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Liardo E, Pham AT, Ghilardi AF, Zhelay T, Szteyn K, Gandi NL, Ekkati A, Koerner S, Kozak JA, Sun L. Discovery of selective Orai channel blockers bearing an indazole or a pyrazole scaffold. Eur J Med Chem 2024; 278:116805. [PMID: 39232360 DOI: 10.1016/j.ejmech.2024.116805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 08/19/2024] [Accepted: 08/26/2024] [Indexed: 09/06/2024]
Abstract
The calcium release activated calcium (CRAC) channel is highly expressed in T lymphocytes and plays a critical role in regulating T cell proliferation and functions including activation of the transcription factor nuclear factor of activated T cells (NFAT), cytokine production and cytotoxicity. The CRAC channel consists of the Orai pore subunit and STIM (stromal interacting molecule) endoplasmic reticulum calcium sensor. Loss of CRAC channel mediated calcium signaling has been identified as an underlying cause of severe combined immunodeficiency (SCID), leading to drastically weakened immunity against infections. Gain-of-function mutations in Orai and STIM have been associated with tubular aggregated myopathy (TAM), a skeletal muscle disease. While a number of small molecules have shown activity in inhibiting the CRAC signaling pathway, the usefulness of those tool compounds is limited by their off-target activity against TRPM4 and TRPM7 ion channels, high lipophilicity, and a lack of understanding of their mechanism of action. We report structure-activity relationship (SAR) studies that resulted in the characterization of compound 4k [1-(cyclopropylmethyl)-N-(3-fluoropyridin-4-yl)-1H-indazole-3-carboxamie] as a fast onset, reversible, and selective CRAC channel blocker. 4k fully blocked the CRAC current (IC50: 4.9 μM) and the nuclear translocation of NFAT at 30 and 10 μM, respectively, without affecting the electrophysiological function of TRPM4 and TRPM7 channels. Computational modeling appears to support its direction binding to Orai proteins that form the transmembrane CRACchannel.
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Affiliation(s)
- Elisa Liardo
- Center for Drug Discovery and Translational Research, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Anh-Tuan Pham
- Center for Drug Discovery and Translational Research, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Amanda F Ghilardi
- Center for Drug Discovery and Translational Research, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Tetyana Zhelay
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Kalina Szteyn
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Naga Lakshmi Gandi
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Anil Ekkati
- Center for Drug Discovery and Translational Research, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Steffi Koerner
- Center for Drug Discovery and Translational Research, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - J Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA.
| | - Lijun Sun
- Center for Drug Discovery and Translational Research, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA.
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2
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Torres-Rico M, García-Calvo V, Gironda-Martínez A, Pascual-Guerra J, García AG, Maneu V. Targeting calciumopathy for neuroprotection: focus on calcium channels Cav1, Orai1 and P2X7. Cell Calcium 2024; 123:102928. [PMID: 39003871 DOI: 10.1016/j.ceca.2024.102928] [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: 05/30/2024] [Revised: 07/02/2024] [Accepted: 07/05/2024] [Indexed: 07/16/2024]
Abstract
As the uncontrolled entry of calcium ions (Ca2+) through plasmalemmal calcium channels is a cell death trigger, the conjecture is here raised that mitigating such an excess of Ca2+ entry should rescue from death the vulnerable neurons in neurodegenerative diseases (NDDs). However, this supposition has failed in some clinical trials (CTs). Thus, a recent CT tested whether isradipine, a blocker of the Cav1 subtype of voltage-operated calcium channels (VOCCs), exerted a benefit in patients with Parkinson's disease (PD); however, outcomes were negative. This is one more of the hundreds of CTs done under the principle of one-drug-one-target, that have failed in Alzheimer's disease (AD) and other NDDs during the last three decades. As there are myriad calcium channels to let Ca2+ ions gain the cell cytosol, it seems reasonable to predict that blockade of Ca2+ entry through a single channel may not be capable of preventing the Ca2+ flood of cells by the uncontrolled Ca2+ entry. Furthermore, as Ca2+ signaling is involved in the regulation of myriad functions in different cell types, it seems also reasonable to guess that a therapy should be more efficient by targeting different cells with various drugs. Here, we propose to mitigate Ca2+ entry by the simultaneous partial blockade of three quite different subtypes of plasmalemmal calcium channels that is, the Cav1 subtype of VOCCs, the Orai1 store-operated calcium channel (SOCC), and the purinergic P2X7 calcium channel. All three channels are expressed in both microglia and neurons. Thus, by targeting the three channels with a combination of three drug blockers we expect favorable changes in some of the pathogenic features of NDDs, namely (i) to mitigate Ca2+ entry into microglia; (ii) to decrease the Ca2+-dependent microglia activation; (iii) to decrease the sustained neuroinflammation; (iv) to decrease the uncontrolled Ca2+ entry into neurons; (v) to rescue vulnerable neurons from death; and (vi) to delay disease progression. In this review we discuss the arguments underlying our triad hypothesis in the sense that the combination of three repositioned medicines targeting Cav1, Orai1, and P2X7 calcium channels could boost neuroprotection and delay the progression of AD and other NDDs.
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Affiliation(s)
| | | | - Adrián Gironda-Martínez
- Instituto Fundación Teófilo Hernando, Madrid, Spain; Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Antonio G García
- Instituto Fundación Teófilo Hernando, Madrid, Spain; Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain; Facultad de Medicina, Instituto de Investigación Sanitaria del Hospital Universitario La Princesa, Universidad Autónoma de Madrid, Madrid, Spain.
| | - Victoria Maneu
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain.
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3
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Nieto-Felipe J, Macias-Díaz A, Jimenez-Velarde V, Lopez JJ, Salido GM, Smani T, Jardin I, Rosado JA. Feedback modulation of Orai1α and Orai1β protein content mediated by STIM proteins. J Cell Physiol 2024:e31450. [PMID: 39359018 DOI: 10.1002/jcp.31450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 09/03/2024] [Accepted: 09/20/2024] [Indexed: 10/04/2024]
Abstract
Store-operated Ca2+ entry is a mechanism controlled by the filling state of the intracellular Ca2+ stores, predominantly the endoplasmic reticulum (ER), where ER-resident proteins STIM1 and STIM2 orchestrate the activation of Orai channels in the plasma membrane, and Orai1 playing a predominant role. Two forms of Orai1, Orai1α and Orai1β, have been identified, which arises the question whether they are equally regulated by STIM proteins. We demonstrate that STIM1 preferentially activates Orai1α over STIM2, yet both STIM proteins similarly activate Orai1β. Under resting conditions, there is a pronounced association between STIM2 and Orai1α. STIM1 and STIM2 are also shown to influence the protein levels of the Orai1 variants, independently of Ca2+ influx, via lysosomal degradation. Interestingly, Orai1α and Orai1β appear to selectively regulate the protein level of STIM1, but not STIM2. These observations offer crucial insights into the regulatory dynamics between STIM proteins and Orai1 variants, enhancing our understanding of the intricate processes that fine-tune intracellular Ca2+ signaling.
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Affiliation(s)
- Joel Nieto-Felipe
- Department of Physiology (Cellular Physiology Research Group), Institute of Molecular Pathology Biomarkers (IMPB), University of Extremadura, Caceres, Spain
| | - Alvaro Macias-Díaz
- Department of Physiology (Cellular Physiology Research Group), Institute of Molecular Pathology Biomarkers (IMPB), University of Extremadura, Caceres, Spain
| | - Vanesa Jimenez-Velarde
- Department of Physiology (Cellular Physiology Research Group), Institute of Molecular Pathology Biomarkers (IMPB), University of Extremadura, Caceres, Spain
| | - Jose J Lopez
- Department of Physiology (Cellular Physiology Research Group), Institute of Molecular Pathology Biomarkers (IMPB), University of Extremadura, Caceres, Spain
| | - Gines M Salido
- Department of Physiology (Cellular Physiology Research Group), Institute of Molecular Pathology Biomarkers (IMPB), University of Extremadura, Caceres, Spain
| | - Tarik Smani
- Group of Cardiovascular Pathophysiology, Institute of Biomedicine of Seville, University Hospital of Virgen del Rocío/University of Seville/CSIC, Seville, Spain
- Department of Medical Physiology and Biophysics, Faculty of Medicine, University of Seville, Seville, Spain
| | - Isaac Jardin
- Department of Physiology (Cellular Physiology Research Group), Institute of Molecular Pathology Biomarkers (IMPB), University of Extremadura, Caceres, Spain
| | - Juan A Rosado
- Department of Physiology (Cellular Physiology Research Group), Institute of Molecular Pathology Biomarkers (IMPB), University of Extremadura, Caceres, Spain
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4
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Ponnusamy T, Velusamy P, Shanmughapriya S. Mrs2-mediated mitochondrial magnesium uptake is essential for the regulation of MCU-mediated mitochondrial Ca 2+ uptake and viability. Mitochondrion 2024; 76:101877. [PMID: 38599304 DOI: 10.1016/j.mito.2024.101877] [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: 12/27/2023] [Revised: 03/07/2024] [Accepted: 04/07/2024] [Indexed: 04/12/2024]
Abstract
Mitochondrial Ca2+ uptake is essential in regulating bioenergetics, cell death, and cytosolic Ca2+ transients. Mitochondrial Calcium Uniporter (MCU) mediates the mitochondrial Ca2+ uptake. Though MCU regulation by MICUs is unequivocally established, there needs to be more knowledge of whether divalent cations regulate MCU. Here, we set out to understand the mitochondrial matrix Mg2+-dependent regulation of MCU activity. We showed that decreased matrix [Mg2+] is associated with increased MCU activity and significantly prompted mitochondrial permeability transition pore opening. Our findings support the critical role of mMg2+ in regulating MCU activity.
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Affiliation(s)
- Thiruvelselvan Ponnusamy
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Prema Velusamy
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Santhanam Shanmughapriya
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA.
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5
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Dynes JL, Yeromin AV, Cahalan MD. Photoswitching alters fluorescence readout of jGCaMP8 Ca 2+ indicators tethered to Orai1 channels. Proc Natl Acad Sci U S A 2023; 120:e2309328120. [PMID: 37729200 PMCID: PMC10523504 DOI: 10.1073/pnas.2309328120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/15/2023] [Indexed: 09/22/2023] Open
Abstract
We used electrophysiology and Ca2+ channel tethering to evaluate the performance of jGCaMP8 genetically encoded Ca2+ indicators (GECIs). Orai1 Ca2+ channel-jGCaMP8 fusions were transfected into HEK 293A cells and jGCaMP8 fluorescence responses recorded by simultaneous total internal reflection fluorescence microscopy and whole-cell patch clamp electrophysiology. Noninactivating currents from the Orai1 Y80E mutant provided a steady flux of Ca2+ controlled on a millisecond time scale by step changes in membrane potential. Test pulses to -100 mV produced Orai1 Y80E-jGCaMP8f fluorescence traces that unexpectedly declined by ~50% over 100 ms before reaching a stable plateau. Testing of Orai1-jGCaMP8f using unroofed cells further demonstrated that rapid and partial fluorescence inactivation is a property of the indicator itself, rather than channel function. Photoinactivation spontaneously recovered over 5 min in the dark, and recovery was accelerated in the absence of Ca2+. Mutational analysis of residues near the tripeptide fluorophore of jGCaMP8f pointed to a mechanism: Q69M/C70V greatly increased (~90%) photoinactivation, reminiscent of fluorescent protein fluorophore cis-trans photoswitching. Indeed, 405-nm illumination of jGCaMP8f or 8m/8s/6f led to immediate photorecovery, and simultaneous illumination with 405 and 488-nm light blocked photoinactivation. Subsequent mutagenesis produced a variant, V203Y, that lacks photoinactivation but largely preserves the desirable properties of jGCaMP8f. Our results point to caution in interpreting rapidly changing Ca2+ signals using jGCaMP8 and earlier series GECIs, suggest strategies to avoid photoswitching, and serve as a starting point to produce more photostable, and thus more accurate, GECI derivatives.
