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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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Bkaily G, Jacques D. Calcium Homeostasis, Transporters, and Blockers in Health and Diseases of the Cardiovascular System. Int J Mol Sci 2023; 24:ijms24108803. [PMID: 37240147 DOI: 10.3390/ijms24108803] [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: 02/21/2023] [Revised: 05/06/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Calcium is a highly positively charged ionic species. It regulates all cell types' functions and is an important second messenger that controls and triggers several mechanisms, including membrane stabilization, permeability, contraction, secretion, mitosis, intercellular communications, and in the activation of kinases and gene expression. Therefore, controlling calcium transport and its intracellular homeostasis in physiology leads to the healthy functioning of the biological system. However, abnormal extracellular and intracellular calcium homeostasis leads to cardiovascular, skeletal, immune, secretory diseases, and cancer. Therefore, the pharmacological control of calcium influx directly via calcium channels and exchangers and its outflow via calcium pumps and uptake by the ER/SR are crucial in treating calcium transport remodeling in pathology. Here, we mainly focused on selective calcium transporters and blockers in the cardiovascular system.
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Affiliation(s)
- Ghassan Bkaily
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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3
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Dixon RE, Trimmer JS. Endoplasmic Reticulum-Plasma Membrane Junctions as Sites of Depolarization-Induced Ca 2+ Signaling in Excitable Cells. Annu Rev Physiol 2023; 85:217-243. [PMID: 36202100 PMCID: PMC9918718 DOI: 10.1146/annurev-physiol-032122-104610] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane contact sites between endoplasmic reticulum (ER) and plasma membrane (PM), or ER-PM junctions, are found in all eukaryotic cells. In excitable cells they play unique roles in organizing diverse forms of Ca2+ signaling as triggered by membrane depolarization. ER-PM junctions underlie crucial physiological processes such as excitation-contraction coupling, smooth muscle contraction and relaxation, and various forms of activity-dependent signaling and plasticity in neurons. In many cases the structure and molecular composition of ER-PM junctions in excitable cells comprise important regulatory feedback loops linking depolarization-induced Ca2+ signaling at these sites to the regulation of membrane potential. Here, we describe recent findings on physiological roles and molecular composition of native ER-PM junctions in excitable cells. We focus on recent studies that provide new insights into canonical forms of depolarization-induced Ca2+ signaling occurring at junctional triads and dyads of striated muscle, as well as the diversity of ER-PM junctions in these cells and in smooth muscle and neurons.
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Affiliation(s)
- Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
| | - James S Trimmer
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
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Paschou M, Liaropoulou D, Kalaitzaki V, Efthimiopoulos S, Papazafiri P. Knockdown of Amyloid Precursor Protein Increases Ion Channel Expression and Alters Ca 2+ Signaling Pathways. Int J Mol Sci 2023; 24:ijms24032302. [PMID: 36768625 PMCID: PMC9917207 DOI: 10.3390/ijms24032302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
Although the physiological role of the full-length Amyloid Precursor Protein (APP) and its proteolytic fragments remains unclear, they are definitively crucial for normal synaptic function. Herein, we report that the downregulation of APP in SH-SY5Y cells, using short hairpin RNA (shRNA), alters the expression pattern of several ion channels and signaling proteins that are involved in synaptic and Ca2+ signaling. Specifically, the levels of GluR2 and GluR4 subunits of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptors (AMPAR) were significantly increased with APP knockdown. Similarly, the expression of the majority of endoplasmic reticulum (ER) residing proteins, such as the ER Ca2+ channels IP3R (Inositol 1,4,5-triphosphate Receptor) and RyR (Ryanodine Receptor), the Ca2+ pump SERCA2 (Sarco/endoplasmic reticulum Ca2+ ATPase 2) and the ER Ca2+ sensor STIM1 (Stromal Interaction Molecule 1) was upregulated. A shift towards the upregulation of p-AKT, p-PP2A, and p-CaMKIV and the downregulation of p-GSK, p-ERK1/2, p-CaMKII, and p-CREB was observed, interconnecting Ca2+ signal transduction from the plasma membrane and ER to the nucleus. Interestingly, we detected reduced responses to several physiological stimuli, with the most prominent being the ineffectiveness of SH-SY5Y/APP- cells to mobilize Ca2+ from the ER upon carbachol-induced Ca2+ release through IP3Rs and RyRs. Our data further support an emerging yet perplexing role of APP within a functional molecular network of membrane and cytoplasmic proteins implicated in Ca2+ signaling.
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Affiliation(s)
- Maria Paschou
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - Danai Liaropoulou
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - Vasileia Kalaitzaki
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
- Institute of Laboratory Animal Science, University of Zurich, 8952 Schlieren, Switzerland
| | - Spiros Efthimiopoulos
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
- Correspondence: (S.E.); (P.P.)
| | - Panagiota Papazafiri
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
- Correspondence: (S.E.); (P.P.)
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5
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The basis of nuclear phospholipase C in cell proliferation. Adv Biol Regul 2021; 82:100834. [PMID: 34710785 DOI: 10.1016/j.jbior.2021.100834] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/17/2021] [Accepted: 10/21/2021] [Indexed: 11/23/2022]
Abstract
Ca2+ is a highly versatile intracellular signal that regulates many biological processes such as cell death and proliferation. Broad Ca2+-signaling machinery is used to assemble signaling systems with a precise spatial and temporal resolution to achieve this versatility. Ca2+-signaling components can be organized in different regions of the cell and local increases in Ca2+ within the nucleus can regulate different cellular functions from the increases in cytosolic Ca2+. However, the mechanisms and pathways that promote localized increases in Ca2+ levels in the nucleus are still under investigation. This review presents evidence that the nucleus has its own Ca2+ stores and signaling machinery, which modulate processes such as cell proliferation and tumor growth. We focus on what is known about the functions of nuclear Phospholipase C (PLC) in the generation of nuclear Ca2+ transients that are involved in cell proliferation.
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Role of IP3 Receptors in Shaping the Carotid Chemoreceptor Response to Hypoxia But Not to Hypercapnia in the Rat Carotid Body: An Evidence Review. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 32767266 DOI: 10.1007/5584_2020_561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
This article addresses the disparity in the transduction pathways for hypoxic and hypercapnic stimuli in carotid body glomus cells. We investigated and reviewed the experimental evidence showing that the response to hypoxia, but not to hypercapnia, is mediated by 1,4,5-inositol triphosphate receptors (IP3R/s) regulating the intracellular calcium content [Ca2+]c in glomus cells. The rationale was based on the past observations that inhibition of oxidative phosphorylation leads to the explicit inhibition of the hypoxic chemoreflex. [Ca2+]c changes were measured using cellular Ca2+-sensitive fluorescent probes, and carotid sinus nerve (CSN) sensory discharge was recorded with bipolar electrodes in in vitro perfused-superfused rat carotid body preparations. The cell-permeant, 2-amino-ethoxy-diphenyl-borate (2-APB; 100 μM) and curcumin (50 μM) were used as the inhibitors of IP3R/s. These agents suppressed the [Ca2+]c, and CSN discharge increases in hypoxia but not in hypercapnia, leading to the conclusion that only the hypoxic effects were mediated via modulation of IP3R/s. The ATP-induced Ca2+ release from intracellular stores in a Ca2+-free medium was blocked with 2-APB, supporting this conclusion.
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7
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Chami M, Checler F. Alterations of the Endoplasmic Reticulum (ER) Calcium Signaling Molecular Components in Alzheimer's Disease. Cells 2020; 9:cells9122577. [PMID: 33271984 PMCID: PMC7760721 DOI: 10.3390/cells9122577] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/18/2020] [Accepted: 11/30/2020] [Indexed: 02/07/2023] Open
Abstract
Sustained imbalance in intracellular calcium (Ca2+) entry and clearance alters cellular integrity, ultimately leading to cellular homeostasis disequilibrium and cell death. Alzheimer’s disease (AD) is the most common cause of dementia. Beside the major pathological features associated with AD-linked toxic amyloid beta (Aβ) and hyperphosphorylated tau (p-tau), several studies suggested the contribution of altered Ca2+ handling in AD development. These studies documented physical or functional interactions of Aβ with several Ca2+ handling proteins located either at the plasma membrane or in intracellular organelles including the endoplasmic reticulum (ER), considered the major intracellular Ca2+ pool. In this review, we describe the cellular components of ER Ca2+ dysregulations likely responsible for AD. These include alterations of the inositol 1,4,5-trisphosphate receptors’ (IP3Rs) and ryanodine receptors’ (RyRs) expression and function, dysfunction of the sarco-endoplasmic reticulum Ca2+ ATPase (SERCA) activity and upregulation of its truncated isoform (S1T), as well as presenilin (PS1, PS2)-mediated ER Ca2+ leak/ER Ca2+ release potentiation. Finally, we highlight the functional consequences of alterations of these ER Ca2+ components in AD pathology and unravel the potential benefit of targeting ER Ca2+ homeostasis as a tool to alleviate AD pathogenesis.
