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Trus M, Atlas D. Non-ionotropic voltage-gated calcium channel signaling. Channels (Austin) 2024; 18:2341077. [PMID: 38601983 PMCID: PMC11017947 DOI: 10.1080/19336950.2024.2341077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
Voltage-gated calcium channels (VGCCs) are the major conduits for calcium ions (Ca2+) within excitable cells. Recent studies have highlighted the non-ionotropic functionality of VGCCs, revealing their capacity to activate intracellular pathways independently of ion flow. This non-ionotropic signaling mode plays a pivotal role in excitation-coupling processes, including gene transcription through excitation-transcription (ET), synaptic transmission via excitation-secretion (ES), and cardiac contraction through excitation-contraction (EC). However, it is noteworthy that these excitation-coupling processes require extracellular calcium (Ca2+) and Ca2+ occupancy of the channel ion pore. Analogous to the "non-canonical" characterization of the non-ionotropic signaling exhibited by the N-methyl-D-aspartate receptor (NMDA), which requires extracellular Ca2+ without the influx of ions, VGCC activation requires depolarization-triggered conformational change(s) concomitant with Ca2+ binding to the open channel. Here, we discuss the contributions of VGCCs to ES, ET, and EC coupling as Ca2+ binding macromolecules that transduces external stimuli to intracellular input prior to elevating intracellular Ca2+. We emphasize the recognition of calcium ion occupancy within the open ion-pore and its contribution to the excitation coupling processes that precede the influx of calcium. The non-ionotropic activation of VGCCs, triggered by the upstroke of an action potential, provides a conceptual framework to elucidate the mechanistic aspects underlying the microseconds nature of synaptic transmission, cardiac contractility, and the rapid induction of first-wave genes.
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Affiliation(s)
- Michael Trus
- Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daphne Atlas
- Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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Follmer ML, Isner T, Ozekin YH, Levitt C, Bates EA. Depolarization induces calcium-dependent BMP4 release from mouse embryonic palate mesenchyme. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598333. [PMID: 38915514 PMCID: PMC11195066 DOI: 10.1101/2024.06.11.598333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Ion channels are essential for proper morphogenesis of the craniofacial skeleton. However, the molecular mechanisms underlying this phenomenon are unknown. Loss of the Kcnj2 potassium channel disrupts Bone Morphogenetic Protein (BMP) signaling within the developing palate. BMP signaling is essential for the correct development of several skeletal structures, including the palate, though little is known about the mechanisms that govern BMP secretion. We introduce a tool to image the release of bone morphogenetic protein 4 (BMP4) from mammalian cells. Using this tool, we show that depolarization induces BMP4 release from mouse embryonic palate mesenchyme cells in a calcium-dependent manner. We show native transient changes in intracellular calcium occur in cranial neural crest cells, the cells from which embryonic palate mesenchyme derives. Waves of transient changes in intracellular calcium suggest that these cells are electrically coupled and may temporally coordinate BMP release. These transient changes in intracellular calcium persist in palate mesenchyme cells from embryonic day (E) 9.5 to 13.5 mice. Disruption of Kcnj2 significantly decreases the amplitude of calcium transients and the ability of cells to secrete BMP. Together, these data suggest that temporal control of developmental cues is regulated by ion channels, depolarization, and changes in intracellular calcium for mammalian craniofacial morphogenesis. SUMMARY We show that embryonic palate mesenchyme cells undergo transient changes in intracellular calcium. Depolarization of these cells induces BMP4 release suggesting that ion channels are a node in BMP4 signaling.
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Lisek M, Tomczak J, Boczek T, Zylinska L. Calcium-Associated Proteins in Neuroregeneration. Biomolecules 2024; 14:183. [PMID: 38397420 PMCID: PMC10887043 DOI: 10.3390/biom14020183] [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: 12/30/2023] [Revised: 01/27/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
The dysregulation of intracellular calcium levels is a critical factor in neurodegeneration, leading to the aberrant activation of calcium-dependent processes and, ultimately, cell death. Ca2+ signals vary in magnitude, duration, and the type of neuron affected. A moderate Ca2+ concentration can initiate certain cellular repair pathways and promote neuroregeneration. While the peripheral nervous system exhibits an intrinsic regenerative capability, the central nervous system has limited self-repair potential. There is evidence that significant variations exist in evoked calcium responses and axonal regeneration among neurons, and individual differences in regenerative capacity are apparent even within the same type of neurons. Furthermore, some studies have shown that neuronal activity could serve as a potent regulator of this process. The spatio-temporal patterns of calcium dynamics are intricately controlled by a variety of proteins, including channels, ion pumps, enzymes, and various calcium-binding proteins, each of which can exert either positive or negative effects on neural repair, depending on the cellular context. In this concise review, we focus on several calcium-associated proteins such as CaM kinase II, GAP-43, oncomodulin, caldendrin, calneuron, and NCS-1 in order to elaborate on their roles in the intrinsic mechanisms governing neuronal regeneration following traumatic damage processes.
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Affiliation(s)
| | | | | | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (M.L.); (J.T.); (T.B.)
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Kameyama M, Minobe E, Shao D, Xu J, Gao Q, Hao L. Regulation of Cardiac Cav1.2 Channels by Calmodulin. Int J Mol Sci 2023; 24:ijms24076409. [PMID: 37047381 PMCID: PMC10094977 DOI: 10.3390/ijms24076409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/19/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023] Open
Abstract
Cav1.2 Ca2+ channels, a type of voltage-gated L-type Ca2+ channel, are ubiquitously expressed, and the predominant Ca2+ channel type, in working cardiac myocytes. Cav1.2 channels are regulated by the direct interactions with calmodulin (CaM), a Ca2+-binding protein that causes Ca2+-dependent facilitation (CDF) and inactivation (CDI). Ca2+-free CaM (apoCaM) also contributes to the regulation of Cav1.2 channels. Furthermore, CaM indirectly affects channel activity by activating CaM-dependent enzymes, such as CaM-dependent protein kinase II and calcineurin (a CaM-dependent protein phosphatase). In this article, we review the recent progress in identifying the role of apoCaM in the channel ‘rundown’ phenomena and related repriming of channels, and CDF, as well as the role of Ca2+/CaM in CDI. In addition, the role of CaM in channel clustering is reviewed.
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Affiliation(s)
- Masaki Kameyama
- Department of Physiology, Graduate School of Medical & Dental Sciences, Kagoshima University, Sakura-ga-oka, Kagoshima 890-8544, Japan
- Correspondence:
| | - Etsuko Minobe
- Department of Physiology, Graduate School of Medical & Dental Sciences, Kagoshima University, Sakura-ga-oka, Kagoshima 890-8544, Japan
| | - Dongxue Shao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110012, China (L.H.)
| | - Jianjun Xu
- Department of Physiology, Graduate School of Medical & Dental Sciences, Kagoshima University, Sakura-ga-oka, Kagoshima 890-8544, Japan
| | - Qinghua Gao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110012, China (L.H.)
| | - Liying Hao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110012, China (L.H.)
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Ulengin-Talkish I, Cyert MS. A cellular atlas of calcineurin signaling. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119366. [PMID: 36191737 PMCID: PMC9948804 DOI: 10.1016/j.bbamcr.2022.119366] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 09/25/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
Abstract
Intracellular Ca2+ signals are temporally controlled and spatially restricted. Signaling occurs adjacent to sites of Ca2+ entry and/or release, where Ca2+-dependent effectors and their substrates co-localize to form signaling microdomains. Here we review signaling by calcineurin, the Ca2+/calmodulin regulated protein phosphatase and target of immunosuppressant drugs, Cyclosporin A and FK506. Although well known for its activation of the adaptive immune response via NFAT dephosphorylation, systematic mapping of human calcineurin substrates and regulators reveals unexpected roles for this versatile phosphatase throughout the cell. We discuss calcineurin function, with an emphasis on where signaling occurs and mechanisms that target calcineurin and its substrates to signaling microdomains, especially binding of cognate short linear peptide motifs (SLiMs). Calcineurin is ubiquitously expressed and regulates events at the plasma membrane, other intracellular membranes, mitochondria, the nuclear pore complex and centrosomes/cilia. Based on our expanding knowledge of localized CN actions, we describe a cellular atlas of Ca2+/calcineurin signaling.
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Affiliation(s)
| | - Martha S Cyert
- Department of Biology, Stanford University, Stanford, CA 94035, United States.
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Sanderson JL, Freund RK, Castano AM, Benke TA, Dell'Acqua ML. The Ca V1.2 G406R mutation decreases synaptic inhibition and alters L-type Ca 2+ channel-dependent LTP at hippocampal synapses in a mouse model of Timothy Syndrome. Neuropharmacology 2022; 220:109271. [PMID: 36162529 PMCID: PMC9644825 DOI: 10.1016/j.neuropharm.2022.109271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/09/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022]
Abstract
Genetic alterations in autism spectrum disorders (ASD) frequently disrupt balance between synaptic excitation and inhibition and alter plasticity in the hippocampal CA1 region. Individuals with Timothy Syndrome (TS), a genetic disorder caused by CaV1.2 L-type Ca2+ channel (LTCC) gain-of function mutations, such as G406R, exhibit social deficits, repetitive behaviors, and cognitive impairments characteristic of ASD that are phenocopied in TS2-neo mice expressing G406R. Here, we characterized hippocampal CA1 synaptic function in male TS2-neo mice and found basal excitatory transmission was slightly increased and inhibitory transmission strongly decreased. We also found distinct impacts on two LTCC-dependent forms of long-term potentiation (LTP) synaptic plasticity that were not readily consistent with LTCC gain-of-function. LTP induced by high-frequency stimulation (HFS) was strongly impaired in TS2-neo mice, suggesting decreased LTCC function. Yet, CaV1.2 expression, basal phosphorylation, and current density were similar for WT and TS2-neo. However, this HFS-LTP also required GABAA receptor activity, and thus may be impaired in TS2-neo due to decreased inhibitory transmission. In contrast, LTP induced in WT mice by prolonged theta-train (PTT) stimulation in the presence of a β-adrenergic receptor agonist to increase CaV1.2 phosphorylation was partially induced in TS2-neo mice by PTT stimulation alone, consistent with increased LTCC function. Overall, our findings provide insights regarding how altered CaV1.2 channel function disrupts basal transmission and plasticity that could be relevant for neurobehavioral alterations in ASD.
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Affiliation(s)
- Jennifer L Sanderson
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8303, Aurora, CO, 80045, USA
| | - Ronald K Freund
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8303, Aurora, CO, 80045, USA
| | - Anna M Castano
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8303, Aurora, CO, 80045, USA
| | - Timothy A Benke
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8303, Aurora, CO, 80045, USA; Departments of Pediatrics, Neurology, and Otolaryngology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8303, Aurora, CO, 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8303, Aurora, CO, 80045, USA.
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Arjun McKinney A, Petrova R, Panagiotakos G. Calcium and activity-dependent signaling in the developing cerebral cortex. Development 2022; 149:276624. [PMID: 36102617 PMCID: PMC9578689 DOI: 10.1242/dev.198853] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Calcium influx can be stimulated by various intra- and extracellular signals to set coordinated gene expression programs into motion. As such, the precise regulation of intracellular calcium represents a nexus between environmental cues and intrinsic genetic programs. Mounting genetic evidence points to a role for the deregulation of intracellular calcium signaling in neuropsychiatric disorders of developmental origin. These findings have prompted renewed enthusiasm for understanding the roles of calcium during normal and dysfunctional prenatal development. In this Review, we describe the fundamental mechanisms through which calcium is spatiotemporally regulated and directs early neurodevelopmental events. We also discuss unanswered questions about intracellular calcium regulation during the emergence of neurodevelopmental disease, and provide evidence that disruption of cell-specific calcium homeostasis and/or redeployment of developmental calcium signaling mechanisms may contribute to adult neurological disorders. We propose that understanding the normal developmental events that build the nervous system will rely on gaining insights into cell type-specific calcium signaling mechanisms. Such an understanding will enable therapeutic strategies targeting calcium-dependent mechanisms to mitigate disease.