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Affiliation(s)
- Joseph L. Dynes
- Department of Physiology and Biophysics, University of California, Irvine, CA92697
| | - Andriy V. Yeromin
- Department of Physiology and Biophysics, University of California, Irvine, CA92697
| | - Michael D. Cahalan
- Department of Physiology and Biophysics, University of California, Irvine, CA92697
- Institute for Immunology, University of California, Irvine, CA92697
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6
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Ponnusamy T, Velusamy P, Kumar A, Morris D, Zhang X, Ning G, Klinger M, Copper JE, Rajan S, Cheung JY, Natarajaseenivasan K, Mnatsakanyan N, Shanmughapriya S. Mitochondrial Magnesium is the cationic rheostat for MCU-mediated mitochondrial Ca 2+ uptake. RESEARCH SQUARE 2023:rs.3.rs-3088175. [PMID: 37502932 PMCID: PMC10371168 DOI: 10.21203/rs.3.rs-3088175/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Calcium (Ca2+) uptake by mitochondria is essential in regulating bioenergetics, cell death, and cytosolic Ca2+ transients. Mitochondrial Calcium Uniporter (MCU) mediates the mitochondrial Ca2+ uptake. MCU is a heterooligomeric complex with a pore-forming component and accessory proteins required for channel activity. Though MCU regulation by MICUs is unequivocally established, there needs to be more knowledge of whether divalent cations regulate MCU. Here we set out to understand the mitochondrial matrix Mg2+-dependent regulation of MCU activity. We showed Mrs2 as the authentic mammalian mitochondrial Mg2+ channel using the planar lipid bilayer recordings. Using a liver-specific Mrs2 KO mouse model, we showed that decreased matrix [Mg2+] is associated with increased MCU activity and matrix Ca2+ overload. The disruption of Mg2+dependent MCU regulation significantly prompted mitochondrial permeability transition pore opening-mediated cell death during tissue IR injury. Our findings support a critical role for mMg2+ in regulating MCU activity and attenuating mCa2+ overload.
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Affiliation(s)
- Thiruvelselvan Ponnusamy
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Prema Velusamy
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Amrendra Kumar
- Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Daniel Morris
- Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Xueqian Zhang
- Cardiovascular Medicine, Department of Medicine, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Gang Ning
- Microscopy Core Facility, Penn State Huck Institutes of the Life Sciences, University Park, PA 16802, USA
| | - Marianne Klinger
- Department of Pathology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Jean E. Copper
- Department of Pathology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Sudarsan Rajan
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Joseph Y Cheung
- Department of Renal Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Nelli Mnatsakanyan
- Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Santhanam Shanmughapriya
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
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7
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Bibollet H, Nguyen EL, Miranda DR, Ward CW, Voss AA, Schneider MF, Hernández‐Ochoa EO. Voltage sensor current, SR Ca 2+ release, and Ca 2+ channel current during trains of action potential-like depolarizations of skeletal muscle fibers. Physiol Rep 2023; 11:e15675. [PMID: 37147904 PMCID: PMC10163276 DOI: 10.14814/phy2.15675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 05/07/2023] Open
Abstract
In skeletal muscle, CaV 1.1 serves as the voltage sensor for both excitation-contraction coupling (ECC) and L-type Ca2+ channel activation. We have recently adapted the technique of action potential (AP) voltage clamp (APVC) to monitor the current generated by the movement of intramembrane voltage sensors (IQ ) during single imposed transverse tubular AP-like depolarization waveforms (IQAP ). We now extend this procedure to monitoring IQAP , and Ca2+ currents during trains of tubular AP-like waveforms in adult murine skeletal muscle fibers, and compare them with the trajectories of APs and AP-induced Ca2+ release measured in other fibers using field stimulation and optical probes. The AP waveform remains relatively constant during brief trains (<1 sec) for propagating APs in non-V clamped fibers. Trains of 10 AP-like depolarizations at 10 Hz (900 ms), 50 Hz (180 ms), or 100 Hz (90 ms) did not alter IQAP amplitude or kinetics, consistent with previous findings in isolated muscle fibers where negligible charge immobilization occurred during 100 ms step depolarizations. Using field stimulation, Ca2+ release did exhibit a considerable decline from pulse to pulse during the train, also consistent with previous findings, indicating that the decline of Ca2+ release during a short train of APs is not correlated to modification of charge movement. Ca2+ currents during single or 10 Hz trains of AP-like depolarizations were hardly detectable, were minimal during 50 Hz trains, and became more evident during 100 Hz trains in some fibers. Our results verify predictions on the behavior of the ECC machinery in response to AP-like depolarizations and provide a direct demonstration that Ca2+ currents elicited by single AP-like waveforms are negligible, but can become more prominent in some fibers during short high-frequency train stimulation that elicits maximal isometric force.
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Affiliation(s)
- Hugo Bibollet
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Elton L. Nguyen
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Daniel R. Miranda
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Christopher W. Ward
- Department of OrthopedicsUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Andrew A. Voss
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Martin F. Schneider
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Erick O. Hernández‐Ochoa
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
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8
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Yeung PSW, Yamashita M, Prakriya M. A pathogenic human Orai1 mutation unmasks STIM1-independent rapid inactivation of Orai1 channels. eLife 2023; 12:82281. [PMID: 36806330 PMCID: PMC9991058 DOI: 10.7554/elife.82281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/10/2023] [Indexed: 02/22/2023] Open
Abstract
Ca2+ release-activated Ca2+ (CRAC) channels are activated by direct physical interactions between Orai1, the channel protein, and STIM1, the endoplasmic reticulum Ca2+ sensor. A hallmark of CRAC channels is fast Ca2+-dependent inactivation (CDI) which provides negative feedback to limit Ca2+ entry through CRAC channels. Although STIM1 is thought to be essential for CDI, its molecular mechanism remains largely unknown. Here, we examined a poorly understood gain-of-function (GOF) human Orai1 disease mutation, L138F, that causes tubular aggregate myopathy. Through pairwise mutational analysis, we determine that large amino acid substitutions at either L138 or the neighboring T92 locus located on the pore helix evoke highly Ca2+-selective currents in the absence of STIM1. We find that the GOF phenotype of the L138 pathogenic mutation arises due to steric clash between L138 and T92. Surprisingly, strongly activating L138 and T92 mutations showed CDI in the absence of STIM1, contradicting prevailing views that STIM1 is required for CDI. CDI of constitutively open T92W and L138F mutants showed enhanced intracellular Ca2+ sensitivity, which was normalized by re-adding STIM1 to the cells. Truncation of the Orai1 C-terminus reduced T92W CDI, indicating a key role for the Orai1 C-terminus for CDI. Overall, these results identify the molecular basis of a disease phenotype with broad implications for activation and inactivation of Orai1 channels.
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Affiliation(s)
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern UniversityChicagoUnited States
| | - Murali Prakriya
- Department of Pharmacology, Northwestern UniversityChicagoUnited States
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9
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Tao Y, Mallet RT, Mathis KW, Ma R. Store-operated Ca 2+ channel signaling: Novel mechanism for podocyte injury in kidney disease. Exp Biol Med (Maywood) 2022; 248:425-433. [PMID: 36533574 DOI: 10.1177/15353702221139187] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Studies over the last decade have markedly broadened our understanding of store-operated Ca2+ channels (SOCs) and their roles in kidney diseases and podocyte dysfunction. Podocytes are terminally differentiated glomerular visceral epithelial cells which are tightly attached to the glomerular capillary basement membrane. Podocytes and their unique foot processes (pedicels) constitute the outer layer of the glomerular filtration membrane and the final barrier preventing filtration of albumin and other plasma proteins. Diabetic nephropathy and other renal diseases are associated with podocyte injury and proteinuria. Recent evidence demonstrates a pivotal role of store-operated Ca2+ entry (SOCE) in maintaining structural and functional integrity of podocytes. This article reviews the current knowledge of SOCE and its contributions to podocyte physiology. Recent studies of the contributions of SOC dysfunction to podocyte injury in both cell culture and animal models are discussed, including work in our laboratory. Several downstream signaling pathways mediating SOC function in podocytes also are examined. Understanding the pivotal roles of SOC in podocyte health and disease is essential, as SOCE-activated signaling pathways are potential treatment targets for podocyte injury-related kidney diseases.
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Affiliation(s)
- Yu Tao
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Keisa W Mathis
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Rong Ma
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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10
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Wang YS, Yeh TK, Chang WC, Liou JP, Liu YM, Huang WC. 2,6-Difluorobenzamide derivatives as store-operated calcium channel (SOC) inhibitors. Eur J Med Chem 2022; 243:114773. [PMID: 36179401 DOI: 10.1016/j.ejmech.2022.114773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 08/17/2022] [Accepted: 09/10/2022] [Indexed: 11/28/2022]
Abstract
The Ca2+ entry from store-operated Ca2+ channel (SOC) is involved in regulating colorectal cancer progression, such as cell migration. SOC activation is due to STIM1 translocation and interaction with Orai1 upon Ca2+ depletion in the ER. Numerous SOC inhibitors, like 2-APB, have been developed and demonstrated their inhibition effects in the preclinical stage. However, most currently used SOC inhibitors have higher cytotoxicity or opposite effects at different doses, and the drugs to target SOC in the clinic are lacking. In this study, a total of 13 difluorobenzamide compounds had been synthesized and examined the inhibitory effects on SOC with Ca2+ imaging and wound-healing migration assay. Among them, 2,6-Difluoro-N-(5-(4-fluorophenyl)pyridine-2-yl)benzamide (MPT0M004, 8a) demonstrated a prominent inhibitory ability on SOC. Furthermore, the cell proliferation assay results showed that MPT0M004 (8a) had lower cytotoxicity than 2-APB, the reference compound. In the pharmacokinetic study, MPT0M004 (8a) has a long half-life (T1/2 = 24 h) and lower daily dose administered intravenously with an oral bioavailability (F = 34%). Therefore, MPT0M004 (8a) has the potential to be a lead compound as a SOC inhibitor and further develop into a potential drug to treat colorectal cancer.
