent ER protein disulfide formation and such impairment can be caused by reductive stress in the ER, we examined the effects of the reductive ER stressor DTT. MANF knockdown in NRVMs increased cell death from DTT-mediated reductive ER stress, but not from nonreductive ER stresses caused by thapsigargin-mediated ER Ca2+ depletion or tunicamycin-mediated inhibition of ER protein glycosylation. In vitro, recombinant MANF exhibited chaperone activity that depended on its conserved cysteine residues. Moreover, in cells, MANF bound to a model ER protein exhibiting improper disulfide bond formation during reductive ER stress but did not bind to this protein during nonreductive ER stress. We conclude that MANF is an ER chaperone that enhances protein folding and myocyte viability during reductive ER stress.
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Affiliation(s)
- Adrian Arrieta
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Erik A Blackwood
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Winston T Stauffer
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Michelle Santo Domingo
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Alina S Bilal
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Donna J Thuerauf
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Amber N Pentoney
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Cathrine Aivati
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Anup V Sarakki
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Shirin Doroudgar
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA.,Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Innere Medizin III, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Christopher C Glembotski
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
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20
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Amin-Wetzel N, Neidhardt L, Yan Y, Mayer MP, Ron D. Unstructured regions in IRE1α specify BiP-mediated destabilisation of the luminal domain dimer and repression of the UPR. eLife 2019; 8:50793. [PMID: 31873072 PMCID: PMC6996924 DOI: 10.7554/elife.50793] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 12/23/2019] [Indexed: 12/15/2022] Open
Abstract
Coupling of endoplasmic reticulum (ER) stress to dimerisation-dependent activation of the UPR transducer IRE1 is incompletely understood. Whilst the luminal co-chaperone ERdj4 promotes a complex between the Hsp70 BiP and IRE1's stress-sensing luminal domain (IRE1LD) that favours the latter's monomeric inactive state and loss of ERdj4 de-represses IRE1, evidence linking these cellular and in vitro observations is presently lacking. We report that enforced loading of endogenous BiP onto endogenous IRE1α repressed UPR signalling in CHO cells and deletions in the IRE1α locus that de-repressed the UPR in cells, encode flexible regions of IRE1LD that mediated BiP-induced monomerisation in vitro. Changes in the hydrogen exchange mass spectrometry profile of IRE1LD induced by ERdj4 and BiP confirmed monomerisation and were consistent with active destabilisation of the IRE1LD dimer. Together, these observations support a competition model whereby waning ER stress passively partitions ERdj4 and BiP to IRE1LD to initiate active repression of UPR signalling.
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Affiliation(s)
- Niko Amin-Wetzel
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, United Kingdom
| | - Lisa Neidhardt
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, United Kingdom
| | - Yahui Yan
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, United Kingdom
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - David Ron
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, United Kingdom
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21
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Liu Q, Liang C, Zhou L. Structural and functional analysis of the Hsp70/Hsp40 chaperone system. Protein Sci 2019; 29:378-390. [PMID: 31509306 DOI: 10.1002/pro.3725] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 08/29/2019] [Accepted: 09/03/2019] [Indexed: 12/22/2022]
Abstract
As one of the most abundant and highly conserved molecular chaperones, the 70-kDa heat shock proteins (Hsp70s) play a key role in maintaining cellular protein homeostasis (proteostasis), one of the most fundamental tasks for every living organism. In this role, Hsp70s are inextricably linked to many human diseases, most notably cancers and neurodegenerative diseases, and are increasingly recognized as important drug targets for developing novel therapeutics for these diseases. Hsp40s are a class of essential and universal partners for Hsp70s in almost all aspects of proteostasis. Thus, Hsp70s and Hsp40s together constitute one of the most important chaperone systems across all kingdoms of life. In recent years, we have witnessed significant progress in understanding the molecular mechanism of this chaperone system through structural and functional analysis. This review will focus on this recent progress, mainly from a structural perspective.
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Affiliation(s)
- Qinglian Liu
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Ce Liang
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Lei Zhou
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
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22
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Perera LA, Rato C, Yan Y, Neidhardt L, McLaughlin SH, Read RJ, Preissler S, Ron D. An oligomeric state-dependent switch in the ER enzyme FICD regulates AMPylation and deAMPylation of BiP. EMBO J 2019; 38:e102177. [PMID: 31531998 PMCID: PMC6826200 DOI: 10.15252/embj.2019102177] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 11/23/2022] Open
Abstract
AMPylation is an inactivating modification that alters the activity of the major endoplasmic reticulum (ER) chaperone BiP to match the burden of unfolded proteins. A single ER-localised Fic protein, FICD (HYPE), catalyses both AMPylation and deAMPylation of BiP. However, the basis for the switch in FICD's activity is unknown. We report on the transition of FICD from a dimeric enzyme, that deAMPylates BiP, to a monomer with potent AMPylation activity. Mutations in the dimer interface, or of residues along an inhibitory pathway linking the dimer interface to the enzyme's active site, favour BiP AMPylation in vitro and in cells. Mechanistically, monomerisation relieves a repressive effect allosterically propagated from the dimer interface to the inhibitory Glu234, thereby permitting AMPylation-competent binding of MgATP. Moreover, a reciprocal signal, propagated from the nucleotide-binding site, provides a mechanism for coupling the oligomeric state and enzymatic activity of FICD to the energy status of the ER.
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Affiliation(s)
- Luke A Perera
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Claudia Rato
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Yahui Yan
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Lisa Neidhardt
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | | | - Randy J Read
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Steffen Preissler
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - David Ron
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
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23
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Needham PG, Guerriero CJ, Brodsky JL. Chaperoning Endoplasmic Reticulum-Associated Degradation (ERAD) and Protein Conformational Diseases. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033928. [PMID: 30670468 DOI: 10.1101/cshperspect.a033928] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Misfolded proteins compromise cellular homeostasis. This is especially problematic in the endoplasmic reticulum (ER), which is a high-capacity protein-folding compartment and whose function requires stringent protein quality-control systems. Multiprotein complexes in the ER are able to identify, remove, ubiquitinate, and deliver misfolded proteins to the 26S proteasome for degradation in the cytosol, and these events are collectively termed ER-associated degradation, or ERAD. Several steps in the ERAD pathway are facilitated by molecular chaperone networks, and the importance of ERAD is highlighted by the fact that this pathway is linked to numerous protein conformational diseases. In this review, we discuss the factors that constitute the ERAD machinery and detail how each step in the pathway occurs. We then highlight the underlying pathophysiology of protein conformational diseases associated with ERAD.