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Affiliation(s)
- Arpana Arjun McKinney
- University of California 1 Graduate Program in Developmental and Stem Cell Biology , , San Francisco, CA 94143 , USA
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California 2 , San Francisco, CA 94143 , USA
- University of California 3 Department of Biochemistry and Biophysics , , San Francisco, CA 94143 , USA
- Kavli Institute for Fundamental Neuroscience, University of California 4 , San Francisco, CA 94143 , USA
| | - Ralitsa Petrova
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California 2 , San Francisco, CA 94143 , USA
- University of California 3 Department of Biochemistry and Biophysics , , San Francisco, CA 94143 , USA
- Kavli Institute for Fundamental Neuroscience, University of California 4 , San Francisco, CA 94143 , USA
| | - Georgia Panagiotakos
- University of California 1 Graduate Program in Developmental and Stem Cell Biology , , San Francisco, CA 94143 , USA
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California 2 , San Francisco, CA 94143 , USA
- University of California 3 Department of Biochemistry and Biophysics , , San Francisco, CA 94143 , USA
- Kavli Institute for Fundamental Neuroscience, University of California 4 , San Francisco, CA 94143 , USA
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8
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Sabarudin MA, Taib H, Wan Mohamad WM. Refining the Mechanism of Drug-Influenced Gingival Enlargement and Its Management. Cureus 2022; 14:e25009. [PMID: 35712334 PMCID: PMC9195644 DOI: 10.7759/cureus.25009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2022] [Indexed: 11/16/2022] Open
Abstract
Drug-influenced gingival enlargement (DIGE) or overgrowth manifests as abnormal enlargement of the gingiva due to an adverse effect of certain drug reactions in patients treated with anticonvulsants, immunosuppressants, or calcium channel blockers (CCBs). As the gingival enlargement became significant, it may interfere with the normal oral hygiene measures, aesthetics, as well as masticatory functions of the patients. The exact mechanism of how this undesirable condition develops is yet unknown, and complicated, with non-inflammatory and inflammatory pathways involved. This review illuminates these putative pathways of DIGE and highlights various treatment approaches based on existing research and current observations.
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9
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Dixon RE, Navedo MF, Binder MD, Santana LF. Mechanisms and Physiological Implications of Cooperative Gating of Ion Channels Clusters. Physiol Rev 2021; 102:1159-1210. [PMID: 34927454 DOI: 10.1152/physrev.00022.2021] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ion channels play a central role in the regulation of nearly every cellular process. Dating back to the classic 1952 Hodgkin-Huxley model of the generation of the action potential, ion channels have always been thought of as independent agents. A myriad of recent experimental findings exploiting advances in electrophysiology, structural biology, and imaging techniques, however, have posed a serious challenge to this long-held axiom as several classes of ion channels appear to open and close in a coordinated, cooperative manner. Ion channel cooperativity ranges from variable-sized oligomeric cooperative gating in voltage-gated, dihydropyridine-sensitive Cav1.2 and Cav1.3 channels to obligatory dimeric assembly and gating of voltage-gated Nav1.5 channels. Potassium channels, transient receptor potential channels, hyperpolarization cyclic nucleotide-activated channels, ryanodine receptors (RyRs), and inositol trisphosphate receptors (IP3Rs) have also been shown to gate cooperatively. The implications of cooperative gating of these ion channels range from fine tuning excitation-contraction coupling in muscle cells to regulating cardiac function and vascular tone, to modulation of action potential and conduction velocity in neurons and cardiac cells, and to control of pace-making activity in the heart. In this review, we discuss the mechanisms leading to cooperative gating of ion channels, their physiological consequences and how alterations in cooperative gating of ion channels may induce a range of clinically significant pathologies.
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Affiliation(s)
- Rose Ellen Dixon
- Department of Physiology and Membrane Biology, University of California, Davis, CA, United States
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, United States
| | - Marc D Binder
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California, Davis, CA, United States
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10
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Chaklader M, Rothermel BA. Calcineurin in the heart: New horizons for an old friend. Cell Signal 2021; 87:110134. [PMID: 34454008 PMCID: PMC8908812 DOI: 10.1016/j.cellsig.2021.110134] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/10/2021] [Accepted: 08/23/2021] [Indexed: 01/20/2023]
Abstract
Calcineurin, also known as PP2B or PPP3, is a member of the PPP family of protein phosphatases that also includes PP1 and PP2A. Together these three phosphatases carryout the majority of dephosphorylation events in the heart. Calcineurin is distinct in that it is activated by the binding of calcium/calmodulin (Ca2+/CaM) and therefore acts as a node for integrating Ca2+ signals with changes in phosphorylation, two fundamental intracellular signaling cascades. In the heart, calcineurin is primarily thought of in the context of pathological cardiac remodeling, acting through the Nuclear Factor of Activated T-cell (NFAT) family of transcription factors. However, calcineurin activity is also essential for normal heart development and homeostasis in the adult heart. Furthermore, it is clear that NFAT-driven changes in transcription are not the only relevant processes initiated by calcineurin in the setting of pathological remodeling. There is a growing appreciation for the diversity of calcineurin substrates that can impact cardiac function as well as the diversity of mechanisms for targeting calcineurin to specific sub-cellular domains in cardiomyocytes and other cardiac cell types. Here, we will review the basics of calcineurin structure, regulation, and function in the context of cardiac biology. Particular attention will be given to: the development of improved tools to identify and validate new calcineurin substrates; recent studies identifying new calcineurin isoforms with unique properties and targeting mechanisms; and the role of calcineurin in cardiac development and regeneration.
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Affiliation(s)
- Malay Chaklader
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA
| | - Beverly A Rothermel
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA.
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11
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Isensee J, van Cann M, Despang P, Araldi D, Moeller K, Petersen J, Schmidtko A, Matthes J, Levine JD, Hucho T. Depolarization induces nociceptor sensitization by CaV1.2-mediated PKA-II activation. J Cell Biol 2021; 220:212600. [PMID: 34431981 PMCID: PMC8404467 DOI: 10.1083/jcb.202002083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/14/2021] [Accepted: 08/05/2021] [Indexed: 01/20/2023] Open
Abstract
Depolarization drives neuronal plasticity. However, whether depolarization drives sensitization of peripheral nociceptive neurons remains elusive. By high-content screening (HCS) microscopy, we revealed that depolarization of cultured sensory neurons rapidly activates protein kinase A type II (PKA-II) in nociceptors by calcium influx through CaV1.2 channels. This effect was modulated by calpains but insensitive to inhibitors of cAMP formation, including opioids. In turn, PKA-II phosphorylated Ser1928 in the distal C terminus of CaV1.2, thereby increasing channel gating, whereas dephosphorylation of Ser1928 involved the phosphatase calcineurin. Patch-clamp and behavioral experiments confirmed that depolarization leads to calcium- and PKA-dependent sensitization of calcium currents ex vivo and local peripheral hyperalgesia in the skin in vivo. Our data suggest a local activity-driven feed-forward mechanism that selectively translates strong depolarization into further activity and thereby facilitates hypersensitivity of nociceptor terminals by a mechanism inaccessible to opioids.
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Affiliation(s)
- Jörg Isensee
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Marianne van Cann
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Patrick Despang
- Department of Pharmacology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Dioneia Araldi
- Division of Neuroscience, Departments of Medicine and Oral & Maxillofacial Surgery, University of California, San Francisco, San Francisco, CA
| | - Katharina Moeller
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Jonas Petersen
- Institute for Pharmacology and Clinical Pharmacy, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Achim Schmidtko
- Institute for Pharmacology and Clinical Pharmacy, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jan Matthes
- Department of Pharmacology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Jon D Levine
- Division of Neuroscience, Departments of Medicine and Oral & Maxillofacial Surgery, University of California, San Francisco, San Francisco, CA
| | - Tim Hucho
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
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12
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Winters BL, Vaughan CW. Mechanisms of endocannabinoid control of synaptic plasticity. Neuropharmacology 2021; 197:108736. [PMID: 34343612 DOI: 10.1016/j.neuropharm.2021.108736] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/13/2023]
Abstract
The endogenous cannabinoid transmitter system regulates synaptic transmission throughout the nervous system. Unlike conventional transmitters, specific stimuli induce synthesis of endocannabinoids (eCBs) in the postsynaptic neuron, and these travel backwards to modulate presynaptic inputs. In doing so, eCBs can induce short-term changes in synaptic strength and longer-term plasticity. While this eCB regulation is near ubiquitous, it displays major regional and synapse specific variations with different synapse specific forms of short-versus long-term plasticity throughout the brain. These differences are due to the plethora of pre- and postsynaptic mechanisms which have been implicated in eCB signalling, the intricacies of which are only just being realised. In this review, we shall describe the current understanding and highlight new advances in this area, with a focus on the retrograde action of eCBs at CB1 receptors (CB1Rs).
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Affiliation(s)
- Bryony Laura Winters
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia.
| | - Christopher Walter Vaughan
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia
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13
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Kar P, Barak P, Zerio A, Lin YP, Parekh AJ, Watts VJ, Cooper DMF, Zaccolo M, Kramer H, Parekh AB. AKAP79 Orchestrates a Cyclic AMP Signalosome Adjacent to Orai1 Ca 2+ Channels. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab036. [PMID: 34458850 PMCID: PMC8394516 DOI: 10.1093/function/zqab036] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/16/2021] [Accepted: 07/27/2021] [Indexed: 01/12/2023]
Abstract
To ensure specificity of response, eukaryotic cells often restrict signalling molecules to sub-cellular regions. The Ca2+ nanodomain is a spatially confined signal that arises near open Ca2+ channels. Ca2+ nanodomains near store-operated Orai1 channels stimulate the protein phosphatase calcineurin, which activates the transcription factor NFAT1, and both enzyme and target are initially attached to the plasma membrane through the scaffolding protein AKAP79. Here, we show that a cAMP signalling nexus also forms adjacent to Orai1. Protein kinase A and phosphodiesterase 4, an enzyme that rapidly breaks down cAMP, both associate with AKAP79 and realign close to Orai1 after stimulation. PCR and mass spectrometry failed to show expression of Ca2+-activated adenylyl cyclase 8 in HEK293 cells, whereas the enzyme was observed in neuronal cell lines. FRET and biochemical measurements of bulk cAMP and protein kinase A activity consistently failed to show an increase in adenylyl cyclase activity following even a large rise in cytosolic Ca2+. Furthermore, expression of AKAP79-CUTie, a cAMP FRET sensor tethered to AKAP79, did not report a rise in cAMP after stimulation, despite AKAP79 association with Orai1. Hence, HEK293 cells do not express functional active Ca2+-activated adenylyl cyclases including adenylyl cyclase 8. Our results show that two ancient second messengers are independently generated in nanodomains close to Orai1 Ca2+ channels.
