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Ismatullah H, Jabeen I, Kiani YS. Structural and functional insight into a new emerging target IP 3R in cancer. J Biomol Struct Dyn 2024; 42:2170-2196. [PMID: 37070253 DOI: 10.1080/07391102.2023.2201332] [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: 01/27/2023] [Accepted: 04/05/2023] [Indexed: 04/19/2023]
Abstract
Calcium signaling has been identified as an important phenomenon in a plethora of cellular processes. Inositol 1,4,5-trisphosphate receptors (IP3Rs) are ER-residing intracellular calcium (Ca2+) release channels responsible for cell bioenergetics by transferring calcium from the ER to the mitochondria. The recent availability of full-length IP3R channel structure has enabled the researchers to design the IP3 competitive ligands and reveal the channel gating mechanism by elucidating the conformational changes induced by ligands. However, limited knowledge is available for IP3R antagonists and the exact mechanism of action of these antagonists within a tumorigenic environment of a cell. Here in this review a summarized information about the role of IP3R in cell proliferation and apoptosis has been discussed. Moreover, structure and gating mechanism of IP3R in the presence of antagonists have been provided in this review. Additionally, compelling information about ligand-based studies (both agonists and antagonists) has been discussed. The shortcomings of these studies and the challenges toward the design of potent IP3R modulators have also been provided in this review. However, the conformational changes induced by antagonists for channel gating mechanism still display some major drawbacks that need to be addressed. However, the design, synthesis and availability of isoform-specific antagonists is a rather challenging one due to intra-structural similarity within the binding domain of each isoform. HighlightsThe intricate complexity of IP3R's in cellular processes declares them an important target whereby, the recently solved structure depicts the receptor's potential involvement in a complex network of processes spanning from cell proliferation to cell death.Pharmacological inhibition of IP3R attenuates the proliferation or invasiveness of cancers, thus inducing necrotic cell death.Despite significant advancements, there is a tremendous need to design new potential hits to target IP3R, based upon 3D structural features and pharmacophoric patterns.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Humaira Ismatullah
- Department of Sciences, School of Interdisciplinary Engineering and Sciences (SINES), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Ishrat Jabeen
- Department of Sciences, School of Interdisciplinary Engineering and Sciences (SINES), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Yusra Sajid Kiani
- Department of Sciences, School of Interdisciplinary Engineering and Sciences (SINES), National University of Sciences and Technology (NUST), Islamabad, Pakistan
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Yao Y, Borkar NA, Zheng M, Wang S, Pabelick CM, Vogel ER, Prakash YS. Interactions between calcium regulatory pathways and mechanosensitive channels in airways. Expert Rev Respir Med 2023; 17:903-917. [PMID: 37905552 PMCID: PMC10872943 DOI: 10.1080/17476348.2023.2276732] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 10/25/2023] [Indexed: 11/02/2023]
Abstract
INTRODUCTION Asthma is a chronic lung disease influenced by environmental and inflammatory triggers and involving complex signaling pathways across resident airway cells such as epithelium, airway smooth muscle, fibroblasts, and immune cells. While our understanding of asthma pathophysiology is continually progressing, there is a growing realization that cellular microdomains play critical roles in mediating signaling relevant to asthma in the context of contractility and remodeling. Mechanosensitive pathways are increasingly recognized as important to microdomain signaling, with Piezo and transient receptor protein (TRP) channels at the plasma membrane considered important for converting mechanical stimuli into cellular behavior. Given their ion channel properties, particularly Ca2+ conduction, a question becomes whether and how mechanosensitive channels contribute to Ca2+ microdomains in airway cells relevant to asthma. AREAS COVERED Mechanosensitive TRP and Piezo channels regulate key Ca2+ regulatory proteins such as store operated calcium entry (SOCE) involving STIM and Orai channels, and sarcoendoplasmic (SR) mechanisms such as IP3 receptor channels (IP3Rs), and SR Ca2+ ATPase (SERCA) that are important in asthma pathophysiology including airway hyperreactivity and remodeling. EXPERT OPINION Physical and/or functional interactions between Ca2+ regulatory proteins and mechanosensitive channels such as TRP and Piezo can toward understanding asthma pathophysiology and identifying novel therapeutic approaches.
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Affiliation(s)
- Yang Yao
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi’an Medical University, Xi’an, Shaanxi, China
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
| | - Niyati A Borkar
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
| | - Mengning Zheng
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
- Department of Respiratory and Critical Care Medicine, Guizhou Province People’s Hospital, Guiyang, Guizhou, China
| | - Shengyu Wang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi’an Medical University, Xi’an, Shaanxi, China
| | - Christina M Pabelick
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Elizabeth R Vogel
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - YS Prakash
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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Callens M, Loncke J, Bultynck G. Dysregulated Ca 2+ Homeostasis as a Central Theme in Neurodegeneration: Lessons from Alzheimer's Disease and Wolfram Syndrome. Cells 2022; 11:cells11121963. [PMID: 35741091 PMCID: PMC9221778 DOI: 10.3390/cells11121963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/06/2022] [Accepted: 06/13/2022] [Indexed: 12/12/2022] Open
Abstract
Calcium ions (Ca2+) operate as important messengers in the cell, indispensable for signaling the underlying numerous cellular processes in all of the cell types in the human body. In neurons, Ca2+ signaling is crucial for regulating synaptic transmission and for the processes of learning and memory formation. Hence, the dysregulation of intracellular Ca2+ homeostasis results in a broad range of disorders, including cancer and neurodegeneration. A major source for intracellular Ca2+ is the endoplasmic reticulum (ER), which has close contacts with other organelles, including mitochondria. In this review, we focus on the emerging role of Ca2+ signaling at the ER–mitochondrial interface in two different neurodegenerative diseases, namely Alzheimer’s disease and Wolfram syndrome. Both of these diseases share some common hallmarks in the early stages, including alterations in the ER and mitochondrial Ca2+ handling, mitochondrial dysfunction and increased Reactive oxygen species (ROS) production. This indicates that similar mechanisms may underly these two disease pathologies and suggests that both research topics might benefit from complementary research.
