1
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Alam MS, Leyva D, Michelin W, Fernandez-Lima F, Miksovska J. Distinct mechanism of Tb 3+ and Eu 3+ binding to NCS1. Phys Chem Chem Phys 2023; 25:9500-9512. [PMID: 36938969 PMCID: PMC10840756 DOI: 10.1039/d2cp05765d] [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] [Indexed: 03/02/2023]
Abstract
Lanthanides have been frequently used as biomimetic compounds for NMR and fluorescence studies of Ca2+ binding proteins due to having similar physical properties and coordination geometry to Ca2+ ions. Here we report that a member of the neuronal calcium sensor family, neuronal calcium sensor 1, complexes with two lanthanide ions Tb3+ and Eu3+. The affinity for Tb3+ is nearly 50 times higher than that for Ca2+ (Kd,Tb3+ = 0.002 ± 0.0001 μM and Kd, Ca2+ = 91 nM) whereas Eu3+ binding is notably weaker, Kd,Eu3+ = 26 ± 1 μM. Interestingly, despite having identical charge and similar ionic radii, Tb3+ and Eu3+ ions exhibit a distinct binding stoichiometry for NCS1 with one Eu3+ and two Tb3+ ions bound per NCS1 monomer, as demonstrated in fluorescence titration and mass spectrometry studies. These results suggest that the lanthanides' affinity for the individual EF hands is fine-tuned by a small variation in the ion charge density as well as EF hand binding loop amino acid sequence. As observed previously for other lanthanide:protein complexes, the emission intensity of Ln3+ is enhanced upon complexation with the protein, likely due to the displacement of water molecules by oxygen atoms from the coordinating amino acid residues. The overall shape of the Tb3+NCS1 and Eu3+NCS1 monomer shows high levels of similarity compared to the Ca2+ bound protein based on their collision cross section. However, the distinct occupation of EF hands impacts NCS1 oligomerization and affinity for the D2R peptide that mimics the NCS1 binding site on the D2R receptor. Specifically, the Tb3+NCS1 complex populates the dimer and has comparable affinity for the D2R peptide, whereas Eu3+ bound NCS1 remains in the monomeric form with a negligible affinity for the D2R peptide.
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Affiliation(s)
- Md Shofiul Alam
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - Dennys Leyva
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - Woodline Michelin
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
- Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
- Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
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2
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Alam MS, Azam S, Pham K, Leyva D, Fouque KJD, Fernandez-Lima F, Miksovska J. Nanomolar affinity of EF-hands in neuronal calcium sensor 1 for bivalent cations Pb2+, Mn2+ and Hg2. Metallomics 2022; 14:6601456. [PMID: 35657675 DOI: 10.1093/mtomcs/mfac039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/31/2022] [Indexed: 11/12/2022]
Abstract
Abiogenic metals Pb and Hg are highly toxic since chronic and/or acute exposure often leads to severe neuropathologies. Mn2+ is an essential metal ion but in excess can impair neuronal function. In this study, we address in vitro the interactions between neuronal calcium sensor 1 (NCS1) and divalent cations. Results showed that non-physiological ions (Pb2+, Mn2+ and Hg2+) bind to EF-hands in NCS1 with nanomolar affinity and lower equilibrium dissociation constant than the physiological Ca2+ ion. (Kd,Pb2+ = 7.0±1.0 nM; Kd,Mn2+ = 34.0±6.0 nM; Kd, Hg2+ = 0.5±0.1 nM and 27.0±13.0 nM and Kd,Ca2+ = 96.0±48.0 nM). Native ultra-high resolution mass spectrometry (FT-ICR MS) and trapped ion mobility spectrometry - mass spectrometry (nESI-TIMS-MS) studies provided the NCS1-metal complex compositions - up to four Ca2+ or Mn2+ ions and three Pb2+ ions (M⋅Pb1-3Ca1-3, M⋅Mn1-4Ca1-2, and M⋅Ca1-4) were observed in complex - and similarity across the mobility profiles suggests that the overall native structure is preserved regardless of the number and type of cations. However, the non-physiological metal ions (Pb2+, Mn2+, and Hg2+) binding to NCS1 leads to more efficient quenching of Trp emission and a decrease in W30 and W103 solvent exposure compared to the apo and Ca2+ bound form, although the secondary structural rearrangement and exposure of hydrophobic sites are analogous to those for Ca2+ bound protein. Only Pb2+ and Hg2+ binding to EF-hands leads to the NCS1 dimerization whereas Mn2+ bound NCS1 remains in the monomeric form, suggesting that other factors in addition to metal ion coordination, are required for protein dimerization.