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Affiliation(s)
- Pulak Kar
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Pradeep Barak
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Anna Zerio
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Yu-Ping Lin
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK,NIEHS/NIH, 111 TW Alexander Drive, Durham, NC 27709, USA
| | - Amy J Parekh
- Stoke Mandeville Hospital, Mandeville Road, Aylesbury, HP21 8AL, UK
| | - Val J Watts
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute of Drug Discovery, Purdue Institute of Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Dermot M F Cooper
- Department of Pharmacology, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Holger Kramer
- Proteomics and Metabolomics Centre, Medical Research Council, London Institute of Medical Sciences, London, W12 0NN, UK
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Lin Z, Wu B, Paul MW, Li KW, Yao Y, Smal I, Proietti Onori M, Hasanbegovic H, Bezstarosti K, Demmers J, Houtsmuller AB, Meijering E, Hoebeek FE, Schonewille M, Smit AB, Gao Z, De Zeeuw CI. Protein Phosphatase 2B Dual Function Facilitates Synaptic Integrity and Motor Learning. J Neurosci 2021; 41:5579-5594. [PMID: 34021041 PMCID: PMC8244972 DOI: 10.1523/jneurosci.1741-20.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 04/01/2021] [Accepted: 04/23/2021] [Indexed: 11/21/2022] Open
Abstract
Protein phosphatase 2B (PP2B) is critical for synaptic plasticity and learning, but the molecular mechanisms involved remain unclear. Here we identified different types of proteins that interact with PP2B, including various structural proteins of the postsynaptic densities (PSDs) of Purkinje cells (PCs) in mice. Deleting PP2B reduced expression of PSD proteins and the relative thickness of PSD at the parallel fiber to PC synapses, whereas reexpression of inactive PP2B partly restored the impaired distribution of nanoclusters of PSD proteins, together indicating a structural role of PP2B. In contrast, lateral mobility of surface glutamate receptors solely depended on PP2B phosphatase activity. Finally, the level of motor learning covaried with both the enzymatic and nonenzymatic functions of PP2B. Thus, PP2B controls synaptic function and learning both through its action as a phosphatase and as a structural protein that facilitates synapse integrity.SIGNIFICANCE STATEMENT Phosphatases are generally considered to serve their critical role in learning and memory through their enzymatic operations. Here, we show that protein phosphatase 2B (PP2B) interacts with structural proteins at the synapses of cerebellar Purkinje cells. Differentially manipulating the enzymatic and structural domains of PP2B leads to different phenotypes in cerebellar learning. We propose that PP2B is crucial for cerebellar learning via two complementary actions, an enzymatic and a structural operation.
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Affiliation(s)
- Zhanmin Lin
- Department of Neuroscience, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | - Bin Wu
- Department of Neuroscience, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
- Department of Neurology and Institute of Neurology, Huashan Hospital, Fudan University, 200040, Shanghai, China
| | - Maarten W Paul
- Optical Imaging Center, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | - Ka Wan Li
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam Neuroscience, 1081 HV, Amsterdam, The Netherlands
| | - Yao Yao
- Department of Medical informatics, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | - Ihor Smal
- Department of Medical informatics, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | | | - Hana Hasanbegovic
- Department of Neuroscience, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | - Karel Bezstarosti
- Center for Proteomics, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | - Jeroen Demmers
- Center for Proteomics, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | | | - Erik Meijering
- School of Computer Science and Engineering & Graduate School of Biomedical Engineering, University of New South Wales, Sydney, 2052, New South Wales, Australia
| | - Freek E Hoebeek
- Department of Neuroscience, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
- Department for Developmental Origins of Disease, Wilhelmina Children's Hospital and Brain Center, Utrecht Medical Center, 3584 EA, Utrecht, The Netherlands
| | | | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam Neuroscience, 1081 HV, Amsterdam, The Netherlands
| | - Zhenyu Gao
- Department of Neuroscience, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, 3015 GE, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience, KNAW, 1105 BA, Amsterdam, The Netherlands
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15
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Di Benedetto G, Iannucci LF, Surdo NC, Zanin S, Conca F, Grisan F, Gerbino A, Lefkimmiatis K. Compartmentalized Signaling in Aging and Neurodegeneration. Cells 2021; 10:cells10020464. [PMID: 33671541 PMCID: PMC7926881 DOI: 10.3390/cells10020464] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/12/2022] Open
Abstract
The cyclic AMP (cAMP) signalling cascade is necessary for cell homeostasis and plays important roles in many processes. This is particularly relevant during ageing and age-related diseases, where drastic changes, generally decreases, in cAMP levels have been associated with the progressive decline in overall cell function and, eventually, the loss of cellular integrity. The functional relevance of reduced cAMP is clearly supported by the finding that increases in cAMP levels can reverse some of the effects of ageing. Nevertheless, despite these observations, the molecular mechanisms underlying the dysregulation of cAMP signalling in ageing are not well understood. Compartmentalization is widely accepted as the modality through which cAMP achieves its functional specificity; therefore, it is important to understand whether and how this mechanism is affected during ageing and to define which is its contribution to this process. Several animal models demonstrate the importance of specific cAMP signalling components in ageing, however, how age-related changes in each of these elements affect the compartmentalization of the cAMP pathway is largely unknown. In this review, we explore the connection of single components of the cAMP signalling cascade to ageing and age-related diseases whilst elaborating the literature in the context of cAMP signalling compartmentalization.
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Affiliation(s)
- Giulietta Di Benedetto
- Neuroscience Institute, National Research Council of Italy (CNR), 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Correspondence: (G.D.B.); (K.L.)
| | - Liliana F. Iannucci
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Nicoletta C. Surdo
- Neuroscience Institute, National Research Council of Italy (CNR), 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
| | - Sofia Zanin
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Filippo Conca
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Biology, University of Padova, 35122 Padova, Italy
| | - Francesca Grisan
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Biology, University of Padova, 35122 Padova, Italy
| | - Andrea Gerbino
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, 70121 Bari, Italy;
| | - Konstantinos Lefkimmiatis
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Correspondence: (G.D.B.); (K.L.)
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16
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Purkey AM, Dell’Acqua ML. Phosphorylation-Dependent Regulation of Ca 2+-Permeable AMPA Receptors During Hippocampal Synaptic Plasticity. Front Synaptic Neurosci 2020; 12:8. [PMID: 32292336 PMCID: PMC7119613 DOI: 10.3389/fnsyn.2020.00008] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/18/2020] [Indexed: 01/28/2023] Open
Abstract
Experience-dependent learning and memory require multiple forms of plasticity at hippocampal and cortical synapses that are regulated by N-methyl-D-aspartate receptors (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptors (NMDAR, AMPAR). These plasticity mechanisms include long-term potentiation (LTP) and depression (LTD), which are Hebbian input-specific mechanisms that rapidly increase or decrease AMPAR synaptic strength at specific inputs, and homeostatic plasticity that globally scales-up or -down AMPAR synaptic strength across many or even all inputs. Frequently, these changes in synaptic strength are also accompanied by a change in the subunit composition of AMPARs at the synapse due to the trafficking to and from the synapse of receptors lacking GluA2 subunits. These GluA2-lacking receptors are most often GluA1 homomeric receptors that exhibit higher single-channel conductance and are Ca2+-permeable (CP-AMPAR). This review article will focus on the role of protein phosphorylation in regulation of GluA1 CP-AMPAR recruitment and removal from hippocampal synapses during synaptic plasticity with an emphasis on the crucial role of local signaling by the cAMP-dependent protein kinase (PKA) and the Ca2+calmodulin-dependent protein phosphatase 2B/calcineurin (CaN) that is coordinated by the postsynaptic scaffold protein A-kinase anchoring protein 79/150 (AKAP79/150).
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Affiliation(s)
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, United States
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17
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A novel phospho-modulatory mechanism contributes to the calcium-dependent regulation of T-type Ca 2+ channels. Sci Rep 2019; 9:15642. [PMID: 31666636 PMCID: PMC6821770 DOI: 10.1038/s41598-019-52194-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 10/13/2019] [Indexed: 11/08/2022] Open
Abstract
Cav3 / T-type Ca2+ channels are dynamically regulated by intracellular Ca2+ ions, which inhibit Cav3 availability. Here, we demonstrate that this inhibition becomes irreversible in the presence of non-hydrolysable ATP analogs, resulting in a strong hyperpolarizing shift in the steady-state inactivation of the residual Cav3 current. Importantly, the effect of these ATP analogs was prevented in the presence of intracellular BAPTA. Additional findings obtained using intracellular dialysis of inorganic phosphate and alkaline phosphatase or NaN3 treatment further support the involvement of a phosphorylation mechanism. Contrasting with Cav1 and Cav2 Ca2+ channels, the Ca2+-dependent modulation of Cav3 channels appears to be independent of calmodulin, calcineurin and endocytic pathways. Similar findings were obtained for the native T-type Ca2+ current recorded in rat thalamic neurons of the central medial nucleus. Overall, our data reveal a new Ca2+ sensitive phosphorylation-dependent mechanism regulating Cav3 channels, with potentially important physiological implications for the multiple cell functions controlled by T-type Ca2+ channels.
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18
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Man KNM, Navedo MF, Horne MC, Hell JW. β 2 Adrenergic Receptor Complexes with the L-Type Ca 2+ Channel Ca V1.2 and AMPA-Type Glutamate Receptors: Paradigms for Pharmacological Targeting of Protein Interactions. Annu Rev Pharmacol Toxicol 2019; 60:155-174. [PMID: 31561738 DOI: 10.1146/annurev-pharmtox-010919-023404] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Formation of signaling complexes is crucial for the orchestration of fast, efficient, and specific signal transduction. Pharmacological disruption of defined signaling complexes has the potential for specific intervention in selected regulatory pathways without affecting organism-wide disruption of parallel pathways. Signaling by epinephrine and norepinephrine through α and β adrenergic receptors acts on many signaling pathways in many cell types. Here, we initially provide an overview of the signaling complexes formed between the paradigmatic β2 adrenergic receptor and two of its most important targets, the L-type Ca2+ channel CaV1.2 and the AMPA-type glutamate receptor. Importantly, both complexes contain the trimeric Gs protein, adenylyl cyclase, and the cAMP-dependent protein kinase, PKA. We then discuss the functional implications of the formation of these complexes, how those complexes can be specifically disrupted, and how such disruption could be utilized in the pharmacological treatment of disease.
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Affiliation(s)
- Kwun Nok Mimi Man
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Mary C Horne
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, California 95616, USA;
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19
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Akt phosphorylation of neuronal nitric oxide synthase regulates gastrointestinal motility in mouse ileum. Proc Natl Acad Sci U S A 2019; 116:17541-17546. [PMID: 31405982 DOI: 10.1073/pnas.1905902116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nitric oxide (NO) is a major inhibitory neurotransmitter that mediates nonadrenergic noncholinergic (NANC) signaling. Neuronal NO synthase (nNOS) is activated by Ca2+/calmodulin to produce NO, which causes smooth muscle relaxation to regulate physiologic tone. nNOS serine1412 (S1412) phosphorylation may reduce the activating Ca2+ requirement and sustain NO production. We developed and characterized a nonphosphorylatable nNOSS1412A knock-in mouse and evaluated its enteric neurotransmission and gastrointestinal (GI) motility to understand the physiologic significance of nNOS S1412 phosphorylation. Electrical field stimulation (EFS) of wild-type (WT) mouse ileum induced nNOS S1412 phosphorylation that was blocked by tetrodotoxin and by inhibitors of the protein kinase Akt but not by PKA inhibitors. Low-frequency depolarization increased nNOS S1412 phosphorylation and relaxed WT ileum but only partially relaxed nNOSS1412A ileum. At higher frequencies, nNOS S1412 had no effect. nNOSS1412A ileum expressed less phosphodiesterase-5 and was more sensitive to relaxation by exogenous NO. Under non-NANC conditions, peristalsis and segmentation were faster in the nNOSS1412A ileum. Together these findings show that neuronal depolarization stimulates enteric nNOS phosphorylation by Akt to promote normal GI motility. Thus, phosphorylation of nNOS S1412 is a significant regulatory mechanism for nitrergic neurotransmission in the gut.