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Anand P, Harper AGS. Human platelets use a cytosolic Ca 2+ nanodomain to activate Ca 2+-dependent shape change independently of platelet aggregation. Cell Calcium 2020; 90:102248. [PMID: 32629299 DOI: 10.1016/j.ceca.2020.102248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/14/2020] [Accepted: 06/22/2020] [Indexed: 10/24/2022]
Abstract
Human platelets use a rise in cytosolic Ca2+ concentration to activate all stages of thrombus formation, however, how they are able to decode cytosolic Ca2+ signals to trigger each of these independently is unknown. Other cells create local Ca2+ signals to activate Ca2+-sensitive effectors specifically localised to these subcellular regions. However, no previous study has demonstrated that agonist-stimulated human platelets can generate a local cytosolic Ca2+ signal. Platelets possess a structure called the membrane complex (MC) where the main intracellular calcium store, the dense tubular system (DTS), is coupled tightly to an invaginated portion of the plasma membrane called the open canalicular system (OCS). Here we hypothesised that human platelets use a Ca2+ nanodomain created within the MC to control the earliest phases of platelet activation. Dimethyl-BAPTA-loaded human platelets were stimulated with thrombin in the absence of extracellular Ca2+ to isolate a cytosolic Ca2+ nanodomain created by Ca2+ release from the DTS. In the absence of any detectable rise in global cytosolic Ca2+ concentration, thrombin stimulation triggered Na+/Ca2+ exchanger (NCX)-dependent Ca2+ removal into the extracellular space, as well as Ca2+-dependent shape change in the absence of platelet aggregation. The NCX-mediated Ca2+ removal was dependent on the normal localisation of the DTS, and immunofluorescent staining of NCX3 demonstrated its localisation to the OCS, consistent with this Ca2+ nanodomain being formed within the MC. These results demonstrated that human platelets possess a functional Ca2+ nanodomain contained within the MC that can control shape change independently of platelet aggregation.
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Affiliation(s)
- Peterson Anand
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Hartshill, Stoke-on-Trent, ST4 7QB, UK
| | - Alan G S Harper
- School of Medicine, Keele University, Keele, Staffordshire, ST5 5BG, UK.
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New Insights in the IP 3 Receptor and Its Regulation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:243-270. [PMID: 31646513 DOI: 10.1007/978-3-030-12457-1_10] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) is a Ca2+-release channel mainly located in the endoplasmic reticulum (ER). Three IP3R isoforms are responsible for the generation of intracellular Ca2+ signals that may spread across the entire cell or occur locally in so-called microdomains. Because of their ubiquitous expression, these channels are involved in the regulation of a plethora of cellular processes, including cell survival and cell death. To exert their proper function a fine regulation of their activity is of paramount importance. In this review, we will highlight the recent advances in the structural analysis of the IP3R and try to link these data with the newest information concerning IP3R activation and regulation. A special focus of this review will be directed towards the regulation of the IP3R by protein-protein interaction. Especially the protein family formed by calmodulin and related Ca2+-binding proteins and the pro- and anti-apoptotic/autophagic Bcl-2-family members will be highlighted. Finally, recently identified and novel IP3R regulatory proteins will be discussed. A number of these interactions are involved in cancer development, illustrating the potential importance of modulating IP3R-mediated Ca2+ signaling in cancer treatment.
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Liu Q, Zhu P, Liu S, Tang M, Wang Y, Tian Y, Jin Z, Li D, Yan D. NMAAP1 Maintains M1 Phenotype in Macrophages Through Binding to IP3R and Activating Calcium-related Signaling Pathways. Protein Pept Lett 2019; 26:751-757. [PMID: 31618170 DOI: 10.2174/0929866526666190503105343] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 04/16/2019] [Accepted: 04/19/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND NMAAP1 plays a role in regulating macrophage differentiation to the M1 type and exerting antitumoral functions. It is not clear what role and mechanism NMAAP1 does play in the reversal of macrophages from M1 to M2. METHODS We detected the typing of macrophages with high or low expression of NMAAP1 by QPCR and ELISA, and detected the colocalization of NMAAP1 and endogenous IP3R by laser confocal microscopy, and detected the protein expression in cells by Western-blotting. RESULTS Our study found that knockdown NMAAP1 in RAW264.7 cells induced macrophage polarization to the M2 type and up-regulation of NMAAP1 in RAW264.7 cells maintain M1 Phenotype even in the presence of IL-4, a stronger inducer of the M2 type. Additionally, Coimmunoprecipitation revealed a protein-protein interaction between NMAAP1 and IP3R and then activates key molecules in the PKC-dependent Raf/MEK/ERK and Ca2+/CaM/CaMKII signaling pathways. Activation of PKC (Thr638/641), ERK1/2 (Thr202/Tyr204) and CaMKII (Thr286) is involved in the regulation of cell differentiation. CONCLUSION NMAAP1 interacts with IP3R, which in turn activates the PKC-dependent Raf/MEK/ERK and Ca2+/CaM/CaMKII signaling pathways. These results provide a new explanation of the mechanism underlying M1 differentiation.
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Affiliation(s)
- Qihui Liu
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China.,Biomedical Transformation Research Institute, Jinan University, Guangzhou, China
| | - Pei Zhu
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China
| | - Shanshan Liu
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China
| | - Mengyan Tang
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China
| | - Yuanxin Wang
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China
| | - Yuan Tian
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China.,Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, China
| | - Zheng Jin
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China
| | - Dong Li
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China
| | - Dongmei Yan
- Department of Immunology, College of basic Medical sciences, Jilin University, Changchun, China
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Nguyen LD, Petri ET, Huynh LK, Ehrlich BE. Characterization of NCS1-InsP3R1 interaction and its functional significance. J Biol Chem 2019; 294:18923-18933. [PMID: 31659121 DOI: 10.1074/jbc.ra119.009736] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 10/11/2019] [Indexed: 11/06/2022] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (InsP3Rs) are endoplasmic reticulum-localized channels that mediate Ca2+ release from the endoplasmic reticulum into the cytoplasm. We previously reported that an EF-hand Ca2+-binding protein, neuronal calcium sensor 1 (NCS1), binds to the InsP3R and thereby increases channel open probability, an event associated with chemotherapy-induced peripheral neuropathy. However, the exact NCS1-binding site on InsP3R remains unknown. Using protein docking, co-immunoprecipitation, and blocking peptides, we mapped the NCS1-binding site to residues 66-110 on the suppressor domain of InsP3R type 1 (InsP3R1). We also identified Leu-89, a residue in the hydrophobic pocket of NCS1, as being critical for facilitating the NCS1-InsP3R1 interaction. Overexpression of WT NCS1 in MDA-MB231 breast cancer cells increased Ca2+ signaling and survival, whereas overexpression of Leu-89 NCS1 variants decreased Ca2+ signaling and survival, further suggesting the importance of this residue in the NCS1-InsP3R1 interaction. In conclusion, we show that NCS1-InsP3R1 interaction enhances intracellular Ca2+ signaling in cells and can be modulated by altering or occluding the hydrophobic pocket of NCS1. This improved understanding of the NCS1-InsP3R1 interaction may facilitate the development of management strategies for diseases resulting from aberrant NCS1 expression.
