1
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Ciccarelli M, Andréasson C. Protein misfolding releases human Heat Shock Factor 1 (HSF1) from HSP70 latency control. J Mol Biol 2024:168740. [PMID: 39122169 DOI: 10.1016/j.jmb.2024.168740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/25/2024] [Accepted: 08/05/2024] [Indexed: 08/12/2024]
Abstract
Heat shock factor 1 (HSF1) responds to stress to mount the heat shock response (HSR), a conserved transcriptional program that allows cells to maintain proteostasis by upregulating heat shock proteins (HSPs). The homeostatic stress regulation of HSF1 plays a key role in human physiology and health but its mechanism has remained difficult to pinpoint. Recent work in the budding yeast model has implicated stress-inducible chaperones of the HSP70 family as direct negative regulators of HSF1 activity. Here, we have investigated the latency control and activation of human HSF1 by HSP70 and misfolded proteins. Purified oligomeric HSF1-HSP70 (HSPA1A) complexes exhibited basal DNA binding activity that was inhibited by increasing the levels of HSP70 and, importantly, misfolded proteins reverted the inhibitory effect. Using site-specific UV photo-crosslinking, we monitored HSP70-HSF1 complexes in HEK293T cells. While HSF1 was bound by the substrate binding domain of HSP70 in unstressed cells, activation of HSF1 by heat shock as well as by inducing the misfolding of newly synthesized proteins resulted in release of HSF1 from the chaperone. Taken our results together, we conclude that latent HSF1 populate dynamic complexes with HSP70, which are sensitive to increased levels of misfolded proteins that compete for binding to the HSP70 substrate binding domain. Thus, human HSF1 is activated by various stress conditions that all titrate available HSP70.
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Affiliation(s)
- Michela Ciccarelli
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
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2
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Álvarez-Guerra I, Block E, Broeskamp F, Gabrijelčič S, Infant T, de Ory A, Habernig L, Andréasson C, Levine TP, Höög JL, Büttner S. LDO proteins and Vac8 form a vacuole-lipid droplet contact site to enable starvation-induced lipophagy in yeast. Dev Cell 2024; 59:759-775.e5. [PMID: 38354739 DOI: 10.1016/j.devcel.2024.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 11/15/2023] [Accepted: 01/18/2024] [Indexed: 02/16/2024]
Abstract
Lipid droplets (LDs) are fat storage organelles critical for energy and lipid metabolism. Upon nutrient exhaustion, cells consume LDs via gradual lipolysis or via lipophagy, the en bloc uptake of LDs into the vacuole. Here, we show that LDs dock to the vacuolar membrane via a contact site that is required for lipophagy in yeast. The LD-localized LDO proteins carry an intrinsically disordered region that directly binds vacuolar Vac8 to form vCLIP, the vacuolar-LD contact site. Nutrient limitation drives vCLIP formation, and its inactivation blocks lipophagy, resulting in impaired caloric restriction-induced longevity. We establish a functional link between lipophagy and microautophagy of the nucleus, both requiring Vac8 to form respective contact sites upon metabolic stress. In sum, we identify the tethering machinery of vCLIP and find that Vac8 provides a platform for multiple and competing contact sites associated with autophagy.
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Affiliation(s)
- Irene Álvarez-Guerra
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Emma Block
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Filomena Broeskamp
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Sonja Gabrijelčič
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Terence Infant
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Ana de Ory
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Lukas Habernig
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Tim P Levine
- UCL Institute of Ophthalmology, Bath Street, London EC1V 9EL, UK
| | - Johanna L Höög
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden.