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Affiliation(s)
- Mounia Chami
- Correspondence: ; Tel.: +33-4939-53457; Fax: +33-4939-53408
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8
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Zhou Y, Wang W, Salauddin NM, Lin L, You M, You S, Yuchi Z. Crystal structure of the N-terminal domain of ryanodine receptor from the honeybee, Apis mellifera. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 125:103454. [PMID: 32781205 DOI: 10.1016/j.ibmb.2020.103454] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/24/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Ryanodine receptors (RyRs) are the molecular target of diamides, a new chemical class of insecticides. Diamide insecticides are used to control lepidopteran pests and were considered relatively safe for mammals and non-targeted beneficial insects, including honey bees. However, recent studies showed that exposure to diamides could cause long-lasting locomotor deficits of bees. Here we report the crystal structure of RyR N-terminal domain A (NTD-A) from the honeybee, Apis mellifera, at 2.5 Å resolution. It shows a similar overall fold as the RyR NTD-A from mammals and the diamondback moth (DBM), Plutella xylostella, and still several loops located at the inter-domain interfaces show insect-specific or bee-specific structural features. A potential insecticide-binding pocket formed by loop9 and loop13 is conserved in lepidopteran but different in both mammals and bees, making it a good candidate targeting site for the development of pest-selective insecticides. Furthermore, a conserved intra-domain disulfide bond was observed in both DBM and bee RyR NTD-A crystal structures, which explains their higher thermal stability compared to mammalian RyR NTD-A. This work provides a basis for the development of novel insecticides with better selectivity between pests and bees by targeting a distinct site on pest RyRs, which would be a promising strategy to overcome the current toxicity problem.
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Affiliation(s)
- Yuanyuan Zhou
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002, China
| | - Wenlan Wang
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Nahiyan Mohammad Salauddin
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Lianyun Lin
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Minsheng You
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002, China
| | - Shijun You
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002, China.
| | - Zhiguang Yuchi
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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Noyer L, Lemonnier L, Mariot P, Gkika D. Partners in Crime: Towards New Ways of Targeting Calcium Channels. Int J Mol Sci 2019; 20:ijms20246344. [PMID: 31888223 PMCID: PMC6940757 DOI: 10.3390/ijms20246344] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/05/2019] [Accepted: 12/13/2019] [Indexed: 12/16/2022] Open
Abstract
The characterization of calcium channel interactome in the last decades opened a new way of perceiving ion channel function and regulation. Partner proteins of ion channels can now be considered as major components of the calcium homeostatic mechanisms, while the reinforcement or disruption of their interaction with the channel units now represents an attractive target in research and therapeutics. In this review we will focus on the targeting of calcium channel partner proteins in order to act on the channel activity, and on its consequences for cell and organism physiology. Given the recent advances in the partner proteins’ identification, characterization, as well as in the resolution of their interaction domain structures, we will develop the latest findings on the interacting proteins of the following channels: voltage-dependent calcium channels, transient receptor potential and ORAI channels, and inositol 1,4,5-trisphosphate receptor.
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Affiliation(s)
- Lucile Noyer
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Loic Lemonnier
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Pascal Mariot
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Dimitra Gkika
- Univ. Lille, Inserm, U1003-PHYCEL-Physiologie Cellulaire, F-59000 Lille, France; (L.N.); (L.L.); (P.M.)
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, 59655 Villeneuve d’Ascq, France
- Correspondence: ; Tél.: +33-(0)3-2043-6838
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10
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Sabatini PV, Speckmann T, Lynn FC. Friend and foe: β-cell Ca 2+ signaling and the development of diabetes. Mol Metab 2019; 21:1-12. [PMID: 30630689 PMCID: PMC6407368 DOI: 10.1016/j.molmet.2018.12.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/03/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The divalent cation Calcium (Ca2+) regulates a wide range of processes in disparate cell types. Within insulin-producing β-cells, increases in cytosolic Ca2+ directly stimulate insulin vesicle exocytosis, but also initiate multiple signaling pathways. Mediated through activation of downstream kinases and transcription factors, Ca2+-regulated signaling pathways leverage substantial influence on a number of critical cellular processes within the β-cell. Additionally, there is evidence that prolonged activation of these same pathways is detrimental to β-cell health and may contribute to Type 2 Diabetes pathogenesis. SCOPE OF REVIEW This review aims to briefly highlight canonical Ca2+ signaling pathways in β-cells and how β-cells regulate the movement of Ca2+ across numerous organelles and microdomains. As a main focus, this review synthesizes experimental data from in vitro and in vivo models on both the beneficial and detrimental effects of Ca2+ signaling pathways for β-cell function and health. MAJOR CONCLUSIONS Acute increases in intracellular Ca2+ stimulate a number of signaling cascades, resulting in (de-)phosphorylation events and activation of downstream transcription factors. The short-term stimulation of these Ca2+ signaling pathways promotes numerous cellular processes critical to β-cell function, including increased viability, replication, and insulin production and secretion. Conversely, chronic stimulation of Ca2+ signaling pathways increases β-cell ER stress and results in the loss of β-cell differentiation status. Together, decades of study demonstrate that Ca2+ movement is tightly regulated within the β-cell, which is at least partially due to its dual roles as a potent signaling molecule.
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Affiliation(s)
- Paul V Sabatini
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada; Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Thilo Speckmann
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Francis C Lynn
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
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11
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Egorova PA, Bezprozvanny IB. Inositol 1,4,5-trisphosphate receptors and neurodegenerative disorders. FEBS J 2018; 285:3547-3565. [PMID: 29253316 DOI: 10.1111/febs.14366] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/27/2017] [Accepted: 12/12/2017] [Indexed: 12/15/2022]
Abstract
The inositol 1,4,5-trisphosphate receptor (IP3 R) is an intracellular ion channel that mediates the release of calcium ions from the endoplasmic reticulum. It plays a role in basic biological functions, such as cell division, differentiation, fertilization and cell death, and is involved in developmental processes including learning, memory and behavior. Deregulation of neuronal calcium signaling results in disturbance of cell homeostasis, synaptic loss and dysfunction, eventually leading to cell death. Three IP3 R subtypes have been identified in mammalian cells and the predominant isoform in neurons is IP3 R type 1. Dysfunction of IP3 R type 1 may play a role in the pathogenesis of certain neurodegenerative diseases as enhanced activity of the IP3 R was observed in models of Huntington's disease, spinocerebellar ataxias and Alzheimer's disease. These results suggest that IP3 R-mediated signaling is a potential target for treatment of these disorders. In this review we discuss the structure, functions and regulation of the IP3 R in healthy neurons and in conditions of neurodegeneration.
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Affiliation(s)
- Polina A Egorova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St Petersburg, Russia
| | - Ilya B Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St Petersburg, Russia.,Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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12
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A chemical chaperone improves muscle function in mice with a RyR1 mutation. Nat Commun 2017; 8:14659. [PMID: 28337975 PMCID: PMC5376670 DOI: 10.1038/ncomms14659] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 01/20/2017] [Indexed: 12/28/2022] Open
Abstract
Mutations in the RYR1 gene cause severe myopathies. Mice with an I4895T mutation in the type 1 ryanodine receptor/Ca2+ release channel (RyR1) display muscle weakness and atrophy, but the underlying mechanisms are unclear. Here we show that the I4895T mutation in RyR1 decreases the amplitude of the sarcoplasmic reticulum (SR) Ca2+ transient, resting cytosolic Ca2+ levels, muscle triadin content and calsequestrin (CSQ) localization to the junctional SR, and increases endoplasmic reticulum (ER) stress/unfolded protein response (UPR) and mitochondrial ROS production. Treatment of mice carrying the I4895T mutation with a chemical chaperone, sodium 4-phenylbutyrate (4PBA), reduces ER stress/UPR and improves muscle function, but does not restore SR Ca2+ transients in I4895T fibres to wild type levels, suggesting that decreased SR Ca2+ release is not the major driver of the myopathy. These findings suggest that 4PBA, an FDA-approved drug, has potential as a therapeutic intervention for RyR1 myopathies that are associated with ER stress. Mutations in the RyR1 channel cause core myopathies. Here the authors show that ER stress and the unfolded protein response underlie the pathology caused by a common RyR1 channel mutation, and show that treatment with a chemical chaperone restores muscle function in mice.