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Affiliation(s)
- Md Shofiul Alam
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Samiol Azam
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Khoa Pham
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Dennys Leyva
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA.,Biomolecular Sciences Institute, Florida International University, Miami, 33199USA
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA.,Biomolecular Sciences Institute, Florida International University, Miami, 33199USA
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA.,Biomolecular Sciences Institute, Florida International University, Miami, 33199USA
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3
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Murphy JG, Gutzmann JJ, Lin L, Hu J, Petralia RS, Wang YX, Hoffman DA. R-type voltage-gated Ca 2+ channels mediate A-type K + current regulation of synaptic input in hippocampal dendrites. Cell Rep 2022; 38:110264. [PMID: 35045307 PMCID: PMC10496648 DOI: 10.1016/j.celrep.2021.110264] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 12/02/2021] [Accepted: 12/22/2021] [Indexed: 01/22/2023] Open
Abstract
The subthreshold voltage-gated transient K+ current (IA) carried by pore-forming Kv4.2 subunits regulates the propagation of synaptic input, dendritic excitability, and synaptic plasticity in CA1 pyramidal neuron dendrites of the hippocampus. We report that the Ca2+ channel subunit Cav2.3 regulates IA in this cell type. We initially identified Cav2.3 as a Kv4.2-interacting protein in a proteomic screen and we confirmed Cav2.3-Kv4.2 complex association using multiple techniques. Functionally, Cav2.3 Ca2+-entry increases Kv4.2-mediated whole-cell current due to an increase in Kv4.2 surface expression. Using pharmacology and Cav2.3 knockout mice, we show that Cav2.3 regulates the dendritic gradient of IA. Furthermore, the loss of Cav2.3 function leads to the enhancement of AMPA receptor-mediated synaptic currents and NMDA receptor-mediated spine Ca2+ influx. These results propose that Cav2.3 and Kv4.2 are integral constituents of an ion channel complex that affects synaptic function in the hippocampus.
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Affiliation(s)
- Jonathan G Murphy
- Molecular Neurophysiology and Biophysics Section, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jakob J Gutzmann
- Molecular Neurophysiology and Biophysics Section, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lin Lin
- Molecular Neurophysiology and Biophysics Section, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jiahua Hu
- Molecular Neurophysiology and Biophysics Section, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ronald S Petralia
- Advanced Imaging Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ya-Xian Wang
- Advanced Imaging Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Dax A Hoffman
- Molecular Neurophysiology and Biophysics Section, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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4
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Lin Y, Gross ML. Mass Spectrometry-Based Structural Proteomics for Metal Ion/Protein Binding Studies. Biomolecules 2022; 12:135. [PMID: 35053283 PMCID: PMC8773722 DOI: 10.3390/biom12010135] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
Metal ions are critical for the biological and physiological functions of many proteins. Mass spectrometry (MS)-based structural proteomics is an ever-growing field that has been adopted to study protein and metal ion interactions. Native MS offers information on metal binding and its stoichiometry. Footprinting approaches coupled with MS, including hydrogen/deuterium exchange (HDX), "fast photochemical oxidation of proteins" (FPOP) and targeted amino-acid labeling, identify binding sites and regions undergoing conformational changes. MS-based titration methods, including "protein-ligand interactions by mass spectrometry, titration and HD exchange" (PLIMSTEX) and "ligand titration, fast photochemical oxidation of proteins and mass spectrometry" (LITPOMS), afford binding stoichiometry, binding affinity, and binding order. These MS-based structural proteomics approaches, their applications to answer questions regarding metal ion protein interactions, their limitations, and recent and potential improvements are discussed here. This review serves as a demonstration of the capabilities of these tools and as an introduction to wider applications to solve other questions.
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Affiliation(s)
- Yanchun Lin
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
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5
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Azam S, Bhattarai N, Riveron A, Rodriguez S, Chapagain PP, Miksovska J. EF-hands in Neuronal Calcium Sensor Downstream Regulatory Element Antagonist Modulator Demonstrate Submillimolar Affinity for Li +: A New Prospect for Li + Therapy. ACS Chem Neurosci 2020; 11:2543-2548. [PMID: 32786300 DOI: 10.1021/acschemneuro.0c00399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Lithium has been used for the treatment of mood disorders for decades though the molecular mechanism of its therapeutic action and intracellular targets remain furtive. We report that neurotropic agent Li+ binds to the neuronal calcium sensor, Downstream Regulatory Element Antagonist Modulator (DREAM), with an equilibrium dissociation constant of 34 ± 4 μM and impacts DREAM structural and dynamic properties in a similar manner as observed for its physiological ligand, Ca2+. Results of fluorescence spectroscopy and molecular dynamics are consistent with Li+ binding at EF-hands. In the Li+ bound form, DREAM association to peptides mimicking DREAM binding sites in a voltage-gated potassium channel is enhanced compared to the apoprotein, whereas DREAM affinity for the presenilin binding site, helix-9, is impeded. These results suggest that DREAM and possibly other members of the neuronal calcium sensor family belong to Li+ intracellular targets and interactions between Li+ and NCS provide a molecular basis for Li+ neuroprotective action.