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20
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Bosse KE, Ghoddoussi F, Eapen AT, Charlton JL, Susick LL, Desai K, Berkowitz BA, Perrine SA, Conti AC. Calcium/calmodulin-stimulated adenylyl cyclases 1 and 8 regulate reward-related brain activity and ethanol consumption. Brain Imaging Behav 2019; 13:396-407. [PMID: 29594872 PMCID: PMC6202255 DOI: 10.1007/s11682-018-9856-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Evidence suggests a predictive link between elevated basal activity within reward-related networks (e.g., cortico-basal ganglia-thalamic networks) and vulnerability for alcoholism. Both calcium channel function and cyclic adenosine monophosphate (cAMP)/protein kinase A-mediated signaling are critical modulators of reward neurocircuitry and reward-related behaviors. Calcium/calmodulin-stimulated adenylyl cyclases (AC) 1 and 8 are sensitive to activity-dependent increases in intracellular calcium and catalyze cAMP production. Therefore, we hypothesized AC1 and 8 regulate brain activity in reward regions of the cortico-basal ganglia-thalamic circuit and that this regulatory influence predicts voluntary ethanol drinking responses. This hypothesis was evaluated by manganese-enhanced magnetic resonance imaging and chronic, intermittent ethanol access procedures. Ethanol-naïve mice with genetic deletion of both AC1 and 8 (DKO mice) exhibited bilateral reductions in baseline activity within cortico-basal ganglia-thalamic regions associated with reward processing compared to wild-type controls (WT, C57BL/6 mice). Significant activity changes were not evident in regions either outside of the cortico-basal ganglia-thalamic network or within the network that are not associated with reward processing. Parallel studies demonstrated that reward network hypoactivity in DKO mice predicted a significant attenuation in consumption and preference levels to escalating ethanol concentrations (12, 20 and 30%) compared to WT mice, an effect that was maintained over extended access (14 sessions) to 20% ethanol. Summarizing, these data support a contribution of AC1 and 8 in cortico-basal ganglia-thalamic activity and the predictive value of this regulatory influence on ethanol drinking behavior, which merits the future evaluation of calcium-stimulated ACs in the neural processes that engender vulnerability to maladaptive alcohol drinking.
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Affiliation(s)
- Kelly E Bosse
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Farhad Ghoddoussi
- Department of Anesthesiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ajay T Eapen
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Jennifer L Charlton
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Laura L Susick
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Kirt Desai
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Alana C Conti
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA.
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA.
- Department of Neurosurgery, Wayne State University, 4646 John R St., Detroit, MI, 48201, USA.
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21
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Dittmer PJ, Dell'Acqua ML, Sather WA. Synaptic crosstalk conferred by a zone of differentially regulated Ca 2+ signaling in the dendritic shaft adjoining a potentiated spine. Proc Natl Acad Sci U S A 2019; 116:13611-13620. [PMID: 31209051 PMCID: PMC6613087 DOI: 10.1073/pnas.1902461116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Patterns of postsynaptic activity that induce long-term potentiation of fast excitatory transmission at glutamatergic synapses between hippocampal neurons cause enlargement of the dendritic spine and promote growth in spine endoplasmic reticulum (ER) content. Such postsynaptic activity patterns also impact Ca2+ signaling in the adjoining dendritic shaft, in a zone centered on the spine-shaft junction and extending ∼10-20 µm in either direction along the shaft. Comparing this specialized zone in the shaft with the dendrite in general, plasticity-inducing stimulation of a single spine causes more profound depletion of Ca2+ stores in the ER, a greater degree of interaction between stromal interaction molecule 1 (STIM1) and L-type Ca2+ channels, and thus stronger STIM1 inhibition of these channels. Here we show that the length of this zone along the dendritic axis can be approximately doubled through the neuromodulatory action of β-adrenergic receptors (βARs). The mechanism of βAR enlargement of the zone arises from protein kinase A-mediated enhancement of L-type Ca2+ current, which in turn lowers [Ca2+]ER through ryanodine receptor-dependent Ca2+-induced Ca2+ release and activates STIM1 feedback inhibition of L-type Ca2+ channels. An important function of this dendritic zone is to support crosstalk between spines along its length such that spines neighboring a strongly stimulated spine are enabled to undergo structural plasticity in response to stimulation that would otherwise be subthreshold for spine structural plasticity. This form of crosstalk requires L-type Ca2+ channel current to activate STIM1, and βAR activity extends the range along the shaft over which such spine-to-spine communication can occur.
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Affiliation(s)
- Philip J Dittmer
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - William A Sather
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
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22
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Murphy JG, Crosby KC, Dittmer PJ, Sather WA, Dell'Acqua ML. AKAP79/150 recruits the transcription factor NFAT to regulate signaling to the nucleus by neuronal L-type Ca 2+ channels. Mol Biol Cell 2019; 30:1743-1756. [PMID: 31091162 PMCID: PMC6727748 DOI: 10.1091/mbc.e19-01-0060] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In neurons, regulation of activity-dependent transcription by the nuclear factor of activated T-cells (NFAT) depends upon Ca2+ influx through voltage-gated L-type calcium channels (LTCC) and NFAT translocation to the nucleus following its dephosphorylation by the Ca2+-dependent phosphatase calcineurin (CaN). CaN is recruited to the channel by A-kinase anchoring protein (AKAP) 79/150, which binds to the LTCC C-terminus via a modified leucine-zipper (LZ) interaction. Here we sought to gain new insights into how LTCCs and signaling to NFAT are regulated by this LZ interaction. RNA interference–mediated knockdown of endogenous AKAP150 and replacement with human AKAP79 lacking its C-terminal LZ domain resulted in loss of depolarization-stimulated NFAT signaling in rat hippocampal neurons. However, the LZ mutation had little impact on the AKAP–LTCC interaction or LTCC function, as measured by Förster resonance energy transfer, Ca2+ imaging, and electrophysiological recordings. AKAP79 and NFAT coimmunoprecipitated when coexpressed in heterologous cells, and the LZ mutation disrupted this association. Critically, measurements of NFAT mobility in neurons employing fluorescence recovery after photobleaching and fluorescence correlation spectroscopy provided further evidence for an AKAP79 LZ interaction with NFAT. These findings suggest that the AKAP79/150 LZ motif functions to recruit NFAT to the LTCC signaling complex to promote its activation by AKAP-anchored calcineurin.
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Affiliation(s)
- Jonathan G Murphy
- Eunice Kennedy Shriver Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.,Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Kevin C Crosby
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Philip J Dittmer
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - William A Sather
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
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23
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Greenwald EC, Mehta S, Zhang J. Genetically Encoded Fluorescent Biosensors Illuminate the Spatiotemporal Regulation of Signaling Networks. Chem Rev 2018; 118:11707-11794. [PMID: 30550275 DOI: 10.1021/acs.chemrev.8b00333] [Citation(s) in RCA: 295] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular signaling networks are the foundation which determines the fate and function of cells as they respond to various cues and stimuli. The discovery of fluorescent proteins over 25 years ago enabled the development of a diverse array of genetically encodable fluorescent biosensors that are capable of measuring the spatiotemporal dynamics of signal transduction pathways in live cells. In an effort to encapsulate the breadth over which fluorescent biosensors have expanded, we endeavored to assemble a comprehensive list of published engineered biosensors, and we discuss many of the molecular designs utilized in their development. Then, we review how the high temporal and spatial resolution afforded by fluorescent biosensors has aided our understanding of the spatiotemporal regulation of signaling networks at the cellular and subcellular level. Finally, we highlight some emerging areas of research in both biosensor design and applications that are on the forefront of biosensor development.
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Affiliation(s)
- Eric C Greenwald
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Sohum Mehta
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Jin Zhang
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
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24
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Gibson ES, Woolfrey KM, Li H, Hogan PG, Nemenoff RA, Heasley LE, Dell'Acqua ML. Subcellular Localization and Activity of the Mitogen-Activated Protein Kinase Kinase 7 (MKK7) γ Isoform are Regulated through Binding to the Phosphatase Calcineurin. Mol Pharmacol 2018; 95:20-32. [PMID: 30404891 DOI: 10.1124/mol.118.113159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/31/2018] [Indexed: 11/22/2022] Open
Abstract
Calcineurin (CaN) phosphatase signaling is regulated by targeting CaN to substrates, inhibitors, and scaffold proteins containing docking motifs with the consensus sequence of PxIxIT. Here, we identify the docking of CaN to the γ isoform of MKK7, a component of the c-Jun N-terminal kinase (JNK) pathway. Because of alternative splicing of a single exon within the N-terminal domain, MKK7γ encodes a unique PxIxIT motif (PIIVIT) that is not present in MKK7α or β We found that MKK7γ bound directly to CaN through this PIIVIT motif in vitro, immunoprecipitated with CaN from cell extracts, and exhibited fluorescence resonance energy transfer (FRET) with CaN in the cytoplasm but not in the nucleus of living cells. In contrast, MKK7α and β exhibited no direct binding or FRET with CaN and were localized more in the nucleus than the cytoplasm. Furthermore, the inhibition of CaN phosphatase activity increased the basal phosphorylation of MKK7γ but not MKK7β Deletion of the MKK7γ PIIVIT motif eliminated FRET with CaN and promoted MKK7γ redistribution to the nucleus; however, the inhibition of CaN activity did not alter MKK7γ localization, indicating that MKK7γ cytoplasmic retention by CaN is phosphatase activity independent. Finally, the inhibition of CaN phosphatase activity in vascular smooth muscle cells, which express MKK7γ mRNA, enhances JNK activation. Overall, we conclude that the MKK7γ-specific PxIxIT motif promotes high-affinity CaN binding that could promote novel cross talk between CaN and JNK signaling by limiting MKK7γ phosphorylation and restricting its localization to the cytoplasm.