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13
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Metabolic Disorders and Cancer: Store-Operated Ca 2+ Entry in Cancer: Focus on IP 3R-Mediated Ca 2+ Release from Intracellular Stores and Its Role in Migration and Invasion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:623-637. [PMID: 28900936 DOI: 10.1007/978-3-319-57732-6_31] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Store-operated calcium entry (SOCE) plays important roles in a multitude of cellular processes, from muscle contraction to cellular proliferation and migration. Dysregulation of SOCE is responsible for the advancement of multiple diseases, ranging from immune diseases, myopathies, to terminal ones like cancer. Naturally, SOCE has been a focus of many studies and review papers which, however, primarily concentrated on the principal players localized to the plasma membrane and responsible for Ca2+ entry into the cell. Much less has been said about other players participating in the entire SOCE event. This review aims to address this shortcoming by discussing the accumulated scientific knowledge focused on the inositol trisphosphate receptors (IP3Rs), principal player responsible for emptying intracellular Ca2+ stores in a majority of cells, and their involvement in regulation of cell migration and invasion in cancer.
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Jones OD. Do group I metabotropic glutamate receptors mediate LTD? Neurobiol Learn Mem 2016; 138:85-97. [PMID: 27545442 DOI: 10.1016/j.nlm.2016.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/01/2016] [Accepted: 08/17/2016] [Indexed: 01/31/2023]
Abstract
Synapses undergo significant structural and functional reorganization in response to varying patterns of stimulation. These forms of plasticity are considered fundamental to cognition and neuronal homeostasis. An increasing number of reports highlight the importance of activity-dependent synaptic strengthening (long term potentiation: LTP) for learning. However, the functional significance of activity-dependent weakening of synapses (long term depression: LTD) remains relatively poorly understood. One form of synaptic weakening, induced by group I metabotropic glutamate receptors (mGluRs), has received significant attention from a mechanistic point of view and because of its augmentation in a murine model of Fragile X Syndrome. Yet, studies of this form of plasticity often yield confusing, contradictory results. These conflicting findings are likely attributable to the bulk stimulation and recording techniques often used to study synaptic plasticity (typically involving evoked extracellular recordings, which represent the summed activity of many synapses). Such studies inherently blur the identity of the synapses undergoing change, thus giving the illusion that synapses per se are being modified when in fact this may only be true of a specific subset of synapses. Indeed, studies employing minimal synaptic activation paint a fundamentally different picture of what is commonly called "mGluR-LTD". Here, I review the evidence in favour of group I mGluRs as mediators of various forms of synaptic downregulation and attempt to explain discrepancies in the literature. I argue that, while multiple forms of synaptic weakening may be triggered by these receptors, the canonical form of group I mGluR-mediated depression, mGluR-LTD, is in fact not a depression of basal synaptic responses. Rather, it is a reversal of established LTP and thus a form of depotentiation. Far from being arbitrary, this distinction has significant implications for the role of group I mGluRs in cognition, both in the healthy brain and in pathological conditions. Further, the differential actions of group I mGluRs at naïve and potentiated synapses suggest these receptors signal in a state-dependent manner to regulate various stages of the learning process.
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Affiliation(s)
- Owen D Jones
- Department of Psychology, Brain Health Research Centre & Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
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Chang CL, Liou J. Homeostatic regulation of the PI(4,5)P2-Ca(2+) signaling system at ER-PM junctions. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:862-873. [PMID: 26924250 DOI: 10.1016/j.bbalip.2016.02.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/17/2016] [Accepted: 02/19/2016] [Indexed: 10/22/2022]
Abstract
The phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-Ca(2+) signaling system is important for cell activation in response to various extracellular stimuli. This signaling system is initiated by receptor-induced hydrolysis of PI(4,5)P2 in the plasma membrane (PM) to generate the soluble second messenger inositol 1,4,5-trisphosphate (IP3). IP3 subsequently triggers the release of Ca(2+) from the endoplasmic reticulum (ER) store to the cytosol to activate Ca(2+)-mediated responses, such as secretion and proliferation. The consumed PM PI(4,5)P2 and ER Ca(2+) must be quickly restored to sustain signaling responses, and to maintain the homeostasis of PI(4,5)P2 and Ca(2+). Since phosphatidylinositol (PI), the precursor lipid for PM PI(4,5)P2, is synthesized in the ER membrane, and a Ca(2+) influx across the PM is required to refill the ER Ca(2+) store, efficient communications between the ER and the PM are critical for the homeostatic regulation of the PI(4,5)P2-Ca(2+) signaling system. This review describes the major findings that established the framework of the PI(4,5)P2-Ca(2+) signaling system, and recent discoveries on feedback control mechanisms at ER-PM junctions that sustain the PI(4,5)P2-Ca(2+) signaling system. Particular emphasis is placed on the characterization of ER-PM junctions where efficient communications between the ER and the PM occur, and the activation mechanisms of proteins that dynamically localize to ER-PM junctions to provide the feedback control during PI(4,5)P2-Ca(2+) signaling, including the ER Ca(2+) sensor STIM1, the extended synaptotagmin E-Syt1, and the PI transfer protein Nir2. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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Affiliation(s)
- Chi-Lun Chang
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jen Liou
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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Jayanarayanan S, Anju TR, Smijin S, Paulose CS. Vitamin D3 supplementation increases insulin level by regulating altered IP3 and AMPA receptor expression in the pancreatic islets of streptozotocin-induced diabetic rat. J Nutr Biochem 2015; 26:1041-9. [PMID: 26054778 DOI: 10.1016/j.jnutbio.2015.04.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 04/13/2015] [Accepted: 04/26/2015] [Indexed: 12/17/2022]
Abstract
Pancreatic islets, particularly insulin-secreting β cells, share common characteristics with neurons. Glutamate is one of the major excitatory neurotransmitter in the brain and pancreas, and its action is mediated through glutamate receptors. In the present work, we analysed the role of vitamin D3 in the modulation of AMPA receptor subunit and their functional role in insulin release. Radio receptor binding study in diabetic rats showed a significant increase in AMPA receptor density. Insulin AMPA colabelling study showed an altered AMPA GluR2 and GluR4 subunit expression in the pancreatic beta cells. We also found lowered IP3 content and decreased IP3 receptor in pancreas of diabetic rats. The alterations in AMPA and IP3 receptor resulted in reduced cytosolic calcium level concentration, which further blocks Ca(2+)-mediated insulin release. Vitamin D3 supplementation restored the alteration in vitamin D receptor expression, AMPA receptor density and AMPA and IP3 receptor expression in the pancreatic islets that helps to restore the calcium-mediated insulin secretion. Our study reveals the antidiabetic property of vitamin D3 that is suggested to have therapeutic role through regulating glutamatergic function in diabetic rats.
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Affiliation(s)
- Sadanandan Jayanarayanan
- Molecular Neurobiology and Cell Biology Unit, Centre for Neuroscience, Cochin University of Science and Technology, Cochin, 682 022, Kerala, India
| | - Thoppil R Anju
- Molecular Neurobiology and Cell Biology Unit, Centre for Neuroscience, Cochin University of Science and Technology, Cochin, 682 022, Kerala, India
| | - Soman Smijin
- Molecular Neurobiology and Cell Biology Unit, Centre for Neuroscience, Cochin University of Science and Technology, Cochin, 682 022, Kerala, India
| | - Cheramadathikudiyil Skaria Paulose
- Molecular Neurobiology and Cell Biology Unit, Centre for Neuroscience, Cochin University of Science and Technology, Cochin, 682 022, Kerala, India.
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17
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Liu WJ, Yang J. Developmental expression of inositol 1, 4, 5-trisphosphate receptor in the post-natal rat cochlea. Eur J Histochem 2015; 59:2486. [PMID: 26150157 PMCID: PMC4503970 DOI: 10.4081/ejh.2015.2486] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/06/2015] [Accepted: 04/06/2015] [Indexed: 11/23/2022] Open
Abstract
Inositol 1, 4, 5-trisphosphate receptor (IP3R) has been established to be essential for hearing. However, the expression of IP3R in the cochlea in the period of auditory development remains unknown. We investigated the expression of IP3R in the developing rat cochlea using immunohistochemistry and real-time reverse transcription polymerase chain reaction (RT-PCR). We observed its presence in the developing rat cochlea, and changes in IP3R protein expressions from the early post-natal period to adult. At birth (post-natal day 0, P0), IP3R expression was only found in Hensen's cell. IP3R immunoreactivity first appeared in the sensory hair cells in the organ of Corti at P2. This localization was confirmed by means of double-labeling experiments with Myosin VIIA, a marker for cochlear hair cells. Colocalization of IP3R and Myosin VIIA from P2 to the second post-natal week suggested early expression of IP3R in developing inner and outer hair cells. Claudius' cells near the spiral ligament were labelled for IP3R from P8 onwards. Transient IP3R expression was observed in the stria vascularis in early post-natal rat from P4 to P8. Spiral ganglion neurons also exhibited weaker IP3R fluorescence signals during post-natal development. The results of RT-PCR demonstrated that all three IP3R isoforms (IP3R1, IP3R2, and IP3R3) were present in rat cochlea during four different developmental stages of cochlea, from P0 to P28. Present immunohistochemical evidence for both change and maintenance of expression of IP3R during post-natal development of the rat cochlea indicated the possible involvement of IP3R-mediated calcium signaling in cochlear development.
