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Abstract
In the body, extracellular stimuli produce inositol 1,4,5-trisphosphate (IP3), an intracellular chemical signal that binds to the IP3 receptor (IP3R) to release calcium ions (Ca2+) from the endoplasmic reticulum. In the past 40 years, the wide-ranging functions mediated by IP3R and its genetic defects causing a variety of disorders have been unveiled. Recent cryo-electron microscopy and X-ray crystallography have resolved IP3R structures and begun to integrate with concurrent functional studies, which can explicate IP3-dependent opening of Ca2+-conducting gates placed ∼90 Å away from IP3-binding sites and its regulation by Ca2+. This review highlights recent research progress on the IP3R structure and function. We also propose how protein plasticity within IP3R, which involves allosteric gating and assembly transformations accompanied by rapid and chronic structural changes, would enable it to regulate diverse functions at cellular microdomains in pathophysiological states.
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Affiliation(s)
- Kozo Hamada
- Laboratory of Cell Calcium Signaling, Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai, 201210, China; ,
| | - Katsuhiko Mikoshiba
- Laboratory of Cell Calcium Signaling, Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai, 201210, China; ,
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Yang D, Xiao P, Li Q, Fu X, Pan C, Lu D, Wen S, Xia W, He D, Li H, Fang H, Shen Y, Xu Z, Lin A, Wang C, Yu X, Wu J, Sun J. Allosteric modulation of the catalytic VYD loop in Slingshot by its N-terminal domain underlies both Slingshot auto-inhibition and activation. J Biol Chem 2018; 293:16226-16241. [PMID: 30154244 DOI: 10.1074/jbc.ra118.004175] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/21/2018] [Indexed: 12/22/2022] Open
Abstract
Slingshots are phosphatases that modulate cytoskeleton dynamics, and their activities are tightly regulated in different physiological contexts. Recently, abnormally elevated Slingshot activity has been implicated in many human diseases, such as cancer, Alzheimer's disease, and vascular diseases. Therefore, Slingshot-specific inhibitors have therapeutic potential. However, an enzymological understanding of the catalytic mechanism of Slingshots and of their activation by actin is lacking. Here, we report that the N-terminal region of human Slingshot2 auto-inhibits its phosphatase activity in a noncompetitive manner. pH-dependent phosphatase assays and leaving-group dependence studies suggested that the N-terminal domain of Slingshot2 regulates the stability of the leaving group of the product during catalysis by modulating the general acid Asp361 in the catalytic VYD loop. F-actin binding relieved this auto-inhibition and restored the function of the general acid. Limited tryptic digestion and biophysical studies identified large conformational changes in Slingshot2 after the F-actin binding. The dissociation of N-terminal structural elements, including Leu63, and the exposure of the loop between α-helix-2 and β-sheet-3 of the phosphatase domain served as the structural basis for Slingshot activation via F-actin binding in vitro and via neuregulin stimulation in cells. Moreover, we designed a FlAsH-BRET-based Slingshot2 biosensor whose readout was highly correlated with the in vivo phosphatase activities of Slingshot2. Our results reveal the auto-inhibitory mechanism and allosteric activation mechanisms of a human Slingshot phosphatase. They also contribute to the design of new strategies to study Slingshot regulation in various cellular contexts and to screen for new activators/inhibitors of Slingshot activity.