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Affiliation(s)
- Lien D Nguyen
- Department of Pharmacology, Yale University, New Haven, Connecticut 06520; Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut 06520
| | - Edward T Petri
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad 21000, Serbia, and the
| | - Larry K Huynh
- Department of Pharmacology, Yale University, New Haven, Connecticut 06520
| | - Barbara E Ehrlich
- Department of Pharmacology, Yale University, New Haven, Connecticut 06520; Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut 06520.
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Piazza M, Taiakina V, Dieckmann T, Guillemette JG. Structural Consequences of Calmodulin EF Hand Mutations. Biochemistry 2017; 56:944-956. [PMID: 28121131 DOI: 10.1021/acs.biochem.6b01296] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Calmodulin (CaM) is a cytosolic Ca2+-binding protein that serves as a control element for many enzymes. It consists of two globular domains, each containing two EF hand pairs capable of binding Ca2+, joined by a flexible central linker region. CaM is able to bind and activate its target proteins in the Ca2+-replete and Ca2+-deplete forms. To study the Ca2+-dependent/independent properties of binding and activation of target proteins by CaM, CaM constructs with Ca2+-binding disrupting mutations of Asp to Ala at position one of each EF hand have been used. These CaM mutant proteins are deficient in binding Ca2+ in either the N-lobe EF hands (CaM12), C-lobe EF hands (CaM34), or all four EF hands (CaM1234). To investigate potential structural changes these mutations may cause, we performed detailed NMR studies of CaM12, CaM34, and CaM1234 including determining the solution structure of CaM1234. We then investigated if these CaM mutants affected the interaction of CaM with a target protein known to interact with apoCaM by determining the solution structure of CaM34 bound to the iNOS CaM binding domain peptide. The structures provide direct structural evidence of changes that are present in these Ca2+-deficient CaM mutants and show these mutations increase the hydrophobic exposed surface and decrease the electronegative surface potential throughout each lobe of CaM. These Ca2+-deficient CaM mutants may not be a true representation of apoCaM and may not allow for native-like interactions of apoCaM with its target proteins.
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Affiliation(s)
- Michael Piazza
- Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Valentina Taiakina
- Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Thorsten Dieckmann
- Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - J Guy Guillemette
- Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
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9
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Shah SZA, Zhao D, Khan SH, Yang L. Regulatory Mechanisms of Endoplasmic Reticulum Resident IP3 Receptors. J Mol Neurosci 2015; 56:938-948. [PMID: 25859934 DOI: 10.1007/s12031-015-0551-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/23/2015] [Indexed: 11/25/2022]
Abstract
Dysregulated calcium signaling and accumulation of aberrant proteins causing endoplasmic reticulum stress are the early sign of intra-axonal pathological events in many neurodegenerative diseases, and apoptotic signaling is initiated when the stress goes beyond the maximum threshold level of endoplasmic reticulum. The fate of the cell to undergo apoptosis is controlled by Ca2(+) signaling and dynamics at the level of the endoplasmic reticulum. Endoplasmic reticulum resident inositol 1,4,5-trisphosphate receptors (IP3R) play a pivotal role in cell death signaling by mediating Ca2(+) flux from the endoplasmic reticulum into the cytosol and mitochondria. Hence, many prosurvival and prodeath signaling pathways and proteins affect Ca2(+) signaling by directly targeting IP3R channels, which can happen in an IP3R-isoform-dependent manner. Here, in this review, we summarize the regulatory mechanisms of inositol triphosphate receptors in calcium regulation and initiation of apoptosis during unfolded protein response.
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Affiliation(s)
- Syed Zahid Ali Shah
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Deming Zhao
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Sher Hayat Khan
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Lifeng Yang
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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Ivanova H, Vervliet T, Missiaen L, Parys JB, De Smedt H, Bultynck G. Inositol 1,4,5-trisphosphate receptor-isoform diversity in cell death and survival. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2164-83. [PMID: 24642269 DOI: 10.1016/j.bbamcr.2014.03.007] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/06/2014] [Accepted: 03/09/2014] [Indexed: 01/22/2023]
Abstract
Cell-death and -survival decisions are critically controlled by intracellular Ca(2+) homeostasis and dynamics at the level of the endoplasmic reticulum (ER). Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) play a pivotal role in these processes by mediating Ca(2+) flux from the ER into the cytosol and mitochondria. Hence, it is clear that many pro-survival and pro-death signaling pathways and proteins affect Ca(2+) signaling by directly targeting IP3R channels, which can happen in an IP3R-isoform-dependent manner. In this review, we will focus on how the different IP3R isoforms (IP3R1, IP3R2 and IP3R3) control cell death and survival. First, we will present an overview of the isoform-specific regulation of IP3Rs by cellular factors like IP3, Ca(2+), Ca(2+)-binding proteins, adenosine triphosphate (ATP), thiol modification, phosphorylation and interacting proteins, and of IP3R-isoform specific expression patterns. Second, we will discuss the role of the ER as a Ca(2+) store in cell death and survival and how IP3Rs and pro-survival/pro-death proteins can modulate the basal ER Ca(2+) leak. Third, we will review the regulation of the Ca(2+)-flux properties of the IP3R isoforms by the ER-resident and by the cytoplasmic proteins involved in cell death and survival as well as by redox regulation. Hence, we aim to highlight the specific roles of the various IP3R isoforms in cell-death and -survival signaling. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Hristina Ivanova
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Tim Vervliet
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Ludwig Missiaen
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Jan B Parys
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Humbert De Smedt
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
| | - Geert Bultynck
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
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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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Abstract
Binding of IP3 (inositol 1,4,5-trisphosphate) to the IP3-binding core (residues 224–604) of IP3Rs (IP3 receptors) initiates opening of these ubiquitous intracellular Ca2+ channels. The mechanisms are unresolved, but require conformational changes to pass through the suppressor domain (residues 1–223). A calmodulin-binding peptide derived from myosin light chain kinase uncouples these events. We identified a similar conserved 1-8-14 calmodulin-binding motif within the suppressor domain of IP3R1 and, using peptides and mutagenesis, we demonstrate that it is essential for IP3R activation, whether assessed by IP3-evoked Ca2+ release or patch-clamp recoding of nuclear IP3R. Mimetic peptides specifically inhibit activation of IP3R by uncoupling the IP3-binding core from the suppressor domain. Mutations of key hydrophobic residues within the endogenous 1-8-14 motif mimic the peptides. Our results show that an endogenous 1-8-14 motif mediates conformational changes that are essential for IP3R activation. The inhibitory effects of calmodulin and related proteins may result from disruption of this essential interaction.
