1
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Konno T, Parutto P, Crapart CC, Davì V, Bailey DMD, Awadelkareem MA, Hockings C, Brown AI, Xiang KM, Agrawal A, Chambers JE, Vander Werp MJ, Koning KM, Elfari LM, Steen S, Metzakopian E, Westrate LM, Koslover EF, Avezov E. Endoplasmic reticulum morphology regulation by RTN4 modulates neuronal regeneration by curbing luminal transport. Cell Rep 2024; 43:114357. [PMID: 38955182 DOI: 10.1016/j.celrep.2024.114357] [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] [Received: 02/14/2024] [Revised: 03/01/2024] [Accepted: 05/29/2024] [Indexed: 07/04/2024] Open
Abstract
Cell functions rely on intracellular transport systems distributing bioactive molecules with high spatiotemporal accuracy. The endoplasmic reticulum (ER) tubular network constitutes a system for delivering luminal solutes, including Ca2+, across the cell periphery. How the ER structure enables this nanofluidic transport system is unclear. Here, we show that ER membrane-localized reticulon 4 (RTN4/Nogo) is sufficient to impose neurite outgrowth inhibition in human cortical neurons while acting as an ER morphoregulator. Improving ER transport visualization methodologies combined with optogenetic Ca2+ dynamics imaging and in silico modeling, we observed that ER luminal transport is modulated by ER tubule narrowing and dilation, proportional to the amount of RTN4. Excess RTN4 limited ER luminal transport and Ca2+ release, while RTN4 elimination reversed the effects. The described morphoregulatory effect of RTN4 defines the capacity of the ER for peripheral Ca2+ delivery for physiological releases and thus may constitute a mechanism for controlling the (re)generation of neurites.
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Affiliation(s)
- Tasuku Konno
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK
| | - Pierre Parutto
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK
| | - Cécile C Crapart
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK
| | - Valentina Davì
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK
| | | | - Mosab Ali Awadelkareem
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK; Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Colin Hockings
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK
| | - Aidan I Brown
- Department of Physics, University of California, San Diego, 9500 Gilman Dr. #0374, La Jolla, CA 92093-0374, USA; Department of Physics, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | | | - Anamika Agrawal
- Department of Physics, University of California, San Diego, 9500 Gilman Dr. #0374, La Jolla, CA 92093-0374, USA
| | - Joseph E Chambers
- Cambridge Institute for Medical Research (CIMR), Department of Medicine, University of Cambridge, The Keith Peters Building, Hills Road, Cambridge CB2 0XY, UK
| | - Molly J Vander Werp
- Department of Chemistry and Biochemistry, Calvin University, Grand Rapids, MI 49546, USA
| | - Katherine M Koning
- Department of Chemistry and Biochemistry, Calvin University, Grand Rapids, MI 49546, USA
| | - Louis Mounir Elfari
- Wellcome-MRC Cambridge Stem Cell Institute Advanced Imaging Facility, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Sam Steen
- Department of Chemistry and Biochemistry, Calvin University, Grand Rapids, MI 49546, USA
| | - Emmanouil Metzakopian
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK
| | - Laura M Westrate
- Department of Chemistry and Biochemistry, Calvin University, Grand Rapids, MI 49546, USA
| | - Elena F Koslover
- Department of Physics, University of California, San Diego, 9500 Gilman Dr. #0374, La Jolla, CA 92093-0374, USA.
| | - Edward Avezov
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK.
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2
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Dobson JR, Jacobson DA. Disrupted Endoplasmic Reticulum Ca 2+ Handling: A Harβinger of β-Cell Failure. BIOLOGY 2024; 13:379. [PMID: 38927260 PMCID: PMC11200644 DOI: 10.3390/biology13060379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 06/28/2024]
Abstract
The β-cell workload increases in the setting of insulin resistance and reduced β-cell mass, which occurs in type 2 and type 1 diabetes, respectively. The prolonged elevation of insulin production and secretion during the pathogenesis of diabetes results in β-cell ER stress. The depletion of β-cell Ca2+ER during ER stress activates the unfolded protein response, leading to β-cell dysfunction. Ca2+ER is involved in many pathways that are critical to β-cell function, such as protein processing, tuning organelle and cytosolic Ca2+ handling, and modulating lipid homeostasis. Mutations that promote β-cell ER stress and deplete Ca2+ER stores are associated with or cause diabetes (e.g., mutations in ryanodine receptors and insulin). Thus, improving β-cell Ca2+ER handling and reducing ER stress under diabetogenic conditions could preserve β-cell function and delay or prevent the onset of diabetes. This review focuses on how mechanisms that control β-cell Ca2+ER are perturbed during the pathogenesis of diabetes and contribute to β-cell failure.
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Affiliation(s)
| | - David A. Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA;
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3
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Michalak M. Calreticulin: Endoplasmic reticulum Ca 2+ gatekeeper. J Cell Mol Med 2024; 28:e17839. [PMID: 37424156 PMCID: PMC10902585 DOI: 10.1111/jcmm.17839] [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: 04/21/2023] [Revised: 06/21/2023] [Accepted: 06/27/2023] [Indexed: 07/11/2023] Open
Abstract
Endoplasmic reticulum (ER) luminal Ca2+ is vital for the function of the ER and regulates many cellular processes. Calreticulin is a highly conserved, ER-resident Ca2+ binding protein and lectin-like chaperone. Over four decades of studying calreticulin demonstrate that this protein plays a crucial role in maintaining Ca2+ supply under different physiological conditions, in managing access to Ca2+ and how Ca2+ is used depending on the environmental events and in making sure that Ca2+ is not misused. Calreticulin plays a role of ER luminal Ca2+ sensor to manage Ca2+-dependent ER luminal events including maintaining interaction with its partners, Ca2+ handling molecules, substrates and stress sensors. The protein is strategically positioned in the lumen of the ER from where the protein manages access to and distribution of Ca2+ for many cellular Ca2+-signalling events. The importance of calreticulin Ca2+ pool extends beyond the ER and includes influence of cellular processes involved in many aspects of cellular pathophysiology. Abnormal handling of the ER Ca2+ contributes to many pathologies from heart failure to neurodegeneration and metabolic diseases.
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Affiliation(s)
- Marek Michalak
- Department of BiochemistryUniversity of AlbertaEdmontonAlbertaCanada
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4
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Neidhardt L, Cloots E, Friemel N, Weiss CAM, Harding HP, McLaughlin SH, Janssens S, Ron D. The IRE1β-mediated unfolded protein response is repressed by the chaperone AGR2 in mucin producing cells. EMBO J 2024; 43:719-753. [PMID: 38177498 PMCID: PMC10907699 DOI: 10.1038/s44318-023-00014-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 11/07/2023] [Accepted: 11/15/2023] [Indexed: 01/06/2024] Open
Abstract
Effector mechanisms of the unfolded protein response (UPR) in the endoplasmic reticulum (ER) are well-characterised, but how ER proteostasis is sensed is less well understood. Here, we exploited the beta isoform of the UPR transducer IRE1, that is specific to mucin-producing cells in order to gauge the relative regulatory roles of activating ligands and repressing chaperones of the specialised ER of goblet cells. Replacement of the stress-sensing luminal domain of endogenous IRE1α in CHO cells (normally expressing neither mucin nor IRE1β) with the luminal domain of IRE1β deregulated basal IRE1 activity. The mucin-specific chaperone AGR2 repressed IRE1 activity in cells expressing the domain-swapped IRE1β/α chimera, but had no effect on IRE1α. Introduction of the goblet cell-specific client MUC2 reversed AGR2-mediated repression of the IRE1β/α chimera. In vitro, AGR2 actively de-stabilised the IRE1β luminal domain dimer and formed a reversible complex with the inactive monomer. These features of the IRE1β-AGR2 couple suggest that active repression of IRE1β by a specialised mucin chaperone subordinates IRE1 activity to a proteostatic challenge unique to goblet cells, a challenge that is otherwise poorly recognised by the pervasive UPR transducers.