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Affiliation(s)
- Emily S Gibson
- Department of Pharmacology (E.S.G., K.M.W., M.L.D.) and Department of Medicine, Division of Renal Diseases and Hypertension (R.A.N.), University of Colorado School of Medicine, Aurora, Colorado; Department of Craniofacial Biology, University of Colorado School of Dental Medicine, Aurora, Colorado (L.E.H.); Immune Disease Institute, Harvard Medical School, Boston, Massachusetts (H.L.); and La Jolla Institute for Allergy and Immunology, La Jolla, California (P.G.H.)
| | - Kevin M Woolfrey
- Department of Pharmacology (E.S.G., K.M.W., M.L.D.) and Department of Medicine, Division of Renal Diseases and Hypertension (R.A.N.), University of Colorado School of Medicine, Aurora, Colorado; Department of Craniofacial Biology, University of Colorado School of Dental Medicine, Aurora, Colorado (L.E.H.); Immune Disease Institute, Harvard Medical School, Boston, Massachusetts (H.L.); and La Jolla Institute for Allergy and Immunology, La Jolla, California (P.G.H.)
| | - Huiming Li
- Department of Pharmacology (E.S.G., K.M.W., M.L.D.) and Department of Medicine, Division of Renal Diseases and Hypertension (R.A.N.), University of Colorado School of Medicine, Aurora, Colorado; Department of Craniofacial Biology, University of Colorado School of Dental Medicine, Aurora, Colorado (L.E.H.); Immune Disease Institute, Harvard Medical School, Boston, Massachusetts (H.L.); and La Jolla Institute for Allergy and Immunology, La Jolla, California (P.G.H.)
| | - Patrick G Hogan
- Department of Pharmacology (E.S.G., K.M.W., M.L.D.) and Department of Medicine, Division of Renal Diseases and Hypertension (R.A.N.), University of Colorado School of Medicine, Aurora, Colorado; Department of Craniofacial Biology, University of Colorado School of Dental Medicine, Aurora, Colorado (L.E.H.); Immune Disease Institute, Harvard Medical School, Boston, Massachusetts (H.L.); and La Jolla Institute for Allergy and Immunology, La Jolla, California (P.G.H.)
| | - Raphael A Nemenoff
- Department of Pharmacology (E.S.G., K.M.W., M.L.D.) and Department of Medicine, Division of Renal Diseases and Hypertension (R.A.N.), University of Colorado School of Medicine, Aurora, Colorado; Department of Craniofacial Biology, University of Colorado School of Dental Medicine, Aurora, Colorado (L.E.H.); Immune Disease Institute, Harvard Medical School, Boston, Massachusetts (H.L.); and La Jolla Institute for Allergy and Immunology, La Jolla, California (P.G.H.)
| | - Lynn E Heasley
- Department of Pharmacology (E.S.G., K.M.W., M.L.D.) and Department of Medicine, Division of Renal Diseases and Hypertension (R.A.N.), University of Colorado School of Medicine, Aurora, Colorado; Department of Craniofacial Biology, University of Colorado School of Dental Medicine, Aurora, Colorado (L.E.H.); Immune Disease Institute, Harvard Medical School, Boston, Massachusetts (H.L.); and La Jolla Institute for Allergy and Immunology, La Jolla, California (P.G.H.)
| | - Mark L Dell'Acqua
- Department of Pharmacology (E.S.G., K.M.W., M.L.D.) and Department of Medicine, Division of Renal Diseases and Hypertension (R.A.N.), University of Colorado School of Medicine, Aurora, Colorado; Department of Craniofacial Biology, University of Colorado School of Dental Medicine, Aurora, Colorado (L.E.H.); Immune Disease Institute, Harvard Medical School, Boston, Massachusetts (H.L.); and La Jolla Institute for Allergy and Immunology, La Jolla, California (P.G.H.)
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25
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Tarasova EO, Gaydukov AE, Balezina OP. Calcineurin and Its Role in Synaptic Transmission. BIOCHEMISTRY (MOSCOW) 2018; 83:674-689. [PMID: 30195324 DOI: 10.1134/s0006297918060056] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Calcineurin (CaN) is a serine/threonine phosphatase widely expressed in different cell types and structures including neurons and synapses. The most studied role of CaN is its involvement in the functioning of postsynaptic structures of central synapses. The role of CaN in the presynaptic structures of central and peripheral synapses is less understood, although it has generated a considerable interest and is a subject of a growing number of studies. The regulatory role of CaN in synaptic vesicle endocytosis in the synapse terminals is actively studied. In recent years, new targets of CaN have been identified and its role in the regulation of enzymes and neurotransmitter secretion in peripheral neuromuscular junctions has been revealed. CaN is the only phosphatase that requires calcium and calmodulin for activation. In this review, we present details of CaN molecular structure and give a detailed description of possible mechanisms of CaN activation involving calcium, enzymes, and endogenous and exogenous inhibitors. Known and newly discovered CaN targets at pre- and postsynaptic levels are described. CaN activity in synaptic structures is discussed in terms of functional involvement of this phosphatase in synaptic transmission and neurotransmitter release.
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Affiliation(s)
- E O Tarasova
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
| | - A E Gaydukov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia. .,Pirogov Russian National Research Medical University, Moscow, 117997, Russia
| | - O P Balezina
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
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26
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Niu J, Dick IE, Yang W, Bamgboye MA, Yue DT, Tomaselli G, Inoue T, Ben-Johny M. Allosteric regulators selectively prevent Ca 2+-feedback of Ca V and Na V channels. eLife 2018; 7:35222. [PMID: 30198845 PMCID: PMC6156082 DOI: 10.7554/elife.35222] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 09/09/2018] [Indexed: 12/31/2022] Open
Abstract
Calmodulin (CaM) serves as a pervasive regulatory subunit of CaV1, CaV2, and NaV1 channels, exploiting a functionally conserved carboxy-tail element to afford dynamic Ca2+-feedback of cellular excitability in neurons and cardiomyocytes. Yet this modularity counters functional adaptability, as global changes in ambient CaM indiscriminately alter its targets. Here, we demonstrate that two structurally unrelated proteins, SH3 and cysteine-rich domain (stac) and fibroblast growth factor homologous factors (fhf) selectively diminish Ca2+/CaM-regulation of CaV1 and NaV1 families, respectively. The two proteins operate on allosteric sites within upstream portions of respective channel carboxy-tails, distinct from the CaM-binding interface. Generalizing this mechanism, insertion of a short RxxK binding motif into CaV1.3 carboxy-tail confers synthetic switching of CaM regulation by Mona SH3 domain. Overall, our findings identify a general class of auxiliary proteins that modify Ca2+/CaM signaling to individual targets allowing spatial and temporal orchestration of feedback, and outline strategies for engineering Ca2+/CaM signaling to individual targets.
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Affiliation(s)
- Jacqueline Niu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States
| | - Ivy E Dick
- Department of Physiology, University of Maryland, Baltimore, United States
| | - Wanjun Yang
- Department of Cardiology, Johns Hopkins University, Baltimore, United States
| | | | - David T Yue
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States
| | - Gordon Tomaselli
- Department of Cardiology, Johns Hopkins University, Baltimore, United States
| | - Takanari Inoue
- Department of Cell Biology, Johns Hopkins University, Baltimore, United States.,Center for Cell Dynamics, Institute for Basic Biomedical Sciences, Johns Hopkins University, Baltimore, United States
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, United States
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27
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Serotonin Disinhibits a Caenorhabditis elegans Sensory Neuron by Suppressing Ca 2+-Dependent Negative Feedback. J Neurosci 2018; 38:2069-2080. [PMID: 29358363 DOI: 10.1523/jneurosci.1908-17.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 01/04/2018] [Accepted: 01/12/2018] [Indexed: 11/21/2022] Open
Abstract
Neuromodulators, such as serotonin (5-HT), alter neuronal excitability and synaptic strengths, and define different behavioral states. Neuromodulator-dependent changes in neuronal activity patterns are frequently measured using calcium reporters because calcium imaging can easily be performed on intact functioning nervous systems. With only 302 neurons, the nematode Caenorhabditis elegans provides a relatively simple, yet powerful, system to understand neuromodulation at the level of individual neurons. C. elegans hermaphrodites are repelled by 1-octanol, and the initiation of these aversive responses is potentiated by 5-HT. 5-HT acts on the ASH polymodal nociceptors that sense the 1-octanol stimulus. Surprisingly, 5-HT suppresses ASH Ca2+ transients while simultaneously potentiating 1-octanol-dependent ASH depolarization. Here we further explore this seemingly inverse relationship. Our results show the following (1) 5-HT acts downstream of depolarization, through Gαq-mediated signaling and calcineurin, to inhibit L-type voltage-gated Ca2+ channels; (2) the 1-octanol-evoked Ca2+ transients in ASHs inhibit depolarization; and (3) the Ca2+-activated K+ channel, SLO-1, acts downstream of 5-HT and is a critical regulator of ASH response dynamics. These findings define a Ca2+-dependent inhibitory feedback loop that can be modulated by 5-HT to increase neuronal excitability and regulate behavior, and highlight the possibility that neuromodulator-induced changes in the amplitudes of Ca2+ transients do not necessarily predict corresponding changes in depolarization.SIGNIFICANCE STATEMENT Neuromodulators, such as 5-HT, modify behavior by regulating excitability and synaptic efficiency in neurons. Neuromodulation is often studied using Ca2+ imaging, whereby neuromodulator-dependent changes in neuronal activity levels can be detected in intact, functioning circuits. Here we show that 5-HT reduces the amplitude of depolarization-dependent Ca2+ transients in a C. elegans nociceptive neuron, through Gαq signaling and calcineurin but that Ca2+ itself inhibits depolarization, likely through Ca2+-activated K+ channels. The net effect of 5-HT, therefore, is to increase neuronal excitability through disinhibition. These results establish a novel 5-HT signal transduction pathway, and demonstrate that neuromodulators can change Ca2+ signals and depolarization amplitudes in opposite directions, simultaneously, within a single neuron.
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28
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Wild AR, Dell'Acqua ML. Potential for therapeutic targeting of AKAP signaling complexes in nervous system disorders. Pharmacol Ther 2017; 185:99-121. [PMID: 29262295 DOI: 10.1016/j.pharmthera.2017.12.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A common feature of neurological and neuropsychiatric disorders is a breakdown in the integrity of intracellular signal transduction pathways. Dysregulation of ion channels and receptors in the cell membrane and the enzymatic mediators that link them to intracellular effectors can lead to synaptic dysfunction and neuronal death. However, therapeutic targeting of these ubiquitous signaling elements can lead to off-target side effects due to their widespread expression in multiple systems of the body. A-kinase anchoring proteins (AKAPs) are multivalent scaffolding proteins that compartmentalize a diverse range of receptor and effector proteins to streamline signaling within nanodomain signalosomes. A number of essential neurological processes are known to critically depend on AKAP-directed signaling and an understanding of the role AKAPs play in nervous system disorders has emerged in recent years. Selective targeting of AKAP protein-protein interactions may be a means to uncouple pathologically active signaling pathways in neurological disorders with a greater degree of specificity. In this review we will discuss the role of AKAPs in both regulating normal nervous system function and dysfunction associated with disease, and the potential for therapeutic targeting of AKAP signaling complexes.
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Affiliation(s)
- Angela R Wild
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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29
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Zhao MM, Lian WW, Li Z, Shao DX, Chen SC, Sun XF, Hu HY, Feng R, Guo F, Hao LY. Astragaloside IV Inhibits Membrane Ca[Formula: see text] Current but Enhances Sarcoplasmic Reticulum Ca[Formula: see text] Release. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2017; 45:863-877. [PMID: 28595501 DOI: 10.1142/s0192415x1750046x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Astragaloside IV (AS-IV) is one of the active ingredients in Astragalus membrananceus (Huangqi), a traditional Chinese medicine. The present study investigated the effects of AS-IV on Ca[Formula: see text] handling in cardiac myocytes to elucidate its possible mechanism in the treatment of cardiac disease. The results showed that AS-IV at 1 and 10[Formula: see text][Formula: see text]M reduced KCl-induced [Ca[Formula: see text]]i increase ([Formula: see text] from 1.33[Formula: see text][Formula: see text][Formula: see text]0.04 (control, [Formula: see text] 28) to 1.22[Formula: see text][Formula: see text][Formula: see text]0.02 ([Formula: see text], [Formula: see text] 29) and 1.22[Formula: see text][Formula: see text][Formula: see text]0.02 ([Formula: see text] 0.01, [Formula: see text]), but it enhanced Ca[Formula: see text] release from SR ([Formula: see text] from 1.04[Formula: see text][Formula: see text][Formula: see text]0.01 (control, [Formula: see text]) to 1.44[Formula: see text][Formula: see text][Formula: see text]0.03 ([Formula: see text], [Formula: see text]) and 1.60[Formula: see text][Formula: see text][Formula: see text]0.04 ([Formula: see text] 0.01, [Formula: see text]0), in H9c2 cells. Similar results were obtained in native cardiomyocytes. AS-IV at 1 and 10[Formula: see text][Formula: see text]M inhibited L-type Ca[Formula: see text] current ([Formula: see text] from [Formula: see text]4.42[Formula: see text][Formula: see text][Formula: see text]0.58 pA/pF of control to [Formula: see text]2.25[Formula: see text][Formula: see text][Formula: see text]0.12 pA/pF ([Formula: see text] 0.01, [Formula: see text] 5) and [Formula: see text]1.78[Formula: see text][Formula: see text][Formula: see text]0.28 pA/pF ([Formula: see text] 0.01, [Formula: see text] 5) respectively, when the interference of [Ca[Formula: see text]]i was eliminated due to the depletion of SR Ca[Formula: see text] store by thapsigargin, an inhibitor of Ca[Formula: see text] ATPase. Moreover, when BAPTA, a rapid Ca[Formula: see text] chelator, was used, CDI (Ca[Formula: see text]-dependent inactivation) of [Formula: see text] was eliminated, and the inhibitory effects of AS-IV on ICaL were significantly reduced at the same time. These results suggest that AS-IV affects Ca[Formula: see text] homeostasis through two opposite pathways: inhibition of Ca[Formula: see text] influx through L-type Ca[Formula: see text] channel, and promotion of Ca[Formula: see text] release from SR.