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3
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Minoia M, Quintana-Cordero J, Jetzinger K, Kotan IE, Turnbull KJ, Ciccarelli M, Masser AE, Liebers D, Gouarin E, Czech M, Hauryliuk V, Bukau B, Kramer G, Andréasson C. Chp1 is a dedicated chaperone at the ribosome that safeguards eEF1A biogenesis. Nat Commun 2024; 15:1382. [PMID: 38360885 PMCID: PMC10869706 DOI: 10.1038/s41467-024-45645-w] [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: 06/02/2023] [Accepted: 01/29/2024] [Indexed: 02/17/2024] Open
Abstract
Cotranslational protein folding depends on general chaperones that engage highly diverse nascent chains at the ribosomes. Here we discover a dedicated ribosome-associated chaperone, Chp1, that rewires the cotranslational folding machinery to assist in the challenging biogenesis of abundantly expressed eukaryotic translation elongation factor 1A (eEF1A). Our results indicate that during eEF1A synthesis, Chp1 is recruited to the ribosome with the help of the nascent polypeptide-associated complex (NAC), where it safeguards eEF1A biogenesis. Aberrant eEF1A production in the absence of Chp1 triggers instant proteolysis, widespread protein aggregation, activation of Hsf1 stress transcription and compromises cellular fitness. The expression of pathogenic eEF1A2 variants linked to epileptic-dyskinetic encephalopathy is protected by Chp1. Thus, eEF1A is a difficult-to-fold protein that necessitates a biogenesis pathway starting with dedicated folding factor Chp1 at the ribosome to protect the eukaryotic cell from proteostasis collapse.
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Affiliation(s)
- Melania Minoia
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Jany Quintana-Cordero
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Katharina Jetzinger
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Ilgin Eser Kotan
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Kathryn Jane Turnbull
- Department of Clinical Microbiology, Rigshospitalet, 2200, Copenhagen, Denmark
- Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Science for Life Laboratory, Umeå University, Umeå, Sweden
| | - Michela Ciccarelli
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Anna E Masser
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Dorina Liebers
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Eloïse Gouarin
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Marius Czech
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Vasili Hauryliuk
- Science for Life Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
- University of Tartu, Institute of Technology, 50411, Tartu, Estonia
| | - Bernd Bukau
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
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4
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Omnus DJ, Fink MJ, Kallazhi A, Xandri Zaragoza M, Leppert A, Landreh M, Jonas K. The heat shock protein LarA activates the Lon protease in response to proteotoxic stress. Nat Commun 2023; 14:7636. [PMID: 37993443 PMCID: PMC10665427 DOI: 10.1038/s41467-023-43385-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 11/07/2023] [Indexed: 11/24/2023] Open
Abstract
The Lon protease is a highly conserved protein degradation machine that has critical regulatory and protein quality control functions in cells from the three domains of life. Here, we report the discovery of a α-proteobacterial heat shock protein, LarA, that functions as a dedicated Lon regulator. We show that LarA accumulates at the onset of proteotoxic stress and allosterically activates Lon-catalysed degradation of a large group of substrates through a five amino acid sequence at its C-terminus. Further, we find that high levels of LarA cause growth inhibition in a Lon-dependent manner and that Lon-mediated degradation of LarA itself ensures low LarA levels in the absence of stress. We suggest that the temporal LarA-dependent activation of Lon helps to meet an increased proteolysis demand in response to protein unfolding stress. Our study defines a regulatory interaction of a conserved protease with a heat shock protein, serving as a paradigm of how protease activity can be tuned under changing environmental conditions.
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Affiliation(s)
- Deike J Omnus
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm, 10691, Sweden
| | - Matthias J Fink
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm, 10691, Sweden
| | - Aswathy Kallazhi
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm, 10691, Sweden
| | - Maria Xandri Zaragoza
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm, 10691, Sweden
| | - Axel Leppert
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, 17165, Solna, Sweden
| | - Michael Landreh
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, 17165, Solna, Sweden
- Department of Cell and Molecular Biology, Uppsala University, Box 596, 751 24, Uppsala, Sweden
| | - Kristina Jonas
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm, 10691, Sweden.