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Affiliation(s)
- Lisa Neidhardt
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
| | - Eva Cloots
- Laboratory for ER stress and Inflammation, VIB Center for Inflammation Research, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Pediatrics and Internal Medicine, Faculty of Medicine and Health Sciences, Ghent University, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
| | - Natalie Friemel
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Caroline A M Weiss
- 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
| | - Stephen H McLaughlin
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Sophie Janssens
- Laboratory for ER stress and Inflammation, VIB Center for Inflammation Research, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Pediatrics and Internal Medicine, Faculty of Medicine and Health Sciences, Ghent University, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
| | - David Ron
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
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5
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Fujii S, Ushioda R, Nagata K. Redox states in the endoplasmic reticulum directly regulate the activity of calcium channel, inositol 1,4,5-trisphosphate receptors. Proc Natl Acad Sci U S A 2023; 120:e2216857120. [PMID: 37216546 PMCID: PMC10235943 DOI: 10.1073/pnas.2216857120] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/14/2023] [Indexed: 05/24/2023] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3Rs) are one of the two types of tetrameric ion channels that release calcium ion (Ca2+) from the endoplasmic reticulum (ER) into the cytosol. Ca2+ released via IP3Rs is a fundamental second messenger for numerous cell functions. Disturbances in the intracellular redox environment resulting from various diseases and aging interfere with proper calcium signaling, however, the details are unclear. Here, we elucidated the regulatory mechanisms of IP3Rs by protein disulfide isomerase family proteins localized in the ER by focusing on four cysteine residues residing in the ER lumen of IP3Rs. First, we revealed that two of the cysteine residues are essential for functional tetramer formation of IP3Rs. Two other cysteine residues, on the contrary, were revealed to be involved in the regulation of IP3Rs activity; its oxidation by ERp46 and the reduction by ERdj5 caused the activation and the inactivation of IP3Rs activity, respectively. We previously reported that ERdj5 can activate the sarco/endoplasmic reticulum Ca2+-ATPase isoform 2b (SERCA2b) using its reducing activity [Ushioda et al., Proc. Natl. Acad. Sci. U.S.A. 113, E6055-E6063 (2016)]. Thus, we here established that ERdj5 exerts the reciprocal regulatory function for IP3Rs and SERCA2b by sensing the ER luminal Ca2+ concentration, which contributes to the calcium homeostasis in the ER.
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Affiliation(s)
- Shohei Fujii
- Laboratory of Molecular and Cellular Biology, Department of Frontier Life Sciences, Faculty of Life Science, Kyoto Sangyo University, Kyoto603-8555, Japan
| | - Ryo Ushioda
- Laboratory of Molecular and Cellular Biology, Department of Frontier Life Sciences, Faculty of Life Science, Kyoto Sangyo University, Kyoto603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto603-8555, Japan
| | - Kazuhiro Nagata
- Laboratory of Molecular and Cellular Biology, Department of Frontier Life Sciences, Faculty of Life Science, Kyoto Sangyo University, Kyoto603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto603-8555, Japan
- JT Biohistory Research Hall, Takatsuki City, Osaka569-1125, Japan
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6
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Lu M, Christensen CN, Weber JM, Konno T, Läubli NF, Scherer KM, Avezov E, Lio P, Lapkin AA, Kaminski Schierle GS, Kaminski CF. ERnet: a tool for the semantic segmentation and quantitative analysis of endoplasmic reticulum topology. Nat Methods 2023; 20:569-579. [PMID: 36997816 DOI: 10.1038/s41592-023-01815-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 02/10/2023] [Indexed: 04/01/2023]
Abstract
The ability to quantify structural changes of the endoplasmic reticulum (ER) is crucial for understanding the structure and function of this organelle. However, the rapid movement and complex topology of ER networks make this challenging. Here, we construct a state-of-the-art semantic segmentation method that we call ERnet for the automatic classification of sheet and tubular ER domains inside individual cells. Data are skeletonized and represented by connectivity graphs, enabling precise and efficient quantification of network connectivity. ERnet generates metrics on topology and integrity of ER structures and quantifies structural change in response to genetic or metabolic manipulation. We validate ERnet using data obtained by various ER-imaging methods from different cell types as well as ground truth images of synthetic ER structures. ERnet can be deployed in an automatic high-throughput and unbiased fashion and identifies subtle changes in ER phenotypes that may inform on disease progression and response to therapy.
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Affiliation(s)
- Meng Lu
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Cambridge Infinitus Research Centre, University of Cambridge, Cambridge, UK
| | - Charles N Christensen
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Artificial Intelligence Group, Department of Computer Science and Technology, University of Cambridge, Cambridge, UK
| | - Jana M Weber
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Delft Bioinformatics Lab, Intelligent Systems Department, Delft University of Technology, Delft, the Netherlands
| | - Tasuku Konno
- UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Nino F Läubli
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Katharina M Scherer
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Edward Avezov
- UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Pietro Lio
- Artificial Intelligence Group, Department of Computer Science and Technology, University of Cambridge, Cambridge, UK
| | - Alexei A Lapkin
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Gabriele S Kaminski Schierle
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Cambridge Infinitus Research Centre, University of Cambridge, Cambridge, UK
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.
- Cambridge Infinitus Research Centre, University of Cambridge, Cambridge, UK.
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7
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Laine RF, Poudel C, Kaminski CF. A method for the fast and photon-efficient analysis of time-domain fluorescence lifetime image data over large dynamic ranges. J Microsc 2022; 287:138-147. [PMID: 35676768 PMCID: PMC9544871 DOI: 10.1111/jmi.13128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/29/2022]
Abstract
Fluorescence lifetime imaging (FLIM) allows the quantification of sub-cellular processes in situ, in living cells. A number of approaches have been developed to extract the lifetime from time-domain FLIM data, but they are often limited in terms of speed, photon efficiency, precision or the dynamic range of lifetimes they can measure. Here, we focus on one of the best performing methods in the field, the centre-of-mass method (CMM), that conveys advantages in terms of speed and photon efficiency over others. In this paper, however, we identify a loss of photon efficiency of CMM for short lifetimes when background noise is present. We subsequently present a new development and generalization of CMM that provides for the rapid and accurate extraction of fluorescence lifetime over a large lifetime dynamic range. We provide software tools to simulate, validate and analyse FLIM data sets and compare the performance of our approach against the standard CMM and the commonly employed least-square minimization (LSM) methods. Our method features a better photon efficiency than standard CMM and LSM and is robust in the presence of background noise. The algorithm is applicable to any time-domain FLIM data set.
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Affiliation(s)
- Romain F. Laine
- Laser Analytics Group, Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhilippa Fawcett DriveCambridgeUK
- Medical Research Council Laboratory for Molecular Cell Biology (LMCB)University College LondonGower StreetLondonWC1E 6BT
| | - Chetan Poudel
- Laser Analytics Group, Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhilippa Fawcett DriveCambridgeUK
- Department of ChemistryUniversity of WashingtonSeattle, WA 98195USA
| | - Clemens F. Kaminski
- Laser Analytics Group, Department of Chemical Engineering and BiotechnologyUniversity of CambridgePhilippa Fawcett DriveCambridgeUK
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8
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Regulation of calcium homeostasis and flux between the endoplasmic reticulum and the cytosol. J Biol Chem 2022; 298:102061. [PMID: 35609712 PMCID: PMC9218512 DOI: 10.1016/j.jbc.2022.102061] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 12/20/2022] Open
Abstract
The concentration of Ca2+ in the endoplasmic reticulum (ER) is critically important for maintaining its oxidizing environment as well as for maintaining luminal ATP levels required for chaperone activity. Therefore, local luminal Ca2+ concentrations and the dynamic Ca2+ flux between the different subcellular compartments are tightly controlled. Influx of Ca2+ into the ER is enabled by a reductive shift, which opens the sarcoendoplasmic reticulum calcium transport ATPase pump, building the Ca2+ gradient across the ER membrane required for ATP import. Meanwhile, Ca2+ leakage from the ER has been reported to occur via the Sec61 translocon following protein translocation. In this review, we provide an overview of the complex regulation of Ca2+ homeostasis, Ca2+ flux between subcellular compartments, and the cellular stress response (the unfolded protein response) induced upon dysregulated luminal Ca2+ metabolism. We also provide insight into the structure and gating mechanism at the Sec61 translocon and examine the role of ER-resident cochaperones in assisting the central ER-resident chaperone BiP in the control of luminal Ca2+ concentrations.