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Affiliation(s)
- Patrick G Needham
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | | | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
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24
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Dhara A, Hussain MS, Datta D, Kumar M. Insights to the Assembly of a Functionally Active Leptospiral ClpP1P2 Protease Complex along with Its ATPase Chaperone ClpX. ACS OMEGA 2019; 4:12880-12895. [PMID: 31460415 PMCID: PMC6682002 DOI: 10.1021/acsomega.9b00399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 07/11/2019] [Indexed: 05/05/2023]
Abstract
Leptospira interrogans genome is predicted to encode multiple isoforms of caseinolytic proteases (ClpP1 and ClpP2). The ClpP proteins with the aid of its ATPase chaperone are known to be involved in establishing cellular proteostasis and have emerged as a target for developing new antibiotics. We report the molecular characterization of recombinant ClpP1 (rClpP1) and rClpP2 of Leptospira along with its ATPase chaperone rClpX. The two isoforms of rClpPs when coupled together in an equivalent concentration exhibit optimum activity on small fluorogenic peptide substrates, whereas the pure rClpP isoforms are enzymatically inactive. Isothermal titration calorimetry analysis suggests that the two rClpP isoforms bind each other moderately in a 1:1 stoichiometry with a dissociation constant of 2.02 ± 0.1 μM at 37 °C and is thermodynamically favored. Size exclusion chromatography fractionates the majority of pure rClpP1 at ≥308 kDa (14-21-mer) and the pure rClpP2 at 308 kDa (tetradecamer), whereas the functionally active rClpP isoform mixture fractionates as a tetradecamer. The distinct and unprecedented oligomeric form of rClpP1 was also evident through native-gel and dynamic light scattering. Moreover, the rClpP isoform mixture formed after the site-directed mutation of either or both the isoforms at one of the catalytic triad residues (Ser 98/97 to Ala 98/97) resulted in the complete loss of protease activity. The rClpP isoform mixture gets stimulated to degrade the casein substrate in the presence of rClpX and in an energy-dependent manner. On the contrary, pure rClpP1 or the rClpP2 isoform in association with rClpX are incapable of forming operative protease. The reported finding suggests that in Leptospira, the enzymatic activity of the rClpP protease complex in the presence or absence of cochaperone is performed solely by the tetradecamer structure which is hypothesized to be composed of 2-stacked ClpP heptameric rings, wherein each ring is a homo-oligomer of ClpP1 and ClpP2 subunits. Understanding the activities and regulation principle of multi-isoforms of ClpP in pathogenic bacteria may aid in intervening disease outcomes particularly to the co-evolving antibiotic resistance strains.
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Affiliation(s)
| | | | | | - Manish Kumar
- E-mail: . Phone: +91-361-258-2230. Fax: +91-361-258-2249
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25
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Preissler S, Ron D. Early Events in the Endoplasmic Reticulum Unfolded Protein Response. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033894. [PMID: 30396883 PMCID: PMC6442202 DOI: 10.1101/cshperspect.a033894] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The physiological consequences of the unfolded protein response (UPR) are mediated by changes in gene expression. Underlying them are rapid processes involving preexisting components. We review recent insights gained into the regulation of the endoplasmic reticulum (ER) Hsp70 chaperone BiP, whose incorporation into inactive oligomers and reversible AMPylation and de-AMPylation present a first line of response to fluctuating levels of unfolded proteins. BiP activity is tied to the regulation of the UPR transducers by a recently discovered cycle of ER-localized, J protein-mediated formation of a repressive IRE1-BiP complex, whose working we contrast to an alternative model for UPR regulation that relies on direct recognition of unfolded proteins. We conclude with a discussion of mechanisms that repress messenger RNA (mRNA) translation to limit the flux of newly synthesized proteins into the ER, a rapid adaptation that does not rely on new macromolecule biosynthesis.
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26
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Sun M, Kotler JLM, Liu S, Street TO. The endoplasmic reticulum (ER) chaperones BiP and Grp94 selectively associate when BiP is in the ADP conformation. J Biol Chem 2019; 294:6387-6396. [PMID: 30787103 DOI: 10.1074/jbc.ra118.007050] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/09/2019] [Indexed: 11/06/2022] Open
Abstract
Hsp70 and Hsp90 chaperones are critical for protein quality control in the cytosol, whereas organelle-specific Hsp70/Hsp90 paralogs provide similar protection for mitochondria and the endoplasmic reticulum (ER). Cytosolic Hsp70/Hsp90 can operate sequentially with Hsp90 selectively associating with Hsp70 after Hsp70 is bound to a client protein. This observation has long suggested that Hsp90 could have a preference for interacting with clients at their later stages of folding. However, recent work has shown that cytosolic Hsp70/Hsp90 can directly interact even in the absence of a client, which opens up an alternative possibility that the ordered interactions of Hsp70/Hsp90 with clients could be a consequence of regulated changes in the direct interactions between Hsp70 and Hsp90. However, it is unknown how such regulation could occur mechanistically. Here, we find that the ER Hsp70/Hsp90 (BiP/Grp94) can form a direct complex in the absence of a client. Importantly, the direct interaction between BiP and Grp94 is nucleotide-specific, with BiP and Grp94 having higher affinity under ADP conditions and lower affinity under ATP conditions. We show that this nucleotide-specific association between BiP and Grp94 is largely due to the conformation of BiP. When BiP is in the ATP conformation its substrate-binding domain blocks Grp94; in contrast, Grp94 can readily associate with the ADP conformation of BiP, which represents the client-bound state of BiP. Our observations provide a mechanism for the sequential involvement of BiP and Grp94 in client folding where the conformation of BiP provides the signal for the subsequent recruitment of Grp94.