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López E, Berna-Erro A, Salido GM, Rosado JA, Redondo PC. FKBP52 is involved in the regulation of SOCE channels in the human platelets and MEG 01 cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:652-62. [PMID: 23228564 DOI: 10.1016/j.bbamcr.2012.11.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 11/17/2012] [Accepted: 11/30/2012] [Indexed: 12/17/2022]
Abstract
Immunophilins are FK506-binding proteins that have been involved in the regulation of calcium homeostasis, either by modulating Ca(2+) channels located in the plasma membrane or in the rough endoplasmic reticulum (RE). We have investigated whether immunophilins would participate in the regulation of stored-operated Ca(2+) entry (SOCE) in human platelets and MEG 01. Both cell types were loaded with fura-2 for determining cytosolic calcium concentration changes ([Ca(2+)](c)), or stimulated and fixed to evaluate the protein interaction profile by performing immunoprecipitation and western blotting. We have found that incubation of platelets with FK506 increases Ca(2+) mobilization. Thapsigargin (TG)-evoked, Thr-evoked SOCE and TG-evoked Mn(2+) entry resulted in significant reduction by treatment of platelets with immunophilin antagonists. We confirmed by immunoprecipitation that immunophilins interact with transient receptor potential channel 1 (TRPC1) and Orai1 in human platelets. FK506 and rapamycin reduced the association between TRPC1 and Orai1 with FK506 binding protein (52) (FKBP52) in human platelets, and between TRPC1 and the type II IP(3)R, which association is known to be crucial for the maintenance of SOCE in human platelets. FKBP52 role in SOCE activation was confirmed by silencing FKBP52 using SiRNA FKBP52 in MEG 01 as demonstrated by single cell configuration imaging technique. TRPC1 silencing and depletion of cell of TRPC1 and FKBP52 simultaneously, impair activation of SOCE evoked by TG in MEG 01. Finally, in MEG 01 incubated with FK506 we observed a reduction in TRPC1/FKBP52 coupling, and similarly, FKBP52 silencing reduced the association between IP3R type II and TRPC1 during SOCE. All together, these results demonstrate that immunophilins participate in the regulation of SOCE in human platelets.
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Affiliation(s)
- Esther López
- Department of Physiology Cellular Physiology Research Group, University of Extremadura, 10003 Cáceres, Spain
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14
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McCue HV, Patel P, Herbert AP, Lian LY, Burgoyne RD, Haynes LP. Solution NMR structure of the Ca2+-bound N-terminal domain of CaBP7: a regulator of golgi trafficking. J Biol Chem 2012; 287:38231-43. [PMID: 22989873 PMCID: PMC3488092 DOI: 10.1074/jbc.m112.402289] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/12/2012] [Indexed: 12/12/2022] Open
Abstract
Calcium-binding protein 7 (CaBP7) is a member of the calmodulin (CaM) superfamily that harbors two high affinity EF-hand motifs and a C-terminal transmembrane domain. CaBP7 has been previously shown to interact with and modulate phosphatidylinositol 4-kinase III-β (PI4KIIIβ) activity in in vitro assays and affects vesicle transport in neurons when overexpressed. Here we show that the N-terminal domain (NTD) of CaBP7 is sufficient to mediate the interaction of CaBP7 with PI4KIIIβ. CaBP7 NTD encompasses the two high affinity Ca(2+) binding sites, and structural characterization through multiangle light scattering, circular dichroism, and NMR reveals unique properties for this domain. CaBP7 NTD binds specifically to Ca(2+) but not Mg(2+) and undergoes significant conformational changes in both secondary and tertiary structure upon Ca(2+) binding. The Ca(2+)-bound form of CaBP7 NTD is monomeric and exhibits an open conformation similar to that of CaM. Ca(2+)-bound CaBP7 NTD has a solvent-exposed hydrophobic surface that is more expansive than observed in CaM or CaBP1. Within this hydrophobic pocket, there is a significant reduction in the number of methionine residues that are conserved in CaM and CaBP1 and shown to be important for target recognition. In CaBP7 NTD, these residues are replaced with isoleucine and leucine residues with branched side chains that are intrinsically more rigid than the flexible methionine side chain. We propose that these differences in surface hydrophobicity, charge, and methionine content may be important in determining highly specific interactions of CaBP7 with target proteins, such as PI4KIIIβ.
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Affiliation(s)
- Hannah V. McCue
- From the Physiological Laboratory, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, and
| | - Pryank Patel
- From the Physiological Laboratory, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, and
| | - Andrew P. Herbert
- From the Physiological Laboratory, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, and
| | - Lu-Yun Lian
- the NMR Centre for Structural Biology, Institute of Integrative Biology, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Robert D. Burgoyne
- From the Physiological Laboratory, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, and
| | - Lee P. Haynes
- From the Physiological Laboratory, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, and
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15
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Goto JI, Mikoshiba K. Inositol 1,4,5-Trisphosphate Receptor-Mediated Calcium Release in Purkinje Cells: From Molecular Mechanism to Behavior. THE CEREBELLUM 2011; 10:820-33. [DOI: 10.1007/s12311-011-0270-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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16
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Saucerman JJ, Bers DM. Calmodulin binding proteins provide domains of local Ca2+ signaling in cardiac myocytes. J Mol Cell Cardiol 2011; 52:312-6. [PMID: 21708171 DOI: 10.1016/j.yjmcc.2011.06.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 05/24/2011] [Accepted: 06/02/2011] [Indexed: 11/25/2022]
Abstract
Calmodulin (CaM) acts as a common Ca(2+) sensor for many signaling pathways, transducing local Ca(2+) signals into specific cellular outcomes. Many of CaM's signaling functions can be explained by its unique biochemical properties, including high and low affinity Ca(2+)-binding sites with slow and fast kinetics, respectively. CaM is expected to have a limited spatial range of action, emphasizing its role in local Ca(2+) signaling. Interactions with target proteins further fine-tune CaM signal transduction. Here, we focus on only three specific cellular targets for CaM signaling in cardiac myocytes: the L-type Ca(2+) channel, the ryanodine receptor, and the IP(3) receptor. We elaborate a working hypothesis that each channel is regulated by two distinct functional populations of CaM: dedicated CaM and promiscuous CaM. Dedicated CaM is typically tethered to each channel and directly regulates channel activity. In addition, a local pool of promiscuous CaM appears poised to sense local Ca(2+) signals and trigger downstream pathways such as Ca(2+)/CaM dependent-protein kinase II and calcineurin. Understanding how promiscuous CaM coordinates multiple distinct signaling pathways remains a challenge, but is aided by the use of mathematical modeling and a new generation of fluorescent biosensors. This article is part of a special issue entitled "Local Signaling in Myocytes."