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9
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Agellon LB, Michalak M. A View of the Endoplasmic Reticulum Through the Calreticulin Lens. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 59:1-11. [PMID: 34050859 DOI: 10.1007/978-3-030-67696-4_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Calreticulin is well known as an ER-resident protein that serves as the major endoplasmic reticulum (ER) Ca2+ binding protein. This protein has been the major topic of discussion in an international workshop that has been meeting for a quarter of a century. In sharing information about this protein, the field also witnessed remarkable insights into the importance of the ER as an organelle and the role of ER Ca2+ in coordinating ER and cellular functions. Recent technological advances have helped to uncover the contributions of calreticulin in maintaining Ca2+ homeostasis in the ER and to unravel its involvement in a multitude of cellular processes as highlighted in this collection of articles. The continuing revelations of unexpected involvement of calreticulin and Ca2+ in many critical aspects of cellular function promises to further improve insights into the significance of this protein in the promotion of physiology as well as prevention of pathology.
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Affiliation(s)
- Luis B Agellon
- School of Human Nutrition, McGill University, Ste. Anne de Bellevue, QC, Canada.
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
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10
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Dual topology of co-chaperones at the membrane of the endoplasmic reticulum. Cell Death Discov 2021; 7:203. [PMID: 34354047 PMCID: PMC8342575 DOI: 10.1038/s41420-021-00594-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/08/2021] [Accepted: 07/22/2021] [Indexed: 11/08/2022] Open
Abstract
Dual topologies of proteins at the ER membrane are known for a variety of proteins allowing the same protein to exert different functions according to the topology adopted. A dual topology of the co-chaperone ERdj4, which resides in the endoplasmic reticulum (ER), was proposed recently, a thesis that we found to align all published data and existing controversies into one whole picture. The aim of this review is to reassess all primary data available in the literature on ER-resident Hsp40 co-chaperones with respect to their topology. After careful and critical analyses of all experimental data published so far, we identified, next to ERdj4, two other co-chaperones, ERdj3 and ERdj6, that also display features of a dual topology at the ER membrane. We assume that during cellular stress subpools of some ER-resident J protein can alter their topology so that these proteins can exert different functions in order to adapt to cellular stress.
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11
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Zhang J, Krishnan A, Wu H, Venkataraman V. Calcium-Dependent Translocation of S100B Is Facilitated by Neurocalcin Delta. Molecules 2021; 26:molecules26010227. [PMID: 33466232 PMCID: PMC7794955 DOI: 10.3390/molecules26010227] [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: 12/14/2020] [Revised: 12/26/2020] [Accepted: 12/28/2020] [Indexed: 11/29/2022] Open
Abstract
S100B is a calcium-binding protein that governs calcium-mediated responses in a variety of cells—especially neuronal and glial cells. It is also extensively investigated as a potential biomarker for several disease conditions, especially neurodegenerative ones. In order to establish S100B as a viable pharmaceutical target, it is critical to understand its mechanistic role in signaling pathways and its interacting partners. In this report, we provide evidence to support a calcium-regulated interaction between S100B and the neuronal calcium sensor protein, neurocalcin delta both in vitro and in living cells. Membrane overlay assays were used to test the interaction between purified proteins in vitro and bimolecular fluorescence complementation assays, for interactions in living cells. Added calcium is essential for interaction in vitro; however, in living cells, calcium elevation causes translocation of the NCALD-S100B complex to the membrane-rich, perinuclear trans-Golgi network in COS7 cells, suggesting that the response is independent of specialized structures/molecules found in neuronal/glial cells. Similar results are also observed with hippocalcin, a closely related paralog; however, the interaction appears less robust in vitro. The N-terminal region of NCALD and HPCA appear to be critical for interaction with S100B based on in vitro experiments. The possible physiological significance of this interaction is discussed.
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Affiliation(s)
- Jingyi Zhang
- Department of Cell Biology and Neuroscience, Graduate School of Biomedical Sciences, School of Osteopathic Medicine, Rowan University, Stratford, NJ 08084, USA; (J.Z.); (A.K.); (H.W.)
| | - Anuradha Krishnan
- Department of Cell Biology and Neuroscience, Graduate School of Biomedical Sciences, School of Osteopathic Medicine, Rowan University, Stratford, NJ 08084, USA; (J.Z.); (A.K.); (H.W.)
| | - Hao Wu
- Department of Cell Biology and Neuroscience, Graduate School of Biomedical Sciences, School of Osteopathic Medicine, Rowan University, Stratford, NJ 08084, USA; (J.Z.); (A.K.); (H.W.)
| | - Venkat Venkataraman
- Department of Cell Biology and Neuroscience, Graduate School of Biomedical Sciences, School of Osteopathic Medicine, Rowan University, Stratford, NJ 08084, USA; (J.Z.); (A.K.); (H.W.)
- Department of Rehabilitation Medicine, NeuroMusculoskeletal Institute, School of Osteopathic Medicine, Rowan University, Stratford, NJ 08084, USA
- Correspondence: ; Tel.: +1-856-566-6418
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12
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Roles of Calreticulin in Protein Folding, Immunity, Calcium Signaling and Cell Transformation. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 59:145-162. [PMID: 34050865 DOI: 10.1007/978-3-030-67696-4_7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The endoplasmic reticulum (ER) is an organelle that mediates the proper folding and assembly of proteins destined for the cell surface, the extracellular space and subcellular compartments such as the lysosomes. The ER contains a wide range of molecular chaperones to handle the folding requirements of a diverse set of proteins that traffic through this compartment. The lectin-like chaperones calreticulin and calnexin are an important class of structurally-related chaperones relevant for the folding and assembly of many N-linked glycoproteins. Despite the conserved mechanism of action of these two chaperones in nascent protein recognition and folding, calreticulin has unique functions in cellular calcium signaling and in the immune response. The ER-related functions of calreticulin in the assembly of major histocompatibility complex (MHC) class I molecules are well-studied and provide many insights into the modes of substrate and co-chaperone recognition by calreticulin. Calreticulin is also detectable on the cell surface under some conditions, where it induces the phagocytosis of apoptotic cells. Furthermore, mutations of calreticulin induce cell transformation in myeloproliferative neoplasms (MPN). Studies of the functions of the mutant calreticulin in cell transformation and immunity have provided many insights into the normal biology of calreticulin, which are discussed.