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5
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Ciccarelli M, Masser AE, Kaimal JM, Planells J, Andréasson C. Genetic inactivation of essential HSF1 reveals an isolated transcriptional stress response selectively induced by protein misfolding. Mol Biol Cell 2023; 34:ar101. [PMID: 37467033 PMCID: PMC10551698 DOI: 10.1091/mbc.e23-05-0153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/06/2023] [Accepted: 07/12/2023] [Indexed: 07/20/2023] Open
Abstract
Heat Shock Factor 1 (Hsf1) in yeast drives the basal transcription of key proteostasis factors and its activity is induced as part of the core heat shock response. Exploring Hsf1 specific functions has been challenging due to the essential nature of the HSF1 gene and the extensive overlap of target promoters with environmental stress response (ESR) transcription factors Msn2 and Msn4 (Msn2/4). In this study, we constructed a viable hsf1∆ strain by replacing the HSF1 open reading frame with genes that constitutively express Hsp40, Hsp70, and Hsp90 from Hsf1-independent promoters. Phenotypic analysis showed that the hsf1∆ strain grows slowly, is sensitive to heat as well as protein misfolding and accumulates protein aggregates. Transcriptome analysis revealed that the transcriptional response to protein misfolding induced by azetidine-2-carboxylic acid is fully dependent on Hsf1. In contrast, the hsf1∆ strain responded to heat shock through the ESR. Following HS, Hsf1 and Msn2/4 showed functional compensatory induction with stronger activation of the remaining stress pathway when the other branch was inactivated. Thus, we provide a long-overdue genetic test of the function of Hsf1 in yeast using the novel hsf1∆ construct. Our data highlight that the accumulation of misfolded proteins is uniquely sensed by Hsf1-Hsp70 chaperone titration inducing a highly selective transcriptional stress response.
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Affiliation(s)
- Michela Ciccarelli
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
| | - Anna E Masser
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
| | | | - Jordi Planells
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
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6
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Transfection of Heat Shock Protein 70 kDa (HSP70). Int J Pept Res Ther 2022. [DOI: 10.1007/s10989-022-10416-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AbstractHeat shock protein 70 kDa (HSP70) is a major protein family in the cell protections against stress-induced denaturation and aggregation and in the folding of nascent proteins. It is a highly conserved protein that can be found in most organisms and is strongly connected to several intracellular pathways such as protein folding and refolding, protein degradation and regulation, and protection against intense stress. Cellular delivery of HSP70 would be of high impact for clarification of its role in these cellular processes.PepFect14 is a cell-penetrating peptide known to be able to mediate the transfection of various oligonucleotides to multiple cell lines with a higher efficacy than most commercially available transfection agents and without inducing significant toxic effects.In this study we demonstrated that PepFect14 was able to form a complex with HSP70 and to deliver it inside cells in the same fashion with oligonucleotide delivery. The delivered HSP70 showed an effect in the cell regulation indicating that the protein was biologically available in the cytoplasm and the interactions with PepFect14 did not impeach its active sites once the plasma barrier crossed.This study reports the first successful delivery of HSP70 to our knowledge and the first protein transfection mediated by PepFect14. It opens new fields of research for both PepFect14 as a delivery agent and HSP70 as a therapeutic agent; with potential in peptide aggregation caused diseases such as Parkinson’s and Alzheimer’s diseases.
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7
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Omnus DJ, Fink MJ, Szwedo K, Jonas K. The Lon protease temporally restricts polar cell differentiation events during the Caulobacter cell cycle. eLife 2021; 10:73875. [PMID: 34693909 PMCID: PMC8545394 DOI: 10.7554/elife.73875] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 09/22/2021] [Indexed: 01/16/2023] Open
Abstract
The highly conserved protease Lon has important regulatory and protein quality control functions in cells from the three domains of life. Despite many years of research on Lon, only a few specific protein substrates are known in most organisms. Here, we used a quantitative proteomics approach to identify novel substrates of Lon in the dimorphic bacterium Caulobacter crescentus. We focused our study on proteins involved in polar cell differentiation and investigated the developmental regulator StaR and the flagella hook length regulator FliK as specific Lon substrates in detail. We show that Lon recognizes these proteins at their C-termini, and that Lon-dependent degradation ensures their temporally restricted accumulation in the cell cycle phase when their function is needed. Disruption of this precise temporal regulation of StaR and FliK levels in a Δlon mutant contributes to defects in stalk biogenesis and motility, respectively, revealing a critical role of Lon in coordinating developmental processes with cell cycle progression. Our work underscores the importance of Lon in the regulation of complex temporally controlled processes by adjusting the concentrations of critical regulatory proteins. Furthermore, this study includes the first characterization of FliK in C. crescentus and uncovers a dual role of the C-terminal amino acids of FliK in protein function and degradation.