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6
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Hagenston AM, Bading H, Bas-Orth C. Functional Consequences of Calcium-Dependent Synapse-to-Nucleus Communication: Focus on Transcription-Dependent Metabolic Plasticity. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035287. [PMID: 31570333 DOI: 10.1101/cshperspect.a035287] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the nervous system, calcium signals play a major role in the conversion of synaptic stimuli into transcriptional responses. Signal-regulated gene transcription is fundamental for a range of long-lasting adaptive brain functions that include learning and memory, structural plasticity of neurites and synapses, acquired neuroprotection, chronic pain, and addiction. In this review, we summarize the diverse mechanisms governing calcium-dependent transcriptional regulation associated with central nervous system plasticity. We focus on recent advances in the field of synapse-to-nucleus communication that include studies of the signal-regulated transcriptome in human neurons, identification of novel regulatory mechanisms such as activity-induced DNA double-strand breaks, and the identification of novel forms of activity- and transcription-dependent adaptations, in particular, metabolic plasticity. We summarize the reciprocal interactions between different kinds of neuroadaptations and highlight the emerging role of activity-regulated epigenetic modifiers in gating the inducibility of signal-regulated genes.
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Affiliation(s)
- Anna M Hagenston
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany
| | - Carlos Bas-Orth
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Heidelberg University, 69120 Heidelberg, Germany
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7
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Formisano L, Guida N, Mascolo L, Serani A, Laudati G, Pizzorusso V, Annunziato L. Transcriptional and epigenetic regulation of ncx1 and ncx3 in the brain. Cell Calcium 2020; 87:102194. [PMID: 32172011 DOI: 10.1016/j.ceca.2020.102194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 01/26/2023]
Abstract
Sodium-calcium exchanger (NCX) 1 and 3, have been demonstrated to play a relevant role in controlling the intracellular homeostasis of sodium and calcium ions in physiological and patho-physiological conditions. While NCX1 and NCX3 knocking-down have been both implicated in brain ischemia, several aspects of the epigenetic regulation of these two antiporters transcription were not yet well characterized. In response to stroke, NCX1 and NCX3 transcriptional regulation occurs from specific promoter sequences. Several evidences have shown that the expression of NCX1 and NCX3 can be determined by epigenetic modifications, consisting in changes of the histone acetylation levels on their promoter sequences. An interesting issue is that histone modifications at the NCX1 and NCX3 promoters could be linked to neurodegeneration occurring after stroke. Therefore, identifying the epigenetic regulation at the NCX1 and NCX3 promoters could permit to identify new molecular targets that can open new strategies for stroke treatment. The current review reassumes the recent knowledge of histone modifications of NCX1 and NCX3 genes in brain in physiological and patho-physiological conditions.
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Affiliation(s)
- Luigi Formisano
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via Pansini, 5, 80131, Naples, Italy.
| | - Natascia Guida
- IRCCS SDN Naples, Via Emanuele Gianturco 113, 80143, Naples, Italy
| | - Luigi Mascolo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via Pansini, 5, 80131, Naples, Italy
| | - Angelo Serani
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via Pansini, 5, 80131, Naples, Italy
| | - Giusy Laudati
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via Pansini, 5, 80131, Naples, Italy
| | - Vincenzo Pizzorusso
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via Pansini, 5, 80131, Naples, Italy
| | - Lucio Annunziato
- IRCCS SDN Naples, Via Emanuele Gianturco 113, 80143, Naples, Italy
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8
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Abstract
Kv channel-interacting proteins (KChIPs) belong to the neuronal calcium sensor (NCS) family of Ca2+-binding EF-hand proteins. KChIPs constitute a group of specific auxiliary β-subunits for Kv4 channels, the molecular substrate of transient potassium currents in both neuronal and non-neuronal tissues. Moreover, KChIPs can interact with presenilins to control ER calcium signaling and apoptosis, and with DNA to control gene transcription. Ca2+ binding via their EF-hands, with the consequence of conformational changes, is well documented for KChIPs. Moreover, the Ca2+ dependence of the presenilin/KChIP complex may be related to Alzheimer’s disease and the Ca2+ dependence of the DNA/KChIP complex to pain sensing. However, only in few cases could the Ca2+ binding to KChIPs be directly linked to the control of excitability in nerve and muscle cells known to express Kv4/KChIP channel complexes. This review summarizes current knowledge about the Ca2+ binding properties of KChIPs and the Ca2+ dependencies of macromolecular complexes containing KChIPs, including those with presenilins, DNA and especially Kv4 channels. The respective physiological or pathophysiolgical roles of Ca2+ binding to KChIPs are discussed.