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13
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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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14
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Ma WX, Li CY, Tao R, Wang XP, Yan LJ. Reductive Stress-Induced Mitochondrial Dysfunction and Cardiomyopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:5136957. [PMID: 32566086 PMCID: PMC7277050 DOI: 10.1155/2020/5136957] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/26/2020] [Accepted: 05/12/2020] [Indexed: 02/05/2023]
Abstract
The goal of this review was to summarize reported studies focusing on cellular reductive stress-induced mitochondrial dysfunction, cardiomyopathy, dithiothreitol- (DTT-) induced reductive stress, and reductive stress-related free radical reactions published in the past five years. Reductive stress is considered to be a double-edged sword in terms of antioxidation and disease induction. As many underlying mechanisms are still unclear, further investigations are obviously warranted. Nonetheless, reductive stress is thought to be caused by elevated levels of cellular reducing power such as NADH, glutathione, and NADPH; and this area of research has attracted increasing attention lately. Albeit, we think there is a need to conduct further studies in identifying more indicators of the risk assessment and prevention of developing heart damage as well as exploring more targets for cardiomyopathy treatment. Hence, it is expected that further investigation of underlying mechanisms of reductive stress-induced mitochondrial dysfunction will provide novel insights into therapeutic approaches for ameliorating reductive stress-induced cardiomyopathy.
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Affiliation(s)
- Wei-Xing Ma
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center (UNTHSC), Fort Worth, Texas 76107, USA
- Qingdao University of Science and Technology, 266042 Qingdao, Shandong, China
| | - Chun-Yan Li
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center (UNTHSC), Fort Worth, Texas 76107, USA
- Shantou University Medical College, 515041 Shantou, Guangdong, China
| | - Ran Tao
- Qingdao Municipal Center for Disease Control & Prevention, 266034 Qingdao, Shandong, China
| | - Xin-Ping Wang
- Qingdao University of Science and Technology, 266042 Qingdao, Shandong, China
| | - Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center (UNTHSC), Fort Worth, Texas 76107, USA
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15
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Lizák B, Birk J, Zana M, Kosztyi G, Kratschmar DV, Odermatt A, Zimmermann R, Geiszt M, Appenzeller-Herzog C, Bánhegyi G. Ca 2+ mobilization-dependent reduction of the endoplasmic reticulum lumen is due to influx of cytosolic glutathione. BMC Biol 2020; 18:19. [PMID: 32101139 PMCID: PMC7043043 DOI: 10.1186/s12915-020-0749-y] [Citation(s) in RCA: 13] [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: 12/17/2019] [Accepted: 02/11/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The lumen of the endoplasmic reticulum (ER) acts as a cellular Ca2+ store and a site for oxidative protein folding, which is controlled by the reduced glutathione (GSH) and glutathione-disulfide (GSSG) redox pair. Although depletion of luminal Ca2+ from the ER provokes a rapid and reversible shift towards a more reducing poise in the ER, the underlying molecular basis remains unclear. RESULTS We found that Ca2+ mobilization-dependent ER luminal reduction was sensitive to inhibition of GSH synthesis or dilution of cytosolic GSH by selective permeabilization of the plasma membrane. A glutathione-centered mechanism was further indicated by increased ER luminal glutathione levels in response to Ca2+ efflux. Inducible reduction of the ER lumen by GSH flux was independent of the Ca2+-binding chaperone calreticulin, which has previously been implicated in this process. However, opening the translocon channel by puromycin or addition of cyclosporine A mimicked the GSH-related effect of Ca2+ mobilization. While the action of puromycin was ascribable to Ca2+ leakage from the ER, the mechanism of cyclosporine A-induced GSH flux was independent of calcineurin and cyclophilins A and B and remained unclear. CONCLUSIONS Our data strongly suggest that ER influx of cytosolic GSH, rather than inhibition of local oxidoreductases, is responsible for the reductive shift upon Ca2+ mobilization. We postulate the existence of a Ca2+- and cyclosporine A-sensitive GSH transporter in the ER membrane. These findings have important implications for ER redox homeostasis under normal physiology and ER stress.
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Affiliation(s)
- Beáta Lizák
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary.
| | - Julia Birk
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Melinda Zana
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- "Momentum" Peroxidase Enzyme Research Group of the Semmelweis University and the Hungarian Academy of Sciences, Budapest, Hungary
| | - Gergely Kosztyi
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Denise V Kratschmar
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Alex Odermatt
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Richard Zimmermann
- Medical Biochemistry and Molecular Biology, Saarland University, 66421, Homburg, Germany
| | - Miklós Geiszt
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- "Momentum" Peroxidase Enzyme Research Group of the Semmelweis University and the Hungarian Academy of Sciences, Budapest, Hungary
| | - Christian Appenzeller-Herzog
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland.
- University Medical Library, University of Basel, Spiegelgasse 5, 4051, Basel, Switzerland.
| | - Gábor Bánhegyi
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
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16
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Sicari D, Delaunay‐Moisan A, Combettes L, Chevet E, Igbaria A. A guide to assessing endoplasmic reticulum homeostasis and stress in mammalian systems. FEBS J 2019; 287:27-42. [DOI: 10.1111/febs.15107] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/10/2019] [Accepted: 10/23/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Daria Sicari
- Inserm U1242 University of Rennes France
- Centre de lutte contre le cancer Eugène Marquis Rennes France
| | - Agnès Delaunay‐Moisan
- Institute for Integrative Biology of the Cell (I2BC) CEA‐Saclay CNRS ISVJC/SBIGEM Laboratoire Stress Oxydant et Cancer Université Paris‐Saclay Gif‐sur‐Yvette France
| | - Laurent Combettes
- UMRS1174 Université Paris Sud Orsay France
- UMRS1174 Institut National de la Santé et de la Recherche Médicale (Inserm) Orsay France
| | - Eric Chevet
- Inserm U1242 University of Rennes France
- Centre de lutte contre le cancer Eugène Marquis Rennes France
| | - Aeid Igbaria
- Inserm U1242 University of Rennes France
- Centre de lutte contre le cancer Eugène Marquis Rennes France
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17
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Laine RF, Sinnige T, Ma KY, Haack AJ, Poudel C, Gaida P, Curry N, Perni M, Nollen EA, Dobson CM, Vendruscolo M, Kaminski Schierle GS, Kaminski CF. Fast Fluorescence Lifetime Imaging Reveals the Aggregation Processes of α-Synuclein and Polyglutamine in Aging Caenorhabditis elegans. ACS Chem Biol 2019; 14:1628-1636. [PMID: 31246415 PMCID: PMC7612977 DOI: 10.1021/acschembio.9b00354] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The nematode worm Caenorhabditis elegans has emerged as an important model organism in the study of the molecular mechanisms of protein misfolding diseases associated with amyloid formation because of its small size, ease of genetic manipulation, and optical transparency. Obtaining a reliable and quantitative read-out of protein aggregation in this system, however, remains a challenge. To address this problem, we here present a fast time-gated fluorescence lifetime imaging (TG-FLIM) method and show that it provides functional insights into the process of protein aggregation in living animals by enabling the rapid characterization of different types of aggregates. Specifically, in longitudinal studies of C. elegans models of Parkinson's and Huntington's diseases, we observed marked differences in the aggregation kinetics and the nature of the protein inclusions formed by α-synuclein and polyglutamine. In particular, we found that α-synuclein inclusions do not display amyloid-like features until late in the life of the worms, whereas polyglutamine forms amyloid characteristics rapidly in early adulthood. Furthermore, we show that the TG-FLIM method is capable of imaging live and non-anaesthetized worms moving in specially designed agarose microchambers. Taken together, our results show that the TG-FLIM method enables high-throughput functional imaging of living C. elegans that can be used to study in vivo mechanisms of protein aggregation and that has the potential to aid the search for therapeutic modifiers of protein aggregation and toxicity.