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Affiliation(s)
- Deike J Omnus
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Matthias J Fink
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Klaudia Szwedo
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Kristina Jonas
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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8
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Duan J, Zhao Y, Li H, Habernig L, Gordon MD, Miao X, Engström Y, Büttner S. Bab2 Functions as an Ecdysone-Responsive Transcriptional Repressor during Drosophila Development. Cell Rep 2020; 32:107972. [PMID: 32726635 DOI: 10.1016/j.celrep.2020.107972] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/30/2020] [Accepted: 07/08/2020] [Indexed: 12/01/2022] Open
Abstract
Drosophila development is governed by distinct ecdysone steroid pulses that initiate spatially and temporally defined gene expression programs. The translation of these signals into tissue-specific responses is crucial for metamorphosis, but the mechanisms that confer specificity to systemic ecdysone pulses are far from understood. Here, we identify Bric-à-brac 2 (Bab2) as an ecdysone-responsive transcriptional repressor that controls temporal gene expression during larval to pupal transition. Bab2 is necessary to terminate Salivary gland secretion (Sgs) gene expression, while premature Bab2 expression blocks Sgs genes and causes precocious salivary gland histolysis. The timely expression of bab2 is controlled by the ecdysone-responsive transcription factor Broad, and manipulation of EcR/USP/Broad signaling induces inappropriate Bab2 expression and termination of Sgs gene expression. Bab2 directly binds to Sgs loci in vitro and represses all Sgs genes in vivo. Our work characterizes Bab2 as a temporal regulator of somatic gene expression in response to systemic ecdysone signaling.
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Affiliation(s)
- Jianli Duan
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden; CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yunpo Zhao
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden; CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China; Department of Zoology, Life Science Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
| | - Haichao Li
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Lukas Habernig
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Michael D Gordon
- Department of Zoology, Life Science Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Xuexia Miao
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Ylva Engström
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden; Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.
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9
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Applications of catalyzed cytoplasmic disulfide bond formation. Biochem Soc Trans 2019; 47:1223-1231. [DOI: 10.1042/bst20190088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/09/2019] [Accepted: 09/20/2019] [Indexed: 12/14/2022]
Abstract
Abstract
Disulfide bond formation is an essential post-translational modification required for many proteins to attain their native, functional structure. The formation of disulfide bonds, otherwise known as oxidative protein folding, occurs in the endoplasmic reticulum and mitochondrial inter-membrane space in eukaryotes and the periplasm of prokaryotes. While there are differences in the molecular mechanisms of oxidative folding in different compartments, it can essentially be broken down into two steps, disulfide formation and disulfide isomerization. For both steps, catalysts exist in all compartments where native disulfide bond formation occurs. Due to the importance of disulfide bonds for a plethora of proteins, considerable effort has been made to generate cell factories which can make them more efficiently and cheaper. Recently synthetic biology has been used to transfer catalysts of native disulfide bond formation into the cytoplasm of prokaryotes such as Escherichia coli. While these engineered systems cannot yet rival natural systems in the range and complexity of disulfide-bonded proteins that can be made, a growing range of proteins have been made successfully and yields of homogenously folded eukaryotic proteins exceeding g/l yields have been obtained. This review will briefly give an overview of such systems, the uses reported to date and areas of future potential development, including combining with engineered systems for cytoplasmic glycosylation.