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Affiliation(s)
- W J Liu
- Shanghai Jiaotong University.
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18
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Clark KB. Basis for a neuronal version of Grover's quantum algorithm. Front Mol Neurosci 2014; 7:29. [PMID: 24860419 PMCID: PMC4029008 DOI: 10.3389/fnmol.2014.00029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/31/2014] [Indexed: 11/25/2022] Open
Abstract
Grover's quantum (search) algorithm exploits principles of quantum information theory and computation to surpass the strong Church–Turing limit governing classical computers. The algorithm initializes a search field into superposed N (eigen)states to later execute nonclassical “subroutines” involving unitary phase shifts of measured states and to produce root-rate or quadratic gain in the algorithmic time (O(N1/2)) needed to find some “target” solution m. Akin to this fast technological search algorithm, single eukaryotic cells, such as differentiated neurons, perform natural quadratic speed-up in the search for appropriate store-operated Ca2+ response regulation of, among other processes, protein and lipid biosynthesis, cell energetics, stress responses, cell fate and death, synaptic plasticity, and immunoprotection. Such speed-up in cellular decision making results from spatiotemporal dynamics of networked intracellular Ca2+-induced Ca2+ release and the search (or signaling) velocity of Ca2+ wave propagation. As chemical processes, such as the duration of Ca2+ mobilization, become rate-limiting over interstore distances, Ca2+ waves quadratically decrease interstore-travel time from slow saltatory to fast continuous gradients proportional to the square-root of the classical Ca2+ diffusion coefficient, D1/2, matching the computing efficiency of Grover's quantum algorithm. In this Hypothesis and Theory article, I elaborate on these traits using a fire-diffuse-fire model of store-operated cytosolic Ca2+ signaling valid for glutamatergic neurons. Salient model features corresponding to Grover's quantum algorithm are parameterized to meet requirements for the Oracle Hadamard transform and Grover's iteration. A neuronal version of Grover's quantum algorithm figures to benefit signal coincidence detection and integration, bidirectional synaptic plasticity, and other vital cell functions by rapidly selecting, ordering, and/or counting optional response regulation choices.
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Affiliation(s)
- Kevin B Clark
- Research and Development Service, Veterans Affairs Greater Los Angeles Healthcare System Los Angeles, CA, USA ; Complex Biological Systems Alliance North Andover, MA, USA
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Fedorenko OA, Popugaeva E, Enomoto M, Stathopulos PB, Ikura M, Bezprozvanny I. Intracellular calcium channels: inositol-1,4,5-trisphosphate receptors. Eur J Pharmacol 2013; 739:39-48. [PMID: 24300389 DOI: 10.1016/j.ejphar.2013.10.074] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 09/28/2013] [Accepted: 10/17/2013] [Indexed: 01/13/2023]
Abstract
The inositol-1,4,5-trisphosphate receptors (InsP3Rs) are the major intracellular Ca(2+)-release channels in cells. Activity of InsP3Rs is essential for elementary and global Ca(2+) events in the cell. There are three InsP3Rs isoforms that are present in mammalian cells. In this review we will focus primarily on InsP3R type 1. The InsP3R1 is a predominant isoform in neurons and it is the most extensively studied isoform. Combination of biophysical and structural methods revealed key mechanisms of InsP3R function and modulation. Cell biological and biochemical studies lead to identification of a large number of InsP3R-binding proteins. InsP3Rs are involved in the regulation of numerous physiological processes, including learning and memory, proliferation, differentiation, development and cell death. Malfunction of InsP3R1 play a role in a number of neurodegenerative disorders and other disease states. InsP3Rs represent a potentially valuable drug target for treatment of these disorders and for modulating activity of neurons and other cells. Future studies will provide better understanding of physiological functions of InsP3Rs in health and disease.
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Affiliation(s)
- Olena A Fedorenko
- Department of Brain Physiology, Bogomoletz Institute of Physiology, 01024 Kiev, Ukraine; State Key Laboratory of Molecular and Cellular Biology, 01024 Kiev, Ukraine
| | - Elena Popugaeva
- Laboratory of Molecular Neurodegeneration, Department of Medical Physics, St. Petersburg State Polytechnical University, 195251 St. Petersburg, Russia
| | - Masahiro Enomoto
- Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7 Toronto, Ontario, Canada
| | - Peter B Stathopulos
- Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7 Toronto, Ontario, Canada
| | - Mitsuhiko Ikura
- Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7 Toronto, Ontario, Canada
| | - Ilya Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Department of Medical Physics, St. Petersburg State Polytechnical University, 195251 St. Petersburg, Russia; Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Baker KD, Edwards TM, Rickard NS. The role of intracellular calcium stores in synaptic plasticity and memory consolidation. Neurosci Biobehav Rev 2013; 37:1211-39. [PMID: 23639769 DOI: 10.1016/j.neubiorev.2013.04.011] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 04/18/2013] [Accepted: 04/22/2013] [Indexed: 12/20/2022]
Abstract
Memory processing requires tightly controlled signalling cascades, many of which are dependent upon intracellular calcium (Ca(2+)). Despite this, most work investigating calcium signalling in memory formation has focused on plasma membrane channels and extracellular sources of Ca(2+). The intracellular Ca(2+) release channels, ryanodine receptors (RyRs) and inositol (1,4,5)-trisphosphate receptors (IP3Rs) have a significant capacity to regulate intracellular Ca(2+) signalling. Evidence at both cellular and behavioural levels implicates both RyRs and IP3Rs in synaptic plasticity and memory formation. Pharmacobehavioural experiments using young chicks trained on a single-trial discrimination avoidance task have been particularly useful by demonstrating that RyRs and IP3Rs have distinct roles in memory formation. RyR-dependent Ca(2+) release appears to aid the consolidation of labile memory into a persistent long-term memory trace. In contrast, IP3Rs are required during long-term memory. This review discusses various functions for RyRs and IP3Rs in memory processing, including neuro- and glio-transmitter release, dendritic spine remodelling, facilitating vasodilation, and the regulation of gene transcription and dendritic excitability. Altered Ca(2+) release from intracellular stores also has significant implications for neurodegenerative conditions.
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Affiliation(s)
- Kathryn D Baker
- School of Psychology and Psychiatry, Monash University, Clayton 3800, Victoria, Australia.
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Agarwal S, Singh MK, Garg S, Chitnis CE, Singh S. Ca2+-mediated exocytosis of subtilisin-like protease 1: a key step in egress ofPlasmodium falciparummerozoites. Cell Microbiol 2012; 15:910-21. [DOI: 10.1111/cmi.12086] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 10/30/2012] [Accepted: 11/23/2012] [Indexed: 11/27/2022]
Affiliation(s)
- Shalini Agarwal
- Malaria Group; International Centre for Genetic Engineering and Biotechnology (ICGEB); New Delhi; India
| | - Maneesh Kumar Singh
- Malaria Group; International Centre for Genetic Engineering and Biotechnology (ICGEB); New Delhi; India
| | - Swati Garg
- Malaria Group; International Centre for Genetic Engineering and Biotechnology (ICGEB); New Delhi; India
| | - Chetan E. Chitnis
- Malaria Group; International Centre for Genetic Engineering and Biotechnology (ICGEB); New Delhi; India
| | - Shailja Singh
- Malaria Group; International Centre for Genetic Engineering and Biotechnology (ICGEB); New Delhi; India
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22
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Matamales M. Neuronal activity-regulated gene transcription: how are distant synaptic signals conveyed to the nucleus? F1000Res 2012; 1:69. [PMID: 24327840 PMCID: PMC3752646 DOI: 10.12688/f1000research.1-69.v1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/04/2012] [Indexed: 01/01/2023] Open
Abstract
Synaptic activity can trigger gene expression programs that are required for the stable change of neuronal properties, a process that is essential for learning and memory. Currently, it is still unclear how the stimulation of dendritic synapses can be coupled to transcription in the nucleus in a timely way given that large distances can separate these two cellular compartments. Although several mechanisms have been proposed to explain long distance communication between synapses and the nucleus, the possible co-existence of these models and their relevance in physiological conditions remain elusive. One model suggests that synaptic activation triggers the translocation to the nucleus of certain transcription regulators localised at postsynaptic sites that function as synapto-nuclear messengers. Alternatively, it has been hypothesised that synaptic activity initiates propagating regenerative intracellular calcium waves that spread through dendrites into the nucleus where nuclear transcription machinery is thereby regulated. It has also been postulated that membrane depolarisation of voltage-gated calcium channels on the somatic membrane is sufficient to increase intracellular calcium concentration and activate transcription without the need for transported signals from distant synapses. Here I provide a critical overview of the suggested mechanisms for coupling synaptic stimulation to transcription, the underlying assumptions behind them and their plausible physiological significance.