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Affiliation(s)
- Yu-Shiuan Wang
- Ph.D. Program in Clinical Drug Development of Chinese Herbal Medicine, College of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan; Single-Molecule Biology Core Lab, Institute of Cellular and Organismic Biology (ICOB), Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 115, Taiwan
| | - Teng-Kuang Yeh
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, No. 35, Keyan Road, Zhunan Town, Miaoli County, 350401, Taiwan
| | - Wei-Chiao Chang
- Department of Clinical Pharmacy, School of Pharmacy, Taipei Medical University, Taipei, 11031, Taiwan; Department of Pharmacy, Wan Fang Hospital, Taipei Medical University, Taipei, 11696, Taiwan; Integrative Research Center for Critical Care, Wan Fang Hospital, Taipei Medical University, Taipei, 11696, Taiwan
| | - Jing-Ping Liou
- TMU Research Center for Drug Discovery, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan; School of Pharmacy, College of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan
| | - Yi-Min Liu
- TMU Research Center for Drug Discovery, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan; School of Pharmacy, College of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan.
| | - Wan-Chen Huang
- Single-Molecule Biology Core Lab, Institute of Cellular and Organismic Biology (ICOB), Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 115, Taiwan.
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11
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Barak P, Kaur S, Scappini E, Tucker CJ, Parekh AB. Plasma Membrane Ca 2+ ATPase Activity Enables Sustained Store-operated Ca 2+ Entry in the Absence of a Bulk Cytosolic Ca 2+ Rise. FUNCTION 2022; 3:zqac040. [PMID: 38989036 PMCID: PMC11234650 DOI: 10.1093/function/zqac040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 07/12/2024] Open
Abstract
In many cell types, the rise in cytosolic Ca2+ due to opening of Ca2+ release-activated Ca2+ (CRAC) channels drives a plethora of responses, including secretion, motility, energy production, and gene expression. The amplitude and time course of the cytosolic Ca2+ rise is shaped by the rates of Ca2+ entry into and removal from the cytosol. However, an extended bulk Ca2+ rise is toxic to cells. Here, we show that the plasma membrane Ca2+ ATPase (PMCA) pump plays a major role in preventing a prolonged cytosolic Ca2+ signal following CRAC channel activation. Ca2+ entry through CRAC channels leads to a sustained sub-plasmalemmal Ca2+ rise but bulk Ca2+ is kept low by the activity of PMCA4b. Despite the low cytosolic Ca2+, membrane permeability to Ca2+ is still elevated and Ca2+ continues to enter through CRAC channels. Ca2+-dependent NFAT activation, driven by Ca2+ nanodomains near the open channels, is maintained despite the return of bulk Ca2+ to near pre-stimulation levels. Our data reveal a central role for PMCA4b in determining the pattern of a functional Ca2+ signal and in sharpening local Ca2+ gradients near CRAC channels, whilst protecting cells from a toxic Ca2+ overload.
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Affiliation(s)
- Pradeep Barak
- Department of Physiology, Anatomy and Genetics, Oxford University, Oxford OX1 3PT, UK
- Oxford Nanoimaging, Linacre House, Jordan Hill Business Park Banbury Road, Oxford OX2 8TA, UK
| | - Suneet Kaur
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, NIH, Research Triangle Park NC 27709, USA
| | - Erica Scappini
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, NIH, Research Triangle Park NC 27709, USA
| | - Charles J Tucker
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, NIH, Research Triangle Park NC 27709, USA
| | - Anant B Parekh
- Department of Physiology, Anatomy and Genetics, Oxford University, Oxford OX1 3PT, UK
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, NIH, Research Triangle Park NC 27709, USA
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12
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Tedeschi V, Sisalli MJ, Pannaccione A, Piccialli I, Molinaro P, Annunziato L, Secondo A. Na +/Ca 2+ exchanger isoform 1 (NCX1) and canonical transient receptor potential channel 6 (TRPC6) are recruited by STIM1 to mediate Store-Operated Calcium Entry in primary cortical neurons. Cell Calcium 2022; 101:102525. [PMID: 34995919 DOI: 10.1016/j.ceca.2021.102525] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/05/2021] [Accepted: 12/26/2021] [Indexed: 02/01/2023]
Abstract
Excessive calcium (Ca2+) release from the endoplasmic reticulum (ER) represents an important hallmark of several neurodegenerative diseases. ER is recharged from Ca2+ through the so-called Store-Operated Calcium Entry (SOCE) thus providing Ca2+ signals to regulate critical cell functions. Single transmembrane-spanning domain protein stromal interacting molecule 1 (STIM1), mainly residing in the ER, and plasmalemmal channel Orai1 represent the SOCE key components at neuronal level. However, many other proteins participate to ER Ca2+ refilling including the Na+/Ca2+ exchanger isoform 1 (NCX1), whose regulation by ER remains unknown. In this study, we tested the possibility that neuronal NCX1 may take part to SOCE through the interaction with STIM1. In rat primary cortical neurons and in nerve growth factor (NGF)-differentiated PC12 cells NCX1 knocking down by siRNA strategy significantly prevented SOCE as well as SOCE pharmacological inhibition by SKF-96365 and 2-APB. A significant reduction of SOCE was recorded also in synaptosomes from ncx1-/- mice brain compared with ncx1+/+ mice. Double labeling confocal experiments showed a large co-localization between NCX1 and STIM1 in rat primary cortical neurons. Accordingly, NCX1 and STIM1 co-immunoprecipitated and functionally interacted each other during ischemic preconditioning, a phenomenon inducing ischemic tolerance. However, STIM1 knocking down reduced NCX1 activity recorded by either patch-clamp electrophysiology or Fura-2 single-cell microfluorimetry. Furthermore, canonical transient receptor potential channel 6 (TRPC6) was identified as the mechanism mediating local increase of sodium (Na+) useful to drive NCX1 reverse mode and, therefore, NCX1-mediated Ca2+ refilling. In fact, TRPC6 not only interacted with STIM1, as shown by the co-localization and co-immunoprecipitation with the ER Ca2+ sensor, but it also mediated 1,3-Benzenedicarboxylic acid, 4,4'-[1,4,10-trioxa-7,13-diazacyclopentadecane-7,13-diylbis(5-methoxy-6,12-benzofurandiyl)]bis-, tetrakis[(acetyloxy)methyl] ester (SBFI)-monitored Na+ increase elicited by thapsigargin in primary cortical neurons. Accordingly, efficient TRPC6 knockdown prevented thapsigargin-induced intracellular Na+ elevation and SOCE. Collectively, we identify NCX1 as a new partner of STIM1 in mediating SOCE, whose activation in the reverse mode may be facilitated by the local increase of Na+ concentration due to the interaction between STIM1 and TRPC6 in primary cortical neurons.
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Affiliation(s)
- Valentina Tedeschi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | - Maria Josè Sisalli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | - Anna Pannaccione
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | - Ilaria Piccialli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | - Pasquale Molinaro
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | | | - Agnese Secondo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via S. Pansini 5, 80131, Naples, Italy.
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13
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Huo J, Lu BZ, Dong H. Mutants only partially represent characteristics of calcium-release-activated calcium channel gating. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2111231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Jun Huo
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
| | - Ben-zhuo Lu
- CEMS, LSEC, NCMIS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences; School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Hao Dong
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
- Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China
- Engineering Research Center of Protein and Peptide Medicine of Ministry of Education, Nanjing University, Nanjing 210023, China
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14
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Plasma Membrane and Organellar Targets of STIM1 for Intracellular Calcium Handling in Health and Neurodegenerative Diseases. Cells 2021; 10:cells10102518. [PMID: 34685498 PMCID: PMC8533710 DOI: 10.3390/cells10102518] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/14/2021] [Accepted: 09/21/2021] [Indexed: 01/08/2023] Open
Abstract
Located at the level of the endoplasmic reticulum (ER) membrane, stromal interacting molecule 1 (STIM1) undergoes a complex conformational rearrangement after depletion of ER luminal Ca2+. Then, STIM1 translocates into discrete ER-plasma membrane (PM) junctions where it directly interacts with and activates plasma membrane Orai1 channels to refill ER with Ca2+. Furthermore, Ca2+ entry due to Orai1/STIM1 interaction may induce canonical transient receptor potential channel 1 (TRPC1) translocation to the plasma membrane, where it is activated by STIM1. All these events give rise to store-operated calcium entry (SOCE). Besides the main pathway underlying SOCE, which mainly involves Orai1 and TRPC1 activation, STIM1 modulates many other plasma membrane proteins in order to potentiate the influxof Ca2+. Furthermore, it is now clear that STIM1 may inhibit Ca2+ currents mediated by L-type Ca2+ channels. Interestingly, STIM1 also interacts with some intracellular channels and transporters, including nuclear and lysosomal ionic proteins, thus orchestrating organellar Ca2+ homeostasis. STIM1 and its partners/effectors are significantly modulated in diverse acute and chronic neurodegenerative conditions. This highlights the importance of further disclosing their cellular functions as they might represent promising molecular targets for neuroprotection.
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15
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Dynes JL, Yeromin AV, Cahalan MD. Cell-wide mapping of Orai1 channel activity reveals functional heterogeneity in STIM1-Orai1 puncta. J Gen Physiol 2021; 152:151900. [PMID: 32589186 PMCID: PMC7478869 DOI: 10.1085/jgp.201812239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/11/2019] [Accepted: 05/21/2020] [Indexed: 12/16/2022] Open
Abstract
Upon Ca2+ store depletion, Orai1 channels cluster and open at endoplasmic reticulum–plasma membrane (ER–PM) junctions in signaling complexes called puncta. Little is known about whether and how Orai1 channel activity may vary between individual puncta. Previously, we developed and validated optical recording of Orai channel activity, using genetically encoded Ca2+ indicators fused to Orai1 or Orai3 N or C termini. We have now combined total internal reflection fluorescence microscopy with whole-cell recording to map functional properties of channels at individual puncta. After Ca2+ store depletion in HEK cells cotransfected with mCherry-STIM1 and Orai1-GCaMP6f, Orai1-GCaMP6f fluorescence increased progressively with increasingly negative test potentials and robust responses could be recorded from individual puncta. Cell-wide fluorescence half-rise and -fall times during steps to −100 mV test potential indicated probe response times of <50 ms. The in situ Orai1-GCaMP6f affinity for Ca2+ was 620 nM, assessed by monitoring fluorescence using buffered Ca2+ solutions in “unroofed” cells. Channel activity and temporal activation profile were tracked in individual puncta using image maps and automated puncta identification and recording. Simultaneous measurement of mCherry-STIM1 fluorescence uncovered an unexpected gradient in STIM1/Orai1 ratio that extends across the cell surface. Orai1-GCaMP6f channel activity was found to vary across the cell, with inactive channels occurring in the corners of cells where the STIM1/Orai1 ratio was lowest; low-activity channels typically at edges displayed a slow activation phase lasting hundreds of milliseconds. Puncta with high STIM1/Orai1 ratios exhibited a range of channel activity that appeared unrelated to the stoichiometric requirements for gating. These findings demonstrate functional heterogeneity of Orai1 channel activity between individual puncta and establish a new experimental platform that facilitates systematic comparisons between puncta composition and activity.