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10
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Masser AE, Kang W, Roy J, Mohanakrishnan Kaimal J, Quintana-Cordero J, Friedländer MR, Andréasson C. Cytoplasmic protein misfolding titrates Hsp70 to activate nuclear Hsf1. eLife 2019; 8:47791. [PMID: 31552827 PMCID: PMC6779467 DOI: 10.7554/elife.47791] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 09/24/2019] [Indexed: 12/21/2022] Open
Abstract
Hsf1 is an ancient transcription factor that responds to protein folding stress by inducing the heat-shock response (HSR) that restore perturbed proteostasis. Hsp70 chaperones negatively regulate the activity of Hsf1 via stress-responsive mechanisms that are poorly understood. Here, we have reconstituted budding yeast Hsf1-Hsp70 activation complexes and find that surplus Hsp70 inhibits Hsf1 DNA-binding activity. Hsp70 binds Hsf1 via its canonical substrate binding domain and Hsp70 regulates Hsf1 DNA-binding activity. During heat shock, Hsp70 is out-titrated by misfolded proteins derived from ongoing translation in the cytosol. Pushing the boundaries of the regulatory system unveils a genetic hyperstress program that is triggered by proteostasis collapse and involves an enlarged Hsf1 regulon. The findings demonstrate how an apparently simple chaperone-titration mechanism produces diversified transcriptional output in response to distinct stress loads.
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Affiliation(s)
- Anna E Masser
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Wenjing Kang
- Department of Molecular Biosciences, The Wenner-Gren Institute, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Joydeep Roy
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | | | - Jany Quintana-Cordero
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Marc R Friedländer
- Department of Molecular Biosciences, The Wenner-Gren Institute, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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11
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Nucleotide exchange factors Fes1 and HspBP1 mimic substrate to release misfolded proteins from Hsp70. Nat Struct Mol Biol 2018; 25:83-89. [PMID: 29323280 DOI: 10.1038/s41594-017-0008-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 11/10/2017] [Indexed: 01/25/2023]
Abstract
Protein quality control depends on the tight regulation of interactions between molecular chaperones and polypeptide substrates. Substrate release from the chaperone Hsp70 is triggered by nucleotide-exchange factors (NEFs) that control folding and degradation fates via poorly understood mechanisms. We found that the armadillo-type NEFs budding yeast Fes1 and its human homolog HspBP1 employ flexible N-terminal release domains (RDs) with substrate-mimicking properties to ensure the efficient release of persistent substrates from Hsp70. The RD contacts the substrate-binding domain of the chaperone, competes with peptide substrate for binding and is essential for proper function in yeast and mammalian cells. Thus, the armadillo domain engages Hsp70 to trigger nucleotide exchange, whereas the RD safeguards the release of substrates. Our findings provide fundamental mechanistic insight into the functional specialization of Hsp70 NEFs and have implications for the understanding of proteostasis-related disorders, including Marinesco-Sjögren syndrome.
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12
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Konczal J, Gray CH. Streamlining workflow and automation to accelerate laboratory scale protein production. Protein Expr Purif 2017; 133:160-169. [PMID: 28330825 DOI: 10.1016/j.pep.2017.03.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 03/17/2017] [Indexed: 12/20/2022]
Abstract
Protein production facilities are often required to produce diverse arrays of proteins for demanding methodologies including crystallography, NMR, ITC and other reagent intensive techniques. It is common for these teams to find themselves a bottleneck in the pipeline of ambitious projects. This pressure to deliver has resulted in the evolution of many novel methods to increase capacity and throughput at all stages in the pipeline for generation of recombinant proteins. This review aims to describe current and emerging options to accelerate the success of protein production in Escherichia coli. We emphasize technologies that have been evaluated and implemented in our laboratory, including innovative molecular biology and expression vectors, small-scale expression screening strategies and the automation of parallel and multidimensional chromatography.
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Affiliation(s)
- Jennifer Konczal
- Drug Discovery Program, CRUK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, United Kingdom
| | - Christopher H Gray
- Drug Discovery Program, CRUK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, United Kingdom.