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Affiliation(s)
- Robert Bähring
- a Institut für Zelluläre und Integrative Physiologie, Zentrum für Experimentelle Medizin , Universitätsklinikum Hamburg-Eppendorf , Hamburg , Germany
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9
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Azam S, Miksovska J. Pb 2+ Binds to Downstream Regulatory Element Antagonist Modulator (DREAM) and Modulates Its Interactions with Binding Partners: A Link between Neuronal Calcium Sensors and Pb 2+ Neurotoxicity. ACS Chem Neurosci 2019; 10:1263-1272. [PMID: 30399317 DOI: 10.1021/acschemneuro.8b00335] [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: 01/13/2023] Open
Abstract
Pb2+ exposure leads to diverse neurological disorders; however, the mechanism of Pb2+-induced neurotoxicity is not clearly understood. Here we demonstrate that Pb2+ binds to EF-hands in apo-DREAM (downstream regulatory element antagonist modulator) with a lower equilibrium dissociation constant ( Kd = 20 ± 2 nM) than Ca2+ ( Kd = 1 μM). Based on the Trp169 emission and CD spectra, we report that Pb2+ association triggers changes in the protein secondary and tertiary structures that are analogous to those previously observed for Ca2+-bound protein. The hydrophobic cavity in the C-terminal domain of DREAM is solvent exposed in the presence of Pb2+ as determined using a hydrophobic probe, 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS). Pb2+ association with DREAM also modulates interactions between DREAM and its intracellular partners as evident from the fact that Pb2+-bound DREAM associates with peptide-based model systems, presenilin-1 helix-9 "PS1HL9" KV4.3(70-90) "site-2" and KV4.3(2-22) "site 1". Namely, dissociation constants for Pb2+-bound DREAM interaction with PS1HL9 ( Kd = 2.4 ± 0.1 μM), site-2 ( Kd = 11.0 ± 0.5 μM) and site 1 ( Kd = 5.0 ± 0.6 μM) are nearly identical to those observed for Ca2+ bound DREAM. Isothermal titration calorimetry data reveal that Pb2+ binds to two high-affinity sites in Ca2+ bound DREAM with the overall apparent constant of 4.81 ± 0.06 μM and its binding to Ca2+ bound DREAM is entropy-driven. Taking into account the structural and sequence similarity between DREAM and other neuronal calcium sensor (NCS) proteins, these results strongly indicate that DREAM and possibly other NCS proteins bind Pb2+ with a higher affinity than that for Ca2+ and Pb2+ interactions with NCS proteins can contribute to Pb2+-induced neurotoxicity.
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Affiliation(s)
- Samiol Azam
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
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10
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Azam S, Louis GS, Miksovska J. Cadmium association with DREAM promotes DREAM interactions with intracellular partners in a similar manner to its physiological ligand, calcium. Metallomics 2019; 11:1115-1127. [DOI: 10.1039/c9mt00059c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cd2+exposure has been associated with neurodegenerative diseases and other pathologies, but the underlying mechanism through which it exerts toxic effects remain unresolved.
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Affiliation(s)
- Samiol Azam
- Department of Chemistry and Biochemistry, Florida International University
- Miami
- USA
| | - Gessica St Louis
- Department of Chemistry and Biochemistry, Florida International University
- Miami
- USA
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University
- Miami
- USA
- Biomolecular Sciences Institute, Florida International University
- Miami
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11
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Néant I, Haiech J, Kilhoffer MC, Aulestia FJ, Moreau M, Leclerc C. Ca 2+-Dependent Transcriptional Repressors KCNIP and Regulation of Prognosis Genes in Glioblastoma. Front Mol Neurosci 2018; 11:472. [PMID: 30618619 PMCID: PMC6305344 DOI: 10.3389/fnmol.2018.00472] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 12/04/2018] [Indexed: 12/18/2022] Open
Abstract
Glioblastomas (GBMs) are the most aggressive and lethal primary astrocytic tumors in adults, with very poor prognosis. Recurrence in GBM is attributed to glioblastoma stem-like cells (GSLCs). The behavior of the tumor, including proliferation, progression, invasion, and significant resistance to therapies, is a consequence of the self-renewing properties of the GSLCs, and their high resistance to chemotherapies have been attributed to their capacity to enter quiescence. Thus, targeting GSLCs may constitute one of the possible therapeutic challenges to significantly improve anti-cancer treatment regimens for GBM. Ca2+ signaling is an important regulator of tumorigenesis in GBM, and the transition from proliferation to quiescence involves the modification of the kinetics of Ca2+ influx through store-operated channels due to an increased capacity of the mitochondria of quiescent GSLC to capture Ca2+. Therefore, the identification of new therapeutic targets requires the analysis of the calcium-regulated elements at transcriptional levels. In this review, we focus onto the direct regulation of gene expression by KCNIP proteins (KCNIP1–4). These proteins constitute the class E of Ca2+ sensor family with four EF-hand Ca2+-binding motifs and control gene transcription directly by binding, via a Ca2+-dependent mechanism, to specific DNA sites on target genes, called downstream regulatory element (DRE). The presence of putative DRE sites on genes associated with unfavorable outcome for GBM patients suggests that KCNIP proteins may contribute to the alteration of the expression of these prognosis genes. Indeed, in GBM, KCNIP2 expression appears to be significantly linked to the overall survival of patients. In this review, we summarize the current knowledge regarding the quiescent GSLCs with respect to Ca2+ signaling and discuss how Ca2+via KCNIP proteins may affect prognosis genes expression in GBM. This original mechanism may constitute the basis of the development of new therapeutic strategies.