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Affiliation(s)
- Ming Sun
- From the Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02453
| | - Judy L M Kotler
- From the Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02453
| | - Shanshan Liu
- From the Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02453
| | - Timothy O Street
- From the Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02453
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27
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Trcka F, Durech M, Vankova P, Chmelik J, Martinkova V, Hausner J, Kadek A, Marcoux J, Klumpler T, Vojtesek B, Muller P, Man P. Human Stress-inducible Hsp70 Has a High Propensity to Form ATP-dependent Antiparallel Dimers That Are Differentially Regulated by Cochaperone Binding. Mol Cell Proteomics 2019; 18:320-337. [PMID: 30459217 PMCID: PMC6356074 DOI: 10.1074/mcp.ra118.001044] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/09/2018] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic protein homeostasis (proteostasis) is largely dependent on the action of highly conserved Hsp70 molecular chaperones. Recent evidence indicates that, apart from conserved molecular allostery, Hsp70 proteins have retained and adapted the ability to assemble as functionally relevant ATP-bound dimers throughout evolution. Here, we have compared the ATP-dependent dimerization of DnaK, human stress-inducible Hsp70, Hsc70 and BiP Hsp70 proteins, showing that their dimerization propensities differ, with stress-inducible Hsp70 being predominantly dimeric in the presence of ATP. Structural analyses using hydrogen/deuterium exchange mass spectrometry, native electrospray ionization mass spectrometry and small-angle X-ray scattering revealed that stress-inducible Hsp70 assembles in solution as an antiparallel dimer with the intermolecular interface closely resembling the ATP-bound dimer interfaces captured in DnaK and BiP crystal structures. ATP-dependent dimerization of stress-inducible Hsp70 is necessary for its efficient interaction with Hsp40, as shown by experiments with dimerization-deficient mutants. Moreover, dimerization of ATP-bound Hsp70 is required for its participation in high molecular weight protein complexes detected ex vivo, supporting its functional role in vivo As human cytosolic Hsp70 can interact with tetratricopeptide repeat (TPR) domain containing cochaperones, we tested the interaction of Hsp70 ATP-dependent dimers with Chip and Tomm34 cochaperones. Although Chip associates with intact Hsp70 dimers to form a larger complex, binding of Tomm34 disrupts the Hsp70 dimer and this event plays an important role in Hsp70 activity regulation. In summary, this study provides structural evidence of robust ATP-dependent antiparallel dimerization of human inducible Hsp70 protein and suggests a novel role of TPR domain cochaperones in multichaperone complexes involving Hsp70 ATP-bound dimers.
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Affiliation(s)
- Filip Trcka
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic
| | - Michal Durech
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic
| | - Pavla Vankova
- BioCeV - Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prumyslova 595, 252 50 Vestec, Czech Republic;; Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic
| | - Josef Chmelik
- BioCeV - Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prumyslova 595, 252 50 Vestec, Czech Republic;; Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic
| | - Veronika Martinkova
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic
| | - Jiri Hausner
- BioCeV - Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prumyslova 595, 252 50 Vestec, Czech Republic;; Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic
| | - Alan Kadek
- BioCeV - Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prumyslova 595, 252 50 Vestec, Czech Republic;; Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic
| | - Julien Marcoux
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Tomas Klumpler
- CEITEC-Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Borivoj Vojtesek
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic
| | - Petr Muller
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic;.
| | - Petr Man
- BioCeV - Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prumyslova 595, 252 50 Vestec, Czech Republic;; Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic;.
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28
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Yan Y, Rato C, Rohland L, Preissler S, Ron D. MANF antagonizes nucleotide exchange by the endoplasmic reticulum chaperone BiP. Nat Commun 2019; 10:541. [PMID: 30710085 PMCID: PMC6358605 DOI: 10.1038/s41467-019-08450-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 01/11/2019] [Indexed: 12/24/2022] Open
Abstract
Despite its known role as a secreted neuroprotectant, much of the mesencephalic astrocyte-derived neurotrophic factor (MANF) is retained in the endoplasmic reticulum (ER) of producer cells. There, by unknown mechanisms, MANF plays a role in protein folding homeostasis in complex with the ER-localized Hsp70 chaperone BiP. Here we report that the SAF-A/B, Acinus, and PIAS (SAP) domain of MANF selectively associates with the nucleotide binding domain (NBD) of ADP-bound BiP. In crystal structures the SAP domain engages the cleft between NBD subdomains Ia and IIa, stabilizing the ADP-bound conformation and clashing with the interdomain linker that occupies this site in ATP-bound BiP. MANF inhibits both ADP release from BiP and ATP binding to BiP, and thereby client release. Cells lacking MANF have fewer ER stress-induced BiP-containing high molecular weight complexes. These findings suggest that MANF contributes to protein folding homeostasis as a nucleotide exchange inhibitor that stabilizes certain BiP-client complexes.
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Affiliation(s)
- Yahui Yan
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Claudia Rato
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Lukas Rohland
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.,Center for Molecular Biology (ZMBH) of Heidelberg University, Heidelberg, Germany
| | - Steffen Preissler
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
| | - David Ron
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
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29
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Dickens JA, Malzer E, Chambers JE, Marciniak SJ. Pulmonary endoplasmic reticulum stress-scars, smoke, and suffocation. FEBS J 2019; 286:322-341. [PMID: 29323786 DOI: 10.1111/febs.14381] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/11/2017] [Accepted: 01/08/2018] [Indexed: 12/14/2022]
Abstract
Protein misfolding within the endoplasmic reticulum (ER stress) can be a cause or consequence of pulmonary disease. Mutation of proteins restricted to the alveolar type II pneumocyte can lead to inherited forms of pulmonary fibrosis, but even sporadic cases of pulmonary fibrosis appear to be strongly associated with activation of the unfolded protein response and/or the integrated stress response. Inhalation of smoke can impair protein folding and may be an important cause of pulmonary ER stress. Similarly, tissue hypoxia can lead to impaired protein homeostasis (proteostasis). But the mechanisms linking smoke and hypoxia to ER stress are only partially understood. In this review, we will examine the role of ER stress in the pathogenesis of lung disease by focusing on fibrosis, smoke, and hypoxia.