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Affiliation(s)
- Joseph L Dynes
- Department of Physiology and Biophysics, University of California at Irvine School of Medicine, Irvine, CA
| | - Andriy V Yeromin
- Department of Physiology and Biophysics, University of California at Irvine School of Medicine, Irvine, CA
| | - Michael D Cahalan
- Department of Physiology and Biophysics, University of California at Irvine School of Medicine, Irvine, CA.,Institute for Immunology, University of California, Irvine, Irvine, CA
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16
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Tiffner A, Derler I. Isoform-Specific Properties of Orai Homologues in Activation, Downstream Signaling, Physiology and Pathophysiology. Int J Mol Sci 2021; 22:8020. [PMID: 34360783 PMCID: PMC8347056 DOI: 10.3390/ijms22158020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 11/21/2022] Open
Abstract
Ca2+ ion channels are critical in a variety of physiological events, including cell growth, differentiation, gene transcription and apoptosis. One such essential entry pathway for calcium into the cell is the Ca2+ release-activated Ca2+ (CRAC) channel. It consists of the Ca2+ sensing protein, stromal interaction molecule 1 (STIM1) located in the endoplasmic reticulum (ER) and a Ca2+ ion channel Orai in the plasma membrane. The Orai channel family includes three homologues Orai1, Orai2 and Orai3. While Orai1 is the "classical" Ca2+ ion channel within the CRAC channel complex and plays a universal role in the human body, there is increasing evidence that Orai2 and Orai3 are important in specific physiological and pathophysiological processes. This makes them an attractive target in drug discovery, but requires a detailed understanding of the three Orai channels and, in particular, their differences. Orai channel activation is initiated via Ca2+ store depletion, which is sensed by STIM1 proteins, and induces their conformational change and oligomerization. Upon STIM1 coupling, Orai channels activate to allow Ca2+ permeation into the cell. While this activation mechanism is comparable among the isoforms, they differ by a number of functional and structural properties due to non-conserved regions in their sequences. In this review, we summarize the knowledge as well as open questions in our current understanding of the three isoforms in terms of their structure/function relationship, downstream signaling and physiology as well as pathophysiology.
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Affiliation(s)
| | - Isabella Derler
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria;
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17
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Cui Y, Chu F, Yin K, Chen X, Wan H, Luo G, Dong H, Xu F. Role of Serosal TRPV4-Constituted SOCE Mechanism in Secretagogues-Stimulated Intestinal Epithelial Anion Secretion. Front Pharmacol 2021; 12:684538. [PMID: 34335254 PMCID: PMC8317263 DOI: 10.3389/fphar.2021.684538] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/24/2021] [Indexed: 12/05/2022] Open
Abstract
As little is known about the role of calcium (Ca2+) signaling mediating the small intestinal epithelial anion secretion, we aimed to study its regulatory role in secretagogue-stimulated duodenal anion secretion and the underlying molecular mechanisms. Therefore, intestinal anion secretion from native mouse duodenal epithelia was examined with Ussing chambers to monitor PGE2-, 5-HT-, and CCh-induced short-circuit currents (Isc). PGE2 (10 μM) and 5-HT (10 μM) induced mouse duodenal Isc, markedly attenuated by serosal Ca2+-free solution and selective blockers of store-operated Ca2+ channels on the serosal side of the duodenum. Furthermore, PGE2- and 5-HT-induced duodenal Isc was also inhibited by ER Ca2+ chelator TPEN. However, dantrolene, a selective blocker of ryanodine receptors, inhibited PGE2-induced duodenal Isc, while LiCl, an inhibitor of IP3 production, inhibited 5-HT-induced Isc. Moreover, duodenal Isc response to the serosal applications of both PGE2 and 5-HT was significantly attenuated in transient receptor potential vanilloid 4 (TRPV4) knockout mice. Finally, mucosal application of carbachol (100 μM) also induced duodenal Isc via selective activation of muscarinic receptors, which was significantly inhibited in serosal Ca2+-free solution but neither in mucosal Ca2+-free solution nor by nifedipine. Therefore, the serosal TRPV4-constituted SOCE mechanism is likely universal for the most common and important secretagogues-induced and Ca2+-dependent intestinal anion secretion. These findings will enhance our knowledge about gastrointestinal (G.I.) epithelial physiology and the associated G.I. diseases, such as diarrhea and constipation.
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Affiliation(s)
- Yinghui Cui
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Fenglan Chu
- Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Kai Yin
- Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Xiongying Chen
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Hanxing Wan
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Gang Luo
- Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Hui Dong
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics, Chongqing, China.,Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Feng Xu
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics, Chongqing, China
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18
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Shalygin A, Kolesnikov D, Glushankova L, Gusev K, Skopin A, Skobeleva K, Kaznacheyeva EV. Role of STIM2 and Orai proteins in regulating TRPC1 channel activity upon calcium store depletion. Cell Calcium 2021; 97:102432. [PMID: 34157631 DOI: 10.1016/j.ceca.2021.102432] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 05/08/2021] [Accepted: 06/04/2021] [Indexed: 11/17/2022]
Abstract
Store-operated calcium channels are the major player in calcium signaling in non-excitable cells. Store-operated calcium entry is associated with the Orai, stromal interaction molecule (STIM), and transient receptor potential canonical (TRPC) protein families. Researchers have provided conflicting data about TRPC1 channel regulation by Orai and STIM. To determine how Orai and STIM influence endogenous TRPC1 pore properties and regulation, we used single channel patch-clamp recordings. Here we showed that knockout or knockdown of Orai1 or Orai3 or overexpression of the dominant-negative mutant Orai1 E106Q did not change the conductance or selectivity of single TRPC1 channels. In addition, these TRPC1 channel properties did not depend on the amount of STIM1 and STIM2 proteins. To study STIM2-mediated regulation of TRPC1 channels, we utilized partial calcium store depletion induced by application of 10 nM thapsigargin (Tg). TRPC1 activation by endogenous STIM2 was greatly decreased in acute extracellular calcium-free experiments. STIM2 overexpression increased both the basal activity and number of silent TRPC1 channels in the plasma membrane. After calcium store depletion, overexpressed STIM2 directly activated TRPC1 in the plasma membrane even without calcium entry in acute experiments. However, this effect was abrogated by co-expression with the non-permeable Orai1 E106Q mutant protein. Taken together, our single-channel patch clamp experiments clearly demonstrated that endogenous TRPC1 forms a channel pore without involving Orai proteins. Calcium entry through Orai triggered TRPC1 channel activation in the plasma membrane, while subsequent STIM2-mediated TRPC1 activity regulation was not dependent on calcium entry.
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Affiliation(s)
- A Shalygin
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia.
| | - D Kolesnikov
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia
| | - L Glushankova
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia
| | - K Gusev
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia
| | - A Skopin
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia
| | - K Skobeleva
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia
| | - E V Kaznacheyeva
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia.
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19
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Ottolini M, Sonkusare SK. The Calcium Signaling Mechanisms in Arterial Smooth Muscle and Endothelial Cells. Compr Physiol 2021; 11:1831-1869. [PMID: 33792900 PMCID: PMC10388069 DOI: 10.1002/cphy.c200030] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The contractile state of resistance arteries and arterioles is a crucial determinant of blood pressure and blood flow. Physiological regulation of arterial contractility requires constant communication between endothelial and smooth muscle cells. Various Ca2+ signals and Ca2+ -sensitive targets ensure dynamic control of intercellular communications in the vascular wall. The functional effect of a Ca2+ signal on arterial contractility depends on the type of Ca2+ -sensitive target engaged by that signal. Recent studies using advanced imaging methods have identified the spatiotemporal signatures of individual Ca2+ signals that control arterial and arteriolar contractility. Broadly speaking, intracellular Ca2+ is increased by ion channels and transporters on the plasma membrane and endoplasmic reticular membrane. Physiological roles for many vascular Ca2+ signals have already been confirmed, while further investigation is needed for other Ca2+ signals. This article focuses on endothelial and smooth muscle Ca2+ signaling mechanisms in resistance arteries and arterioles. We discuss the Ca2+ entry pathways at the plasma membrane, Ca2+ release signals from the intracellular stores, the functional and physiological relevance of Ca2+ signals, and their regulatory mechanisms. Finally, we describe the contribution of abnormal endothelial and smooth muscle Ca2+ signals to the pathogenesis of vascular disorders. © 2021 American Physiological Society. Compr Physiol 11:1831-1869, 2021.
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Affiliation(s)
- Matteo Ottolini
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Swapnil K Sonkusare
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.,Department of Molecular Physiology & Biological Physics, University of Virginia, Charlottesville, Virginia, USA.,Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
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20
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Latoszek E, Czeredys M. Molecular Components of Store-Operated Calcium Channels in the Regulation of Neural Stem Cell Physiology, Neurogenesis, and the Pathology of Huntington's Disease. Front Cell Dev Biol 2021; 9:657337. [PMID: 33869222 PMCID: PMC8047111 DOI: 10.3389/fcell.2021.657337] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/10/2021] [Indexed: 12/11/2022] Open
Abstract
One of the major Ca2+ signaling pathways is store-operated Ca2+ entry (SOCE), which is responsible for Ca2+ flow into cells in response to the depletion of endoplasmic reticulum Ca2+ stores. SOCE and its molecular components, including stromal interaction molecule proteins, Orai Ca2+ channels, and transient receptor potential canonical channels, are involved in the physiology of neural stem cells and play a role in their proliferation, differentiation, and neurogenesis. This suggests that Ca2+ signaling is an important player in brain development. Huntington’s disease (HD) is an incurable neurodegenerative disorder that is caused by polyglutamine expansion in the huntingtin (HTT) protein, characterized by the loss of γ-aminobutyric acid (GABA)-ergic medium spiny neurons (MSNs) in the striatum. However, recent research has shown that HD is also a neurodevelopmental disorder and Ca2+ signaling is dysregulated in HD. The relationship between HD pathology and elevations of SOCE was demonstrated in different cellular and mouse models of HD and in induced pluripotent stem cell-based GABAergic MSNs from juvenile- and adult-onset HD patient fibroblasts. The present review discusses the role of SOCE in the physiology of neural stem cells and its dysregulation in HD pathology. It has been shown that elevated expression of STIM2 underlying the excessive Ca2+ entry through store-operated calcium channels in induced pluripotent stem cell-based MSNs from juvenile-onset HD. In the light of the latest findings regarding the role of Ca2+ signaling in HD pathology we also summarize recent progress in the in vitro differentiation of MSNs that derive from different cell sources. We discuss advances in the application of established protocols to obtain MSNs from fetal neural stem cells/progenitor cells, embryonic stem cells, induced pluripotent stem cells, and induced neural stem cells and the application of transdifferentiation. We also present recent progress in establishing HD brain organoids and their potential use for examining HD pathology and its treatment. Moreover, the significance of stem cell therapy to restore normal neural cell function, including Ca2+ signaling in the central nervous system in HD patients will be considered. The transplantation of MSNs or their precursors remains a promising treatment strategy for HD.