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Affiliation(s)
- Romain F. Laine
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
| | - Tessa Sinnige
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Kai Yu Ma
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Amanda J. Haack
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
- Molecular Neuroscience Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
| | - Chetan Poudel
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
| | - Peter Gaida
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
| | - Nathan Curry
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
| | - Michele Perni
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Ellen A.A. Nollen
- European Research Institute for the Biology of Ageing, University Medical Centre Groningen, 9700 AD Groningen, The Netherlands
| | - Christopher M. Dobson
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Gabriele S. Kaminski Schierle
- Molecular Neuroscience Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
| | - Clemens F. Kaminski
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, United Kingdom
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18
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Ushioda R, Nagata K. Redox-Mediated Regulatory Mechanisms of Endoplasmic Reticulum Homeostasis. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033910. [PMID: 30396882 DOI: 10.1101/cshperspect.a033910] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The endoplasmic reticulum (ER) is a dynamic organelle responsible for many cellular functions in eukaryotic cells. Proper redox conditions in the ER are necessary for the functions of many luminal pathways and the maintenance of homeostasis. The redox environment in the ER is oxidative compared with that of the cytosol, and a network of oxidoreductases centering on the protein disulfide isomerase (PDI)-Ero1α hub complex is constructed for efficient electron transfer. Although these oxidizing environments are advantageous for oxidative folding for protein maturation, electron transfer is strictly controlled by Ero1α structurally and spatially. The ER redox environment shifts to a reductive environment under certain stress conditions. In this review, we focus on the reducing reactions that maintain ER homeostasis and introduce their significance in an oxidative ER environment.
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Affiliation(s)
- Ryo Ushioda
- Laboratory of Molecular and Cellular Biology, Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Kazuhiro Nagata
- Laboratory of Molecular and Cellular Biology, Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto 603-8555, Japan
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19
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Joseph SK, Booth DM, Young MP, Hajnóczky G. Redox regulation of ER and mitochondrial Ca 2+ signaling in cell survival and death. Cell Calcium 2019; 79:89-97. [PMID: 30889512 DOI: 10.1016/j.ceca.2019.02.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/12/2019] [Accepted: 02/12/2019] [Indexed: 12/16/2022]
Abstract
Physiological signaling by reactive oxygen species (ROS) and their pathophysiological role in cell death are well recognized. This review focuses on two ROS targets that are key to local Ca2+ signaling at the ER/mitochondrial interface - notably, inositol trisphosphate receptors (IP3Rs) and the mitochondrial calcium uniporter (MCU). Both transport systems are central to molecular mechanisms in cell survival and death. Methods for the measurement of the redox state of these proteins and for the detection of ROS nanodomains are described. Recent results on the redox regulation of these proteins are reviewed.
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Affiliation(s)
- Suresh K Joseph
- MitoCare, Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
| | - David M Booth
- MitoCare, Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Michael P Young
- MitoCare, Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - György Hajnóczky
- MitoCare, Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
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20
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Chambers JE, Kubánková M, Huber RG, López-Duarte I, Avezov E, Bond PJ, Marciniak SJ, Kuimova MK. An Optical Technique for Mapping Microviscosity Dynamics in Cellular Organelles. ACS NANO 2018; 12:4398-4407. [PMID: 29648785 DOI: 10.1021/acsnano.8b00177] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Microscopic viscosity (microviscosity) is a key determinant of diffusion in the cell and defines the rate of biological processes occurring at the nanoscale, including enzyme-driven metabolism and protein folding. Here we establish a rotor-based organelle viscosity imaging (ROVI) methodology that enables real-time quantitative mapping of cell microviscosity. This approach uses environment-sensitive dyes termed molecular rotors, covalently linked to genetically encoded probes to provide compartment-specific microviscosity measurements via fluorescence lifetime imaging. ROVI visualized spatial and temporal dynamics of microviscosity with suborganellar resolution, reporting on a microviscosity difference of nearly an order of magnitude between subcellular compartments. In the mitochondrial matrix, ROVI revealed several striking findings: a broad heterogeneity of microviscosity among individual mitochondria, unparalleled resilience to osmotic stress, and real-time changes in microviscosity during mitochondrial depolarization. These findings demonstrate the use of ROVI to explore the biophysical mechanisms underlying cell biological processes.
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Affiliation(s)
- Joseph E Chambers
- Cambridge Institute for Medical Research (CIMR), Department of Medicine , University of Cambridge , Wellcome Trust/MRC Building, Hills Road , Cambridge , CB2 0XY , United Kingdom
| | - Markéta Kubánková
- Department of Chemistry , Imperial College London , South Kensington , London , SW7 2AZ , United Kingdom
| | - Roland G Huber
- Bioinformatics Institute (BII) , Agency for Science, Technology, and Research (A*STAR) , Matrix 07-01, 30 Biopolis Street , 138671 Singapore
| | - Ismael López-Duarte
- Department of Chemistry , Imperial College London , South Kensington , London , SW7 2AZ , United Kingdom
| | - Edward Avezov
- UK Dementia Research Institute at the University of Cambridge , Cambridge Biomedical Campus, Cambridge CB2 0AH , United Kingdom
| | - Peter J Bond
- Bioinformatics Institute (BII) , Agency for Science, Technology, and Research (A*STAR) , Matrix 07-01, 30 Biopolis Street , 138671 Singapore
- Department of Biological Sciences , National University of Singapore , 14 Science Drive 4 , 117543 Singapore
| | - Stefan J Marciniak
- Cambridge Institute for Medical Research (CIMR), Department of Medicine , University of Cambridge , Wellcome Trust/MRC Building, Hills Road , Cambridge , CB2 0XY , United Kingdom
| | - Marina K Kuimova
- Department of Chemistry , Imperial College London , South Kensington , London , SW7 2AZ , United Kingdom
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21
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Arunagiri A, Haataja L, Cunningham CN, Shrestha N, Tsai B, Qi L, Liu M, Arvan P. Misfolded proinsulin in the endoplasmic reticulum during development of beta cell failure in diabetes. Ann N Y Acad Sci 2018; 1418:5-19. [PMID: 29377149 DOI: 10.1111/nyas.13531] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/14/2017] [Accepted: 09/25/2017] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) is broadly distributed throughout the cytoplasm of pancreatic beta cells, and this is where all proinsulin is initially made. Healthy beta cells can synthesize 6000 proinsulin molecules per second. Ordinarily, nascent proinsulin entering the ER rapidly folds via the formation of three evolutionarily conserved disulfide bonds (B7-A7, B19-A20, and A6-A11). A modest amount of proinsulin misfolding, including both intramolecular disulfide mispairing and intermolecular disulfide-linked protein complexes, is a natural by-product of proinsulin biosynthesis, as is the case for many proteins. The steady-state level of misfolded proinsulin-a potential ER stressor-is linked to (1) production rate, (2) ER environment, (3) presence or absence of naturally occurring (mutational) defects in proinsulin, and (4) clearance of misfolded proinsulin molecules. Accumulation of misfolded proinsulin beyond a certain threshold begins to interfere with the normal intracellular transport of bystander proinsulin, leading to diminished insulin production and hyperglycemia, as well as exacerbating ER stress. This is most obvious in mutant INS gene-induced Diabetes of Youth (MIDY; an autosomal dominant disease) but also likely to occur in type 2 diabetes owing to dysregulation in proinsulin synthesis, ER folding environment, or clearance.