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Affiliation(s)
- Jennifer A Dickens
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, UK
| | - Elke Malzer
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, UK
| | - Joseph E Chambers
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, UK
| | - Stefan J Marciniak
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, UK
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30
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Wright MA, Aprile FA, Bellaiche MMJ, Michaels TCT, Müller T, Arosio P, Vendruscolo M, Dobson CM, Knowles TPJ. Cooperative Assembly of Hsp70 Subdomain Clusters. Biochemistry 2018; 57:3641-3649. [PMID: 29763298 PMCID: PMC6202011 DOI: 10.1021/acs.biochem.8b00151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Many molecular chaperones exist as oligomeric complexes in their functional states, yet the physical determinants underlying such self-assembly behavior, as well as the role of oligomerization in the activity of molecular chaperones in inhibiting protein aggregation, have proven to be difficult to define. Here, we demonstrate direct measurements under native conditions of the changes in the average oligomer populations of a chaperone system as a function of concentration and time and thus determine the thermodynamic and kinetic parameters governing the self-assembly process. We access this self-assembly behavior in real time under native-like conditions by monitoring the changes in the micrometer-scale diffusion of the different complexes in time and space using a microfluidic platform. Using this approach, we find that the oligomerization mechanism of the Hsp70 subdomain occurs in a cooperative manner and involves structural constraints that limit the size of the species formed beyond the limits imposed by mass balance. These results illustrate the ability of microfluidic methods to probe polydisperse protein self-assembly in real time in solution and to shed light on the nature and dynamics of oligomerization processes.
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Affiliation(s)
- Maya A Wright
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.,Fluidic Analytics Ltd. , Cambridge , U.K
| | - Francesco A Aprile
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Mathias M J Bellaiche
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.,Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases , National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Thomas C T Michaels
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.,Paulson School of Engineering and Applied Sciences , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Thomas Müller
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.,Fluidic Analytics Ltd. , Cambridge , U.K
| | - Paolo Arosio
- Institute for Chemical and Bioengineering , ETH Zurich , Vladimir-Prelog-Weg 1, ETH Hönggerberg, HCI F 105 , 8093 Zurich , Switzerland
| | - Michele Vendruscolo
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Christopher M Dobson
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Tuomas P J Knowles
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.,Cavendish Laboratory, Department of Physics , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K
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31
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Abstract
Posttranslational modifications are covalent changes made to proteins that typically alter the function or location of the protein. AMPylation is an emerging posttranslational modification that involves the addition of adenosine monophosphate (AMP) to a protein. Like other, more well-studied posttranslational modifications, AMPylation is predicted to regulate the activity of the modified target proteins. However, the scope of this modification both in bacteria and in eukaryotes remains to be fully determined. In this review, we provide an up to date overview of the known AMPylating enzymes, the regulation of these enzymes, and the effect of this modification on target proteins.
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Affiliation(s)
- Amanda K. Casey
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard NA5.120F, Dallas, Texas 75390-9148, United States
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard NA5.120F, Dallas, Texas 75390-9148, United States
- Howard Hughes Medical Institute, 6000 Harry Hines Boulevard NA5.120F, Dallas, Texas 75390-9148, United States
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32
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Sowers CR, Wang R, Bourne RA, McGrath BC, Hu J, Bevilacqua SC, Paton JC, Paton AW, Collardeau-Frachon S, Nicolino M, Cavener DR. The protein kinase PERK/EIF2AK3 regulates proinsulin processing not via protein synthesis but by controlling endoplasmic reticulum chaperones. J Biol Chem 2018; 293:5134-5149. [PMID: 29444822 DOI: 10.1074/jbc.m117.813790] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 02/06/2018] [Indexed: 11/06/2022] Open
Abstract
Loss-of-function mutations of the protein kinase PERK (EIF2AK3) in humans and mice cause permanent neonatal diabetes and severe proinsulin aggregation in the endoplasmic reticulum (ER), highlighting the essential role of PERK in insulin production in pancreatic β cells. As PERK is generally known as a translational regulator of the unfolded protein response (UPR), the underlying cause of these β cell defects has often been attributed to derepression of proinsulin synthesis, resulting in proinsulin overload in the ER. Using high-resolution imaging and standard protein fractionation and immunological methods we have examined the PERK-dependent phenotype more closely. We found that whereas proinsulin aggregation requires new protein synthesis, global protein and proinsulin synthesis are down-regulated in PERK-inhibited cells, strongly arguing against proinsulin overproduction being the root cause of their aberrant ER phenotype. Furthermore, we show that PERK regulates proinsulin proteostasis by modulating ER chaperones, including BiP and ERp72. Transgenic overexpression of BiP and BiP knockdown (KD) both promoted proinsulin aggregation, whereas ERp72 overexpression and knockdown rescued it. These findings underscore the importance of ER chaperones working in concert to achieve control of insulin production and identify a role for PERK in maintaining a functional balance among these chaperones.