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Affiliation(s)
- Miriam Matamales
- Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4072, Australia
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Abstract
Cerebellar Purkinje neurons receive synaptic inputs from three different sources: the excitatory parallel fibre and climbing fibre synapses as well as the inhibitory synapses from molecular layer stellate and basket cells. These three synaptic systems use distinct mechanisms in order to generate Ca(2+) signals that are specialized for specific modes of neurotransmitter release and post-synaptic signal integration. In this review, we first describe the repertoire of Ca(2+) regulatory mechanisms that generate and regulate the amplitude and timing of Ca(2+) fluxes during synaptic transmission and then explore how these mechanisms interact to generate the unique functional properties of each of the Purkinje neuron synapses.
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Raturi A, Simmen T. Where the endoplasmic reticulum and the mitochondrion tie the knot: the mitochondria-associated membrane (MAM). BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:213-24. [PMID: 22575682 DOI: 10.1016/j.bbamcr.2012.04.013] [Citation(s) in RCA: 343] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 04/12/2012] [Accepted: 04/25/2012] [Indexed: 01/01/2023]
Abstract
More than a billion years ago, bacterial precursors of mitochondria became endosymbionts in what we call eukaryotic cells today. The true significance of the word "endosymbiont" has only become clear to cell biologists with the discovery that the endoplasmic reticulum (ER) superorganelle dedicates a special domain for the metabolic interaction with mitochondria. This domain, identified in all eukaryotic cell systems from yeast to man and called the mitochondria-associated membrane (MAM), has a distinct proteome, specific tethers on the cytosolic face and regulatory proteins in the ER lumen of the ER. The MAM has distinct biochemical properties and appears as ER tubules closely apposed to mitochondria on electron micrographs. The functions of the MAM range from lipid metabolism and calcium signaling to inflammasome formation. Consistent with these functions, the MAM is enriched in lipid metabolism enzymes and calcium handling proteins. During cellular stress situations, like an altered cellular redox state, the MAM alters its set of regulatory proteins and thus alters MAM functions. Notably, this set prominently comprises ER chaperones and oxidoreductases that connect protein synthesis and folding inside the ER to mitochondrial metabolism. Moreover, ER membranes associated with mitochondria also accommodate parts of the machinery that determines mitochondrial membrane dynamics and connect mitochondria to the cytoskeleton. Together, these exciting findings demonstrate that the physiological interactions between the ER and mitochondria are so bilateral that we are tempted to compare their relationship to the one of a married couple: distinct, but inseparable and certainly dependent on each other. In this paradigm, the MAM stands for the intracellular location where the two organelles tie the knot. Resembling "real life", the happy marriage between the two organelles prevents the onset of diseases that are characterized by disrupted metabolism and decreased lifespan, including neurodegeneration and cancer. This article is part of a Special Issue entitled: Mitochondrial dynamics and physiology.
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Affiliation(s)
- Arun Raturi
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
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Zampese E, Pizzo P. Intracellular organelles in the saga of Ca2+ homeostasis: different molecules for different purposes? Cell Mol Life Sci 2012; 69:1077-104. [PMID: 21968921 PMCID: PMC11114864 DOI: 10.1007/s00018-011-0845-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/15/2011] [Accepted: 09/19/2011] [Indexed: 11/28/2022]
Abstract
An increase in the concentration of cytosolic free Ca(2+) is a key component regulating different cellular processes ranging from egg fertilization, active secretion and movement, to cell differentiation and death. The multitude of phenomena modulated by Ca(2+), however, do not simply rely on increases/decreases in its concentration, but also on specific timing, shape and sub-cellular localization of its signals that, combined together, provide a huge versatility in Ca(2+) signaling. Intracellular organelles and their Ca(2+) handling machineries exert key roles in this complex and precise mechanism, and this review will try to depict a map of Ca(2+) routes inside cells, highlighting the uniqueness of the different Ca(2+) toolkit components and the complexity of the interactions between them.
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Affiliation(s)
- Enrico Zampese
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
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Parys JB, De Smedt H. Inositol 1,4,5-trisphosphate and its receptors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:255-79. [PMID: 22453946 DOI: 10.1007/978-94-007-2888-2_11] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Activation of cells by many extracellular agonists leads to the production of inositol 1,4,5-trisphosphate (IP₃). IP₃ is a global messenger that easily diffuses in the cytosol. Its receptor (IP₃R) is a Ca(2+)-release channel located on intracellular membranes, especially the endoplasmic reticulum (ER). The IP₃R has an affinity for IP(3) in the low nanomolar range. A prime regulator of the IP₃R is the Ca(2+) ion itself. Cytosolic Ca(2+) is considered as a co-agonist of the IP₃R, as it strongly increases IP(3)R activity at concentrations up to about 300 nM. In contrast, at higher concentrations, cytosolic Ca(2+) inhibits the IP₃R. Also the luminal Ca(2+) sensitizes the IP₃R. In higher organisms three genes encode for an IP₃R and additional diversity exists as a result of alternative splicing mechanisms and the formation of homo- and heterotetramers. The various IP₃R isoforms have a similar structure and a similar function, but due to differences in their affinity for IP₃, their variable sensitivity to regulatory parameters, their differential interaction with associated proteins, and the variation in their subcellular localization, they participate differently in the formation of intracellular Ca(2+) signals and this affects therefore the physiological consequences of these signals.
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Affiliation(s)
- Jan B Parys
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N1 - Bus 802, Herestraat 49, Belgium.
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Rossi AM, Tovey SC, Rahman T, Prole DL, Taylor CW. Analysis of IP3 receptors in and out of cells. Biochim Biophys Acta Gen Subj 2011; 1820:1214-27. [PMID: 22033379 DOI: 10.1016/j.bbagen.2011.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 10/07/2011] [Accepted: 10/08/2011] [Indexed: 10/16/2022]
Abstract
BACKGROUND Inositol 1,4,5-trisphosphate receptors (IP3R) are expressed in almost all animal cells. Three mammalian genes encode closely related IP3R subunits, which assemble into homo- or hetero-tetramers to form intracellular Ca2+ channels. SCOPE OF THE REVIEW In this brief review, we first consider a variety of complementary methods that allow the links between IP3 binding and channel gating to be defined. How does IP3 binding to the IP3-binding core in each IP3R subunit cause opening of a cation-selective pore formed by residues towards the C-terminal? We then describe methods that allow IP3, Ca2+ signals and IP3R mobility to be examined in intact cells. A final section briefly considers genetic analyses of IP3R signalling. MAJOR CONCLUSIONS All IP3R are regulated by both IP3 and Ca2+. This allows them to initiate and regeneratively propagate intracellular Ca2+ signals. The elementary Ca2+ release events evoked by IP3 in intact cells are mediated by very small numbers of active IP3R and the Ca2+-mediated interactions between them. The spatial organization of these Ca2+ signals and their stochastic dependence on so few IP3Rs highlight the need for methods that allow the spatial organization of IP3R signalling to be addressed with single-molecule resolution. GENERAL SIGNIFICANCE A variety of complementary methods provide insight into the structural basis of IP3R activation and the contributions of IP3-evoked Ca2+ signals to cellular physiology. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signaling.
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Kesherwani V, Agrawal SK. Upregulation of RyR2 in hypoxic/reperfusion injury. J Neurotrauma 2011; 29:1255-65. [PMID: 21612318 DOI: 10.1089/neu.2011.1780] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Calcium influx into cells is responsible for initiating the cell death in neuronal tissue after hypoxic injury. Changes in intracellular calcium with subsequent increased expression of ryanodine receptor 2 (RyR2) are hypothesized to cause cell death after hypoxic injury. In the present study we have examined the time-dependent changes of RyR2 expression in hypoxic/reperfusion injury of spinal cord dorsal column. In this study we used western blotting, real time PCR (RT-PCR) and immunohistochemistry to examine changes in protein and gene expression of RyR2 after spinal cord injury (SCI) in the rat. Quantitative immunoblotting showed increase in the expression of RyR2 at 4 h during hypoxic/reperfusion injury of dorsal column. Moreover, RT-PCR showed 36-fold increases in mRNA of RyR2 after 4 h of hypoxic injury of white matter. By double immunofluorescence staining, RyR2 was localized on axons and astrocytes in the white matter of the spinal cord. After treatment with KN-62; (inhibitor of CaMKII) and SP600125 (inhibitor of JNK), there is a significant reduction in the expression of RyR2, indicating the role of these molecules in RyR2 regulation. Further removal of extracellular calcium does not have significant effect on RyR2 expression and phosphorylation of CaMKII, which was further confirmed by treatment with intracellular Ca(++) chelator BAPTA-AM. Finally, bioassay with quantitative analysis showed that treatment with inhibitor significantly reduced the cellular oxidative stress suggesting RyR2 is responsible for increased cellular oxidative load. In summary, we provide evidence that RyR2 gene and protein expression in astrocyte and axons is markedly increased after hypoxic injury. Further CaMKII/JNK pathway upregulates RyR2 expression after hypoxic injury. Therefore we propose that inhibitors of CaMKII/JNK pathway would reduce the cellular oxidative load and thereby have a neuroprotective role.