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Affiliation(s)
- Duxiao Yang
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and
| | - Peng Xiao
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and.,the School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong 250012, China
| | - Qing Li
- the Department of Physiology, Shandong University School of Medicine, Jinan, Shandong 250012, China
| | - Xiaolei Fu
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and
| | - Chang Pan
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and
| | - Di Lu
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and
| | - Shishuai Wen
- the School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong 250012, China
| | - Wanying Xia
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and
| | - Dongfang He
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and
| | - Hui Li
- the Department of Physiology, Shandong University School of Medicine, Jinan, Shandong 250012, China
| | - Hao Fang
- the School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong 250012, China
| | - Yuemao Shen
- the School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong 250012, China
| | - Zhigang Xu
- the School of Life Science, Shandong University, Jinan, Shandong 250003, China
| | - Amy Lin
- the School of Medicine, Duke University, Durham, North Carolina 27705
| | - Chuan Wang
- the Department of Pharmacology, Hebei Medical University, Shijiazhuang 050017, China
| | - Xiao Yu
- the Department of Physiology, Shandong University School of Medicine, Jinan, Shandong 250012, China
| | - Jiawei Wu
- the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jinpeng Sun
- From the Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, and .,the Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China, and.,the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Peking University, Beijing 100191, China
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3
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Abstract
Inositol 1,4,5-trisphosphate receptors (IP3Rs) and ryanodine receptors are the channels responsible for Ca(2+)release from the endoplasmic and sarcoplasmic reticulum. Research inScience Signalingby Alzayadyet al show that all four IP3-binding sites within the tetrameric IP3R must bind IP3before the channel can open, which has important consequences for the distribution of both IP3and IP3R activity within cells.
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Affiliation(s)
- Colin W Taylor
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK.
| | - Vera Konieczny
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
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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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Aberrant calcium signaling by transglutaminase-mediated posttranslational modification of inositol 1,4,5-trisphosphate receptors. Proc Natl Acad Sci U S A 2014; 111:E3966-75. [PMID: 25201980 DOI: 10.1073/pnas.1409730111] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The inositol 1,4,5-trisphosphate receptor (IP3R) in the endoplasmic reticulum mediates calcium signaling that impinges on intracellular processes. IP3Rs are allosteric proteins comprising four subunits that form an ion channel activated by binding of IP3 at a distance. Defective allostery in IP3R is considered crucial to cellular dysfunction, but the specific mechanism remains unknown. Here we demonstrate that a pleiotropic enzyme transglutaminase type 2 targets the allosteric coupling domain of IP3R type 1 (IP3R1) and negatively regulates IP3R1-mediated calcium signaling and autophagy by locking the subunit configurations. The control point of this regulation is the covalent posttranslational modification of the Gln2746 residue that transglutaminase type 2 tethers to the adjacent subunit. Modification of Gln2746 and IP3R1 function was observed in Huntington disease models, suggesting a pathological role of this modification in the neurodegenerative disease. Our study reveals that cellular signaling is regulated by a new mode of posttranslational modification that chronically and enzymatically blocks allosteric changes in the ligand-gated channels that relate to disease states.
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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: 142] [Impact Index Per Article: 14.2] [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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Bhanumathy C, da Fonseca PCA, Morris EP, Joseph SK. Identification of functionally critical residues in the channel domain of inositol trisphosphate receptors. J Biol Chem 2012; 287:43674-84. [PMID: 23086950 PMCID: PMC3527953 DOI: 10.1074/jbc.m112.415786] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have combined alanine mutagenesis and functional assays to identify amino acid residues in the channel domain that are critical for inositol 1,4,5-trisphosphate receptor (IP(3)R) channel function. The residues selected were highly conserved in all three IP(3)R isoforms and were located in the cytosolic end of the S6 pore-lining helix and proximal portion of the C-tail. Two adjacent hydrophobic amino acids (Ile-2588 and Ile-2589) at the putative cytosolic interface of the S6 helix inactivated channel function and could be candidates for the channel gate. Of five negatively charged residues mutated, none completely eliminated channel function. Of five positively charged residues mutated, only one inactivated the channel (Arg-2596). In addition to the previously identified role of a pair of cysteines in the C-tail (Cys-2610 and Cys-2613), a pair of highly conserved histidines (His-2630 and His-2635) were also essential for channel function. Expression of the H2630A and H2635A mutants (but not R2596A) produced receptors with destabilized interactions between the N-terminal fragment and the channel domain. A previously unrecognized association between the cytosolic C-tail and the TM 4,5-loop was demonstrated using GST pulldown assays. However, none of the mutations in the C-tail interfered with this interaction or altered the ability of the C-tail to assemble into dimers. Our present findings and recent information on IP(3)R structure from electron microscopy and crystallography are incorporated into a revised model of channel gating.