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Affiliation(s)
- Anoop Arunagiri
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan
| | - Corey N Cunningham
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan
| | - Neha Shrestha
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan
| | - Ling Qi
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Ming Liu
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan.,Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan
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22
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Delaunay-Moisan A, Ponsero A, Toledano MB. Reexamining the Function of Glutathione in Oxidative Protein Folding and Secretion. Antioxid Redox Signal 2017; 27:1178-1199. [PMID: 28791880 DOI: 10.1089/ars.2017.7148] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SIGNIFICANCE Disturbance of glutathione (GSH) metabolism is a hallmark of numerous diseases, yet GSH functions are poorly understood. One key to this question is to consider its functional compartmentation. GSH is present in the endoplasmic reticulum (ER), where it competes with substrates for oxidation by the oxidative folding machinery, composed in eukaryotes of the thiol oxidase Ero1 and proteins from the disulfide isomerase family (protein disulfide isomerase). Yet, whether GSH is required for proper ER oxidative protein folding is a highly debated question. Recent Advances: Oxidative protein folding has been thoroughly dissected over the past decades, and its actors and their mode of action elucidated. Genetically encoded GSH probes have recently provided an access to subcellular redox metabolism, including the ER. CRITICAL ISSUES Of the few often-contradictory models of the role of GSH in the ER, the most popular suggest it serves as reducing power. Yet, as a reductant, GSH also activates Ero1, which questions how GSH can nevertheless support protein reduction. Hence, whether GSH operates in the ER as a reductant, an oxidant, or just as a "blank" compound mirroring ER/periplasm redox activity is a highly debated question, which is further stimulated by the puzzling occurrence of GSH in the Escherichia coli periplasmic "secretory" compartment, aside from the Dsb thiol-reducing and oxidase pathways. FUTURE DIRECTIONS Addressing the mechanisms controlling GSH traffic in and out of the ER/periplasm and its recycling will help address GSH function in secretion. In addition, as thioredoxin reductase was recently implicated in ER oxidative protein folding, the relative contribution of each of these two reducing pathways should now be addressed. Antioxid. Redox Signal. 27, 1178-1199.
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Affiliation(s)
- Agnès Delaunay-Moisan
- Institute for Integrative Biology of the Cell (I2BC), LSOC, SBIGEM, CEA, CNRS, Université Paris-Sud , Université Paris-Saclay, Gif-sur-Yvette, France
| | - Alise Ponsero
- Institute for Integrative Biology of the Cell (I2BC), LSOC, SBIGEM, CEA, CNRS, Université Paris-Sud , Université Paris-Saclay, Gif-sur-Yvette, France
| | - Michel B Toledano
- Institute for Integrative Biology of the Cell (I2BC), LSOC, SBIGEM, CEA, CNRS, Université Paris-Sud , Université Paris-Saclay, Gif-sur-Yvette, France
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23
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Abstract
Cysteine thiols are among the most reactive functional groups in proteins, and their pairing in disulfide linkages is a common post-translational modification in proteins entering the secretory pathway. This modest amino acid alteration, the mere removal of a pair of hydrogen atoms from juxtaposed cysteine residues, contrasts with the substantial changes that characterize most other post-translational reactions. However, the wide variety of proteins that contain disulfides, the profound impact of cross-linking on the behavior of the protein polymer, the numerous and diverse players in intracellular pathways for disulfide formation, and the distinct biological settings in which disulfide bond formation can take place belie the simplicity of the process. Here we lay the groundwork for appreciating the mechanisms and consequences of disulfide bond formation in vivo by reviewing chemical principles underlying cysteine pairing and oxidation. We then show how enzymes tune redox-active cofactors and recruit oxidants to improve the specificity and efficiency of disulfide formation. Finally, we discuss disulfide bond formation in a cellular context and identify important principles that contribute to productive thiol oxidation in complex, crowded, dynamic environments.
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Affiliation(s)
- Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Colin Thorpe
- Department of Chemistry and Biochemistry, University of Delaware , Newark, Delaware 19716, United States
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24
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Macedo JA, Schrama D, Duarte I, Tavares E, Renaut J, Futschik ME, Rodrigues PM, Melo EP. Membrane-enriched proteome changes and prion protein expression during neural differentiation and in neuroblastoma cells. BMC Genomics 2017; 18:319. [PMID: 28431525 PMCID: PMC5401558 DOI: 10.1186/s12864-017-3694-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 04/08/2017] [Indexed: 01/12/2023] Open
Abstract
Background The function of the prion protein, involved in the so-called prion diseases, remains a subject of intense debate and the possibility that it works as a pleiotropic protein through the interaction with multiple membrane proteins is somehow supported by recent reports. Therefore, the use of proteomic and bioinformatics combined to uncover cellular processes occurring together with changes in the expression of the prion protein may provide further insight into the putative pleiotropic role of the prion protein. Results This study assessed the membrane-enriched proteome changes accompanying alterations in the expression of the prion protein. A 2D-DIGE approach was applied to two cell lines after prefractionation towards the membrane protein subset: an embryonic stem cell line and the PK1 subline of neuroblastoma cells which efficiently propagates prion infection. Several proteins were differentially abundant with the increased expression of the prion protein during neural differentiation of embryonic stem cells and with the knockdown of the prion protein in PK1 cells. The identity of around 20% of the differentially abundant proteins was obtained by tandem MS. The catalytic subunit A of succinate dehydrogenase, a key enzyme for the aerobic energy metabolism and redox homeostasis, showed a similar abundance trend as the prion protein in both proteomic experiments. A gene ontology analysis revealed “myelin sheath”, “organelle membrane” and “focal adhesion” associated proteins as the main cellular components, and “protein folding” and “ATPase activity” as the biological processes enriched in the first set of differentially abundant proteins. The known interactome of these differentially abundant proteins was customized to reveal four interactors with the prion protein, including two heat shock proteins and a protein disulfide isomerase. Conclusions Overall, our study shows that expression of the prion protein occurs concomitantly with changes in chaperone activity and cell-redox homeostasis, emphasizing the functional link between these cellular processes and the prion protein. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3694-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- J A Macedo
- CBMR, Center for Biomedical Research, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - D Schrama
- CCMAR, Centre of Marine Sciences of Algarve, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - I Duarte
- CBMR, Center for Biomedical Research, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - E Tavares
- CBMR, Center for Biomedical Research, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - J Renaut
- LIST, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg
| | - M E Futschik
- CCMAR, Centre of Marine Sciences of Algarve, University of Algarve, Campus de Gambelas, Faro, Portugal.,School of Biomedical & Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK
| | - P M Rodrigues
- CCMAR, Centre of Marine Sciences of Algarve, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - E P Melo
- CBMR, Center for Biomedical Research, University of Algarve, Campus de Gambelas, Faro, Portugal.
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25
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Koizume S, Miyagi Y. Potential Coagulation Factor-Driven Pro-Inflammatory Responses in Ovarian Cancer Tissues Associated with Insufficient O₂ and Plasma Supply. Int J Mol Sci 2017; 18:ijms18040809. [PMID: 28417928 PMCID: PMC5412393 DOI: 10.3390/ijms18040809] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/05/2017] [Accepted: 04/06/2017] [Indexed: 02/07/2023] Open
Abstract
Tissue factor (TF) is a cell surface receptor for coagulation factor VII (fVII). The TF-activated fVII (fVIIa) complex is an essential initiator of the extrinsic blood coagulation process. Interactions between cancer cells and immune cells via coagulation factors and adhesion molecules can promote progression of cancer, including epithelial ovarian cancer (EOC). This process is not necessarily advantageous, as tumor tissues generally undergo hypoxia due to aberrant vasculature, followed by reduced access to plasma components such as coagulation factors. However, hypoxia can activate TF expression. Expression of fVII, intercellular adhesion molecule-1 (ICAM-1), and multiple pro-inflammatory cytokines can be synergistically induced in EOC cells in response to hypoxia along with serum deprivation. Thus, pro-inflammatory responses associated with the TF-fVIIa-ICAM-1 interaction are expected within hypoxic tissues. Tumor tissue consists of multiple components such as stromal cells, interstitial fluid, albumin, and other micro-factors such as proton and metal ions. These factors, together with metabolism reprogramming in response to hypoxia and followed by functional modification of TF, may contribute to coagulation factor-driven inflammatory responses in EOC tissues. The aim of this review was to describe potential coagulation factor-driven inflammatory responses in hypoxic EOC tissues. Arguments were extended to clinical issues targeting this characteristic tumor environment.