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Affiliation(s)
- Varun Kesherwani
- Section of Neurosurgery, Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska 68198-6250, USA
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Fujimoto M, Hayashi T. New Insights into the Role of Mitochondria-Associated Endoplasmic Reticulum Membrane. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 292:73-117. [DOI: 10.1016/b978-0-12-386033-0.00002-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Structure Dependence of the Calcium Dynamics in Purkinje Neuron Dendrites during Generation of Bursting Discharges: a Simulation Study. NEUROPHYSIOLOGY+ 2010. [DOI: 10.1007/s11062-010-9136-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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31
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Lee H, Choi J, Shin H, Jeon Y, Jeong B, Lee H, Kim J, Choi E, Carp R, Kim Y. Altered expression of type 1 inositol 1,4,5-trisphosphate receptor in the Ngsk Prnp deficient mice. Neuroscience 2010; 167:799-808. [DOI: 10.1016/j.neuroscience.2010.02.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 02/18/2010] [Accepted: 02/19/2010] [Indexed: 10/19/2022]
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Novorodovskaya TS. A Simulation Study of Calcium Dynamics Features Caused by Exchange between the Cytosol and Organellar Stores of Neurons. NEUROPHYSIOLOGY+ 2010. [DOI: 10.1007/s11062-010-9116-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Novorodovskaya TS, Korogod SM. Comparative Model Analysis of Calcium Exchange between the Cytosol and Stores of Mitochondria or Endoplasmic Reticulum. NEUROPHYSIOLOGY+ 2010. [DOI: 10.1007/s11062-010-9107-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Distinct external signals trigger sequential release of apical organelles during erythrocyte invasion by malaria parasites. PLoS Pathog 2010; 6:e1000746. [PMID: 20140184 PMCID: PMC2816683 DOI: 10.1371/journal.ppat.1000746] [Citation(s) in RCA: 212] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 12/31/2009] [Indexed: 11/24/2022] Open
Abstract
The invasion of erythrocytes by Plasmodium merozoites requires specific interactions between host receptors and parasite ligands. Parasite proteins that bind erythrocyte receptors during invasion are localized in apical organelles called micronemes and rhoptries. The regulated secretion of microneme and rhoptry proteins to the merozoite surface to enable receptor binding is a critical step in the invasion process. The sequence of these secretion events and the external signals that trigger release are not known. We have used time-lapse video microscopy to study changes in intracellular calcium levels in Plasmodium falciparum merozoites during erythrocyte invasion. In addition, we have developed flow cytometry based methods to measure relative levels of cytosolic calcium and study surface expression of apical organelle proteins in P. falciparum merozoites in response to different external signals. We demonstrate that exposure of P. falciparum merozoites to low potassium ion concentrations as found in blood plasma leads to a rise in cytosolic calcium levels through a phospholipase C mediated pathway. Rise in cytosolic calcium triggers secretion of microneme proteins such as the 175 kD erythrocyte binding antigen (EBA175) and apical membrane antigen-1 (AMA-1) to the merozoite surface. Subsequently, interaction of EBA175 with glycophorin A (glyA), its receptor on erythrocytes, restores basal cytosolic calcium levels and triggers release of rhoptry proteins. Our results identify for the first time the external signals responsible for the sequential release of microneme and rhoptry proteins during erythrocyte invasion and provide a starting point for the dissection of signal transduction pathways involved in regulated exocytosis of these key apical organelles. Signaling pathway components involved in apical organelle discharge may serve as novel targets for drug development since inhibition of microneme and rhoptry secretion can block invasion and limit blood-stage parasite growth. Malaria remains a major public health problem in many parts of the tropical world. All the clinical symptoms of malaria are attributed to the blood stage of the parasite life cycle during which Plasmodium merozoites invade and multiply within host erythrocytes. Invasion by Plasmodium merozoites is a complex process that requires multiple molecular interactions between the invading parasite and target erythrocyte. Parasite proteins that mediate such interactions are localized in membrane bound internal organelles at the apical end of merozoites called micronemes and rhoptries. The timely secretion of microneme and rhoptry proteins to the merozoite surface to allow receptor binding is a crucial step in the invasion process. In this study, we demonstrate that exposure of Plasmodium falciparum merozoites to low potassium ion concentrations as found in blood plasma provides the natural signal that triggers a rise in intracellular calcium, which in turn triggers secretion of microneme proteins to the merozoite surface. Subsequently, binding of released microneme proteins with erythrocyte receptors provides the signal for release of rhoptry proteins. These studies open the path for analysis of signal transduction pathways involved in apical organelle secretion. A clear understanding of these pathways will enable development of inhibitors that block secretion of key parasite proteins required for receptor-binding. Such inhibitors will block erythrocyte invasion and inhibit parasite growth, providing promising leads for development of novel drugs against malaria.
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Best MD, Zhang H, Prestwich GD. Inositol polyphosphates, diphosphoinositol polyphosphates and phosphatidylinositol polyphosphate lipids: Structure, synthesis, and development of probes for studying biological activity. Nat Prod Rep 2010; 27:1403-30. [DOI: 10.1039/b923844c] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Kaufmann WA, Ferraguti F, Fukazawa Y, Kasugai Y, Shigemoto R, Laake P, Sexton JA, Ruth P, Wietzorrek G, Knaus HG, Storm JF, Ottersen OP. Large-conductance calcium-activated potassium channels in purkinje cell plasma membranes are clustered at sites of hypolemmal microdomains. J Comp Neurol 2009; 515:215-30. [PMID: 19412945 DOI: 10.1002/cne.22066] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Calcium-activated potassium channels have been shown to be critically involved in neuronal function, but an elucidation of their detailed roles awaits identification of the microdomains where they are located. This study was undertaken to unravel the precise subcellular distribution of the large-conductance calcium-activated potassium channels (called BK, KCa1.1, or Slo1) in the somatodendritic compartment of cerebellar Purkinje cells by means of postembedding immunogold cytochemistry and SDS-digested freeze-fracture replica labeling (SDS-FRL). We found BK channels to be unevenly distributed over the Purkinje cell plasma membrane. At distal dendritic compartments, BK channels were scattered over the plasma membrane of dendritic shafts and spines but absent from postsynaptic densities. At the soma and proximal dendrites, BK channels formed two distinct pools. One pool was scattered over the plasma membrane, whereas the other pool was clustered in plasma membrane domains overlying subsurface cisterns. The labeling density ratio of clustered to scattered channels was about 60:1, established in SDS-FRL. Subsurface cisterns, also called hypolemmal cisterns, are subcompartments of the endoplasmic reticulum likely representing calciosomes that unload and refill Ca2+ independently. Purkinje cell subsurface cisterns are enriched in inositol 1,4,5-triphosphate receptors that mediate the effects of several neurotransmitters, hormones, and growth factors by releasing Ca2+ into the cytosol, generating local Ca2+ sparks. Such increases in cytosolic [Ca2+] may be sufficient for BK channel activation. Clustered BK channels in the plasma membrane may thus participate in building a functional unit (plasmerosome) with the underlying calciosome that contributes significantly to local signaling in Purkinje cells.
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Affiliation(s)
- Walter A Kaufmann
- Department of Pharmacology, Innsbruck Medical University, 6020 Innsbruck, Austria.
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Zhang XF, Forscher P. Rac1 modulates stimulus-evoked Ca(2+) release in neuronal growth cones via parallel effects on microtubule/endoplasmic reticulum dynamics and reactive oxygen species production. Mol Biol Cell 2009; 20:3700-12. [PMID: 19570918 DOI: 10.1091/mbc.e08-07-0730] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The small G protein Rac regulates cytoskeletal protein dynamics in neuronal growth cones and has been implicated in axon growth, guidance, and branching. Intracellular Ca(2+) is another well known regulator of growth cone function; however, effects of Rac activity on intracellular Ca(2+) metabolism have not been well characterized. Here, we investigate how Rac1 activity affects release of Ca(2+) from intracellular endoplasmic reticulum (ER) stores stimulated by application of serotonin (5-hydroxytriptamine). We also address how Rac1 effects on microtubule assembly dynamics affect distribution of Ca(2+) release sites. Multimode fluorescent microscopy was used to correlate microtubule and ER behavior, and ratiometric imaging was used to assess intracellular Ca(2+) dynamics. We report that Rac1 activity both promotes Ca(2+) release and affects its spatial distribution in neuronal growth cones. The underlying mechanism involves synergistic Rac1 effects on microtubule assembly and reactive oxygen species (ROS) production. Rac1 activity modulates Ca(2+) by 1) enhancing microtubule assembly which in turn promotes spread of the ER-based Ca(2+) release machinery into the growth cone periphery, and 2) by increasing ROS production which facilitated inositol 1,4,5-trisphosphate-dependent Ca(2+) release. These results cast Rac1 as a key modulator of intracellular Ca(2+) function in the neuronal growth cone.