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Affiliation(s)
- Ewelina Latoszek
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Magdalena Czeredys
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
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21
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Huo J, Dong H. Gating and regulation of the calcium release-activated calcium channel: Recent progress from experiments and molecular modeling. Biopolymers 2021; 111:e23392. [PMID: 33460071 DOI: 10.1002/bip.23392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 11/08/2022]
Abstract
Calcium release-activated calcium (CRAC) channels are highly calcium ion (Ca2+)-selective channels in the plasma membrane. The transient drop of endoplasmic reticulum Ca2+ level activates its calcium sensor stromal interaction molecule (STIM) and then triggers the gating of the CRAC channel pore unit Orai. This process involves a variety of activities of the immune system. Therefore, understanding how the activation and regulation of the CRAC channel can be accomplished is essential. Here we briefly summarize the recent progress on Orai gating and its regulation by 2-aminoethoxydiphenylborate (2-APB) obtained from structural biology studies, biochemical and electrophysiological measurements, as well as molecular modeling. Indeed, integration between experiments and computations has further deepened our understanding of the channel gating and regulation.
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Affiliation(s)
- Jun Huo
- Kuang Yaming Honors School, Nanjing University, Nanjing, China
| | - Hao Dong
- Kuang Yaming Honors School, Nanjing University, Nanjing, China.,Institute for Brain Sciences, Nanjing University, Nanjing, China
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22
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The Orai Pore Opening Mechanism. Int J Mol Sci 2021; 22:ijms22020533. [PMID: 33430308 PMCID: PMC7825772 DOI: 10.3390/ijms22020533] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 12/30/2020] [Accepted: 01/02/2021] [Indexed: 02/07/2023] Open
Abstract
Cell survival and normal cell function require a highly coordinated and precise regulation of basal cytosolic Ca2+ concentrations. The primary source of Ca2+ entry into the cell is mediated by the Ca2+ release-activated Ca2+ (CRAC) channel. Its action is stimulated in response to internal Ca2+ store depletion. The fundamental constituents of CRAC channels are the Ca2+ sensor, stromal interaction molecule 1 (STIM1) anchored in the endoplasmic reticulum, and a highly Ca2+-selective pore-forming subunit Orai1 in the plasma membrane. The precise nature of the Orai1 pore opening is currently a topic of intensive research. This review describes how Orai1 gating checkpoints in the middle and cytosolic extended transmembrane regions act together in a concerted manner to ensure an opening-permissive Orai1 channel conformation. In this context, we highlight the effects of the currently known multitude of Orai1 mutations, which led to the identification of a series of gating checkpoints and the determination of their role in diverse steps of the Orai1 activation cascade. The synergistic action of these gating checkpoints maintains an intact pore geometry, settles STIM1 coupling, and governs pore opening. We describe the current knowledge on Orai1 channel gating mechanisms and summarize still open questions of the STIM1-Orai1 machinery.
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23
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A calcium optimum for cytotoxic T lymphocyte and natural killer cell cytotoxicity. Semin Cell Dev Biol 2020; 115:10-18. [PMID: 33358089 DOI: 10.1016/j.semcdb.2020.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 11/24/2020] [Accepted: 12/08/2020] [Indexed: 02/07/2023]
Abstract
Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells are required for host defense. They destroy malignant target cells like cancer cells. Among metal cations, Ca2+ plays a prescinded role for CTL and NK cytotoxicity as it is the only cation used as ubiquitous second messenger. Measuring intracellular Ca2+ concentrations [Ca2+]int in single cells has greatly changed our understanding of Ca2+ signaling. Yet, comparing the role of Ca2+ in the pre-[Ca2+]int and [Ca2+]int measurement era reveals that even in the pre-[Ca2+]int measurement era (before 1980), the functions of Ca2+ and some other metal cations for the cytotoxic immune response were well established. It was even shown that Ca2+ influx across the plasma membrane but not Ca2+ release from intracellular sources is relevant for lymphocyte cytotoxicity and that very little Ca2+ is needed for efficient lymphocyte cytotoxicity against cancer cells. In the [Ca2+]int measurement era after 1980, many of the important findings were better and more quantitatively refined and in addition the molecules important for Ca2+ transport were defined. The unexpected finding that there is a Ca2+ optimum of CTL and NK cell cytotoxicity deserves some attention and may be important for anti-cancer therapy.
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24
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Czeredys M. Dysregulation of Neuronal Calcium Signaling via Store-Operated Channels in Huntington's Disease. Front Cell Dev Biol 2020; 8:611735. [PMID: 33425919 PMCID: PMC7785827 DOI: 10.3389/fcell.2020.611735] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/01/2020] [Indexed: 12/17/2022] Open
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder that is characterized by motor, cognitive, and psychiatric problems. It is caused by a polyglutamine expansion in the huntingtin protein that leads to striatal degeneration via the transcriptional dysregulation of several genes, including genes that are involved in the calcium (Ca2+) signalosome. Recent research has shown that one of the major Ca2+ signaling pathways, store-operated Ca2+ entry (SOCE), is significantly elevated in HD. SOCE refers to Ca2+ flow into cells in response to the depletion of endoplasmic reticulum Ca2+ stores. The dysregulation of Ca2+ homeostasis is postulated to be a cause of HD progression because the SOCE pathway is indirectly and abnormally activated by mutant huntingtin (HTT) in γ-aminobutyric acid (GABA)ergic medium spiny neurons (MSNs) from the striatum in HD models before the first symptoms of the disease appear. The present review summarizes recent studies that revealed a relationship between HD pathology and elevations of SOCE in different models of HD, including YAC128 mice (a transgenic model of HD), cellular HD models, and induced pluripotent stem cell (iPSC)-based GABAergic medium spiny neurons (MSNs) that are obtained from adult HD patient fibroblasts. SOCE in MSNs was shown to be mediated by currents through at least two different channel groups, Ca2+ release-activated Ca2+ current (ICRAC) and store-operated Ca2+ current (ISOC), which are composed of stromal interaction molecule (STIM) proteins and Orai or transient receptor potential channel (TRPC) channels. Their role under physiological and pathological conditions in HD are discussed. The role of Huntingtin-associated protein 1 isoform A in elevations of SOCE in HD MSNs and potential compounds that may stabilize elevations of SOCE in HD are also summarized. Evidence is presented that shows that the dysregulation of molecular components of SOCE or pathways upstream of SOCE in HD MSN neurons is a hallmark of HD, and these changes could lead to HD pathology, making them potential therapeutic targets.
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Affiliation(s)
- Magdalena Czeredys
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
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25
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Tiffner A, Derler I. Molecular Choreography and Structure of Ca 2+ Release-Activated Ca 2+ (CRAC) and K Ca2+ Channels and Their Relevance in Disease with Special Focus on Cancer. MEMBRANES 2020; 10:E425. [PMID: 33333945 PMCID: PMC7765462 DOI: 10.3390/membranes10120425] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Ca2+ ions play a variety of roles in the human body as well as within a single cell. Cellular Ca2+ signal transduction processes are governed by Ca2+ sensing and Ca2+ transporting proteins. In this review, we discuss the Ca2+ and the Ca2+-sensing ion channels with particular focus on the structure-function relationship of the Ca2+ release-activated Ca2+ (CRAC) ion channel, the Ca2+-activated K+ (KCa2+) ion channels, and their modulation via other cellular components. Moreover, we highlight their roles in healthy signaling processes as well as in disease with a special focus on cancer. As KCa2+ channels are activated via elevations of intracellular Ca2+ levels, we summarize the current knowledge on the action mechanisms of the interplay of CRAC and KCa2+ ion channels and their role in cancer cell development.
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Affiliation(s)
| | - Isabella Derler
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria;
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26
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Jansen C, Shimoda LMN, Starkus J, Lange I, Rysavy N, Maaetoft-Udsen K, Tobita C, Stokes AJ, Turner H. In vitro exposure to Hymenoptera venom and constituents activates discrete ionotropic pathways in mast cells. Channels (Austin) 2020; 13:264-286. [PMID: 31237176 PMCID: PMC8670737 DOI: 10.1080/19336950.2019.1629225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Calcium entry is central to the functional processes in mast cells and basophils that contribute to the induction and maintenance of inflammatory responses. Mast cells and basophils express an array of calcium channels, which mediate responses to diverse stimuli triggered by small bioactive molecules, physicochemical stimuli and immunological inputs including antigens and direct immune cell interactions. These cells are also highly responsive to certain venoms (such as Hymenoptera envenomations), which cause histamine secretion, cytokine release and an array of pro-inflammatory functional responses. There are gaps in our understanding of the coupling of venom exposure to specific signaling pathways such as activation of calcium channels. In the present study, we performed a current survey of a model mast cell line selected for its pleiotropic responsiveness to multiple pro-inflammatory inputs. As a heterogenous stimulus, Hymenoptera venom activates multiple classes of conductance at the population level but tend to lead to the measurement of only one type of conductance per cell, despite the cell co-expressing multiple channel types. The data show that ICRAC, IARC, and TRPV-like currents are present in the model mast cell populations and respond to venom exposure. We further assessed individual venom components, specifically secretagogues and arachidonic acid, and identified the conductances associated with these stimuli in mast cells. Single-cell calcium assays and immunofluorescence analysis show that there is heterogeneity of channel expression across the cell population, but this heterogeneity does not explain the apparent selectivity for specific channels in response to exposure to venom as a composite stimulus.
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Affiliation(s)
- C Jansen
- a Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics , Chaminade University , Honolulu , Hawai'I , USA
| | - L M N Shimoda
- a Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics , Chaminade University , Honolulu , Hawai'I , USA
| | - J Starkus
- a Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics , Chaminade University , Honolulu , Hawai'I , USA
| | - I Lange
- b Department of Pharmaceutical Sciences , Daniel K. Inouye College of Pharmacy, University of Hawai'i at Hilo , Hilo , Hawai'i , USA
| | - N Rysavy
- a Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics , Chaminade University , Honolulu , Hawai'I , USA
| | - K Maaetoft-Udsen
- a Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics , Chaminade University , Honolulu , Hawai'I , USA
| | - C Tobita
- a Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics , Chaminade University , Honolulu , Hawai'I , USA
| | - A J Stokes
- c Department of Cell and Molecular Biology, Laboratory of Experimental Medicine, John A. Burns School of Medicine , University of Hawai'i , Honolulu , Hawai'i , USA
| | - H Turner
- a Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics , Chaminade University , Honolulu , Hawai'I , USA
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27
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Noble M, Lin QT, Sirko C, Houpt JA, Novello MJ, Stathopulos PB. Structural Mechanisms of Store-Operated and Mitochondrial Calcium Regulation: Initiation Points for Drug Discovery. Int J Mol Sci 2020; 21:E3642. [PMID: 32455637 PMCID: PMC7279490 DOI: 10.3390/ijms21103642] [Citation(s) in RCA: 2] [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: 04/13/2020] [Revised: 05/11/2020] [Accepted: 05/17/2020] [Indexed: 12/18/2022] Open
Abstract
Calcium (Ca2+) is a universal signaling ion that is essential for the life and death processes of all eukaryotes. In humans, numerous cell stimulation pathways lead to the mobilization of sarco/endoplasmic reticulum (S/ER) stored Ca2+, resulting in the propagation of Ca2+ signals through the activation of processes, such as store-operated Ca2+ entry (SOCE). SOCE provides a sustained Ca2+ entry into the cytosol; moreover, the uptake of SOCE-mediated Ca2+ by mitochondria can shape cytosolic Ca2+ signals, function as a feedback signal for the SOCE molecular machinery, and drive numerous mitochondrial processes, including adenosine triphosphate (ATP) production and distinct cell death pathways. In recent years, tremendous progress has been made in identifying the proteins mediating these signaling pathways and elucidating molecular structures, invaluable for understanding the underlying mechanisms of function. Nevertheless, there remains a disconnect between using this accumulating protein structural knowledge and the design of new research tools and therapies. In this review, we provide an overview of the Ca2+ signaling pathways that are involved in mediating S/ER stored Ca2+ release, SOCE, and mitochondrial Ca2+ uptake, as well as pinpoint multiple levels of crosstalk between these pathways. Further, we highlight the significant protein structures elucidated in recent years controlling these Ca2+ signaling pathways. Finally, we describe a simple strategy that aimed at applying the protein structural data to initiating drug design.