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MESH Headings
- Amino Acid Substitution
- Animals
- COS Cells
- Chlorocebus aethiops
- HEK293 Cells
- Humans
- Inositol 1,4,5-Trisphosphate Receptors/chemistry
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Ion Channel Gating/physiology
- Models, Molecular
- Mutation, Missense
- Protein Multimerization/physiology
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Rats
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Affiliation(s)
- Cunnigaiper Bhanumathy
- From the Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 and
| | - Paula C. A. da Fonseca
- the Institute for Cancer Research, Chester Beatty Laboratories, London, SW3 6JB, United Kingdom
| | - Edward P. Morris
- the Institute for Cancer Research, Chester Beatty Laboratories, London, SW3 6JB, United Kingdom
| | - Suresh K. Joseph
- From the Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 and
- To whom correspondence should be addressed: Dept. of Pathology & Cell Biology, Rm. 230A JAH, 1020 Locust St., Philadelphia, PA 19107. Tel.: 215-503-1222; E-mail:
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Akl H, Bultynck G. Altered Ca(2+) signaling in cancer cells: proto-oncogenes and tumor suppressors targeting IP3 receptors. Biochim Biophys Acta Rev Cancer 2012; 1835:180-93. [PMID: 23232185 DOI: 10.1016/j.bbcan.2012.12.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/30/2012] [Accepted: 12/01/2012] [Indexed: 01/15/2023]
Abstract
Proto-oncogenes and tumor suppressors critically control cell-fate decisions like cell survival, adaptation and death. These processes are regulated by Ca(2+) signals arising from the endoplasmic reticulum, which at distinct sites is in close proximity to the mitochondria. These organelles are linked by different mechanisms, including Ca(2+)-transport mechanisms involving the inositol 1,4,5-trisphosphate receptor (IP3R) and the voltage-dependent anion channel (VDAC). The amount of Ca(2+) transfer from the endoplasmic reticulum to mitochondria determines the susceptibility of cells to apoptotic stimuli. Suppressing the transfer of Ca(2+) from the endoplasmic reticulum to the mitochondria increases the apoptotic resistance of cells and may decrease the cellular responsiveness to apoptotic signaling in response to cellular damage or alterations. This can result in the survival, growth and proliferation of cells with oncogenic features. Clearly, proper maintenance of endoplasmic reticulum Ca(2+) homeostasis and dynamics including its links with the mitochondrial network is essential to detect and eliminate altered cells with oncogenic features through the apoptotic pathway. Proto-oncogenes and tumor suppressors exploit the central role of Ca(2+) signaling by targeting the IP3R. There are an increasing number of reports showing that activation of proto-oncogenes or inactivation of tumor suppressors directly affects IP3R function and endoplasmic reticulum Ca(2+) homeostasis, thereby decreasing mitochondrial Ca(2+) uptake and mitochondrial outer membrane permeabilization. In this review, we provide an overview of the current knowledge on the proto-oncogenes and tumor suppressors identified as IP3R-regulatory proteins and how they affect endoplasmic reticulum Ca(2+) homeostasis and dynamics.
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Affiliation(s)
- Haidar Akl
- Department Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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Blanco R, Alarcón B. TCR Nanoclusters as the Framework for Transmission of Conformational Changes and Cooperativity. Front Immunol 2012; 3:115. [PMID: 22582078 PMCID: PMC3348506 DOI: 10.3389/fimmu.2012.00115] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 04/22/2012] [Indexed: 12/30/2022] Open
Abstract
Increasing evidence favors the notion that, before triggering, the T cell antigen receptor (TCR) forms nanometer-scale oligomers that are called nanoclusters. The organization of the TCR in pre-existing oligomers cannot be ignored when analyzing the properties of ligand (pMHC) recognition and signal transduction. As with other membrane receptors, the existence of TCR oligomers points out to cooperativity phenomena. We review the data in support of conformational changes in the TCR as the basic principle to transduce the activation signal to the cytoplasm and the incipient data suggesting cooperativity within nanoclusters.