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Affiliation(s)
- Xiao-Feng Zhang
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven CT 06520, USA
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Impact of Geometrical Characteristics of the Organellar Store and Organelle-Free Cytosol on Intracellular Calcium Dynamics in the Dendrite: a Simulation Study. NEUROPHYSIOLOGY+ 2009. [DOI: 10.1007/s11062-009-9072-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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39
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Fairbank M, St-Pierre P, Nabi IR. The complex biology of autocrine motility factor/phosphoglucose isomerase (AMF/PGI) and its receptor, the gp78/AMFR E3 ubiquitin ligase. MOLECULAR BIOSYSTEMS 2009; 5:793-801. [PMID: 19603112 DOI: 10.1039/b820820b] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Phosphoglucose isomerase (PGI) is a glycolytic enzyme that exhibits a dual function as an extracellular cytokine, under the name autocrine motility factor (AMF). Its cell surface receptor, gp78/AMFR, is also localized to the endoplasmic reticulum where it functions as an E3 ubiquitin ligase. Expression of both AMF/PGI and gp78/AMFR is associated with cancer and, in this review, we will discuss various aspects of the biology of this ligand-receptor complex and its role in tumor progression.
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Affiliation(s)
- Maria Fairbank
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC V6P 5V8, Canada
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Morikawa K, Goto T, Tanimura A, Kobayashi S, Maki K. Distribution of inositol 1,4,5-trisphosphate receptors in rat osteoclasts. Acta Histochem Cytochem 2008; 41:7-13. [PMID: 18493589 PMCID: PMC2386513 DOI: 10.1267/ahc.07027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 03/12/2008] [Indexed: 01/15/2023] Open
Abstract
Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) are Ca2+ channels that localize to intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Recently, IP3Rs were found to participate in the formation of the cytoskeleton and cellular adhesions. In this study, we examined the cellular localization of type I, II, and III IP3Rs to assess their role in cellular adhesion in rat osteoclasts. Rat bone marrow cells were cultured in α-MEM with 10% fetal bovine serum, M-CSF, RANKL, and 1,25(OH)2D3 for 1 week to promote osteoclast formation. Type I, II, and III IP3R expression in the osteoclasts was then examined by RT-PCR. Double-staining was performed using antibodies against type I, II, and III IP3Rs and DiOC6, an ER marker, or TRITC-phalloidin, an actin filament marker. Expression of all three IP3Rs was detected in the newly formed osteoclasts; however, the localization of the type I and II IP3Rs was predominantly close to nuclear, and possibly colocalized with the ER, while the type III IP3Rs were localized to the ER and podosomes, actin-rich adhesion structures in osteoclasts. These findings suggest that type III IP3Rs are associated with osteoclast adhesion.
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Affiliation(s)
- Kazumasa Morikawa
- Division of Developmental Stomatognathic Function Science, Kyushu Dental College
| | - Tetsuya Goto
- Division of Anatomy, Kyushu Dental College, Kitakyushu 803–8580, Japan
| | - Akihiko Tanimura
- Division of Pharmacology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061–0293, Japan
| | - Shigeru Kobayashi
- Division of Anatomy, Kyushu Dental College, Kitakyushu 803–8580, Japan
| | - Kenshi Maki
- Division of Developmental Stomatognathic Function Science, Kyushu Dental College
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Mikoshiba K, Furuichi T, Miyawaki A, Yoshikawa S, Maeda N, Niinobe M, Nakade S, Nakagawa T, Okano H, Aruga J. The inositol 1,4,5-trisphosphate receptor. CIBA FOUNDATION SYMPOSIUM 2007; 164:17-29; discussion 29-35. [PMID: 1327678 DOI: 10.1002/9780470514207.ch3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Inositol 1,4,5-trisphosphate (InsP3) is a second messenger that releases Ca2+ from its intracellular stores. The InsP3 receptor has been purified and its cDNA has been cloned. We have found that the InsP3 receptor is identical to P400 protein, first identified as a protein enriched in cerebellar Purkinje cells. We have generated an L-fibroblast cell transfectant that produces cDNA-derived InsP3 receptors. The protein displays high affinity and specificity for InsP3. InsP3 induces greater Ca2+ release from membrane vesicles from transfected cells than from those from control L-fibroblasts. After incorporation of the purified InsP3 receptor into lipid bilayers InsP3-induced Ca2+ currents were demonstrated. These results suggest that the InsP3 receptor is involved in physiological Ca2+ release. Immunogold labelling using monoclonal antibodies against the receptor showed that it is highly concentrated on the smooth-surfaced endoplasmic reticulum and slightly on the outer nuclear membrane and rough endoplasmic reticulum; no labelling of Golgi apparatus, mitochondria and plasmalemma was seen. Cross-linking experiments showed that the receptor forms a homotetramer. The approximately 650 N-terminal amino acids are highly conserved between mouse and Drosophila, and this region contains the critical sequences for InsP3 binding. We have investigated the heterogeneity of the InsP3 receptor using the polymerase chain reaction and have found novel subtypes of the mouse InsP3 receptor that are expressed in a tissue-specific and developmentally specific manner.
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Affiliation(s)
- K Mikoshiba
- Institute for Protein Research, Osaka University, Japan
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42
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Petersen OH, Wakui M, Petersen CC. Intracellular effects of aluminium on receptor-activated cytoplasmic Ca2+ signals in pancreatic acinar cells. CIBA FOUNDATION SYMPOSIUM 2007; 169:237-47; discussion 247-53. [PMID: 1337034 DOI: 10.1002/9780470514306.ch14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The hypothesis that intracellular aluminium may interfere with cytoplasmic Ca2+ signals evoked by the activation of receptors linked to inositol lipid hydrolysis has been tested. Single mouse pancreatic acinar cells were used, because there is much information in this system on the mechanism by which acetylcholine (ACh) evokes cytoplasmic Ca2+ oscillations (spiking) and these spikes can be monitored in internally perfused cells by measuring the Ca(2+)-dependent chloride current. ACh normally evokes repetitive Ca2+ spikes, but when aluminium (1 microM-1 mM) is present in the internal perfusion solution the responses are reduced or absent. When aluminium is acutely infused into the internal perfusion solution the ACh-evoked Ca2+ signals quickly disappear. Aluminium also inhibits Ca2+ signals evoked by the Ca2+ releasing agent caffeine. Preliminary results suggest that silicic acid may protect against the toxic effects of aluminium. Silicic acid and citrate, in the absence of added Al3+, have the effect of enhancing the ACh-evoked Ca2+ signals. This could be due to binding of traces of Al3+ in the solutions. We conclude that aluminium can disrupt receptor-activated cytosolic Ca2+ signals when present inside cells.
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Affiliation(s)
- O H Petersen
- Physiological Laboratory, University of Liverpool, UK
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Goetz JG, Genty H, St-Pierre P, Dang T, Joshi B, Sauvé R, Vogl W, Nabi IR. Reversible interactions between smooth domains of the endoplasmic reticulum and mitochondria are regulated by physiological cytosolic Ca2+ levels. J Cell Sci 2007; 120:3553-64. [PMID: 17895372 DOI: 10.1242/jcs.03486] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The 3F3A monoclonal antibody to autocrine motility factor receptor (AMFR) labels mitochondria-associated smooth endoplasmic reticulum (ER) tubules. siRNA down-regulation of AMFR expression reduces mitochondria-associated 3F3A labelling. The 3F3A-labelled ER domain does not overlap with reticulon-labelled ER tubules, the nuclear membrane or perinuclear ER markers and only partially overlaps with the translocon component Sec61alpha. Upon overexpression of FLAG-tagged AMFR, 3F3A labelling is mitochondria associated, excluded from the perinuclear ER and co-distributes with reticulon. 3F3A labelling therefore defines a distinct mitochondria-associated ER domain. Elevation of free cytosolic Ca(2+) levels with ionomycin promotes dissociation of 3F3A-labelled tubules from mitochondria and, judged by electron microscopy, disrupts close contacts (<50 nm) between smooth ER tubules and mitochondria. The ER tubule-mitochondria association is similarly disrupted upon thapsigargin-induced release of ER Ca(2+) stores or purinergic receptor stimulation by ATP. The inositol (1,4,5)-trisphosphate [Ins(1,4,5)P(3)] receptor (IP3R) colocalises to 3F3A-labelled mitochondria-associated ER tubules, and conditions that induce ER tubule-mitochondria dissociation disrupt continuity between 3F3A- and IP3R-labelled ER domains. RAS-transformed NIH-3T3 cells have increased basal cytosolic Ca(2+) levels and show dissociation of the 3F3A-labelled, but not IP3R-labelled, ER from mitochondria. Our data indicate that regulation of the ER-mitochondria association by free cytosolic Ca(2+) is a characteristic of smooth ER domains and that multiple mechanisms regulate the interaction between these organelles.