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Affiliation(s)
- Carrie R Sowers
- From the Department of Biology, Penn State University, University Park, Pennsylvania 16802
| | - Rong Wang
- From the Department of Biology, Penn State University, University Park, Pennsylvania 16802
| | - Rebecca A Bourne
- From the Department of Biology, Penn State University, University Park, Pennsylvania 16802
| | - Barbara C McGrath
- From the Department of Biology, Penn State University, University Park, Pennsylvania 16802
| | - Jingjie Hu
- From the Department of Biology, Penn State University, University Park, Pennsylvania 16802
| | - Sarah C Bevilacqua
- From the Department of Biology, Penn State University, University Park, Pennsylvania 16802
| | - James C Paton
- the Department of Molecular and Cellular Biology, Research Centre for Infectious Diseases, University of Adelaide, Adelaide 5005, Australia
| | - Adrienne W Paton
- the Department of Molecular and Cellular Biology, Research Centre for Infectious Diseases, University of Adelaide, Adelaide 5005, Australia
| | - Sophie Collardeau-Frachon
- the Department of Pathology, Hôpital-Femme-Mère-Enfant, Hospices Civils de Lyon, Université Claude Bernard Lyon I and CarMeN, INSERM Unit U1060, 69677 Bron, France, and
| | - Marc Nicolino
- the Service d'endocrinologie et de diabétologie pédiatriques et maladies héréditaires du métabolisme, Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, F-69677 Bron, France
| | - Douglas R Cavener
- From the Department of Biology, Penn State University, University Park, Pennsylvania 16802,
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33
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Livezey M, Kim JE, Shapiro DJ. A New Role for Estrogen Receptor α in Cell Proliferation and Cancer: Activating the Anticipatory Unfolded Protein Response. Front Endocrinol (Lausanne) 2018; 9:325. [PMID: 29963013 PMCID: PMC6013567 DOI: 10.3389/fendo.2018.00325] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 05/31/2018] [Indexed: 12/19/2022] Open
Abstract
Cells react to a variety of stresses, including accumulation of unfolded or misfolded protein, by activating the endoplasmic reticulum (EnR) stress sensor, the unfolded protein response (UPR). The UPR is highly conserved and plays a key role in the maintenance of protein folding quality control and homeostasis. In contrast to the classical reactive mode of UPR activation, recent studies describe a hormone-activated anticipatory UPR. In this pathway, mitogenic hormones, such as estrogen (E2), epidermal growth factor, and vascular endothelial growth factor rapidly activate the UPR in anticipation of a future need for increased protein folding capacity upon cell proliferation. Here, we focus on this recently unveiled pathway of E2-estrogen receptor α (ERα) action. Notably, rapid activation of the anticipatory UPR pathway is essential for subsequent activation of the E2-ERα regulated transcription program. Moreover, activation of the UPR at diagnosis is a powerful prognostic marker in ERα positive breast cancer. Furthermore, in cells containing ERα mutations that confer estrogen independence and are common in metastatic breast cancer, the UPR is constitutively activated and linked to antiestrogen resistance. Lethal ERα-dependent hyperactivation of the anticipatory UPR represents a promising therapeutic approach exploited by a new class of small molecule ERα biomodulator.
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Affiliation(s)
- Mara Livezey
- Department of Biochemistry, University of Illinois, Urbana, IL, United States
| | - Ji Eun Kim
- Department of Biochemistry, University of Illinois, Urbana, IL, United States
| | - David J. Shapiro
- Department of Biochemistry, University of Illinois, Urbana, IL, United States
- Center for Cancer Research, University of Illinois, Urbana, IL, United States
- *Correspondence: David J. Shapiro,
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34
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Amin-Wetzel N, Saunders RA, Kamphuis MJ, Rato C, Preissler S, Harding HP, Ron D. A J-Protein Co-chaperone Recruits BiP to Monomerize IRE1 and Repress the Unfolded Protein Response. Cell 2017; 171:1625-1637.e13. [PMID: 29198525 PMCID: PMC5733394 DOI: 10.1016/j.cell.2017.10.040] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/04/2017] [Accepted: 10/25/2017] [Indexed: 12/29/2022]
Abstract
When unfolded proteins accumulate in the endoplasmic reticulum (ER), the unfolded protein response (UPR) increases ER-protein-folding capacity to restore protein-folding homeostasis. Unfolded proteins activate UPR signaling across the ER membrane to the nucleus by promoting oligomerization of IRE1, a conserved transmembrane ER stress receptor. However, the coupling of ER stress to IRE1 oligomerization and activation has remained obscure. Here, we report that the ER luminal co-chaperone ERdj4/DNAJB9 is a selective IRE1 repressor that promotes a complex between the luminal Hsp70 BiP and the luminal stress-sensing domain of IRE1α (IRE1LD). In vitro, ERdj4 is required for complex formation between BiP and IRE1LD. ERdj4 associates with IRE1LD and recruits BiP through the stimulation of ATP hydrolysis, forcibly disrupting IRE1 dimers. Unfolded proteins compete for BiP and restore IRE1LD to its default, dimeric, and active state. These observations establish BiP and its J domain co-chaperones as key regulators of the UPR. The endoplasmic reticulum co-chaperone ERdj4 selectively represses IRE1 signaling ERdj4 associates with the IRE1 luminal domain and recruits the Hsp70 BiP Recruited BiP hydrolyzes ATP to disrupt the active IRE1 luminal domain dimer Unfolded proteins compete for the repressive machinery to restore IRE1 dimers
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Affiliation(s)
- Niko Amin-Wetzel
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Reuben A Saunders
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Maarten J Kamphuis
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Claudia Rato
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Steffen Preissler
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Heather P Harding
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - David Ron
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK.
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35
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Carroni M, Franke KB, Maurer M, Jäger J, Hantke I, Gloge F, Linder D, Gremer S, Turgay K, Bukau B, Mogk A. Regulatory coiled-coil domains promote head-to-head assemblies of AAA+ chaperones essential for tunable activity control. eLife 2017; 6. [PMID: 29165246 PMCID: PMC5699869 DOI: 10.7554/elife.30120] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/22/2017] [Indexed: 12/20/2022] Open
Abstract
Ring-forming AAA+ chaperones exert ATP-fueled substrate unfolding by threading through a central pore. This activity is potentially harmful requiring mechanisms for tight repression and substrate-specific activation. The AAA+ chaperone ClpC with the peptidase ClpP forms a bacterial protease essential to virulence and stress resistance. The adaptor MecA activates ClpC by targeting substrates and stimulating ClpC ATPase activity. We show how ClpC is repressed in its ground state by determining ClpC cryo-EM structures with and without MecA. ClpC forms large two-helical assemblies that associate via head-to-head contacts between coiled-coil middle domains (MDs). MecA converts this resting state to an active planar ring structure by binding to MD interaction sites. Loss of ClpC repression in MD mutants causes constitutive activation and severe cellular toxicity. These findings unravel an unexpected regulatory concept executed by coiled-coil MDs to tightly control AAA+ chaperone activity.