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Affiliation(s)
- Isabelle Néant
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse, France
| | - Jacques Haiech
- Laboratoire d'Excellence Medalis, CNRS, LIT UMR 7200, Université de Strasbourg, Strasbourg, France
| | - Marie-Claude Kilhoffer
- Laboratoire d'Excellence Medalis, CNRS, LIT UMR 7200, Université de Strasbourg, Strasbourg, France
| | - Francisco J Aulestia
- Department of Basic Science and Craniofacial Biology, NYU College of Dentistry, New York, NY, United States
| | - Marc Moreau
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse, France
| | - Catherine Leclerc
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse, France
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12
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Groen C, Bähring R. Modulation of human Kv4.3/KChIP2 channel inactivation kinetics by cytoplasmic Ca 2. Pflugers Arch 2017; 469:1457-1470. [PMID: 28735419 DOI: 10.1007/s00424-017-2039-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/11/2017] [Accepted: 07/13/2017] [Indexed: 10/19/2022]
Abstract
The transient outward current (I to) in the human heart is mediated by Kv4.3 channels complexed with Kv channel interacting protein (KChIP) 2, a cytoplasmic Ca2+-binding EF-hand protein known to modulate Kv4.3 inactivation gating upon heterologous co-expression. We studied Kv4.3 channels co-expressed with wild-type (wt) or EF-hand-mutated (ΔEF) KChIP2 in human embryonic kidney (HEK) 293 cells. Co-expression took place in the absence or presence of BAPTA-AM, and macroscopic currents were recorded in the whole-cell patch-clamp configuration with different free Ca2+ concentrations in the patch-pipette. Our data indicate that Ca2+ is not necessary for Kv4.3/KChIP2 complex formation. The Kv4.3/KChIP2-mediated current decay was faster and the recovery of Kv4.3/KChIP2 channels from inactivation slower with 50 μM Ca2+ than with BAPTA (nominal Ca2+-free) in the patch-pipette. The apparent Ca2+-mediated slowing of recovery kinetics was still observed when EF-hand 4 of KChIP2 was mutated (ΔEF4) but not when EF-hand 2 (ΔEF2) was mutated, and turned into a Ca2+-mediated acceleration of recovery kinetics when EF-hand 3 (ΔEF3) was mutated. In the presence of the Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-93 cytoplasmic Ca2+ (50 μM) induced an acceleration of Kv4.3/KChIP2 recovery kinetics, which was still observed when EF-hand 2 was mutated (ΔEF2) but not when EF-hand 3 (ΔEF3) or EF-hand 4 (ΔEF4) was mutated. Our results support the notion that binding of Ca2+ to KChIP2 EF-hands can acutely modulate Kv4.3/KChIP2 channel inactivation gating, but the Ca2+-dependent gating modulation depends on CaMKII action. Our findings speak for an acute modulation of I to kinetics and frequency-dependent I to availability in cardiomyocytes under conditions with elevated Ca2+ levels and CaMKII activity.
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Affiliation(s)
- Christiane Groen
- Institut für Zelluläre und Integrative Physiologie, Zentrum für Experimentelle Medizin, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Robert Bähring
- Institut für Zelluläre und Integrative Physiologie, Zentrum für Experimentelle Medizin, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
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13
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Zhang J, Li J, Craig TA, Kumar R, Gross ML. Hydrogen-Deuterium Exchange Mass Spectrometry Reveals Calcium Binding Properties and Allosteric Regulation of Downstream Regulatory Element Antagonist Modulator (DREAM). Biochemistry 2017. [PMID: 28627884 DOI: 10.1021/acs.biochem.7b00100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Downstream regulatory element antagonist modulator (DREAM) is an EF-hand Ca2+-binding protein that also binds to a specific DNA sequence, downstream regulatory elements (DRE), and thereby regulates transcription in a calcium-dependent fashion. DREAM binds to DRE in the absence of Ca2+ but detaches from DRE under Ca2+ stimulation, allowing gene expression. The Ca2+ binding properties of DREAM and the consequences of the binding on protein structure are key to understanding the function of DREAM. Here we describe the application of hydrogen-deuterium exchange mass spectrometry (HDX-MS) and site-directed mutagenesis to investigate the Ca2+ binding properties and the subsequent conformational changes of full-length DREAM. We demonstrate that all EF-hands undergo large conformation changes upon calcium binding even though the EF-1 hand is not capable of binding to Ca2+. Moreover, EF-2 is a lower-affinity site compared to EF-3 and -4 hands. Comparison of HDX profiles between wild-type DREAM and two EF-1 mutated constructs illustrates that the conformational changes in the EF-1 hand are induced by long-range structural interactions. HDX analyses also reveal a conformational change in an N-terminal leucine-charged residue-rich domain (LCD) remote from Ca2+-binding EF-hands. This LCD domain is responsible for the direct interaction between DREAM and cAMP response element-binding protein (CREB) and regulates the recruitment of the co-activator, CREB-binding protein. These long-range interactions strongly suggest how conformational changes transmit the Ca2+ signal to CREB-mediated gene transcription.