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Affiliation(s)
- Jeffrey J Saucerman
- Department of Biomedical Engineering, Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA.
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17
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Calmodulin protects against alcohol-induced pancreatic trypsinogen activation elicited via Ca2+ release through IP3 receptors. Proc Natl Acad Sci U S A 2011; 108:5873-8. [PMID: 21436055 DOI: 10.1073/pnas.1016534108] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Alcohol abuse is a major global health problem, but there is still much uncertainty about the mechanisms of action. So far, the effects of ethanol on ion channels in the plasma membrane have received the most attention. We have now investigated actions on intracellular calcium channels in pancreatic acinar cells. Our aim was to discover the mechanism by which alcohol influences calcium homeostasis and thereby understand how alcohol can trigger premature intracellular trypsinogen activation, which is the initiating step for alcohol-induced pancreatitis. We used intact or two-photon permeabilized acinar cells isolated from wild-type mice or mice in which inositol trisphosphate receptors of type 2 or types 2 and 3 were knocked out. In permeabilized pancreatic acinar cells even a relatively low ethanol concentration elicited calcium release from intracellular stores and intracellular trypsinogen activation. The calcium sensor calmodulin (at a normal intracellular concentration) markedly reduced ethanol-induced calcium release and trypsinogen activation in permeabilized cells, effects prevented by the calmodulin inhibitor peptide. A calmodulin activator virtually abolished the modest ethanol effects in intact cells. Both ethanol-elicited calcium liberation and trypsinogen activation were significantly reduced in cells from type 2 inositol trisphosphate receptor knockout mice. More profound reductions were seen in cells from double inositol trisphosphate receptor (types 2 and 3) knockout mice. The inositol trisphosphate receptors, required for normal pancreatic stimulus-secretion coupling, are also responsible for the toxic ethanol action. Calmodulin protects by reducing calcium release sensitivity.
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18
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Kang S, Kwon H, Wen H, Song Y, Frueh D, Ahn HC, Yoo SH, Wagner G, Park S. Global dynamic conformational changes in the suppressor domain of IP3 receptor by stepwise binding of the two lobes of calmodulin. FASEB J 2010; 25:840-50. [PMID: 21084695 DOI: 10.1096/fj.10-160705] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The roles of calmodulin (CaM) have been key points of controversy in the regulation of inositol-1,4,5-trisphosphate receptor (IP(3)R). To address the issue, we studied the interaction between CaM and the suppressor domain of IP(3)R, a key allosteric regulatory domain. First, by means of a pulldown and a fluorescence titration experiment, we confirmed the interaction. Through subsequent NMR binding experiments, we observed dramatic peak disappearances of the suppressor domain on interaction with apo-CaM. The data indicated that apo-CaM induces large-scale dynamic conformational changes in the suppressor domain, involving partial unfolding and subdomain rearrangement. Analysis of the NMR data of CaM surprisingly revealed that its C lobe alone can cause such changes. Further binding experiments showed that calcium allows the free N lobe to bind to the suppressor domain, which induces extra conformational changes in both of the proteins. These results were also confirmed with CaM deletion mutants with either the N or C lobe. On the basis of this novel binding mechanism, we propose a model in which the partial unfolding of the suppressor domain by apo-CaM and the stepwise binding of the N lobe of CaM to the suppressor domain are important elements of calcium/CaM inhibition of IP(3)R. We believe that our working model encompasses previous regulation mechanisms of IP(3)R by calcium/CaM and provides new insights into the CaM-target interaction.
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Affiliation(s)
- Sunmi Kang
- Department of Biochemistry and Center for Advanced Medical Education by BK21 Project, School of Medicine, Inha University, Chungsuk Bldg., Rm. 505, Shinheung-dong, Chung-gu, Incheon, Korea, 400-712
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19
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Sammels E, Devogelaere B, Mekahli D, Bultynck G, Missiaen L, Parys JB, De Smedt H. Unraveling the role of polycystin-2/inositol 1,4,5-trisphosphate receptor interaction in Ca signaling. Commun Integr Biol 2010; 3:530-2. [PMID: 21331231 DOI: 10.4161/cib.3.6.12751] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 06/18/2010] [Indexed: 01/04/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) arises as a consequence of mutations of the genes PKD1 and PKD2, encoding respectively the integral membrane proteins polycystin-1 and polycystin-2 (TRPP2), resulting in a disturbance in intracellular Ca(2+) signaling. Previously we investigated the interaction between TRPP2 and the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R), an intracellular Ca(2+) channel in the endoplasmic reticulum (ER). We identified the molecular determinants of this interaction and observed an enhanced IP(3)-induced Ca(2+) release (IICR). Since we found that TRPP2 strongly bound to a cluster of positively charged amino acids in the N-terminal ligand-binding domain (LBD) of the IP(3)R, we now investigated whether TRPP2 would interfere with the binding of IP(3) to the IP(3)R. In in vitro experiments we observed that TRPP2 partially inhibited the binding of IP(3) to the LBD of the IP(3)R with an IC(50) of ∼350 nM. The suppressor domain, i.e., the N-terminal 225 amino acids of the LBD of the IP(3)R, mediated this inhibitory effect of TRPP2 on IP(3) binding. The observation that the interaction between the IP(3)R and TRPP2 decreased IP(3) binding is in apparent contrast to the increased IICR. The data can be explained however by a subsequent activation of Ca(2+)-induced Ca(2+) release (CICR) via TRPP2. Implications of this mechanism for cellular Ca(2+) signaling are discussed in this addendum.