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Affiliation(s)
- Marta Carroni
- Swedish Cryo-EM Facility, Science for Life Laboratory Stockholm University, Solna, Sweden
| | - Kamila B Franke
- DKFZ-ZMBH Alliance, Center for Molecular Biology of the University of Heidelberg (ZMBH) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Maurer
- DKFZ-ZMBH Alliance, Center for Molecular Biology of the University of Heidelberg (ZMBH) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jasmin Jäger
- DKFZ-ZMBH Alliance, Center for Molecular Biology of the University of Heidelberg (ZMBH) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ingo Hantke
- Institute for Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | | | - Daniela Linder
- DKFZ-ZMBH Alliance, Center for Molecular Biology of the University of Heidelberg (ZMBH) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sebastian Gremer
- DKFZ-ZMBH Alliance, Center for Molecular Biology of the University of Heidelberg (ZMBH) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kürşad Turgay
- Institute for Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | - Bernd Bukau
- DKFZ-ZMBH Alliance, Center for Molecular Biology of the University of Heidelberg (ZMBH) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Axel Mogk
- DKFZ-ZMBH Alliance, Center for Molecular Biology of the University of Heidelberg (ZMBH) and German Cancer Research Center (DKFZ), Heidelberg, Germany
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36
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Casey AK, Moehlman AT, Zhang J, Servage KA, Krämer H, Orth K. Fic-mediated deAMPylation is not dependent on homodimerization and rescues toxic AMPylation in flies. J Biol Chem 2017; 292:21193-21204. [PMID: 29089387 DOI: 10.1074/jbc.m117.799296] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/17/2017] [Indexed: 01/30/2023] Open
Abstract
Protein chaperones play a critical role in proteostasis. The activity of the major endoplasmic reticulum chaperone BiP (GRP78) is regulated by Fic-mediated AMPylation during resting states. By contrast, during times of stress, BiP is deAMPylated. Here, we show that excessive AMPylation by a constitutively active FicE247G mutant is lethal in Drosophila This lethality is cell-autonomous, as directed expression of the mutant FicE247G to the fly eye does not kill the fly but rather results in a rough and reduced eye. Lethality and eye phenotypes are rescued by the deAMPylation activity of wild-type Fic. Consistent with Fic acting as a deAMPylation enzyme, its activity was both time- and concentration-dependent. Furthermore, Fic deAMPylation activity was sufficient to suppress the AMPylation activity mediated by the constitutively active FicE247G mutant in Drosophila S2 lysates. Further, we show that the dual enzymatic activity of Fic is, in part, regulated by Fic dimerization, as loss of this dimerization increases AMPylation and reduces deAMPylation of BiP.
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Affiliation(s)
| | | | - Junmei Zhang
- From the Department of Molecular Biology.,the Howard Hughes Medical Institute, and
| | - Kelly A Servage
- From the Department of Molecular Biology.,the Howard Hughes Medical Institute, and
| | | | - Kim Orth
- From the Department of Molecular Biology, .,the Howard Hughes Medical Institute, and.,the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9148
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37
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Preissler S, Rohland L, Yan Y, Chen R, Read RJ, Ron D. AMPylation targets the rate-limiting step of BiP's ATPase cycle for its functional inactivation. eLife 2017; 6:29428. [PMID: 29064368 PMCID: PMC5667935 DOI: 10.7554/elife.29428] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 10/22/2017] [Indexed: 12/21/2022] Open
Abstract
The endoplasmic reticulum (ER)-localized Hsp70 chaperone BiP contributes to protein folding homeostasis by engaging unfolded client proteins in a process that is tightly coupled to ATP binding and hydrolysis. The inverse correlation between BiP AMPylation and the burden of unfolded ER proteins suggests a post-translational mechanism for adjusting BiP's activity to changing levels of ER stress, but the underlying molecular details are unexplored. We present biochemical and crystallographic studies indicating that irrespective of the identity of the bound nucleotide AMPylation biases BiP towards a conformation normally attained by the ATP-bound chaperone. AMPylation does not affect the interaction between BiP and J-protein co-factors but appears to allosterically impair J protein-stimulated ATP-hydrolysis, resulting in the inability of modified BiP to attain high affinity for its substrates. These findings suggest a molecular mechanism by which AMPylation serves as a switch to inactivate BiP, limiting its interactions with substrates whilst conserving ATP.
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Affiliation(s)
- Steffen Preissler
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Lukas Rohland
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Yahui Yan
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Ruming Chen
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Randy J Read
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - David Ron
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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38
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Vincenz-Donnelly L, Hipp MS. The endoplasmic reticulum: A hub of protein quality control in health and disease. Free Radic Biol Med 2017; 108:383-393. [PMID: 28363604 DOI: 10.1016/j.freeradbiomed.2017.03.031] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 03/20/2017] [Accepted: 03/27/2017] [Indexed: 01/03/2023]
Abstract
One third of the eukaryotic proteome is synthesized at the endoplasmic reticulum (ER), whose unique properties provide a folding environment substantially different from the cytosol. A healthy, balanced proteome in the ER is maintained by a network of factors referred to as the ER quality control (ERQC) machinery. This network consists of various protein folding chaperones and modifying enzymes, and is regulated by stress response pathways that prevent the build-up as well as the secretion of potentially toxic and aggregation-prone misfolded protein species. Here, we describe the components of the ERQC machinery, investigate their response to different forms of stress, and discuss the consequences of ERQC break-down.