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Affiliation(s)
- Jun Zhang
- Department of Chemistry, Washington University in St. Louis , St. Louis, Missouri 63130, United States
| | - Jing Li
- Department of Chemistry, Washington University in St. Louis , St. Louis, Missouri 63130, United States
| | - Theodore A Craig
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Rajiv Kumar
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis , St. Louis, Missouri 63130, United States
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14
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Benedet T, Gonzalez P, Oliveros JC, Dopazo JM, Ghimire K, Palczewska M, Mellstrom B, Naranjo JR. Transcriptional repressor DREAM regulates trigeminal noxious perception. J Neurochem 2017; 141:544-552. [DOI: 10.1111/jnc.13584] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/04/2016] [Accepted: 02/10/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Tomaso Benedet
- National Centre for Biotechnology; C.S.I.C.; Madrid Spain
| | - Paz Gonzalez
- National Centre for Biotechnology; C.S.I.C.; Madrid Spain
- CIBERNED; Madrid Spain
| | | | - Jose M. Dopazo
- National Centre for Biotechnology; C.S.I.C.; Madrid Spain
- CIBERNED; Madrid Spain
| | - Kedar Ghimire
- National Centre for Biotechnology; C.S.I.C.; Madrid Spain
| | | | - Britt Mellstrom
- National Centre for Biotechnology; C.S.I.C.; Madrid Spain
- CIBERNED; Madrid Spain
| | - Jose R. Naranjo
- National Centre for Biotechnology; C.S.I.C.; Madrid Spain
- CIBERNED; Madrid Spain
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15
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Downstream Regulatory Element Antagonist Modulator (DREAM), a target for anti-thrombotic agents. Pharmacol Res 2017; 117:283-287. [PMID: 28065857 DOI: 10.1016/j.phrs.2017.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/03/2017] [Indexed: 11/21/2022]
Abstract
Circulating platelets participate in the process of numerous diseases including thrombosis, inflammation, and cancer. Thus, it is of great importance to understand the underlying mechanisms mediating platelet activation under disease conditions. Emerging evidence indicates that despite the lack of a nucleus, platelets possess molecules that are involved in gene transcription in nucleated cells. This review will summarize downstream regulatory element antagonist modulator (DREAM), a transcriptional repressor, and highlight recent findings suggesting its novel non-transcriptional role in hemostasis and thrombosis.
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16
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DREAM plays an important role in platelet activation and thrombogenesis. Blood 2016; 129:209-225. [PMID: 27903531 DOI: 10.1182/blood-2016-07-724419] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/23/2016] [Indexed: 01/18/2023] Open
Abstract
Downstream regulatory element antagonist modulator (DREAM), a transcriptional repressor, is known to modulate pain responses. However, it is unknown whether DREAM is expressed in anucleate platelets and plays a role in thrombogenesis. By using intravital microscopy with DREAM-null mice and their bone marrow chimeras, we demonstrated that both hematopoietic and nonhematopoietic cell DREAMs are required for platelet thrombus formation following laser-induced arteriolar injury. In a FeCl3-induced thrombosis model, we found that compared with wild-type (WT) control and nonhematopoietic DREAM knockout (KO) mice, DREAM KO control and hematopoietic DREAM KO mice showed a significant delay in time to occlusion. Tail bleeding time was prolonged in DREAM KO control mice, but not in WT or DREAM bone marrow chimeric mice. In vivo adoptive transfer experiments further indicated the importance of platelet DREAM in thrombogenesis. We found that DREAM deletion does not alter the ultrastructural features of platelets but significantly impairs platelet aggregation and adenosine triphosphate secretion induced by numerous agonists (collagen-related peptide, adenosine 5'-diphosphate, A23187, thrombin, or U46619). Biochemical studies revealed that platelet DREAM positively regulates phosphoinositide 3-kinase (PI3K) activity during platelet activation. Using DREAM-null platelets and PI3K isoform-specific inhibitors, we observed that platelet DREAM is important for α-granule secretion, Ca2+ mobilization, and aggregation through PI3K class Iβ (PI3K-Iβ). Genetic and pharmacological studies in human megakaryoblastic MEG-01 cells showed that DREAM is important for A23187-induced Ca2+ mobilization and its regulatory function requires Ca2+ binding and PI3K-Iβ activation. These results suggest that platelet DREAM regulates PI3K-Iβ activity and plays an important role during thrombus formation.