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Affiliation(s)
- Eva Sammels
- Laboratory of Molecular and Cellular Signaling; Department of Molecular Cell Biology; K.U. Leuven, Leuven Belgium
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20
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Sammels E, Devogelaere B, Mekahli D, Bultynck G, Missiaen L, Parys JB, Cai Y, Somlo S, De Smedt H. Polycystin-2 activation by inositol 1,4,5-trisphosphate-induced Ca2+ release requires its direct association with the inositol 1,4,5-trisphosphate receptor in a signaling microdomain. J Biol Chem 2010; 285:18794-805. [PMID: 20375013 DOI: 10.1074/jbc.m109.090662] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Autosomal dominant polycystic kidney disease is characterized by the loss-of-function of a signaling complex involving polycystin-1 and polycystin-2 (TRPP2, an ion channel of the TRP superfamily), resulting in a disturbance in intracellular Ca(2+) signaling. Here, we identified the molecular determinants of the interaction between TRPP2 and the inositol 1,4,5-trisphosphate receptor (IP(3)R), an intracellular Ca(2+) channel in the endoplasmic reticulum. Glutathione S-transferase pulldown experiments combined with mutational analysis led to the identification of an acidic cluster in the C-terminal cytoplasmic tail of TRPP2 and a cluster of positively charged residues in the N-terminal ligand-binding domain of the IP(3)R as directly responsible for the interaction. To investigate the functional relevance of TRPP2 in the endoplasmic reticulum, we re-introduced the protein in TRPP2(-/-) mouse renal epithelial cells using an adenoviral expression system. The presence of TRPP2 resulted in an increased agonist-induced intracellular Ca(2+) release in intact cells and IP(3)-induced Ca(2+) release in permeabilized cells. Using pathological mutants of TRPP2, R740X and D509V, and competing peptides, we demonstrated that TRPP2 amplified the Ca(2+) signal by a local Ca(2+)-induced Ca(2+)-release mechanism, which only occurred in the presence of the TRPP2-IP(3)R interaction, and not via altered IP(3)R channel activity. Moreover, our results indicate that this interaction was instrumental in the formation of Ca(2+) microdomains necessary for initiating Ca(2+)-induced Ca(2+) release. The data strongly suggest that defects in this mechanism may account for the altered Ca(2+) signaling associated with pathological TRPP2 mutations and therefore contribute to the development of autosomal dominant polycystic kidney disease.
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Affiliation(s)
- Eva Sammels
- Department of Molecular Cell Biology, Laboratory of Molecular and Cellular Signaling, KU Leuven, Campus Gasthuisberg O&N1, Herestraat 49 bus 802, B-3000 Leuven, Belgium
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21
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Xiong LW, Kleerekoper QK, Wang X, Putkey JA. Intra- and interdomain effects due to mutation of calcium-binding sites in calmodulin. J Biol Chem 2010; 285:8094-103. [PMID: 20048169 DOI: 10.1074/jbc.m109.065243] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The IQ-motif protein PEP-19, binds to the C-domain of calmodulin (CaM) with significantly different k(on) and k(off) rates in the presence and absence of Ca(2+), which could play a role in defining the levels of free CaM during Ca(2+) transients. The initial goal of the current study was to determine whether Ca(2+) binding to sites III or IV in the C-domain of CaM was responsible for affecting the kinetics of binding PEP-19. EF-hand Ca(2+)-binding sites were selectively inactivated by the common strategy of changing Asp to Ala at the X-coordination position. Although Ca(2+) binding to both sites III and IV appeared necessary for native-like interactions with PEP-19, the data also indicated that the mutations caused undesirable structural alterations as evidenced by significant changes in amide chemical shifts for apoCaM. Mutations in the C-domain also affected chemical shifts in the unmodified N-domain, and altered the Ca(2+) binding properties of the N-domain. Conversion of Asp(93) to Ala caused the greatest structural perturbations, possibly due to the loss of stabilizing hydrogen bonds between the side chain of Asp(93) and backbone amides in apo loop III. Thus, although these mutations inhibit binding of Ca(2+), the mutated CaM may not be able to support potentially important native-like activity of the apoprotein. This should be taken into account when designing CaM mutants for expression in cell culture.
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Affiliation(s)
- Liang-Wen Xiong
- Department of Biochemistry and Molecular Biology and the Structural Biology Center, University of Texas, Houston Medical School, Houston, Texas 77030, USA
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22
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Keddie NS, Bultynck G, Luyten T, Slawin AM, Conway SJ. A type 2 Ferrier rearrangement-based synthesis of d-myo-inositol 1,4,5-trisphosphate. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.tetasy.2009.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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23
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Anyatonwu G, Joseph SK. Surface accessibility and conformational changes in the N-terminal domain of type I inositol trisphosphate receptors: studies using cysteine substitution mutagenesis. J Biol Chem 2009; 284:8093-102. [PMID: 19141613 DOI: 10.1074/jbc.m806932200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To identify surface-accessible residues and monitor conformational changes of the type I inositol 1,4,5-trisphosphate receptor protein in membranes, we have introduced 10 cysteine substitutions into the N-terminal ligand-binding domain. The reactivity of these mutants with progressively larger maleimide-polyethylene glycol derivatives (MPEG) was measured using a gel shift assay of tryptic fragments. The results indicate that the mutations fall into four categories as follows: sites that are highly accessible based on reactivity with the largest 20-kDa MPEG (S2C); sites that are moderately accessible based on reactivity only with 5-kDa MPEG (S6C, S7C, A189C, and S277C); sites whose accessibility is markedly enhanced by Ca(2+) (S171C, S277C, and A575C); and sites that are inaccessible irrespective of incubation conditions (S217C, A245C, and S436C). The stimulation of accessibility induced by Ca(2+) at the S277C site occurred with an EC(50) of 0.8 mum and was mimicked by Sr(2+) but not Ba(2+). Inositol 1,4,5-trisphosphate alone did not affect reactivity of any of the mutants in the presence or absence of Ca(2+). The data are interpreted using crystal structures and EM reconstructions of the receptor. Our data identify N-terminal regions of the protein that become exposed upon Ca(2+) binding and suggest possible orientations of the suppressor and ligand-binding domains that have implications for the mechanism of gating of the channel.