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Affiliation(s)
- Lisa Vincenz-Donnelly
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, 82152 Martinsried, Germany
| | - Mark S Hipp
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, 82152 Martinsried, Germany
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39
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Liu Q, Li H, Yang Y, Tian X, Su J, Zhou L, Liu Q. A disulfide-bonded DnaK dimer is maintained in an ATP-bound state. Cell Stress Chaperones 2017; 22:201-212. [PMID: 27975204 PMCID: PMC5352592 DOI: 10.1007/s12192-016-0752-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/16/2016] [Accepted: 11/28/2016] [Indexed: 01/16/2023] Open
Abstract
DnaK, a major Hsp70 molecular chaperones in Escherichia coli, is a widely used model for studying Hsp70s. We recently solved a crystal structure of DnaK in complex with ATP and showed that DnaK was packed as a dimer in the crystal structure. Our previous biochemical studies supported the formation of a specific DnaK dimer as observed in the crystal structure in solution in the presence of ATP and suggested an important role of this dimer in efficient interaction with Hsp40 co-chaperones. In this study, we dissected the biochemical properties of this DnaK dimer. To restrict DnaK in this dimer form, we mutated two residues on the dimer interface to cysteine, A303C, and H541C. Upon oxidation, this DnaK-A303C-H541C protein formed a specific dimer linked by disulfide bonds formed between A303C and H541C only in the presence of ATP, consistent with the crystal structure. Intriguingly, this disulfide-bond-linked dimer of DnaK-A303C-H541C has reduced ATPase activity and decreased affinity for peptide substrate. More interestingly, unlike wild-type DnaK, the peptide substrate-binding kinetics of this dimer is drastically accelerated even in the absence of ATP, suggesting this dimer is restricted in an ATP-bound conformation regardless of nucleotide bound, which was further supported by our analysis using tryptophan fluorescence and ATP-induced peptide release. Thus, formation of the dimer restricted DnaK in an ATP-bound state and blocked the progression through the chaperone cycle. Productive progression through the chaperone cycle requires the dissociation of this transient dimer. Surprisingly, a significantly compromised interaction with Hsp40 co-chaperone was observed for this disulfide-bond-linked dimer. Thus, dissociation of this DnaK dimer is equally crucial for efficient Hsp40 interaction. An initial interaction between Hsp70 and Hsp40 requires the formation of DnaK dimer; but a stable Hsp70-Hsp40 interaction may follow the dissociation of the dimer.
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Affiliation(s)
- Qingdai Liu
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, 300457, China.
| | - Hongtao Li
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Ying Yang
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, 300457, China
| | - Xueli Tian
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, 300457, China
| | - Jiayue Su
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, 300457, China
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Lei Zhou
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Qinglian Liu
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA.
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40
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Shirriff CS, Heikkila JJ. Characterization of cadmium chloride-induced BiP accumulation in Xenopus laevis A6 kidney epithelial cells. Comp Biochem Physiol C Toxicol Pharmacol 2017; 191:117-128. [PMID: 27746171 DOI: 10.1016/j.cbpc.2016.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/05/2016] [Accepted: 10/10/2016] [Indexed: 12/22/2022]
Abstract
Endoplasmic reticulum (ER) stress can result in the accumulation of unfolded/misfolded protein in the ER lumen, which can trigger the unfolded protein response (UPR) resulting in the activation of various genes including immunoglobulin-binding protein (BiP; also known as glucose-regulated protein 78 or HSPA5). BiP, an ER heat shock protein 70 (HSP70) family member, binds to unfolded protein, inhibits their aggregation and re-folds them in an ATP-dependent manner. While cadmium, an environmental contaminant, was shown to induce the accumulation of HSP70 in vertebrate cells, less information is available regarding the effect of this metal on BiP accumulation or function. In this study, cadmium chloride treatment of Xenopus laevis A6 kidney epithelial cells induced a dose- and time-dependent increase in BiP, HSP70 and heme oxygenase-1 (HO-1) accumulation. Exposure of cells to a relatively low cadmium concentration at a mild heat shock temperature of 30°C greatly enhanced BiP and HSP70 accumulation compared to cadmium at 22°C. Treatment of cells with the glutathione synthesis inhibitor, buthionine sulfoximine, enhanced cadmium-induced BiP and HSP70 accumulation. Immunocytochemistry revealed that cadmium-induced BiP accumulation occurred in a punctate pattern in the perinuclear region. In some cells treated with cadmium chloride or the proteasomal inhibitor, MG132, large BiP complexes were observed that co-localized with aggregated protein or aggresome-like structures. These BiP/aggresome-like structures were also observed in cells treated simultaneously with cadmium at 30°C or in the presence of buthionine sulfoximine. In amphibians, the association of BiP with unfolded protein and its possible role in aggresome function may be vital in the maintenance of cellular proteostasis.
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Affiliation(s)
- Cody S Shirriff
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - John J Heikkila
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
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41
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FICD acts bifunctionally to AMPylate and de-AMPylate the endoplasmic reticulum chaperone BiP. Nat Struct Mol Biol 2016; 24:23-29. [PMID: 27918543 PMCID: PMC5221731 DOI: 10.1038/nsmb.3337] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/07/2016] [Indexed: 02/08/2023]
Abstract
Protein folding homeostasis in the endoplasmic reticulum (ER) is defended by an unfolded protein response (UPR) that matches ER chaperone capacity to the burden of unfolded proteins. As levels of unfolded proteins decline, a metazoan-specific FIC-domain containing ER-localized enzyme, FICD (HYPE), rapidly inactivates the major ER chaperone BiP by AMPylating T518. Here we show that the single catalytic domain of FICD can also release the attached AMP, restoring functionality to BiP. Consistent with a role for endogenous FICD in de-AMPylating BiP, FICD-/- hamster cells are hypersensitive to introduction of a constitutively AMPylating, de-AMPylation defective mutant FICD. These opposing activities hinge on a regulatory residue, E234, whose default state renders FICD a constitutive de-AMPylase in vitro. The location of E234 on a conserved regulatory helix and the mutually antagonistic activities of FICD in vivo, suggest a mechanism whereby fluctuating unfolded protein load actively switches FICD from a de-AMPylase to an AMPylase.