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Affiliation(s)
- Megan Noble
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Qi-Tong Lin
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Christian Sirko
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Jacob A. Houpt
- Department of Medicine, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada;
| | - Matthew J. Novello
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Peter B. Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
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28
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Store-Operated Calcium Channels: From Function to Structure and Back Again. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035055. [PMID: 31570335 DOI: 10.1101/cshperspect.a035055] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Store-operated calcium (Ca2+) entry (SOCE) occurs through a widely distributed family of ion channels activated by the loss of Ca2+ from the endoplasmic reticulum (ER). The best understood of these is the Ca2+ release-activated Ca2+ (CRAC) channel, which is notable for its unique activation mechanism as well as its many essential physiological functions and the diverse pathologies that result from dysregulation. In response to ER Ca2+ depletion, CRAC channels are formed through a diffusion trap mechanism at ER-plasma membrane (PM) junctions, where the ER Ca2+-sensing stromal interaction molecule (STIM) proteins bind and activate hexamers of Orai pore-forming proteins to trigger Ca2+ entry. Cell biological studies are clarifying the architecture of ER-PM junctions, their roles in Ca2+ and lipid transport, and functional interactions with cytoskeletal proteins. Molecular structures of STIM and Orai have inspired a multitude of mutagenesis and electrophysiological studies that reveal potential mechanisms for how STIM is toggled between inactive and active states, how it binds and activates Orai, and the importance of STIM-binding stoichiometry for opening the channel and establishing its signature characteristics of extremely high Ca2+ selectivity and low Ca2+ conductance.
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29
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Zuconelli CR, Schmidt S, Wallbrecher R, van Oostrum J, Bartels YL, Didan Y, Berendsen ML, Brock R, Adjobo-Hermans MJ. Modulation of Orai1 by cationic peptides triggers their direct cytosolic uptake. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183155. [DOI: 10.1016/j.bbamem.2019.183155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/29/2019] [Accepted: 12/10/2019] [Indexed: 02/07/2023]
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30
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Angenendt A, Steiner R, Knörck A, Schwär G, Konrad M, Krause E, Lis A. Orai, STIM, and PMCA contribute to reduced calcium signal generation in CD8 + T cells of elderly mice. Aging (Albany NY) 2020; 12:3266-3286. [PMID: 32062611 PMCID: PMC7066920 DOI: 10.18632/aging.102809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/24/2020] [Indexed: 12/22/2022]
Abstract
Ca2+ is a crucial second messenger for proper T cell function. Considering the relevance of Ca2+ signals for T cell functionality it is surprising that no mechanistic insights into T cell Ca2+ signals from elderly individuals are reported. The main Ca2+ entry mechanism in T cells are STIM-activated Orai channels. Their role during lymphocyte aging is completely unknown. Here, we report not only reduced Ca2+ signals in untouched and stimulated, but also in central and effector memory CD8+ T cells from elderly (18-24 months) compared to adult (3-6 months) mice. Two mechanisms contribute to the overall reduction in Ca2+ signals of CD8+ T cells of elderly mice: 1) Reduced Ca2+ currents through Orai channels due to decreased expressions of STIMs and Orais. 2) A faster extrusion of Ca2+ owing to an increased expression of PMCA4. The reduced Ca2+ signals correlated with a resistance of the cytotoxic efficiency of CD8+ T cells to varying free [Ca2+]ext with age. In summary, reduced STIM/Orai expression and increased Ca2+ clearing rates following enhanced PMCA4 expression contribute to reduced Ca2+ signals in CD8+ T cells of elderly mice. These changes are apparently relevant to immune function as they reduce the Ca2+ dependency of CTL cytotoxicity.
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Affiliation(s)
- Adrian Angenendt
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Romy Steiner
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg 66421, Germany.,Present address: Section of Transplantation Immunology, Department of Surgery, Medical University of Vienna, Vienna 1090, Austria
| | - Arne Knörck
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Gertrud Schwär
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Maik Konrad
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Elmar Krause
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Annette Lis
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg 66421, Germany
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31
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Butorac C, Krizova A, Derler I. Review: Structure and Activation Mechanisms of CRAC Channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:547-604. [PMID: 31646526 DOI: 10.1007/978-3-030-12457-1_23] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Ca2+ release activated Ca2+ (CRAC) channels represent a primary pathway for Ca2+ to enter non-excitable cells. The two key players in this process are the stromal interaction molecule (STIM), a Ca2+ sensor embedded in the membrane of the endoplasmic reticulum, and Orai, a highly Ca2+ selective ion channel located in the plasma membrane. Upon depletion of the internal Ca2+ stores, STIM is activated, oligomerizes, couples to and activates Orai. This review provides an overview of novel findings about the CRAC channel activation mechanisms, structure and gating. In addition, it highlights, among diverse STIM and Orai mutants, also the disease-related mutants and their implications.
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Affiliation(s)
- Carmen Butorac
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria
| | - Adéla Krizova
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria.
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32
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Schober R, Bonhenry D, Lunz V, Zhu J, Krizova A, Frischauf I, Fahrner M, Zhang M, Waldherr L, Schmidt T, Derler I, Stathopulos PB, Romanin C, Ettrich RH, Schindl R. Sequential activation of STIM1 links Ca 2+ with luminal domain unfolding. Sci Signal 2019; 12:eaax3194. [PMID: 31744929 DOI: 10.1126/scisignal.aax3194] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The stromal interaction molecule 1 (STIM1) has two important functions, Ca2+ sensing within the endoplasmic reticulum and activation of the store-operated Ca2+ channel Orai1, enabling plasma-membrane Ca2+ influx. We combined molecular dynamics (MD) simulations with live-cell recordings and determined the sequential Ca2+-dependent conformations of the luminal STIM1 domain upon activation. Furthermore, we identified the residues within the canonical and noncanonical EF-hand domains that can bind to multiple Ca2+ ions. In MD simulations, a single Ca2+ ion was sufficient to stabilize the luminal STIM1 complex. Ca2+ store depletion destabilized the two EF hands, triggering disassembly of the hydrophobic cleft that they form together with the stable SAM domain. Point mutations associated with tubular aggregate myopathy or cancer that targeted the canonical EF hand, and the hydrophobic cleft yielded constitutively clustered STIM1, which was associated with activation of Ca2+ entry through Orai1 channels. On the basis of our results, we present a model of STIM1 Ca2+ binding and refine the currently known initial steps of STIM1 activation on a molecular level.
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Affiliation(s)
- Romana Schober
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Daniel Bonhenry
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Nove Hrady CZ-373 33, Czech Republic
| | - Victoria Lunz
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Jinhui Zhu
- Schulich Dentistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Adela Krizova
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Irene Frischauf
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Marc Fahrner
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - MengQi Zhang
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Linda Waldherr
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Tony Schmidt
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Isabella Derler
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Christoph Romanin
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Rüdiger H Ettrich
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Nove Hrady CZ-373 33, Czech Republic.
- College of Biomedical Sciences, Larkin University, Miami, FL 33169, USA
| | - Rainer Schindl
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria.
- BioTechMed-Graz, A-8010 Graz, Austria
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33
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GPR40 activation initiates store-operated Ca 2+ entry and potentiates insulin secretion via the IP3R1/STIM1/Orai1 pathway in pancreatic β-cells. Sci Rep 2019; 9:15562. [PMID: 31664108 PMCID: PMC6820554 DOI: 10.1038/s41598-019-52048-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/12/2019] [Indexed: 12/17/2022] Open
Abstract
The long-chain fatty acid receptor GPR40 plays an important role in potentiation of glucose-induced insulin secretion (GIIS) from pancreatic β-cells. Previous studies demonstrated that GPR40 activation enhances Ca2+ release from the endoplasmic reticulum (ER) by activating inositol 1,4,5-triphosphate (IP3) receptors. However, it remains unknown how ER Ca2+ release via the IP3 receptor is linked to GIIS potentiation. Recently, stromal interaction molecule (STIM) 1 was identified as a key regulator of store-operated Ca2+ entry (SOCE), but little is known about its contribution in GPR40 signaling. We show that GPR40-mediated potentiation of GIIS is abolished by knockdown of IP3 receptor 1 (IP3R1), STIM1 or Ca2+-channel Orai1 in insulin-secreting MIN6 cells. STIM1 and Orai1 knockdown significantly impaired SOCE and the increase of intracellular Ca2+ by the GPR40 agonist, fasiglifam. Furthermore, β-cell-specific STIM1 knockout mice showed impaired fasiglifam-mediated GIIS potentiation not only in isolated islets but also in vivo. These results indicate that the IP3R1/STIM1/Orai1 pathway plays an important role in GPR40-mediated SOCE initiation and GIIS potentiation in pancreatic β-cells.
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34
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Go CK, Hooper R, Aronson MR, Schultz B, Cangoz T, Nemani N, Zhang Y, Madesh M, Soboloff J. The Ca 2+ export pump PMCA clears near-membrane Ca 2+ to facilitate store-operated Ca 2+ entry and NFAT activation. Sci Signal 2019; 12:12/602/eaaw2627. [PMID: 31594854 DOI: 10.1126/scisignal.aaw2627] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Ca2+ signals, which facilitate pluripotent changes in cell fate, reflect the balance between cation entry and export. We found that overexpression of either isoform of the Ca2+-extruding plasma membrane calcium ATPase 4 (PMCA4) pump in Jurkat T cells unexpectedly increased activation of the Ca2+-dependent transcription factor nuclear factor of activated T cells (NFAT). Coexpression of the endoplasmic reticulum-resident Ca2+ sensor stromal interaction molecule 1 (STIM1) with the PMCA4b splice variant further enhanced NFAT activity; however, coexpression with PMCA4a depressed NFAT. No PMCA4 splice variant dependence in STIM1 association was observed, whereas partner of STIM1 (POST) preferentially associated with PMCA4b over PMCA4a, which enhanced, rather than inhibited, PMCA4 function. A comparison of global and near-membrane cytosolic Ca2+ abundances during store-operated Ca2+ entry revealed that PMCA4 markedly depressed near-membrane Ca2+ concentrations, particularly when PMCA4b was coexpressed with STIM1. PMCA4b closely associated with both POST and the store-operated Ca2+ channel Orai1. Furthermore, POST knockdown increased the near-membrane Ca2+ concentration, inhibiting the global cytosolic Ca2+ increase. These observations reveal an unexpected role for POST in coupling PMCA4 to Orai1 to promote Ca2+ entry during T cell activation through Ca2+ disinhibition.