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13
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Nejedla M, Li Z, Masser AE, Biancospino M, Spiess M, Mackowiak SD, Friedländer MR, Karlsson R. A Fluorophore Fusion Construct of Human Profilin I with Non-Compromised Poly(L-Proline) Binding Capacity Suitable for Imaging. J Mol Biol 2017; 429:964-976. [DOI: 10.1016/j.jmb.2017.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/06/2016] [Accepted: 01/03/2017] [Indexed: 10/24/2022]
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14
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Nejedla M, Sadi S, Sulimenko V, de Almeida FN, Blom H, Draber P, Aspenström P, Karlsson R. Profilin connects actin assembly with microtubule dynamics. Mol Biol Cell 2016; 27:2381-93. [PMID: 27307590 PMCID: PMC4966980 DOI: 10.1091/mbc.e15-11-0799] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 06/09/2016] [Indexed: 12/29/2022] Open
Abstract
Profilin is a well-known regulator of actin filament formation. It indirectly associates with microtubules and influences their growth rate. Formins are the linker molecules, and the turnover of the actin microfilament system balances profilin association with the microtubules. Profilin controls actin nucleation and assembly processes in eukaryotic cells. Actin nucleation and elongation promoting factors (NEPFs) such as Ena/VASP, formins, and WASP-family proteins recruit profilin:actin for filament formation. Some of these are found to be microtubule associated, making actin polymerization from microtubule-associated platforms possible. Microtubules are implicated in focal adhesion turnover, cell polarity establishment, and migration, illustrating the coupling between actin and microtubule systems. Here we demonstrate that profilin is functionally linked to microtubules with formins and point to formins as major mediators of this association. To reach this conclusion, we combined different fluorescence microscopy techniques, including superresolution microscopy, with siRNA modulation of profilin expression and drug treatments to interfere with actin dynamics. Our studies show that profilin dynamically associates with microtubules and this fraction of profilin contributes to balance actin assembly during homeostatic cell growth and affects microtubule dynamics. Hence profilin functions as a regulator of microtubule (+)-end turnover in addition to being an actin control element.
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Affiliation(s)
- Michaela Nejedla
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Sara Sadi
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Vadym Sulimenko
- Institute of Molecular Genetics, ASCR, 142 20 Prague 4, Czech Republic
| | | | - Hans Blom
- Science for Life Laboratory, SE-171 21 Solna, Sweden
| | - Pavel Draber
- Institute of Molecular Genetics, ASCR, 142 20 Prague 4, Czech Republic
| | - Pontus Aspenström
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Roger Karlsson
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
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15
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Gowda NKC, Kaimal JM, Masser AE, Kang W, Friedländer MR, Andréasson C. Cytosolic splice isoform of Hsp70 nucleotide exchange factor Fes1 is required for the degradation of misfolded proteins in yeast. Mol Biol Cell 2016; 27:1210-9. [PMID: 26912797 PMCID: PMC4831876 DOI: 10.1091/mbc.e15-10-0697] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/17/2016] [Indexed: 12/14/2022] Open
Abstract
Yeast Hsp70 nucleotide exchange factor Fes1 is expressed by rare alternative splicing as two isoforms. Fes1L is targeted to the nucleus, and Fes1S localizes to the cytosol and is required for the efficient proteasomal degradation of cytosolic misfolded proteins, as well as of species that are imported into the nucleus for degradation. Cells maintain proteostasis by selectively recognizing and targeting misfolded proteins for degradation. In Saccharomyces cerevisiae, the Hsp70 nucleotide exchange factor Fes1 is essential for the degradation of chaperone-associated misfolded proteins by the ubiquitin-proteasome system. Here we show that the FES1 transcript undergoes unique 3′ alternative splicing that results in two equally active isoforms with alternative C-termini, Fes1L and Fes1S. Fes1L is actively targeted to the nucleus and represents the first identified nuclear Hsp70 nucleotide exchange factor. In contrast, Fes1S localizes to the cytosol and is essential to maintain proteostasis. In the absence of Fes1S, the heat-shock response is constitutively induced at normally nonstressful conditions. Moreover, cells display severe growth defects when elevated temperatures, amino acid analogues, or the ectopic expression of misfolded proteins, induce protein misfolding. Importantly, misfolded proteins are not targeted for degradation by the ubiquitin-proteasome system. These observations support the notion that cytosolic Fes1S maintains proteostasis by supporting the removal of toxic misfolded proteins by proteasomal degradation. This study provides key findings for the understanding of the organization of protein quality control mechanisms in the cytosol and nucleus.
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Affiliation(s)
| | | | - Anna E Masser
- Department of Molecular Biosciences, Stockholm University, S-10691 Stockholm, Sweden
| | - Wenjing Kang
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
| | - Marc R Friedländer
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-10691 Stockholm, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, Stockholm University, S-10691 Stockholm, Sweden
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