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Affiliation(s)
- Georgia Anyatonwu
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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24
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A calmodulin antagonist reveals a calmodulin-independent interdomain interaction essential for activation of inositol 1,4,5-trisphosphate receptors. Biochem J 2008; 416:243-53. [PMID: 18637794 DOI: 10.1042/bj20080861] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
CaM (calmodulin) has been implicated in the regulation of IP3R [IP3 (inositol 1,4,5-trisphosphate) receptors] and a recent report suggested that CaM tightly tethered to IP3R was essential for IP3R activation [Nadif Kasri, Torok, Galione, Garnham, Callewaert, Missiaen, Parys and De Smedt (2006) J. Biol. Chem. 281, 8332-8338]. In the present study, we confirm that a CaM-binding peptide derived from MLCK (myosin light chain kinase) inhibits IP3-evoked Ca2+ release via all three IP3R subtypes. However,inhibition by MLCK peptide is not mimicked by other CaM antagonists that effectively block regulation of IP3R by CaM. Inhibition by MLCK peptide is rapid, fully reversible and occurs under conditions where there is no CaM associated with IP3R. MLCK peptide stimulates IP3 binding to IP3R1 and to its bacterially expressed N-terminal, but not after removal of the suppressor domain (residues 1-224).We suggest that MLCK peptide mimics a sequence within the suppressor domain that is similar to a1-8-14 CaM-binding motif. The peptide may thereby unzip an interdomain interaction that is essential for IP3R activation. We conclude that CaM is not essential for IP3R activation, and that MLCK peptide is a selective antagonist of the IP3R that binds directly to the N-terminal to uncouple IP3 binding from channel gating. The results of the present study highlight the importance of the suppressor domain in IP3R activation and suggest that MLCK peptide may provide a route to novel non-competitive antagonists of IP3R.
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25
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Devogelaere B, Verbert L, Parys JB, Missiaen L, De Smedt H. The complex regulatory function of the ligand-binding domain of the inositol 1,4,5-trisphosphate receptor. Cell Calcium 2007; 43:17-27. [PMID: 17499849 DOI: 10.1016/j.ceca.2007.04.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 03/23/2007] [Indexed: 11/21/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) can be divided in three functionally distinct regions: a ligand-binding domain, a modulatory domain and a channel domain. Numerous regulatory mechanisms including inter- and intra-molecular protein-protein interactions and phosphorylation events act via these domains to regulate the function of the IP(3)R. Regulation at the level of the ligand-binding domain primarily affects the affinity for IP(3). The extent of IP(3)-induced Ca(2+) release (IICR) is, however, not only determined by the affinity for IP(3) but also by the effectiveness of the coupling between ligand binding and channel opening. As a result, regulation as well as malfunction of IICR may be affected by both steps in the activation mechanism. The 3D structures of the two subdomains of the ligand-binding domain have recently been determined by X-ray diffraction analysis. This allows a more detailed molecular explanation of the regulatory events situated at the ligand-binding domain of the IP(3)R. In this review, we will focus on recent structural and functional data on the ligand-binding domain that have extended and clarified the view on the molecular mechanisms of IP(3)R regulation.
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Affiliation(s)
- Benoit Devogelaere
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
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26
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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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27
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Devogelaere B, Nadif Kasri N, Derua R, Waelkens E, Callewaert G, Missiaen L, Parys JB, De Smedt H. Binding of IRBIT to the IP3 receptor: Determinants and functional effects. Biochem Biophys Res Commun 2006; 343:49-56. [PMID: 16527252 DOI: 10.1016/j.bbrc.2006.02.119] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Accepted: 02/21/2006] [Indexed: 11/26/2022]
Abstract
IRBIT has previously been shown to interact with the inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) in an IP3-sensitive way. So far it remained to be elucidated whether this interaction was direct or indirect, and whether it was functionally relevant. We now show that IRBIT can directly interact with the IP3R, and that both the suppressor domain and the IP3-binding core of the IP3R are essential for a strong interaction. Moreover, we identified a PEST motif and a PDZ-ligand on IRBIT which were critical for the interaction with the IP3R. Furthermore, we identified Asp-73 as a critical residue for this interaction. Finally, we demonstrated that this interaction functionally affects the IP3R: IRBIT inhibits both IP3 binding and IP3-induced Ca2+ release.
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Affiliation(s)
- Benoit Devogelaere
- Laboratorium voor Fysiologie, Katholieke Universiteit Leuven Campus Gasthuisberg O/N1, Leuven, Belgium
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28
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Kasri NN, Török K, Galione A, Garnham C, Callewaert G, Missiaen L, Parys JB, De Smedt H. Endogenously Bound Calmodulin Is Essential for the Function of the Inositol 1,4,5-Trisphosphate Receptor. J Biol Chem 2006; 281:8332-8. [PMID: 16410249 DOI: 10.1074/jbc.m510971200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Calmodulin (CaM) is a ubiquitous Ca2+ sensor protein that plays an important role in regulating a large number of Ca2+ channels, including the inositol 1,4,5-trisphosphate receptor (IP3R). Despite many efforts, the exact mechanism by which CaM regulates the IP3R still remains elusive. Here we show, using unidirectional 45Ca2+ flux experiments on permeabilized L15 fibroblasts and COS-1 cells, that endogenously bound CaM is essential for the proper activation of the IP3R. Removing endogenously bound CaM by titration with a high affinity (pM) CaM-binding peptide derived from smooth muscle myosin light-chain kinase (MLCK peptide) strongly inhibited IP3-induced Ca2+ release. This inhibition was concentration- and time-dependent. Removing endogenously bound CaM affected the maximum release capacity but not its sensitivity to IP3. A mutant peptide with a strongly reduced affinity for CaM did not affect inhibited IP3-induced Ca2+ release. Furthermore, the inhibition by the MLCK peptide was fully reversible. Re-adding exogenous CaM, but not CaM1234, reactivated the IP3R. These data suggest that, by using a specific CaM-binding peptide, we removed endogenously bound CaM from a high affinity CaM-binding site on the IP3R, and this resulted in a complete loss of the IP3R activity. Our data support a new model whereby CaM is constitutively associated with the IP3R and functions as an essential subunit for proper functioning of the IP3R.
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Affiliation(s)
- Nael Nadif Kasri
- Laboratorium voor Fysiologie, K. U. Leuven Campus Gasthuisberg, O/N Herestraat 49/802, B-3000 Leuven, Belgium
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Bezprozvanny I. The inositol 1,4,5-trisphosphate receptors. Cell Calcium 2005; 38:261-72. [PMID: 16102823 DOI: 10.1016/j.ceca.2005.06.030] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 10/25/2022]
Abstract
The inositol (1,4,5)-trisphosphate receptors (InsP3R) are the intracellular calcium (Ca2+) release channels that play a key role in Ca2+ signaling in cells. Three InsP3R isoforms-InsP3R type 1 (InsP3R1), InsP3R type 2 (InsP3R2), and InsP3R type 3 (InsP3R3) are expressed in mammals. A single InsP3R isoform is expressed in Drosophila melanogaster (DmInsP3R) and Caenorhabditis elegans (CeInsP3R). The progress made during last decade towards understanding the function and the properties of the InsP3R is briefly reviewed in this chapter. The main emphasis is on studies that revealed structural determinants responsible for the ligand recognition by the InsP3R, ion permeability of the InsP3R, modulation of the InsP3R by cytosolic Ca2+, ATP and PKA phosphorylation and on the recently identified InsP3R-binding partners. The main focus is on the InsP3R1, but the recent information about properties of other InsP3R isoforms is also discussed.