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Affiliation(s)
- Christina K Go
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.,Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Robert Hooper
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.,Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Matthew R Aronson
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Bryant Schultz
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Taha Cangoz
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Neeharika Nemani
- Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Yi Zhang
- Department of Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Muniswamy Madesh
- Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Jonathan Soboloff
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA. .,Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
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Bhuvaneshwari S, Sankaranarayanan K. Structural and Mechanistic Insights of CRAC Channel as a Drug Target in Autoimmune Disorder. Curr Drug Targets 2019; 21:55-75. [PMID: 31556856 DOI: 10.2174/1389450120666190926150258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/20/2019] [Accepted: 08/20/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND Calcium (Ca2+) ion is a major intracellular signaling messenger, controlling a diverse array of cellular functions like gene expression, secretion, cell growth, proliferation, and apoptosis. The major mechanism controlling this Ca2+ homeostasis is store-operated Ca2+ release-activated Ca2+ (CRAC) channels. CRAC channels are integral membrane protein majorly constituted via two proteins, the stromal interaction molecule (STIM) and ORAI. Following Ca2+ depletion in the Endoplasmic reticulum (ER) store, STIM1 interacts with ORAI1 and leads to the opening of the CRAC channel gate and consequently allows the influx of Ca2+ ions. A plethora of studies report that aberrant CRAC channel activity due to Loss- or gain-of-function mutations in ORAI1 and STIM1 disturbs this Ca2+ homeostasis and causes several autoimmune disorders. Hence, it clearly indicates that the therapeutic target of CRAC channels provides the space for a new approach to treat autoimmune disorders. OBJECTIVE This review aims to provide the key structural and mechanical insights of STIM1, ORAI1 and other molecular modulators involved in CRAC channel regulation. RESULTS AND CONCLUSION Understanding the structure and function of the protein is the foremost step towards improving the effective target specificity by limiting their potential side effects. Herein, the review mainly focusses on the structural underpinnings of the CRAC channel gating mechanism along with its biophysical properties that would provide the solid foundation to aid the development of novel targeted drugs for an autoimmune disorder. Finally, the immune deficiencies caused due to mutations in CRAC channel and currently used pharmacological blockers with their limitation are briefly summarized.
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Affiliation(s)
- Sampath Bhuvaneshwari
- Ion Channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai -600 044, India
| | - Kavitha Sankaranarayanan
- Ion Channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai -600 044, India
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Wani SA, Khan LA, Basir SF. Role of calcium channels and endothelial factors in nickel induced aortic hypercontraction in Wistar rats. J Smooth Muscle Res 2019; 54:71-82. [PMID: 30210089 PMCID: PMC6135920 DOI: 10.1540/jsmr.54.71] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aim: To investigate the mechanism of nickel augmented phenylephrine
(PE)-induced contraction in isolated segments of Wistar rat aorta. Materials and
Methods: Effect of varying concentrations of nickel on PE-induced contraction
were investigated in isolated segments of Wistar rat aorta using an organ bath system.
Aortic rings were pre-incubated with verapamil (1 µM and 20 µM), gadolinium, apocynin,
indomethacin or N-G-nitro-L-arginine methyl ester (L-NAME) separately before incubation
with nickel. Results: Endothelium intact aortic rings incubated with 100
nM, 1 µM or 100 µM of nickel exhibited 80%, 43% and 28% increase in PE-induced
contraction, respectively, while no such enhancing responses were observed in endothelium
denuded aorta. Incubation of aortic rings with 1 µM and 20 µM verapamil suggested an
involvement of influx of calcium through T-type calcium channels in smooth muscle cells,
while aortic rings pre-incubated with gadolinium showed no role of store operated calcium
channels in the nickel effect on PE-induced contractions. The enhancing effect of nickel
on PE-induced contractions was inhibited by apocynin, indomethacin or L-NAME.
Conclusion: Nickel has caused augmentation of PE-induced contractions
as a result of the endothelial generation of reactive oxygen species (ROS) and
cyclooxygenase 2 (COX2) dependent endothelium contracting factors (EDCFs), which increases
the influx of extracellular calcium through T-type Ca2+ channels in smooth
muscle cells.
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Affiliation(s)
| | - Luqman Ahmad Khan
- Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India
| | - Seemi Farhat Basir
- Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India
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Krizova A, Maltan L, Derler I. Critical parameters maintaining authentic CRAC channel hallmarks. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2019; 48:425-445. [PMID: 30903264 PMCID: PMC6647248 DOI: 10.1007/s00249-019-01355-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/20/2018] [Accepted: 03/06/2019] [Indexed: 12/20/2022]
Abstract
Ca2+ ions represent versatile second messengers that regulate a huge diversity of processes throughout the cell's life. One prominent Ca2+ entry pathway into the cell is the Ca2+ release-activated Ca2+ (CRAC) ion channel. It is fully reconstituted by the two molecular key players: the stromal interaction molecule (STIM1) and Orai. STIM1 is a Ca2+ sensor located in the membrane of the endoplasmic reticulum, and Orai, a highly Ca2+ selective ion channel embedded in the plasma membrane. Ca2+ store-depletion leads initially to the activation of STIM1 which subsequently activates Orai channels via direct binding. Authentic CRAC channel hallmarks and biophysical characteristics include high Ca2+ selectivity with a reversal potential in the range of + 50 mV, small unitary conductance, fast Ca2+-dependent inactivation and enhancements in currents upon the switch from a Na+-containing divalent-free to a Ca2+-containing solution. This review provides an overview on the critical determinants and structures within the STIM1 and Orai proteins that establish these prominent CRAC channel characteristics.
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Affiliation(s)
- Adéla Krizova
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020, Linz, Austria
| | - Lena Maltan
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020, Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020, Linz, Austria.
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Yeung PSW, Yamashita M, Prakriya M. Molecular basis of allosteric Orai1 channel activation by STIM1. J Physiol 2019; 598:1707-1723. [PMID: 30950063 DOI: 10.1113/jp276550] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/19/2019] [Indexed: 12/13/2022] Open
Abstract
Store-operated Ca2+ entry through Orai1 channels is a primary mechanism for Ca2+ entry in many cells and mediates numerous cellular effector functions ranging from gene transcription to exocytosis. Orai1 channels are amongst the most Ca2+ -selective channels known and are activated by direct physical interactions with the endoplasmic reticulum Ca2+ sensor stromal interaction molecule 1 (STIM1) in response to store depletion triggered by stimulation of a variety of cell surface G-protein coupled and tyrosine kinase receptors. Work in the last decade has revealed that the Orai1 gating process is highly cooperative and strongly allosteric, likely driven by a wave of interdependent conformational changes throughout the protein originating in the peripheral C-terminal ligand binding site and culminating in pore opening. In this review, we survey the structural and molecular features in Orai1 that contribute to channel gating and consider how they give rise to the unique biophysical fingerprint of Orai1 currents.
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Affiliation(s)
- Priscilla See-Wai Yeung
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
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Zhang F, Wan H, Yang X, He J, Lu C, Yang S, Tuo B, Dong H. Molecular mechanisms of caffeine-mediated intestinal epithelial ion transports. Br J Pharmacol 2019; 176:1700-1716. [PMID: 30808064 DOI: 10.1111/bph.14640] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 01/10/2019] [Accepted: 01/31/2019] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE As little is known about the effect of caffeine, one of the most widely consumed substances worldwide, on intestinal function, we aimed to study its action on intestinal anion secretion and the underlying molecular mechanisms. EXPERIMENTAL APPROACH Anion secretion and channel expression were examined in mouse duodenal epithelium by Ussing chambers and immunocytochemistry. Ca2+ imaging was also performed in intestinal epithelial cells (IECs). KEY RESULTS Caffeine (10 mM) markedly increased mouse duodenal short-circuit current (Isc ), which was attenuated by a removal of either Cl- or HCO3 - , Ca2+ -free serosal solutions and selective blockers of store-operated Ca2+ channels (SOC/Ca2+ release-activated Ca2+ channels), and knockdown of Orai1 channels on the serosal side of duodenal tissues. Caffeine induced SOC entry in IEC, which was inhibited by ruthenium red and selective blockers of SOC. Caffeine-stimulated duodenal Isc was inhibited by the endoplasmic reticulum Ca2+ chelator (N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine), selective blockers (ruthenium red and dantrolene) of ryanodine receptors (RyR), and of Ca2+ -activated Cl- channels (niflumic acid and T16A). There was synergism between cAMP and Ca2+ signalling, in which cAMP/PKA promoted caffeine/Ca2+ -mediated anion secretion. Expression of STIM1 and Orai1 was detected in mouse duodenal mucosa and human IECs. The Orai1 proteins were primarily co-located with the basolateral marker Na+ , K+ -ATPase. CONCLUSIONS AND IMPLICATIONS Caffeine stimulated intestinal anion secretion mainly through the RyR/Orai1/Ca2+ signalling pathway. There is synergism between cAMP/PKA and caffeine/Ca2+ -mediated anion secretion. Our findings suggest that a caffeine-mediated RyR/Orai1/Ca2+ pathway could provide novel potential drug targets to control intestinal anion secretion.
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Affiliation(s)
- Fenglian Zhang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Hanxing Wan
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xin Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jialin He
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Cheng Lu
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Shiming Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical College, and Digestive Disease Institute of Guizhou Province, Zunyi, China
| | - Hui Dong
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China.,Department of Medicine, School of Medicine, University of California, San Diego, California, USA
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Friedmann KS, Bozem M, Hoth M. Calcium signal dynamics in T lymphocytes: Comparing in vivo and in vitro measurements. Semin Cell Dev Biol 2019; 94:84-93. [PMID: 30630031 DOI: 10.1016/j.semcdb.2019.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/18/2018] [Accepted: 01/05/2019] [Indexed: 02/06/2023]
Abstract
Amplitude and kinetics of intracellular Ca2+ signals ([Ca2+]int) determine many immune cell functions. To mimic in vivo changes of [Ca2+]int in human immune cells, two approaches may be best suited: 1) Analyze primary human immune cells taken from blood under conditions resembling best physiological or pathophysiological conditions. 2.) Analyze the immune system in vivo or ex vivo in explanted tissue from small vertebrate animals, such as mice. With the help of genetically encoded Ca2+ indicators and intravital microscopy, [Ca2+]int have been investigated in murine T lymphocytes (T cells) in vivo during the last five years and in explanted lymph node (LN) during the last 10 years. There are several important reasons to compare [Ca2+]int measured in primary murine T lymphocytes in vivo and in vitro with [Ca2+]int measured in primary human T lymphocytes in vitro. First, how do human and murine data compare? Second, how do in vivo and in vitro data compare? Third, can in vitro data predict in vivo data? The last point is particularly important considering the many technical challenges that limit in vivo measurements and to reduce the number of animals sacrificed. This review summarizes and compares the results of the available publications on in vivo and in vitro [Ca2+]int measurements in T lymphocytes stimulated focally by antigen-presenting cells (APC) after forming an immunological synapse.
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Affiliation(s)
- Kim S Friedmann
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Medical Faculty, Saarland University, Homburg, Germany
| | - Monika Bozem
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Medical Faculty, Saarland University, Homburg, Germany
| | - Markus Hoth
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Medical Faculty, Saarland University, Homburg, Germany.