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Affiliation(s)
- Raquel Blanco
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid Madrid, Spain
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10
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Abstract
Ca2+ transfer from endoplasmic reticulum (ER) to mitochondria can trigger apoptotic pathways by inducing release of mitochondrial pro-apoptotic factors. Three different types of inositol 1,4,5-trisphosphate receptor (IP3R) serve to discharge Ca2+ from ER, but possess some peculiarities, especially in apoptosis induction. The anti-apoptotic protein Akt can phosphorylate all IP3R isoforms and protect cells from apoptosis, reducing ER Ca2+ release. However, it has not been elucidated which IP3R subtypes mediate these effects. Here, we show that Akt activation in COS7 cells, which lack of IP3R I, strongly suppresses IP3-mediated Ca2+ release and apoptosis. Conversely, in SH-SY 5Y cells, which are type III-deficient, Akt is unable to modulate ER Ca2+ flux, losing its anti-apoptotic activity. In SH-SY 5Y-expressing subtype III, Akt recovers its protective function on cell death, by reduction of Ca2+ release. Moreover, regulating Ca2+ flux to mitochondria, Akt maintains the mitochondrial integrity and delays the trigger of apoptosis, in a type III-dependent mechanism. These results demonstrate a specific activity of Akt on IP3R III, leading to diminished Ca2+ transfer to mitochondria and protection from apoptosis, suggesting an additional level of cell death regulation mediated by Akt.
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Decuypere JP, Monaco G, Bultynck G, Missiaen L, De Smedt H, Parys JB. The IP(3) receptor-mitochondria connection in apoptosis and autophagy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1813:1003-13. [PMID: 21146562 DOI: 10.1016/j.bbamcr.2010.11.023] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 11/24/2010] [Accepted: 11/25/2010] [Indexed: 01/08/2023]
Abstract
The amount of Ca(2+) taken up in the mitochondrial matrix is a crucial determinant of cell fate; it plays a decisive role in the choice of the cell between life and death. The Ca(2+) ions mainly originate from the inositol 1,4,5-trisphosphate (IP(3))-sensitive Ca(2+) stores of the endoplasmic reticulum (ER). The uptake of these Ca(2+) ions in the mitochondria depends on the functional properties and the subcellular localization of the IP(3) receptor (IP(3)R) in discrete domains near the mitochondria. To allow for an efficient transfer of the Ca(2+) ions from the ER to the mitochondria, structural interactions between IP(3)Rs and mitochondria are needed. This review will focus on the key proteins involved in these interactions, how they are regulated, and what are their physiological roles in apoptosis, necrosis and autophagy. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
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Affiliation(s)
- Jean-Paul Decuypere
- Laboratory of Molecular and Cellular Signalling, Dept. Molecular and Cellular, campus Gasthuisberg O/N1 K.U.Leuven, Bus 802, B-3000 Leuven, Belgium
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Joseph SK. Role of thiols in the structure and function of inositol trisphosphate receptors. CURRENT TOPICS IN MEMBRANES 2010; 66:299-322. [PMID: 22353485 DOI: 10.1016/s1063-5823(10)66013-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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13
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Yule DI, Betzenhauser MJ, Joseph SK. Linking structure to function: Recent lessons from inositol 1,4,5-trisphosphate receptor mutagenesis. Cell Calcium 2010; 47:469-79. [PMID: 20510450 DOI: 10.1016/j.ceca.2010.04.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 04/21/2010] [Accepted: 04/22/2010] [Indexed: 12/12/2022]
Abstract
Great insight has been gained into the structure and function of the inositol 1,4,5 trisphosphate receptor (InsP(3)R) by studies employing mutagenesis of the cDNA encoding the receptor. Notably, early studies using this approach defined the key constituents required for InsP(3) binding in the N-terminus and the membrane spanning regions in the C-terminal domain responsible for channel formation, targeting and function. In this article we evaluate recent studies which have used a similar approach to investigate key residues underlying the in vivo modulation by select regulatory factors. In addition, we review studies defining the structural requirements in the channel domain which comprise the conduction pathway and are suggested to be involved in the gating of the channel.
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Affiliation(s)
- David I Yule
- Department of Pharmacology and Physiology, University of Rochester, NY, United States.
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