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Affiliation(s)
- Mei-Mi Zhao
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Wen-Wen Lian
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Zhuo Li
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Dong-Xue Shao
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Si-Chong Chen
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Xue-Fei Sun
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Hui-Yuan Hu
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Rui Feng
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Feng Guo
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
| | - Li-Ying Hao
- 1 Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, P. R. China
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30
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STIM1 Ca 2+ Sensor Control of L-type Ca 2+-Channel-Dependent Dendritic Spine Structural Plasticity and Nuclear Signaling. Cell Rep 2017; 19:321-334. [PMID: 28402855 DOI: 10.1016/j.celrep.2017.03.056] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 11/07/2016] [Accepted: 03/17/2017] [Indexed: 12/23/2022] Open
Abstract
Potentiation of synaptic strength relies on postsynaptic Ca2+ signals, modification of dendritic spine structure, and changes in gene expression. One Ca2+ signaling pathway supporting these processes routes through L-type Ca2+ channels (LTCC), whose activity is subject to tuning by multiple mechanisms. Here, we show in hippocampal neurons that LTCC inhibition by the endoplasmic reticulum (ER) Ca2+ sensor, stromal interaction molecule 1 (STIM1), is engaged by the neurotransmitter glutamate, resulting in regulation of spine ER structure and nuclear signaling by the NFATc3 transcription factor. In this mechanism, depolarization by glutamate activates LTCC Ca2+ influx, releases Ca2+ from the ER, and consequently drives STIM1 aggregation and an inhibitory interaction with LTCCs that increases spine ER content but decreases NFATc3 nuclear translocation. These findings of negative feedback control of LTCC signaling by STIM1 reveal interplay between Ca2+ influx and release from stores that controls both postsynaptic structural plasticity and downstream nuclear signaling.
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31
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Cazade M, Bidaud I, Lory P, Chemin J. Activity-dependent regulation of T-type calcium channels by submembrane calcium ions. eLife 2017; 6. [PMID: 28109159 PMCID: PMC5308894 DOI: 10.7554/elife.22331] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 01/20/2017] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated Ca2+ channels are involved in numerous physiological functions and various mechanisms finely tune their activity, including the Ca2+ ion itself. This is well exemplified by the Ca2+-dependent inactivation of L-type Ca2+ channels, whose alteration contributes to the dramatic disease Timothy Syndrome. For T-type Ca2+ channels, a long-held view is that they are not regulated by intracellular Ca2+. Here we challenge this notion by using dedicated electrophysiological protocols on both native and expressed T-type Ca2+ channels. We demonstrate that a rise in submembrane Ca2+ induces a large decrease in T-type current amplitude due to a hyperpolarizing shift in the steady-state inactivation. Activation of most representative Ca2+-permeable ionotropic receptors similarly regulate T-type current properties. Altogether, our data clearly establish that Ca2+ entry exerts a feedback control on T-type channel activity, by modulating the channel availability, a mechanism that critically links cellular properties of T-type Ca2+ channels to their physiological roles. DOI:http://dx.doi.org/10.7554/eLife.22331.001 Neurons, muscle cells and many other types of cells use electrical signals to exchange information and coordinate their behavior. Proteins known as calcium channels sit in the membrane that surrounds the cell and can generate electrical signals by allowing calcium ions to cross the membrane and enter the cell during electrical activities. Although calcium ions are needed to generate these electrical signals, and for many other processes in cells, if the levels of calcium ions inside cells become too high they can be harmful and cause disease. Cells have a “feedback” mechanism that prevents calcium ion levels from becoming too high. This mechanism relies on the calcium ions that are already in the cell being able to close the calcium channels. This feedback mechanism has been extensively studied in two types of calcium channel, but it is not known whether a third group of channels – known as Cav3 channels – are also regulated in this way. Cav3 channels are important in electrical signaling in neurons and have been linked with epilepsy, chronic pain and various other conditions in humans. Cazade et al. investigated whether calcium ions can regulate the activity of human Cav3 channels. The experiments show that these channels are indeed regulated by calcium ions, but using a distinct mechanism to other types of calcium channels. For the Cav3 channels, calcium ions alter the gating properties of the channels so that they are less easily activated . As a result, fewer Cav3 channels are “available” to provide calcium ions with a route into the cell. The next steps following on from this work will be to identify the molecular mechanisms underlying this new feedback mechanism. Another challenge will be to find out what role this calcium ion-driven feedback plays in neurological disorders that are linked with altered Cav3 channel activity. DOI:http://dx.doi.org/10.7554/eLife.22331.002
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Affiliation(s)
- Magali Cazade
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Isabelle Bidaud
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Philippe Lory
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Jean Chemin
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
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32
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FRET biosensors reveal AKAP-mediated shaping of subcellular PKA activity and a novel mode of Ca(2+)/PKA crosstalk. Cell Signal 2016; 28:294-306. [PMID: 26772752 DOI: 10.1016/j.cellsig.2016.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 12/18/2015] [Accepted: 01/04/2016] [Indexed: 02/01/2023]
Abstract
Scaffold proteins play a critical role in cellular homeostasis by anchoring signaling enzymes in close proximity to downstream effectors. In addition to anchoring static enzyme complexes, some scaffold proteins also form dynamic signalosomes that can traffic to different subcellular compartments upon stimulation. Gravin (AKAP12), a multivalent scaffold, anchors PKA and other enzymes to the plasma membrane under basal conditions, but upon [Ca(2+)]i elevation, is rapidly redistributed to the cytosol. Because gravin redistribution also impacts PKA localization, we postulate that gravin acts as a calcium "switch" that modulates PKA-substrate interactions at the plasma membrane, thus facilitating a novel crosstalk mechanism between Ca(2+) and PKA-dependent pathways. To assess this, we measured the impact of gravin-V5/His expression on compartmentalized PKA activity using the FRET biosensor AKAR3 in cultured cells. Upon treatment with forskolin or isoproterenol, cells expressing gravin-V5/His showed elevated levels of plasma membrane PKA activity, but cytosolic PKA activity levels were reduced compared with control cells lacking gravin. This effect required both gravin interaction with PKA and localization at the plasma membrane. Pretreatment with calcium-elevating agents thapsigargin or ATP caused gravin redistribution away from the plasma membrane and prevented gravin from elevating PKA activity levels at the membrane. Importantly, this mode of Ca(2+)/PKA crosstalk was not observed in cells expressing a gravin mutant that resisted calcium-mediated redistribution from the cell periphery. These results reveal that gravin impacts subcellular PKA activity levels through the spatial targeting of PKA, and that calcium elevation modulates downstream β-adrenergic/PKA signaling through gravin redistribution, thus supporting the hypothesis that gravin mediates crosstalk between Ca(2+) and PKA-dependent signaling pathways. Based on these results, AKAP localization dynamics may represent an important paradigm for the regulation of cellular signaling networks.
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33
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AKAP150 participates in calcineurin/NFAT activation during the down-regulation of voltage-gated K(+) currents in ventricular myocytes following myocardial infarction. Cell Signal 2015; 28:733-40. [PMID: 26724383 DOI: 10.1016/j.cellsig.2015.12.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 12/22/2015] [Indexed: 12/19/2022]
Abstract
The Ca(2+)-responsive phosphatase calcineurin/protein phosphatase 2B dephosphorylates the transcription factor NFATc3. In the myocardium activation of NFATc3 down-regulates the expression of voltage-gated K(+) (Kv) channels after myocardial infarction (MI). This prolongs action potential duration and increases the probability of arrhythmias. Although recent studies infer that calcineurin is activated by local and transient Ca(2+) signals the molecular mechanism that underlies the process is unclear in ventricular myocytes. Here we test the hypothesis that sequestering of calcineurin to the sarcolemma of ventricular myocytes by the anchoring protein AKAP150 is required for acute activation of NFATc3 and the concomitant down-regulation of Kv channels following MI. Biochemical and cell based measurements resolve that approximately 0.2% of the total calcineurin activity in cardiomyocytes is associated with AKAP150. Electrophysiological analyses establish that formation of this AKAP150-calcineurin signaling dyad is essential for the activation of the phosphatase and the subsequent down-regulation of Kv channel currents following MI. Thus AKAP150-mediated targeting of calcineurin to sarcolemmal micro-domains in ventricular myocytes contributes to the local and acute gene remodeling events that lead to the down-regulation of Kv currents.
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34
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Mari Y, Katnik C, Cuevas J. σ-1 Receptor Inhibition of ASIC1a Channels is Dependent on a Pertussis Toxin-Sensitive G-Protein and an AKAP150/Calcineurin Complex. Neurochem Res 2015; 40:2055-67. [PMID: 24925261 DOI: 10.1007/s11064-014-1324-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 04/17/2014] [Accepted: 05/03/2014] [Indexed: 10/25/2022]
Abstract
ASIC1a channels play a major role in various pathophysiological conditions including depression, anxiety, epilepsy, and neurodegeneration following ischemic stroke. Sigma-1 (σ-1) receptor stimulation depresses the activity of ASIC1a channels in cortical neurons, but the mechanism(s) by which σ-1 receptors exert their influence on ASIC1a remains unknown. Experiments were undertaken to elucidate the signaling cascade linking σ-1 receptors to ASIC1a channels. Immunohistochemical studies showed that σ-1 receptors, ASIC1a and A-kinase anchoring peptide 150 colocalize in the plasma membrane of the cell body and processes of cortical neurons. Fluorometric Ca(2+) imaging experiments showed that disruption of the macromolecular complexes containing AKAP150 diminished the effects of the σ-1 on ASIC1a, as did application of the calcineurin inhibitors, cyclosporin A and FK-506. Moreover, whole-cell patch clamp experiments showed that σ-1 receptors were less effective at decreasing ASIC1a-mediated currents in the presence of the VIVIT peptide, which binds to calcineurin and prevents cellular effects dependent on AKAP150/calcineurin interaction. The coupling of σ-1 to ASIC1a was also disrupted by preincubation of the neurons in the G-protein inhibitor, pertussis toxin (PTX). Taken together, our data reveal that σ-1 receptor block of ASIC1a function is dependent on activation of a PTX-sensitive G-protein and stimulation of AKAP150 bound calcineurin.