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17
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Li C, Lim S, Braunewell KH, Ames JB. Structure and Calcium Binding Properties of a Neuronal Calcium-Myristoyl Switch Protein, Visinin-Like Protein 3. PLoS One 2016; 11:e0165921. [PMID: 27820860 PMCID: PMC5098827 DOI: 10.1371/journal.pone.0165921] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/19/2016] [Indexed: 12/13/2022] Open
Abstract
Visinin-like protein 3 (VILIP-3) belongs to a family of Ca2+-myristoyl switch proteins that regulate signal transduction in the brain and retina. Here we analyze Ca2+ binding, characterize Ca2+-induced conformational changes, and determine the NMR structure of myristoylated VILIP-3. Three Ca2+ bind cooperatively to VILIP-3 at EF2, EF3 and EF4 (KD = 0.52 μM and Hill slope of 1.8). NMR assignments, mutagenesis and structural analysis indicate that the covalently attached myristoyl group is solvent exposed in Ca2+-bound VILIP-3, whereas Ca2+-free VILIP-3 contains a sequestered myristoyl group that interacts with protein residues (E26, Y64, V68), which are distinct from myristate contacts seen in other Ca2+-myristoyl switch proteins. The myristoyl group in VILIP-3 forms an unusual L-shaped structure that places the C14 methyl group inside a shallow protein groove, in contrast to the much deeper myristoyl binding pockets observed for recoverin, NCS-1 and GCAP1. Thus, the myristoylated VILIP-3 protein structure determined in this study is quite different from those of other known myristoyl switch proteins (recoverin, NCS-1, and GCAP1). We propose that myristoylation serves to fine tune the three-dimensional structures of neuronal calcium sensor proteins as a means of generating functional diversity.
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Affiliation(s)
- Congmin Li
- Department of Chemistry, University of California Davis, Davis, CA, United States of America
| | - Sunghyuk Lim
- Department of Chemistry, University of California Davis, Davis, CA, United States of America
| | - Karl H. Braunewell
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | - James B. Ames
- Department of Chemistry, University of California Davis, Davis, CA, United States of America
- * E-mail:
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18
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Pham K, Miksovska J. Molecular insight of DREAM and presenilin 1 C-terminal fragment interactions. FEBS Lett 2016; 590:1114-22. [PMID: 27009418 DOI: 10.1002/1873-3468.12156] [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: 01/14/2016] [Revised: 02/24/2016] [Accepted: 03/21/2016] [Indexed: 12/21/2022]
Abstract
Interactions between downstream regulatory element antagonist modulator (DREAM) and presenilin 1 (PS1) are related to numerous neuronal processes. We demonstrate that association of PS1 carboxyl peptide (residues 445-467, HL9) with DREAM is calcium dependent and stabilized by a cluster of three aromatic residues: F462 and F465 from PS1 and F252 from DREAM. Additional stabilization is provided by residues in a loop connecting α helices 7 and 8 in DREAM and residues of PS1, namely cation-π interactions between R200 in DREAM and F465 in PS1 and the salt bridges formed by R207 in DREAM and D450 and D458 in PS1.
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Affiliation(s)
- Khoa Pham
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA.,Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
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19
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Gonzalez WG, Ramos V, Diaz M, Garabedian A, Molano-Arevalo JC, Fernandez-Lima F, Miksovska J. Characterization of the Photophysical, Thermodynamic, and Structural Properties of the Terbium(III)-DREAM Complex. Biochemistry 2016; 55:1873-86. [PMID: 26901070 PMCID: PMC4867112 DOI: 10.1021/acs.biochem.6b00067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DREAM (also known as K(+) channel interacting protein 3 and calsenilin) is a calcium binding protein and an active modulator of KV4 channels in neuronal cells as well as a novel Ca(2+)-regulated transcriptional modulator. DREAM has also been associated with the regulation of Alzheimer's disease through the prevention of presenilin-2 fragmentation. Many interactions of DREAM with its binding partners (Kv4, calmodulin, DNA, and drugs) have been shown to be dependent on calcium. Therefore, understanding the structural changes induced by binding of metals to DREAM is essential for elucidating the mechanism of signal transduction and biological activity of this protein. Here, we show that the fluorescence emission and excitation spectra of the calcium luminescent analogue, Tb(3+), are enhanced upon binding to the EF-hands of DREAM due to a mechanism of energy transfer between Trp and Tb(3+). We also observe that unlike Tb(3+)-bound calmodulin, the luminescence lifetime of terbium bound to DREAM decays as a complex multiexponential (τaverage ∼ 1.8 ms) that is sensitive to perturbation of the protein structure and drug (NS5806) binding. Using isothermal calorimetry, we have determined that Tb(3+) binds to at least three sites with high affinity (Kd = 1.8 μM in the presence of Ca(2+)) and displaces bound Ca(2+) through an entropically driven mechanism (ΔH ∼ 12 kcal mol(-1), and TΔS ∼ 22 kcal mol(-1)). Furthermore, the hydrophobic probe 1,8-ANS shows that Tb(3+), like Ca(2+), triggers the exposure of a hydrophobic surface on DREAM, which modulates ligand binding. Analogous to Ca(2+) binding, Tb(3+) binding also induces the dimerization of DREAM. Secondary structural analyses using far-UV circular dichroism and trapped ion mobility spectrometry-mass spectrometry reveal that replacement of Ca(2+) with Tb(3+) preserves the folding state with minimal changes to the overall structure of DREAM. These findings pave the way for further investigation of the metal binding properties of DREAM using lanthanides as well as the study of DREAM-protein complexes by lanthanide resonance energy transfer or nuclear magnetic resonance.