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Affiliation(s)
- Shiro Koizume
- Molecular Pathology and Genetics Division, Kanagawa Cancer Center Research Institute, 2-3-2 Nakao, Asahi-ku, Yokohama 241-8515, Japan.
| | - Yohei Miyagi
- Molecular Pathology and Genetics Division, Kanagawa Cancer Center Research Institute, 2-3-2 Nakao, Asahi-ku, Yokohama 241-8515, Japan.
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26
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Melo EP, Lopes C, Gollwitzer P, Lortz S, Lenzen S, Mehmeti I, Kaminski CF, Ron D, Avezov E. TriPer, an optical probe tuned to the endoplasmic reticulum tracks changes in luminal H 2O 2. BMC Biol 2017; 15:24. [PMID: 28347335 PMCID: PMC5368998 DOI: 10.1186/s12915-017-0367-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 03/14/2017] [Indexed: 11/27/2022] Open
Abstract
Background The fate of hydrogen peroxide (H2O2) in the endoplasmic reticulum (ER) has been inferred indirectly from the activity of ER-localized thiol oxidases and peroxiredoxins, in vitro, and the consequences of their genetic manipulation, in vivo. Over the years hints have suggested that glutathione, puzzlingly abundant in the ER lumen, might have a role in reducing the heavy burden of H2O2 produced by the luminal enzymatic machinery for disulfide bond formation. However, limitations in existing organelle-targeted H2O2 probes have rendered them inert in the thiol-oxidizing ER, precluding experimental follow-up of glutathione’s role in ER H2O2 metabolism. Results Here we report on the development of TriPer, a vital optical probe sensitive to changes in the concentration of H2O2 in the thiol-oxidizing environment of the ER. Consistent with the hypothesized contribution of oxidative protein folding to H2O2 production, ER-localized TriPer detected an increase in the luminal H2O2 signal upon induction of pro-insulin (a disulfide-bonded protein of pancreatic β-cells), which was attenuated by the ectopic expression of catalase in the ER lumen. Interfering with glutathione production in the cytosol by buthionine sulfoximine (BSO) or enhancing its localized destruction by expression of the glutathione-degrading enzyme ChaC1 in the lumen of the ER further enhanced the luminal H2O2 signal and eroded β-cell viability. Conclusions A tri-cysteine system with a single peroxidatic thiol enables H2O2 detection in oxidizing milieux such as that of the ER. Tracking ER H2O2 in live pancreatic β-cells points to a role for glutathione in H2O2 turnover. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0367-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eduardo Pinho Melo
- University of Cambridge, Cambridge Institute for Medical Research, the Wellcome Trust MRC Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK.,Centre for Biomedical Research, Universidade do Algarve, Faro, Portugal
| | - Carlos Lopes
- Centre for Biomedical Research, Universidade do Algarve, Faro, Portugal
| | - Peter Gollwitzer
- University of Cambridge, Cambridge Institute for Medical Research, the Wellcome Trust MRC Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - Stephan Lortz
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, 30625, Germany
| | - Sigurd Lenzen
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, 30625, Germany
| | - Ilir Mehmeti
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, 30625, Germany
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB2 3RA, UK
| | - David Ron
- University of Cambridge, Cambridge Institute for Medical Research, the Wellcome Trust MRC Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK.
| | - Edward Avezov
- University of Cambridge, Cambridge Institute for Medical Research, the Wellcome Trust MRC Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK.
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27
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ER-luminal thiol/selenol-mediated regulation of Ca2+ signalling. Biochem Soc Trans 2016; 44:452-9. [PMID: 27068954 DOI: 10.1042/bst20150233] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Indexed: 01/05/2023]
Abstract
The endoplasmic reticulum (ER) is the main cellular Ca(2+)storage unit. Among other signalling outputs, the ER can release Ca(2+)ions, which can, for instance, communicate the status of ER protein folding to the cytosol and to other organelles, in particular the mitochondria. As a consequence, ER Ca(2+)flux can alter the apposition of the ER with mitochondria, influence mitochondrial ATP production or trigger apoptosis. All aspects of ER Ca(2+)flux have emerged as processes that are intimately controlled by intracellular redox conditions. In this review, we focus on ER-luminal redox-driven regulation of Ca(2+)flux. This involves the direct reduction of disulfides within ER Ca(2+)handling proteins themselves, but also the regulated interaction of ER chaperones and oxidoreductases such as calnexin or ERp57 with them. Well-characterized examples are the activating interactions of Ero1α with inositol 1,4,5-trisphosphate receptors (IP3Rs) or of selenoprotein N (SEPN1) with sarco/endoplasmic reticulum Ca(2+)transport ATPase 2 (SERCA2). The future discovery of novel ER-luminal modulators of Ca(2+)handling proteins is likely. Based on the currently available information, we describe how the variable ER redox conditions govern Ca(2+)flux from the ER.
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28
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Soares Moretti AI, Martins Laurindo FR. Protein disulfide isomerases: Redox connections in and out of the endoplasmic reticulum. Arch Biochem Biophys 2016; 617:106-119. [PMID: 27889386 DOI: 10.1016/j.abb.2016.11.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/08/2016] [Accepted: 11/21/2016] [Indexed: 12/13/2022]
Abstract
Protein disulfide isomerases are thiol oxidoreductase chaperones from thioredoxin superfamily. As redox folding catalysts from the endoplasmic reticulum (ER), their roles in ER-related redox homeostasis and signaling are well-studied. PDIA1 exerts thiol oxidation/reduction and isomerization, plus chaperone effects. Also, substantial evidence indicates that PDIs regulate thiol-disulfide switches in other cell locations such as cell surface and possibly cytosol. Subcellular PDI translocation routes remain unclear and seem Golgi-independent. The list of signaling and structural proteins reportedly regulated by PDIs keeps growing, via thiol switches involving oxidation, reduction and isomerization, S-(de)nytrosylation, (de)glutathyonylation and protein oligomerization. PDIA1 is required for agonist-triggered Nox NADPH oxidase activation and cell migration in vascular cells and macrophages, while PDIA1-dependent cytoskeletal regulation appears a converging pathway. Extracellularly, PDIs crucially regulate thiol redox signaling of thrombosis/platelet activation, e.g., integrins, and PDIA1 supports expansive caliber remodeling during injury repair via matrix/cytoskeletal organization. Some proteins display regulatory PDI-like motifs. PDI effects are orchestrated by expression levels or post-translational modifications. PDI is redox-sensitive, although probably not a mass-effect redox sensor due to kinetic constraints. Rather, the "all-in-one" organization of its peculiar redox/chaperone properties likely provide PDIs with precision and versatility in redox signaling, making them promising therapeutic targets.
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Affiliation(s)
- Ana Iochabel Soares Moretti
- Vascular Biology Laboratory, Heart Institute (InCor), University of São Paulo, School of Medicine, São Paulo, Brazil
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29
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Redox-assisted regulation of Ca2+ homeostasis in the endoplasmic reticulum by disulfide reductase ERdj5. Proc Natl Acad Sci U S A 2016; 113:E6055-E6063. [PMID: 27694578 DOI: 10.1073/pnas.1605818113] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Calcium ion (Ca2+) is an important second messenger that regulates numerous cellular functions. Intracellular Ca2+ concentration ([Ca2+]i) is strictly controlled by Ca2+ channels and pumps on the endoplasmic reticulum (ER) and plasma membranes. The ER calcium pump, sarco/endoplasmic reticulum calcium ATPase (SERCA), imports Ca2+ from the cytosol into the ER in an ATPase activity-dependent manner. The activity of SERCA2b, the ubiquitous isoform of SERCA, is negatively regulated by disulfide bond formation between two luminal cysteines. Here, we show that ERdj5, a mammalian ER disulfide reductase, which we reported to be involved in the ER-associated degradation of misfolded proteins, activates the pump function of SERCA2b by reducing its luminal disulfide bond. Notably, ERdj5 activated SERCA2b at a lower ER luminal [Ca2+] ([Ca2+]ER), whereas a higher [Ca2+]ER induced ERdj5 to form oligomers that were no longer able to interact with the pump, suggesting [Ca2+]ER-dependent regulation. Binding Ig protein, an ER-resident molecular chaperone, exerted a regulatory role in the oligomerization by binding to the J domain of ERdj5. These results identify ERdj5 as one of the master regulators of ER calcium homeostasis and thus shed light on the importance of cross talk among redox, Ca2+, and protein homeostasis in the ER.