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41
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Tuning store-operated calcium entry to modulate Ca 2+-dependent physiological processes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:1037-1045. [PMID: 30521873 DOI: 10.1016/j.bbamcr.2018.11.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/28/2018] [Accepted: 11/29/2018] [Indexed: 01/10/2023]
Abstract
The intracellular calcium signaling processes are tightly regulated to ensure the generation of calcium signals with the specific spatiotemporal characteristics required for regulating various cell functions. Compartmentalization of the molecular components involved in the generation of these signals at discrete intracellular sites ensures the signaling specificity and transduction fidelity of the signal for regulating downstream effector processes. Store-operated calcium entry (SOCE) is ubiquitously present in cells and is critical for essential cell functions in a variety of tissues. SOCE is mediated via plasma membrane Ca2+ channels that are activated when luminal [Ca2+] of the endoplasmic reticulum ([Ca2+]ER) is decreased. The ER-resident stromal interaction molecules, STIM1 and STIM2, respond to decreases in [Ca2+]ER by undergoing conformational changes that cause them to aggregate at the cell periphery in ER-plasma membrane (ER-PM) junctions. At these sites, STIM proteins recruit Orai1 channels and trigger their activation. Importantly, the two STIM proteins concertedly modulate Orai1 function as well as the sensitivity of SOCE to ER-Ca2+ store depletion. Another family of plasma membrane Ca2+ channels, known as the Transient Receptor Potential Canonical (TRPC) channels (TRPC1-7) also contribute to sustained [Ca2+]i elevation. Although Ca2+ signals generated by these channels overlap with those of Orai1, they regulate distinct functions in the cells. Importantly, STIM1 is also required for plasma membrane localization and activation of some TRPCs. In this review, we will discuss various molecular components and factors that govern the activation, regulation and modulation of the Ca2+ signal generated by Ca2+ entry pathways in response to depletion of ER-Ca2+ stores. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
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42
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Schober R, Waldherr L, Schmidt T, Graziani A, Stilianu C, Legat L, Groschner K, Schindl R. STIM1 and Orai1 regulate Ca 2+ microdomains for activation of transcription. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:1079-1091. [PMID: 30408546 DOI: 10.1016/j.bbamcr.2018.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 02/07/2023]
Abstract
Since calcium (Ca2+) regulates a large variety of cellular signaling processes in a cell's life, precise control of Ca2+ concentrations within the cell is essential. This enables the transduction of information via Ca2+ changes in a time-dependent and spatially defined manner. Here, we review molecular and functional aspects of how the store-operated Ca2+ channel Orai1 creates spatiotemporal Ca2+ microdomains. The architecture of this channel is unique, with a long helical pore and a six-fold symmetry. Energetic barriers within the Ca2+ channel pathway limit permeation to allow an extensive local Ca2+ increase in close proximity to the channel. The precise timing of the Orai1 channel function is controlled by direct binding to STIM proteins upon Ca2+ depletion in the endoplasmic reticulum. These induced Ca2+ microdomains are tailored to, and sufficient for, triggering long-term activation processes, such as transcription factor activation and subsequent gene regulation. We describe the principles of spatiotemporal activation of the transcription factor NFAT and compare its signaling characteristics to those of the autophagy regulating transcription factors, MITF and TFEB.
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Affiliation(s)
- Romana Schober
- Institute for Biophysics, Johannes Kepler University Linz, A-4040 Linz, Austria.
| | - Linda Waldherr
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Tony Schmidt
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Annarita Graziani
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Clemens Stilianu
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Lorenz Legat
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Klaus Groschner
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Rainer Schindl
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria.
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43
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Abstract
Yeung and Prakriya highlight new research showing that STIM1 must bind to all six Orai1 subunits to effectively activate the channel.
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Affiliation(s)
- Priscilla See-Wai Yeung
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Murali Prakriya
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL
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44
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CRAC Channel Components Quantitative Expression (In Tissues and Cell Lines) Using qPCR. Methods Mol Biol 2018. [PMID: 30203280 DOI: 10.1007/978-1-4939-8704-7_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Since last decade real-time qPCR has become a routine and robust approach for measuring the expression of genes of interest. Indeed, using qPCR, expression profile analyses are now possible and participate to the understanding of physiological or pathological role of channels such as calcium release-activated channels (CRAC). Initially discovered in lymphocyte T and immunity perturbations, recent studies have highlighted the role of CRAC channels in other pathologies such as cancer. Here we describe a protocol to quantify CRAC components expression, in tissue sample and cell lines, to validate knockdown strategies or identify their roles in physiological and pathological conditions (Hoth and Penner, J Physiol 465:359-386, 1993; Hoth and Penner, Nature 355:353-356, 1992; and Zweifach and Lewis, Proc Natl Acad Sci U S A 90:6295-6299, 1993).
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45
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Wu G, Yang X, Shen Y. Identification of a single aspartate residue critical for both fast and slow calcium-dependent inactivation of the human TRPML1 channel. J Biol Chem 2018; 293:11736-11745. [PMID: 29884771 DOI: 10.1074/jbc.ra118.003250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 06/05/2018] [Indexed: 01/16/2023] Open
Abstract
Transient receptor potential mucolipin subfamily 1 (TRPML1) is a nonselective cation channel mainly located in late endosomes and lysosomes. Mutations of the gene encoding human TRPML1 can cause severe lysosomal diseases. The activity of TRPML1 is regulated by both Ca2+ and H+, which are important for its critical physiological functions in membrane trafficking, exocytosis, autophagy, and intracellular signal transduction. However, the molecular mechanism of its dual regulation by Ca2+ and H+ remains elusive. Here, using a mutant screening method in combination with a whole-cell patch clamp technique, we identified a key TRPML1 residue, Asp-472, responsible for both fast calcium-dependent inactivation (FCDI) and slow calcium-dependent inactivation (SCDI) as well as H+ regulation. We also found that, in acidic pH, H+ can significantly delay FCDI and abolish SCDI and thereby presumably facilitate the ion conductance of the human TRPML1 channel. In summary, we have identified a key residue critical for Ca2+-induced inhibition of TRPML1 channel currents and uncovered pH-dependent regulation of this channel, providing vital information regarding the detailed mechanism of action of human TRPML1.
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Affiliation(s)
- Guangyan Wu
- From the State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China and
| | - Xue Yang
- From the State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China and
| | - Yuequan Shen
- From the State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China and .,the Synergetic Innovation Center of Chemical Science and Engineering, 94 Weijin Road, Tianjin 300071, China
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46
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CRAC channels as targets for drug discovery and development. Cell Calcium 2018; 74:147-159. [PMID: 30075400 DOI: 10.1016/j.ceca.2018.07.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/16/2018] [Accepted: 07/16/2018] [Indexed: 12/13/2022]
Abstract
Calcium release-activated calcium (CRAC) channels have been the target of drug discovery for many years. The identification of STIM and Orai proteins as key components of CRAC channels greatly facilitated this process because their co-expression in cell lines produced electrophysiological currents (ICRAC) much larger than those in native cells, making it easier to confirm and characterize the effects of modulatory compounds. A driving force in the quest for CRAC channel drugs has been the immunocompromised phenotype displayed by humans and mice with null or loss-of-function mutations in STIM1 or Orai1, suggesting that CRAC channel inhibitors could be useful therapeutics for autoimmune or inflammatory conditions. Emerging data also suggests that other therapeutic conditions may benefit from CRAC channel inhibition. However, only recently have CRAC channel inhibitors reached clinical trials. This review discusses the challenges associated with drug discovery and development on CRAC channels and the approaches employed to date, as well as the results, starting from initial high-throughput screens for CRAC channel modulators and progressing through target selection and justification, descriptions of pharmacological, safety and toxicological profiles of compounds, and finally the entry of CRAC channel inhibitors into clinical trials.
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Abstract
Photoreceptor chromophore, 11-cis retinal (11CR) and the photoproduct, all-trans retinal (ATR), are present in the retina at higher concentrations and interact with the visual cells. Non-visual cells in the body are also exposed to retinal that enters the circulation. Although the cornea and the lens of the eye are transparent to the blue light region where retinal can absorb and undergo excitation, the reported phototoxicity in the eye has been assigned to lipophilic non-degradable materials known as lipofuscins, which also includes retinal condensation products. The possibility of blue light excited retinal interacting with cells; intercepting signaling in the presence or absence of light has not been explored. Using live cell imaging and optogenetic signaling control, we uncovered that blue light-excited ATR and 11CR irreversibly change/distort plasma membrane (PM) bound phospholipid; phosphatidylinositol 4,5 bisphosphate (PIP2) and disrupt its function. This distortion in PIP2 was independent of visual or non-visual G-protein coupled receptor activation. The change in PIP2 was followed by an increase in the cytosolic calcium, excessive cell shape change, and cell death. Blue light alone or retinal alone did not perturb PIP2 or elicit cytosolic calcium increase. Our data also suggest that photoexcited retinal-induced PIP2 distortion and subsequent oxidative damage incur in the core of the PM. These findings suggest that retinal exerts light sensitivity to both photoreceptor and non-photoreceptor cells, and intercepts crucial signaling events, altering the cellular fate.
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48
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Affiliation(s)
- James W Putney
- Scientist Emeritus, National Institute of Environmental Health Sciences - NIH, Research Triangle Park, NC 27709, USA
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49
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Tsvilovskyy V, Solís-López A, Schumacher D, Medert R, Roers A, Kriebs U, Freichel M. Deletion of Orai2 augments endogenous CRAC currents and degranulation in mast cells leading to enhanced anaphylaxis. Cell Calcium 2018; 71:24-33. [DOI: 10.1016/j.ceca.2017.11.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 11/05/2017] [Accepted: 11/26/2017] [Indexed: 12/25/2022]
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50
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Distinct gating mechanism of SOC channel involving STIM-Orai coupling and an intramolecular interaction of Orai in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2018; 115:E4623-E4632. [PMID: 29712850 DOI: 10.1073/pnas.1714986115] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Store-operated calcium entry (SOCE), an important mechanism of Ca2+ signaling in a wide range of cell types, is mediated by stromal interaction molecule (STIM), which senses the depletion of endoplasmic reticulum Ca2+ stores and binds and activates Orai channels in the plasma membrane. This inside-out mechanism of Ca2+ signaling raises an interesting question about the evolution of SOCE: How did these two proteins existing in different cellular compartments evolve to interact with each other? We investigated the gating mechanism of Caenorhabditis elegans Orai channels. Our analysis revealed a mechanism of Orai gating by STIM binding to the intracellular 2-3 loop of Orai in C. elegans that is radically different from Orai gating by STIM binding to the N and C termini of Orai in mammals. In addition, we found that the conserved hydrophobic amino acids in the 2-3 loop of Orai1 are important for the oligomerization and gating of channels and are regulated via an intramolecular interaction mechanism mediated by the N and C termini of Orai1. This study identifies a previously unknown SOCE mechanism in C. elegans and suggests that, while the STIM-Orai interaction is conserved between invertebrates and mammals, the gating mechanism for Orai channels differs considerably.
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