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Affiliation(s)
- Yelenis Mari
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, 12901 Bruce B. Downs Blvd., MDC-9, Tampa, FL, 33612-4799, USA
| | - Christopher Katnik
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, 12901 Bruce B. Downs Blvd., MDC-9, Tampa, FL, 33612-4799, USA
| | - Javier Cuevas
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, 12901 Bruce B. Downs Blvd., MDC-9, Tampa, FL, 33612-4799, USA.
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35
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Abstract
In this issue of Cell Reports, Murphy et al. and Dittmer et al. present exciting new insight into the regulation of Ca2+ influx via the L-type Ca2+ channel Cav1.2 and how increased Ca2+ influx translates into localized activation of the nuclear transcription factor NFAT upon depolarization in neurons.
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Affiliation(s)
- Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA 95615, USA.
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, CA 95615, USA.
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36
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Tarasova EO, Gaydukov AE, Balezina OP. Methods of activation and the role of calcium/calmodulin-dependent protein kinase II in the regulation of acetylcholine secretion in the motor synapses of mice. NEUROCHEM J+ 2015. [DOI: 10.1134/s1819712415020099] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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37
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Evans RC, Herin GA, Hawes SL, Blackwell KT. Calcium-dependent inactivation of calcium channels in the medial striatum increases at eye opening. J Neurophysiol 2015; 113:2979-86. [PMID: 25673739 DOI: 10.1152/jn.00818.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 02/06/2015] [Indexed: 01/12/2023] Open
Abstract
Influx of calcium through voltage-gated calcium channels (VGCCs) is essential for striatal function and plasticity. VGCCs expressed in striatal neurons have varying kinetics, voltage dependences, and densities resulting in heterogeneous subcellular calcium dynamics. One factor that determines the calcium dynamics in striatal medium spiny neurons is inactivation of VGCCs. Aside from voltage-dependent inactivation, VGCCs undergo calcium-dependent inactivation (CDI): inactivating in response to an influx of calcium. CDI is a negative feedback control mechanism; however, its contribution to striatal neuron function is unknown. Furthermore, although the density of VGCC expression changes with development, it is unclear whether CDI changes with development. Because calcium influx through L-type calcium channels is required for striatal synaptic depression, a change in CDI could contribute to age-dependent changes in striatal synaptic plasticity. Here we use whole cell voltage clamp to characterize CDI over developmental stages and across striatal regions. We find that CDI increases at the age of eye opening in the medial striatum but not the lateral striatum. The developmental increase in CDI mostly involves L-type channels, although calcium influx through non-L-type channels contributes to the CDI in both age groups. Agents that enhance protein kinase A (PKA) phosphorylation of calcium channels reduce the magnitude of CDI after eye opening, suggesting that the developmental increase in CDI may be related to a reduction in the phosphorylation state of the L-type calcium channel. These results are the first to show that modifications in striatal neuron properties correlate with changes to sensory input.
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Affiliation(s)
- R C Evans
- George Mason University, The Krasnow Institute for Advanced Studies, Fairfax, Virginia; and
| | - G A Herin
- Eastern Mennonite University, Harrisonburg, Virginia
| | - S L Hawes
- George Mason University, The Krasnow Institute for Advanced Studies, Fairfax, Virginia; and
| | - K T Blackwell
- George Mason University, The Krasnow Institute for Advanced Studies, Fairfax, Virginia; and
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38
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Mehta S, Zhang J. Dynamic visualization of calcium-dependent signaling in cellular microdomains. Cell Calcium 2015; 58:333-41. [PMID: 25703691 DOI: 10.1016/j.ceca.2015.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/20/2015] [Accepted: 01/21/2015] [Indexed: 11/17/2022]
Abstract
Cells rely on the coordinated action of diverse signaling molecules to sense, interpret, and respond to their highly dynamic external environment. To ensure the specific and robust flow of information, signaling molecules are often spatially organized to form distinct signaling compartments, and our understanding of the molecular mechanisms that guide intracellular signaling hinges on the ability to directly probe signaling events within these cellular microdomains. Ca(2+) signaling in particular owes much of its functional versatility to this type of exquisite spatial regulation. As discussed below, a number of methods have been developed to investigate the mechanistic and functional implications of microdomains of Ca(2+) signaling, ranging from the application of Ca(2+) buffers to the direct and targeted visualization of Ca(2+) signaling microdomains using genetically encoded fluorescent reporters.
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Affiliation(s)
- Sohum Mehta
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jin Zhang
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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39
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Ben-Johny M, Yue DT. Calmodulin regulation (calmodulation) of voltage-gated calcium channels. ACTA ACUST UNITED AC 2014; 143:679-92. [PMID: 24863929 PMCID: PMC4035741 DOI: 10.1085/jgp.201311153] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Calmodulin regulation (calmodulation) of the family of voltage-gated CaV1-2 channels comprises a prominent prototype for ion channel regulation, remarkable for its powerful Ca(2+) sensing capabilities, deep in elegant mechanistic lessons, and rich in biological and therapeutic implications. This field thereby resides squarely at the epicenter of Ca(2+) signaling biology, ion channel biophysics, and therapeutic advance. This review summarizes the historical development of ideas in this field, the scope and richly patterned organization of Ca(2+) feedback behaviors encompassed by this system, and the long-standing challenges and recent developments in discerning a molecular basis for calmodulation. We conclude by highlighting the considerable synergy between mechanism, biological insight, and promising therapeutics.
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Affiliation(s)
- Manu Ben-Johny
- Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - David T Yue
- Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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40
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Brown RS, Arany PR. Mechanism of drug-induced gingival overgrowth revisited: a unifying hypothesis. Oral Dis 2014; 21:e51-61. [PMID: 24893951 DOI: 10.1111/odi.12264] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 04/27/2014] [Accepted: 05/28/2014] [Indexed: 12/26/2022]
Abstract
Drug-induced gingival overgrowth (DIGO) is a disfiguring side effect of anti-convulsants, calcineurin inhibitors, and calcium channel blocking agents. A unifying hypothesis has been constructed which begins with cation flux inhibition induced by all three of these drug categories. Decreased cation influx of folic acid active transport within gingival fibroblasts leads to decreased cellular folate uptake, which in turn leads to changes in matrix metalloproteinases metabolism and the failure to activate collagenase. Decreased availability of activated collagenase results in decreased degradation of accumulated connective tissue which presents as DIGO. Studies supporting this hypothesis are discussed.
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Affiliation(s)
- R S Brown
- Division of Oral Diagnosis, Department of Comprehensive Dentistry, Howard University College of Dentistry, Washington, DC, USA; Department of Otolaryngology, Georgetown University Medical Center, Washington, DC, USA; Hematology Branch, NHLBI/NIH, Bethesda, MD, USA
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41
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Dittmer PJ, Dell'Acqua ML, Sather WA. Ca2+/calcineurin-dependent inactivation of neuronal L-type Ca2+ channels requires priming by AKAP-anchored protein kinase A. Cell Rep 2014; 7:1410-1416. [PMID: 24835998 DOI: 10.1016/j.celrep.2014.04.039] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 03/21/2014] [Accepted: 04/25/2014] [Indexed: 10/25/2022] Open
Abstract
Within neurons, Ca2+-dependent inactivation (CDI) of voltage-gated L-type Ca2+ channels shapes cytoplasmic Ca2+ signals. CDI is initiated by Ca2+ binding to channel-associated calmodulin and subsequent Ca2+/calmodulin activation of the Ca2+-dependent phosphatase, calcineurin (CaN), which is targeted to L channels by the A-kinase-anchoring protein AKAP79/150. Here, we report that CDI of neuronal L channels was abolished by inhibition of PKA activity or PKA anchoring to AKAP79/150 and that CDI was also suppressed by stimulation of PKA activity. Although CDI was reduced by positive or negative manipulation of PKA, interference with PKA anchoring or activity lowered Ca2+ current density whereas stimulation of PKA activity elevated it. In contrast, inhibition of CaN reduced CDI but had no effect on current density. These results suggest a model wherein PKA-dependent phosphorylation enhances neuronal L current, thereby priming channels to undergo CDI, and Ca2+/calmodulin-activated CaN actuates CDI by reversing PKA-mediated enhancement of channel activity.
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Affiliation(s)
- Philip J Dittmer
- Department of Pharmacology, University of Colorado School of Medicine, Mail Stop 8315, 12800 East 19(th) Avenue, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Mail Stop 8315, 12800 East 19(th) Avenue, Aurora, CO 80045, USA
| | - William A Sather
- Department of Pharmacology, University of Colorado School of Medicine, Mail Stop 8315, 12800 East 19(th) Avenue, Aurora, CO 80045, USA.
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AKAP-anchored PKA maintains neuronal L-type calcium channel activity and NFAT transcriptional signaling. Cell Rep 2014; 7:1577-1588. [PMID: 24835999 DOI: 10.1016/j.celrep.2014.04.027] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 03/18/2014] [Accepted: 04/15/2014] [Indexed: 11/23/2022] Open
Abstract
L-type voltage-gated Ca2+ channels (LTCC) couple neuronal excitation to gene transcription. LTCC activity is elevated by the cyclic AMP (cAMP)-dependent protein kinase (PKA) and depressed by the Ca2+-dependent phosphatase calcineurin (CaN), and both enzymes are localized to the channel by A-kinase anchoring protein 79/150 (AKAP79/150). AKAP79/150 anchoring of CaN also promotes LTCC activation of transcription through dephosphorylation of the nuclear factor of activated T cells (NFAT). We report here that the basal activity of AKAP79/150-anchored PKA maintains neuronal LTCC coupling to CaN-NFAT signaling by preserving LTCC phosphorylation in opposition to anchored CaN. Genetic disruption of AKAP-PKA anchoring promoted redistribution of the kinase out of postsynaptic dendritic spines, profound decreases in LTCC phosphorylation and Ca2+ influx, and impaired NFAT movement to the nucleus and activation of transcription. Thus, LTCC-NFAT transcriptional signaling in neurons requires precise organization and balancing of PKA and CaN activities in the channel nanoenvironment, which is only made possible by AKAP79/150 scaffolding.
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43
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Hofmann F, Flockerzi V, Kahl S, Wegener JW. L-type CaV1.2 calcium channels: from in vitro findings to in vivo function. Physiol Rev 2014; 94:303-26. [PMID: 24382889 DOI: 10.1152/physrev.00016.2013] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The L-type Cav1.2 calcium channel is present throughout the animal kingdom and is essential for some aspects of CNS function, cardiac and smooth muscle contractility, neuroendocrine regulation, and multiple other processes. The L-type CaV1.2 channel is built by up to four subunits; all subunits exist in various splice variants that potentially affect the biophysical and biological functions of the channel. Many of the CaV1.2 channel properties have been analyzed in heterologous expression systems including regulation of the L-type CaV1.2 channel by Ca(2+) itself and protein kinases. However, targeted mutations of the calcium channel genes confirmed only some of these in vitro findings. Substitution of the respective serines by alanine showed that β-adrenergic upregulation of the cardiac CaV1.2 channel did not depend on the phosphorylation of the in vitro specified amino acids. Moreover, well-established in vitro phosphorylation sites of the CaVβ2 subunit of the cardiac L-type CaV1.2 channel were found to be irrelevant for the in vivo regulation of the channel. However, the molecular basis of some kinetic properties, such as Ca(2+)-dependent inactivation and facilitation, has been approved by in vivo mutagenesis of the CaV1.2α1 gene. This article summarizes recent findings on the in vivo relevance of well-established in vitro results.