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30
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Booth DM, Joseph SK, Hajnóczky G. Subcellular ROS imaging methods: Relevance for the study of calcium signaling. Cell Calcium 2016; 60:65-73. [PMID: 27209367 DOI: 10.1016/j.ceca.2016.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 05/02/2016] [Accepted: 05/03/2016] [Indexed: 12/20/2022]
Abstract
Recent advances in genetically encoded fluorescent probes have dramatically increased the toolkit available for imaging the intracellular environment. Perhaps the biggest improvements have been made in sensing specific reactive oxygen species (ROS) and redox changes under physiological conditions. The new generation of probes may be targeted to a wide range of subcellular environments. By targeting such probes to compartments and organelle surfaces they may be exposed to environments, which support local signal transduction and regulation. The close apposition of the endoplasmic reticulum (ER) with mitochondria and other organelles forms such a local environment where Ca(2+) dynamics are greatly enhanced compared to the bulk cytosol. We describe here how newly developed genetically encoded redox indicators (GERIs) might be used to monitor ROS and probe their interaction with Ca(2+) at both global and local level.
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Affiliation(s)
- David M Booth
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
| | - Suresh K Joseph
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - György Hajnóczky
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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31
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Development of a stable ERroGFP variant suitable for monitoring redox dynamics in the ER. Biosci Rep 2016; 36:BSR20160027. [PMID: 26934978 PMCID: PMC4832336 DOI: 10.1042/bsr20160027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 02/16/2016] [Indexed: 12/16/2022] Open
Abstract
We have created ERroGFP-S4, a novel ER redox probe suitable for monitoring redox dynamics in the oxidative environment of the ER. ERroGFP-S4 can be used for detection of aberrant ER redox states related to various physiological and pathological conditions. The endoplasmic reticulum (ER) is an essential organelle for cellular metabolic homeostasis including folding and maturation of secretory and membrane proteins. Disruption of ER proteostasis has been implicated in the pathogenesis of various diseases such as diabetes and neurodegenerative diseases. The ER redox state, which is an oxidative environment suitable for disulfide-bond formation, is essential for ER protein quality control. Hence, detection of the ER redox state, especially in living cells, is essential to understand the mechanism by which the redox state of the ER is maintained. However, methods to detect the redox state of the ER have not been well-established because of inefficient folding and stability of roGFP variants with oxidative redox potential like roGFP-iL. Here we have improved the folding efficiency of ER-targeted roGFP-iL (ERroGFP-iL) in cells by introducing superfolder GFP (sfGFP) mutations. Four specific amino acid substitutions (S30R, Y39N, T105N and I171V) greatly improved folding efficiency in Escherichia coli and in the ER of HeLa cells, as well as the thermostability of the purified proteins. Introduction of these mutations also enhanced the dynamic range for redox change both in vitro and in the ER of living cells. ER-targeted roGFP-S4 (ERroGFP-S4) possessing these four mutations could detect physiological redox changes within the ER. ERroGFP-S4 is therefore a novel probe suitable for monitoring redox change in the ER. ERroGFP-S4 can be applied to detect aberrant ER redox states associated with various pathological conditions and to identify the mechanisms used to maintain the redox state of the ER.
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32
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Konno T, Pinho Melo E, Lopes C, Mehmeti I, Lenzen S, Ron D, Avezov E. ERO1-independent production of H2O2 within the endoplasmic reticulum fuels Prdx4-mediated oxidative protein folding. J Cell Biol 2016; 211:253-9. [PMID: 26504166 PMCID: PMC4621842 DOI: 10.1083/jcb.201506123] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Tracking the kinetics of equilibration of H2O2 between compartments reveals unexpected isolation of the endoplasmic reticulum and hints at a hitherto unsuspected local source of peroxide. The endoplasmic reticulum (ER)–localized peroxiredoxin 4 (PRDX4) supports disulfide bond formation in eukaryotic cells lacking endoplasmic reticulum oxidase 1 (ERO1). The source of peroxide that fuels PRDX4-mediated disulfide bond formation has remained a mystery, because ERO1 is believed to be a major producer of hydrogen peroxide (H2O2) in the ER lumen. We report on a simple kinetic technique to track H2O2 equilibration between cellular compartments, suggesting that the ER is relatively isolated from cytosolic or mitochondrial H2O2 pools. Furthermore, expression of an ER-adapted catalase to degrade lumenal H2O2 attenuated PRDX4-mediated disulfide bond formation in cells lacking ERO1, whereas depletion of H2O2 in the cytosol or mitochondria had no similar effect. ER catalase did not effect the slow residual disulfide bond formation in cells lacking both ERO1 and PRDX4. These observations point to exploitation of a hitherto unrecognized lumenal source of H2O2 by PRDX4 and a parallel slow H2O2-independent pathway for disulfide formation.
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Affiliation(s)
- Tasuku Konno
- University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust Medical Research Council Institute of Metabolic Science and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, CB2 0XY, UK
| | - Eduardo Pinho Melo
- Center for Biomedical Research, Universidade do Algarve, Faro, Portugal 8005-139
| | - Carlos Lopes
- Center for Biomedical Research, Universidade do Algarve, Faro, Portugal 8005-139
| | - Ilir Mehmeti
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Sigurd Lenzen
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - David Ron
- University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust Medical Research Council Institute of Metabolic Science and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, CB2 0XY, UK
| | - Edward Avezov
- University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust Medical Research Council Institute of Metabolic Science and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, CB2 0XY, UK
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33
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Kitamura A, Nagata K, Kinjo M. Conformational analysis of misfolded protein aggregation by FRET and live-cell imaging techniques. Int J Mol Sci 2015; 16:6076-92. [PMID: 25785563 PMCID: PMC4394520 DOI: 10.3390/ijms16036076] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/05/2015] [Accepted: 03/11/2015] [Indexed: 12/18/2022] Open
Abstract
Cellular homeostasis is maintained by several types of protein machinery, including molecular chaperones and proteolysis systems. Dysregulation of the proteome disrupts homeostasis in cells, tissues, and the organism as a whole, and has been hypothesized to cause neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD). A hallmark of neurodegenerative disorders is formation of ubiquitin-positive inclusion bodies in neurons, suggesting that the aggregation process of misfolded proteins changes during disease progression. Hence, high-throughput determination of soluble oligomers during the aggregation process, as well as the conformation of sequestered proteins in inclusion bodies, is essential for elucidation of physiological regulation mechanism and drug discovery in this field. To elucidate the interaction, accumulation, and conformation of aggregation-prone proteins, in situ spectroscopic imaging techniques, such as Förster/fluorescence resonance energy transfer (FRET), fluorescence correlation spectroscopy (FCS), and bimolecular fluorescence complementation (BiFC) have been employed. Here, we summarize recent reports in which these techniques were applied to the analysis of aggregation-prone proteins (in particular their dimerization, interactions, and conformational changes), and describe several fluorescent indicators used for real-time observation of physiological states related to proteostasis.
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Affiliation(s)
- Akira Kitamura
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.
| | - Kazuhiro Nagata
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan.
| | - Masataka Kinjo
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.
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