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42
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Shapiro DJ, Livezey M, Yu L, Zheng X, Andruska N. Anticipatory UPR Activation: A Protective Pathway and Target in Cancer. Trends Endocrinol Metab 2016; 27:731-741. [PMID: 27354311 PMCID: PMC5035594 DOI: 10.1016/j.tem.2016.06.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 01/18/2023]
Abstract
The endoplasmic reticulum (EnR) stress sensor, the unfolded protein response (UPR), plays a key role in regulating intracellular protein homeostasis. The extensively studied reactive mode of UPR activation is characterized by unfolded protein, or other EnR stress, triggering UPR activation. Here we focus on the emerging anticipatory mode of UPR activation in which mitogenic steroid and peptide hormones and other effectors preactivate the UPR and anticipate a future need for increased protein folding capacity. Mild UPR activation in breast cancer can be protective and contributes to antiestrogen resistance. Hyperactivation of the anticipatory UPR pathway in cancer cells with a small molecule converts it from cytoprotective to cytotoxic, highlighting its potential as a therapeutic target in estrogen receptor-positive breast cancer.
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Affiliation(s)
- David J Shapiro
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
| | - Mara Livezey
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
| | - Liqun Yu
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
| | - Xiaobin Zheng
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
| | - Neal Andruska
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA; College of Medicine, University of Illinois, Urbana, IL 61801, USA
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43
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A Conserved Cysteine within the ATPase Domain of the Endoplasmic Reticulum Chaperone BiP is Necessary for a Complete Complement of BiP Activities. J Mol Biol 2016; 428:4168-4184. [PMID: 27543005 DOI: 10.1016/j.jmb.2016.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 08/04/2016] [Accepted: 08/06/2016] [Indexed: 01/25/2023]
Abstract
Among the amino acids, cysteine stands apart based on its highly reactive sulfur group. In general, cysteine is underrepresented in proteins. Yet, when present, the features of cysteine often afford unique function. We have shown previously that a cysteine within the ATPase domain of yeast BiP (Kar2) serves as a sensor of the endoplasmic reticulum (ER) redox environment [1, 2]. Under conditions of increased oxidant (oxidative stress), this cysteine becomes oxidized, changing Kar2 from an ATP-dependent foldase to an ATP-independent holdase. We were struck by the high degree of conservation for this cysteine between BiP orthologs, and we sought to determine how cysteine substitution impacts Kar2 function. We observed that no single amino acid replacement is capable of recreating the range of functions that can be achieved by wild-type Kar2 with its cysteine in either unmodified or oxidized states. However, we were able to generate mutants that could selectively replicate the distinct activities exhibited by either unmodified or oxidized Kar2. We found that the ATPase activity displayed by unmodified Kar2 is fully maintained when Cys63 is replaced with Ala or Val. Conversely, we demonstrate that several amino acid substitutions (including His, Phe, Pro, Trp, and Tyr) support an enhanced viability during oxidative stress associated with oxidized Kar2, although these alleles are compromised as an ATPase. We reveal that the range of activity demonstrated by wild-type Kar2 can be replicated by co-expression of Kar2 mutants that mimic either the unmodified or oxidized Kar2 state, allowing for growth during standard and oxidative stress conditions.
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44
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Clathrin-coat disassembly illuminates the mechanisms of Hsp70 force generation. Nat Struct Mol Biol 2016; 23:821-9. [PMID: 27478930 PMCID: PMC5016234 DOI: 10.1038/nsmb.3272] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/06/2016] [Indexed: 01/04/2023]
Abstract
Hsp70s use ATP hydrolysis to disrupt protein:protein associations or move macromolecules. One example is Hsc70-mediated disassembly of clathrin coats that form on vesicles during endocytosis. We exploit the exceptional features of these coats to test three models—Brownian ratchet, power-stroke and entropic pulling—proposed to explain how Hsp70s transform their substrates. Our data rule out the ratchet and power-stroke models, and instead support a collision pressure mechanism whereby collisions between clathrin coat walls and Hsc70s drive coats apart. Collision pressure is the complement to the pulling force described in the entropic pulling model. We also find that self-association can augment collision pressure to allow disassembly of clathrin lattices predicted to resist disassembly. These results illuminate how Hsp70s generate the forces that transform their substrates.
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45
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Preissler S, Rato C, Chen R, Antrobus R, Ding S, Fearnley IM, Ron D. AMPylation matches BiP activity to client protein load in the endoplasmic reticulum. eLife 2015; 4:e12621. [PMID: 26673894 PMCID: PMC4739761 DOI: 10.7554/elife.12621] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/14/2015] [Indexed: 01/11/2023] Open
Abstract
The endoplasmic reticulum (ER)-localized Hsp70 chaperone BiP affects protein folding homeostasis and the response to ER stress. Reversible inactivating covalent modification of BiP is believed to contribute to the balance between chaperones and unfolded ER proteins, but the nature of this modification has so far been hinted at indirectly. We report that deletion of FICD, a gene encoding an ER-localized AMPylating enzyme, abolished detectable modification of endogenous BiP enhancing ER buffering of unfolded protein stress in mammalian cells, whilst deregulated FICD activity had the opposite effect. In vitro, FICD AMPylated BiP to completion on a single residue, Thr(518). AMPylation increased, in a strictly FICD-dependent manner, as the flux of proteins entering the ER was attenuated in vivo. In vitro, Thr(518) AMPylation enhanced peptide dissociation from BiP 6-fold and abolished stimulation of ATP hydrolysis by J-domain cofactor. These findings expose the molecular basis for covalent inactivation of BiP.
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Affiliation(s)
- Steffen Preissler
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Cláudia Rato
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Ruming Chen
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Shujing Ding
- MRC Mitochondrial Biology Unit, Cambridge, United Kingdom
| | - Ian M Fearnley
- MRC Mitochondrial Biology Unit, Cambridge, United Kingdom
| | - David Ron
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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