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44
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Oldach L, Zhang J. Genetically encoded fluorescent biosensors for live-cell visualization of protein phosphorylation. ACTA ACUST UNITED AC 2014; 21:186-97. [PMID: 24485761 DOI: 10.1016/j.chembiol.2013.12.012] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Revised: 11/22/2013] [Accepted: 12/10/2013] [Indexed: 11/30/2022]
Abstract
Fluorescence-based, genetically encodable biosensors are widely used tools for real-time analysis of biological processes. Over the last few decades, the number of available genetically encodable biosensors and the types of processes they can monitor have increased rapidly. Here, we aim to introduce the reader to general principles and practices in biosensor development and highlight ways in which biosensors can be used to illuminate outstanding questions of biological function. Specifically, we focus on sensors developed for monitoring kinase activity and use them to illustrate some common considerations for biosensor design. We describe several uses to which kinase and second-messenger biosensors have been put, and conclude with considerations for the use of biosensors once they are developed. Overall, as fluorescence-based biosensors continue to diversify and improve, we expect them to continue to be widely used as reliable and fruitful tools for gaining deeper insights into cellular and organismal function.
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Affiliation(s)
- Laurel Oldach
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 307 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205, USA
| | - Jin Zhang
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 307 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Department of Oncology, The Johns Hopkins University School of Medicine, 307 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205, USA.
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45
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Striessnig J, Pinggera A, Kaur G, Bock G, Tuluc P. L-type Ca 2+ channels in heart and brain. ACTA ACUST UNITED AC 2014; 3:15-38. [PMID: 24683526 PMCID: PMC3968275 DOI: 10.1002/wmts.102] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
L-type calcium channels (Cav1) represent one of the three major classes (Cav1–3) of voltage-gated calcium channels. They were identified as the target of clinically used calcium channel blockers (CCBs; so-called calcium antagonists) and were the first class accessible to biochemical characterization. Four of the 10 known α1 subunits (Cav1.1–Cav1.4) form the pore of L-type calcium channels (LTCCs) and contain the high-affinity drug-binding sites for dihydropyridines and other chemical classes of organic CCBs. In essentially all electrically excitable cells one or more of these LTCC isoforms is expressed, and therefore it is not surprising that many body functions including muscle, brain, endocrine, and sensory function depend on proper LTCC activity. Gene knockouts and inherited human diseases have allowed detailed insight into the physiological and pathophysiological role of these channels. Genome-wide association studies and analysis of human genomes are currently providing even more hints that even small changes of channel expression or activity may be associated with disease, such as psychiatric disease or cardiac arrhythmias. Therefore, it is important to understand the structure–function relationship of LTCC isoforms, their differential contribution to physiological function, as well as their fine-tuning by modulatory cellular processes.
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Affiliation(s)
- Jörg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Alexandra Pinggera
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Gurjot Kaur
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Gabriella Bock
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Petronel Tuluc
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
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46
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Yu K, Zhu J, Qu Z, Cui YY, Hartzell HC. Activation of the Ano1 (TMEM16A) chloride channel by calcium is not mediated by calmodulin. ACTA ACUST UNITED AC 2014; 143:253-67. [PMID: 24420770 PMCID: PMC4001774 DOI: 10.1085/jgp.201311047] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Calcium-mediated activation of the TMEM16A chloride channel does not depend on changes in phosphorylation status or the calcium-binding protein calmodulin. The Ca2+-activated Cl channel anoctamin-1 (Ano1; Tmem16A) plays a variety of physiological roles, including epithelial fluid secretion. Ano1 is activated by increases in intracellular Ca2+, but there is uncertainty whether Ca2+ binds directly to Ano1 or whether phosphorylation or additional Ca2+-binding subunits like calmodulin (CaM) are required. Here we show that CaM is not necessary for activation of Ano1 by Ca2+ for the following reasons. (a) Exogenous CaM has no effect on Ano1 currents in inside-out excised patches. (b) Overexpression of Ca2+-insensitive mutants of CaM have no effect on Ano1 currents, whereas they eliminate the current mediated by the small-conductance Ca2+-activated K+ (SK2) channel. (c) Ano1 does not coimmunoprecipitate with CaM, whereas SK2 does. Furthermore, Ano1 binds very weakly to CaM in pull-down assays. (d) Ano1 is activated in excised patches by low concentrations of Ba2+, which does not activate CaM. In addition, we conclude that reversible phosphorylation/dephosphorylation is not required for current activation by Ca2+ because the current can be repeatedly activated in excised patches in the absence of ATP or other high-energy compounds. Although Ano1 is blocked by the CaM inhibitor trifluoperazine (TFP), we propose that TFP inhibits the channel in a CaM-independent manner because TFP does not inhibit Ano1 when applied to the cytoplasmic side of excised patches. These experiments lead us to conclude that CaM is not required for activation of Ano1 by Ca2+. Although CaM is not required for channel opening by Ca2+, work of other investigators suggests that CaM may have effects in modulating the biophysical properties of the channel.
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Affiliation(s)
- Kuai Yu
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
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47
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Esseltine JL, Scott JD. AKAP signaling complexes: pointing towards the next generation of therapeutic targets? Trends Pharmacol Sci 2013; 34:648-55. [PMID: 24239028 DOI: 10.1016/j.tips.2013.10.005] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/11/2013] [Accepted: 10/14/2013] [Indexed: 10/26/2022]
Abstract
A-kinase anchoring proteins (AKAPs) streamline signal transduction by localizing signaling enzymes with their substrates. Great strides have been made in elucidating the role of these macromolecular signaling complexes as new binding partners and novel AKAPs are continually being uncovered. The mechanics and dynamics of these multi-enzyme assemblies suggest that AKAP complexes are viable targets for therapeutic intervention. This review will highlight recent advances in AKAP research focusing on local signaling events that are perturbed in disease.
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Affiliation(s)
- Jessica L Esseltine
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, WA, USA
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48
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Plattner H. Calcium regulation in the protozoan model, Paramecium tetraurelia. J Eukaryot Microbiol 2013; 61:95-114. [PMID: 24001309 DOI: 10.1111/jeu.12070] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/21/2013] [Accepted: 06/28/2013] [Indexed: 01/24/2023]
Abstract
Early in eukaryotic evolution, the cell has evolved a considerable inventory of proteins engaged in the regulation of intracellular Ca(2+) concentrations, not only to avoid toxic effects but beyond that to exploit the signaling capacity of Ca(2+) by small changes in local concentration. Among protozoa, the ciliate Paramecium may now be one of the best analyzed models. Ciliary activity and exo-/endocytosis are governed by Ca(2+) , the latter by Ca(2+) mobilization from alveolar sacs and a superimposed store-operated Ca(2+) -influx. Paramecium cells possess plasma membrane- and endoplasmic reticulum-resident Ca(2+) -ATPases/pumps (PMCA, SERCA), a variety of Ca(2+) influx channels, including mechanosensitive and voltage-dependent channels in the plasma membrane, furthermore a plethora of Ca(2+) -release channels (CRC) of the inositol 1,4,5-trisphosphate and ryanodine receptor type in different compartments, notably the contractile vacuole complex and the alveolar sacs, as well as in vesicles participating in vesicular trafficking. Additional types of CRC probably also occur but they have not been identified at a molecular level as yet, as is the equivalent of synaptotagmin as a Ca(2+) sensor for exocytosis. Among established targets and sensors of Ca(2+) in Paramecium are calmodulin, calcineurin, as well as Ca(2+) /calmodulin-dependent protein kinases, all with multiple functions. Thus, basic elements of Ca(2+) signaling are available for Paramecium.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P.O. Box 5544, 78457, Konstanz, Germany
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49
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Casanova JR, Nishimura M, Le J, Lam TT, Swann JW. Rapid hippocampal network adaptation to recurring synchronous activity--a role for calcineurin. Eur J Neurosci 2013; 38:3115-27. [PMID: 23879713 DOI: 10.1111/ejn.12315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 06/10/2013] [Accepted: 06/19/2013] [Indexed: 11/29/2022]
Abstract
Neuronal networks are thought to gradually adapt to altered neuronal activity over many hours and days. For instance, when activity is increased by suppressing synaptic inhibition, excitatory synaptic transmission is reduced. The underlying compensatory cellular and molecular mechanisms are thought to contribute in important ways to maintaining normal network operations. Seizures, due to their massive and highly synchronised discharging, probably challenge the adaptive properties of neurons, especially when seizures are frequent and intense - a condition common in early childhood. In the experiments reported here, we used rat and mice hippocampal slice cultures to explore the effects that recurring seizure-like activity has on the developing hippocampus. We found that developing networks adapted rapidly to recurring synchronised activity in that the duration of seizure-like events was reduced by 42% after 4 h of activity. At the same time, the frequency of spontaneous excitatory postsynaptic currents in pyramidal cells, the expression of biochemical biomarkers for glutamatergic synapses and the branching of pyramidal cell dendrites were all dramatically reduced. Experiments also showed that the reduction in N-methyl-D-aspartate receptor subunits and postsynaptic density protein 95 expression were N-methyl-D-aspartate receptor-dependent. To explore calcium signaling mechanisms in network adaptation, we tested inhibitors of calcineurin, a protein phosphatase known to play roles in synaptic plasticity and activity-dependent dendrite remodeling. We found that FK506 was able to prevent all of the electrophysiological, biochemical, and anatomical changes produced by synchronised network activity. Our results show that hippocampal pyramidal cells and their networks adapt rapidly to intense synchronised activity and that calcineurin play an important role in the underlying processes.
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Affiliation(s)
- J R Casanova
- The Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Street, Suite 1225, Houston, TX, 77030, USA
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50
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Slupe AM, Merrill RA, Flippo KH, Lobas MA, Houtman JCD, Strack S. A calcineurin docking motif (LXVP) in dynamin-related protein 1 contributes to mitochondrial fragmentation and ischemic neuronal injury. J Biol Chem 2013; 288:12353-65. [PMID: 23486469 PMCID: PMC3636919 DOI: 10.1074/jbc.m113.459677] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fission and fusion events dynamically control the shape and function of mitochondria. The activity of the mitochondrial fission enzyme dynamin-related protein 1 (Drp1) is finely tuned by several post-translational modifications. Phosphorylation of Ser-656 by cAMP-dependent protein kinase (PKA) inhibits Drp1, whereas dephosphorylation by a mitochondrial protein phosphatase 2A isoform and the calcium-calmodulin-dependent phosphatase calcineurin (CaN) activates Drp1. Here, we identify a conserved CaN docking site on Drp1, an LXVP motif, which mediates the interaction between the phosphatase and mechanoenzyme. We mutated the LXVP motif in Drp1 to either increase or decrease similarity to the prototypical LXVP motif in the transcription factor NFAT, and assessed stability of the mutant Drp1-CaN complexes by affinity precipitation and isothermal titration calorimetry. Furthermore, we quantified effects of LXVP mutations on Drp1 dephosphorylation kinetics in vitro and in intact cells. With tools for bidirectional control of the CaN-Drp1 signaling axis in hand, we demonstrate that the Drp1 LXVP motif shapes mitochondria in neuronal and non-neuronal cells, and that CaN-mediated Drp1 dephosphorylation promotes neuronal death following oxygen-glucose deprivation. These results point to the CaN-Drp1 complex as a potential target for neuroprotective therapy of ischemic stroke.
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Affiliation(s)
- Andrew M Slupe
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA
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