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MESH Headings
- Animals
- Humans
- Inositol 1,4,5-Trisphosphate/chemistry
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate/physiology
- Inositol 1,4,5-Trisphosphate Receptors/chemistry
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/physiology
- Protein Isoforms/chemistry
- Protein Isoforms/genetics
- Protein Isoforms/physiology
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Affiliation(s)
- Ilya Bezprozvanny
- University of Texas, Department of Physiology, UT Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, Texas 75390-9040, USA.
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Nadif Kasri N, Bultynck G, Parys JB, Callewaert G, Missiaen L, De Smedt H. Suramin and disulfonated stilbene derivatives stimulate the Ca2+-induced Ca2+ -release mechanism in A7r5 cells. Mol Pharmacol 2005; 68:241-50. [PMID: 15851651 DOI: 10.1124/mol.105.013045] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We have described previously a novel Ca2+-induced Ca2+-release (CICR) mechanism in permeabilized A7r5 cells (embryonic rat aorta) and 16HBE14o-cells (human bronchial mucosa) cells (J Biol Chem 278:27548-27555, 2003). This CICR mechanism was activated upon the elevation of the free cytosolic calcium concentration [Ca2+]c and was not inhibited by pharmacological inhibitors of the inositol-1,4,5-trisphosphate (IP3) receptor nor of the ryanodine receptor. This CICR mechanism was inhibited by calmodulin (CaM)1234, a Ca2+-insensitive CaM mutant, and by different members of the superfamily of CaM-like Ca2+-binding proteins. Here, we present evidence that the CICR mechanism that is expressed in A7r5 and 16HBE14o-cells is strongly activated by suramin and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS). We found several indications that both activation mechanisms are indeed two different modes of the same release system. Suramin/DIDS-induced Ca2+ release was only detected in cells that displayed the CICR mechanism, and cell types that do not express this type of CICR mechanism did not exhibit suramin/DIDS-induced Ca2+ release. Furthermore, we show that the suramin-stimulated Ca2+ release is regulated by Ca2+ and CaM in a similar way as the previously described CICR mechanism. The pharmacological characterization of the suramin/DIDS-induced Ca2+ release further confirms its properties as a novel CaM-regulated Ca2+-release mechanism. We also investigated the effects of disulfonated stilbene derivatives on IP3-induced Ca2+ release and found, in contrast to the effect on CICR, a strong inhibition by DIDS and 4'-acetoamido-4'-isothiocyanostilbene-2',2'-disulfonic acid.
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Affiliation(s)
- Nael Nadif Kasri
- Laboratorium voor Fysiologie, Katholieke Universiteit Leuven Campus Gasthuisberg Herestraat 49/802, B-3000 Leuven, Belgium
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Bosanac I, Yamazaki H, Matsu-Ura T, Michikawa T, Mikoshiba K, Ikura M. Crystal Structure of the Ligand Binding Suppressor Domain of Type 1 Inositol 1,4,5-Trisphosphate Receptor. Mol Cell 2005; 17:193-203. [PMID: 15664189 DOI: 10.1016/j.molcel.2004.11.047] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2004] [Revised: 11/15/2004] [Accepted: 11/24/2004] [Indexed: 12/31/2022]
Abstract
Binding of inositol 1,4,5-trisphosphate (IP(3)) to the amino-terminal region of IP(3) receptor promotes Ca(2+) release from the endoplasmic reticulum. Within the amino terminus, the first 220 residues directly preceding the IP(3) binding core domain play a key role in IP(3) binding suppression and regulatory protein interaction. Here we present a crystal structure of the suppressor domain of the mouse type 1 IP(3) receptor at 1.8 A. Displaying a shape akin to a hammer, the suppressor region contains a Head subdomain forming the beta-trefoil fold and an Arm subdomain possessing a helix-turn-helix structure. The conserved region on the Head subdomain appeared to interact with the IP(3) binding core domain and is in close proximity to the previously proposed binding sites of Homer, RACK1, calmodulin, and CaBP1. The present study sheds light onto the mechanism underlying the receptor's sensitivity to the ligand and its communication with cellular signaling proteins.
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Affiliation(s)
- Ivan Bosanac
- Division of Molecular and Structural Biology, Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ontario, M5G 2M9, Canada
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Bosanac I, Michikawa T, Mikoshiba K, Ikura M. Structural insights into the regulatory mechanism of IP3 receptor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1742:89-102. [PMID: 15590059 DOI: 10.1016/j.bbamcr.2004.09.016] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Revised: 09/10/2004] [Accepted: 09/14/2004] [Indexed: 12/15/2022]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP(3)R) are intracellular Ca(2+) release channels whose opening requires binding of two intracellular messengers IP(3) and Ca(2+). The regulation of IP(3)R function has also been shown to involve a variety of cellular proteins. Recent biochemical and structural analyses have deepened our understanding of how the IP(3)-operated Ca(2+) channel functions. Specifically, the atomic resolution structure of the IP(3)-binding region has provided a sound structural basis for the receptor interaction with the natural ligand. Electron microscopic studies have also shed light on the overall shape of the tetrameric receptor. This review aims to provide comprehensive overview of the current information available on the structure and function relationship of IP(3)R.
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Affiliation(s)
- Ivan Bosanac
- Division of Molecular and Structural Biology, Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ontario, Canada M5G 2M9
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Rossi AM, Taylor CW. Ca2+Regulation of Inositol 1,4,5-trisphosphate Receptors: Can Ca2+Function without Calmodulin? Mol Pharmacol 2004; 66:199-203. [PMID: 15266009 DOI: 10.1124/mol.104.002592] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
All Ca(2+) channels are regulated by Ca(2+), a feature that allows them to respond to their own activity and to the activities of neighboring Ca(2+) channels. Inhibition by Ca(2+) protects cells from potentially hazardous increases in cytosolic [Ca(2+)], and stimulation can mediate facilitation and regenerative propagation of Ca(2+) signals. Calmodulin is emerging as a key player in regulation of Ca(2+) channels by Ca(2+), but its role is more complex and more beautiful than might have been imagined.
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Affiliation(s)
- Ana M Rossi
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK.
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