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Affiliation(s)
- Jacky G Goetz
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver V6T 1Z3, Canada
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Conway SJ, Miller GJ. Biology-enabling inositol phosphates, phosphatidylinositol phosphates and derivatives. Nat Prod Rep 2007; 24:687-707. [PMID: 17653355 DOI: 10.1039/b407701f] [Citation(s) in RCA: 247] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review highlights inositol polyphosphate- and phosphatidylinositol-based small molecule probes that have advanced our understanding of intracellular signalling.
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Affiliation(s)
- Stuart J Conway
- EaStCHEM, School of Chemistry and Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews, Fife, UK KY16 9ST
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Abstract
The inositol 1,4,5-trisphosphate (InsP3) receptors (InsP3Rs) are a family of Ca2+ release channels localized predominately in the endoplasmic reticulum of all cell types. They function to release Ca2+ into the cytoplasm in response to InsP3 produced by diverse stimuli, generating complex local and global Ca2+ signals that regulate numerous cell physiological processes ranging from gene transcription to secretion to learning and memory. The InsP3R is a calcium-selective cation channel whose gating is regulated not only by InsP3, but by other ligands as well, in particular cytoplasmic Ca2+. Over the last decade, detailed quantitative studies of InsP3R channel function and its regulation by ligands and interacting proteins have provided new insights into a remarkable richness of channel regulation and of the structural aspects that underlie signal transduction and permeation. Here, we focus on these developments and review and synthesize the literature regarding the structure and single-channel properties of the InsP3R.
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Affiliation(s)
- J Kevin Foskett
- Department of Physiology, University of Pennsylvania, Philadelphia 19104-6085, USA.
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Mafe OA, Gregg EV, Medina-Ortiz WE, Koulen P. Localization of inositol 1,4,5-trisphosphate receptors in mouse retinal ganglion cells. J Neurosci Res 2007; 84:1750-8. [PMID: 17061256 DOI: 10.1002/jnr.21090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP(3)R) are ligand-gated intracellular Ca(2+)channels that mediate release of Ca(2+) from intracellular stores into the cytosol on activation by second messenger IP(3.). Similarly, IP(3)R mediated changes in cytosolic Ca(2+) concentrations control neuronal functions ranging from synaptic transmission to differentiation and apoptosis. IP(3)R-generated cytosolic Ca(2+) transients also control intracellular Ca(2+) release and subsequent retinal ganglion cell (RGC) physiology and pathophysiology. The distribution of IP(3)R isotypes in primary adult mouse RGC cultures was determined to identify molecular substrates of IP(3)R mediated signaling in these neurons. Immunocytochemical labeling of IP(3)Rs in retinal sections and cultured RGCs was carried out using isoform specific antibodies and was detected with fluorescence microscopy. RGCs were identified by the use of morphologic criteria and RGC-specific immunocytochemical markers, neurofilament 68 kDa, Thy 1.1, and Thy 1.2. RGC morphology and immunoreactivity to neurofilament 68 kDa and Thy 1.1 or Thy 1.2 were identified in both RGC primary cultures and tissue cryosections. RGCs showed localization on intracellular membranes with a differential distribution of IP(3)R isoforms 1, 2, and 3. IP(3)R Types 1 and 3 were detected intracellularly throughout the cell whereas Type 2 was expressed predominantly in soma. Expression of all three IP(3)Rs by RGCs indicates that all IP(3)R types potentially play a role in Ca(2+) homeostasis and Ca(2+) signaling in these cells. Differential localization of IP(3) receptor subtypes in combination with biophysical properties of IP(3)R types may be an important molecular mechanism by which RGCs organize their cytosolic Ca(2+) signals.
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Affiliation(s)
- Oloruntoyin A Mafe
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX 76107-2699, USA
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Abstract
An increase in nuclear Ca(2+) concentration may activate nuclear Ca(2+)-sensitive proteins and thereby regulate gene transcription. Ca(2+) can enter the nucleus from the cytoplasm either through nuclear pores or less certainly by release from the nuclear envelope. Recent studies indicate that the nuclear membrane of cerebellar Purkinje, but not granule neurons, contains multiple inositol 1,4,5-trisphosphate receptors (InsP(3)Rs) localized to the inner nuclear membrane. These data suggest that the nuclear envelope in some neurons is a Ca(2+) store specialized to release Ca(2+) directly into the nucleoplasm and thereby to amplify Ca(2+) signals entering the nucleus from the cytoplasm or to generate nuclear Ca(2+) transients on its own. Here we review current data on the mechanisms of regulation of Ca(2+) in the cell nucleus with particular emphasis on cerebellar Purkinje neurons.
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Rizzuto R, Pozzan T. Microdomains of intracellular Ca2+: molecular determinants and functional consequences. Physiol Rev 2006; 86:369-408. [PMID: 16371601 DOI: 10.1152/physrev.00004.2005] [Citation(s) in RCA: 876] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Calcium ions are ubiquitous and versatile signaling molecules, capable of decoding a variety of extracellular stimuli (hormones, neurotransmitters, growth factors, etc.) into markedly different intracellular actions, ranging from contraction to secretion, from proliferation to cell death. The key to this pleiotropic role is the complex spatiotemporal organization of the [Ca(2+)] rise evoked by extracellular agonists, which allows selected effectors to be recruited and specific actions to be initiated. In this review, we discuss the structural and functional bases that generate the subcellular heterogeneity in cellular Ca(2+) levels at rest and under stimulation. This complex choreography requires the concerted action of many different players; the central role is, of course, that of the calcium ion, with the main supporting characters being all the entities responsible for moving Ca(2+) between different compartments, while the cellular architecture provides a determining framework within which all the players have their exits and their entrances. In particular, we concentrate on the molecular mechanisms that lead to the generation of cytoplasmic Ca(2+) microdomains, focusing on their different subcellular location, mechanism of generation, and functional role.
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Affiliation(s)
- Rosario Rizzuto
- Department of Experimental and Diagnostic Medicine, and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Ferrara, Italy
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49
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Parry H, McDougall A, Whitaker M. Microdomains bounded by endoplasmic reticulum segregate cell cycle calcium transients in syncytial Drosophila embryos. ACTA ACUST UNITED AC 2005; 171:47-59. [PMID: 16216922 PMCID: PMC2171230 DOI: 10.1083/jcb.200503139] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Cell cycle calcium signals are generated by the inositol trisphosphate (InsP3)–mediated release of calcium from internal stores (Ciapa, B., D. Pesando, M. Wilding, and M. Whitaker. 1994. Nature. 368:875–878; Groigno, L., and M. Whitaker. 1998. Cell. 92:193–204). The major internal calcium store is the endoplasmic reticulum (ER); thus, the spatial organization of the ER during mitosis may be important in shaping and defining calcium signals. In early Drosophila melanogaster embryos, ER surrounds the nucleus and mitotic spindle during mitosis, offering an opportunity to determine whether perinuclear localization of ER conditions calcium signaling during mitosis. We establish that the nuclear divisions in syncytial Drosophila embryos are accompanied by both cortical and nuclear localized calcium transients. Constructs that chelate InsP3 also prevent nuclear division. An analysis of nuclear calcium concentrations demonstrates that they are differentially regulated. These observations demonstrate that mitotic calcium signals in Drosophila embryos are confined to mitotic microdomains and offer an explanation for the apparent absence of detectable global calcium signals during mitosis in some cell types.
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Affiliation(s)
- Huw Parry
- Institute for Cell and Molecular Biosciences, University of Newcastle upon Tyne Medical School, Newcastle upon Tyne NE2 4HH, England, UK
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Pattni K, Banting G. Ins(1,4,5)P3 metabolism and the family of IP3-3Kinases. Cell Signal 2005; 16:643-54. [PMID: 15093605 DOI: 10.1016/j.cellsig.2003.10.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Accepted: 10/24/2003] [Indexed: 11/17/2022]
Abstract
The release of Ca2+ from intracellular stores is triggered by the second messenger inositol (1,4,5)-trisphosphate (Ins(1,4,5)P3). The regulation of this process is critically important for cellular homeostasis. Ins(1,4,5)P3 is rapidly metabolised, either to inositol (1,4)-bisphosphate (Ins(1,4)P2) by inositol polyphosphate 5-phosphatases or to inositol (1,3,4,5)-tetrakisphosphate (Ins(1,3,4,5)P4) by one of a family of inositol (1,4,5)P3 3-kinases (IP3-3Ks). Three isoforms of IP3-3K have now been identified in mammals; they have a conserved C-terminal catalytic domain, but divergent N-termini. This review discusses the metabolism of Ins(1,4,5)P3, compares the IP3-3K isoforms and addresses potential mechanisms by which their activity might be regulated.
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Affiliation(s)
- Krupa Pattni
- Department of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
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