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Affiliation(s)
- Walter G. Gonzalez
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Victoria Ramos
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Maurizio Diaz
- School for Advanced Studies Homestead, Homestead, Florida 33030, United States
| | - Alyssa Garabedian
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Juan Camilo Molano-Arevalo
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
- Biomolecular Science Institute, Florida International University, Miami, Florida 33199, United States
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
- Biomolecular Science Institute, Florida International University, Miami, Florida 33199, United States
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20
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Duda J, Pötschke C, Liss B. Converging roles of ion channels, calcium, metabolic stress, and activity pattern of Substantia nigra dopaminergic neurons in health and Parkinson's disease. J Neurochem 2016; 139 Suppl 1:156-178. [PMID: 26865375 PMCID: PMC5095868 DOI: 10.1111/jnc.13572] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/03/2016] [Accepted: 02/05/2016] [Indexed: 12/18/2022]
Abstract
Dopamine‐releasing neurons within the Substantia nigra (SN DA) are particularly vulnerable to degeneration compared to other dopaminergic neurons. The age‐dependent, progressive loss of these neurons is a pathological hallmark of Parkinson's disease (PD), as the resulting loss of striatal dopamine causes its major movement‐related symptoms. SN DA neurons release dopamine from their axonal terminals within the dorsal striatum, and also from their cell bodies and dendrites within the midbrain in a calcium‐ and activity‐dependent manner. Their intrinsically generated and metabolically challenging activity is created and modulated by the orchestrated function of different ion channels and dopamine D2‐autoreceptors. Here, we review increasing evidence that the mechanisms that control activity patterns and calcium homeostasis of SN DA neurons are not only crucial for their dopamine release within a physiological range but also modulate their mitochondrial and lysosomal activity, their metabolic stress levels, and their vulnerability to degeneration in PD. Indeed, impaired calcium homeostasis, lysosomal and mitochondrial dysfunction, and metabolic stress in SN DA neurons represent central converging trigger factors for idiopathic and familial PD. We summarize double‐edged roles of ion channels, activity patterns, calcium homeostasis, and related feedback/feed‐forward signaling mechanisms in SN DA neurons for maintaining and modulating their physiological function, but also for contributing to their vulnerability in PD‐paradigms. We focus on the emerging roles of maintained neuronal activity and calcium homeostasis within a physiological bandwidth, and its modulation by PD‐triggers, as well as on bidirectional functions of voltage‐gated L‐type calcium channels and metabolically gated ATP‐sensitive potassium (K‐ATP) channels, and their probable interplay in health and PD.
We propose that SN DA neurons possess several feedback and feed‐forward mechanisms to protect and adapt their activity‐pattern and calcium‐homeostasis within a physiological bandwidth, and that PD‐trigger factors can narrow this bandwidth. We summarize roles of ion channels in this view, and findings documenting that both, reduced as well as elevated activity and associated calcium‐levels can trigger SN DA degeneration.
This article is part of a special issue on Parkinson disease.
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Affiliation(s)
- Johanna Duda
- Department of Applied Physiology, Ulm University, Ulm, Germany
| | | | - Birgit Liss
- Department of Applied Physiology, Ulm University, Ulm, Germany.
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21
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Mauceri D, Hagenston AM, Schramm K, Weiss U, Bading H. Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture. J Biol Chem 2015; 290:23039-49. [PMID: 26231212 DOI: 10.1074/jbc.m115.654962] [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: 03/26/2015] [Indexed: 12/20/2022] Open
Abstract
Calcium-binding proteins (CaBPs) such as parvalbumin are part of the cellular calcium buffering system that determines intracellular calcium diffusion and influences the spatiotemporal dynamics of calcium signals. In neurons, CaBPs are primarily localized to the cytosol and function, for example, in nerve terminals in short-term synaptic plasticity. However, CaBPs are also expressed in the cell nucleus, suggesting that they modulate nuclear calcium signals, which are key regulators of neuronal gene expression. Here we show that the calcium buffering capacity of the cell nucleus in mouse hippocampal neurons regulates neuronal architecture by modulating the expression levels of VEGFD and the complement factor C1q-c, two nuclear calcium-regulated genes that control dendrite geometry and spine density, respectively. Increasing the levels of nuclear calcium buffers by means of expression of a nuclearly targeted form of parvalbumin fused to mCherry (PV.NLS-mC) led to a reduction in VEGFD expression and, as a result, to a decrease in total dendritic length and complexity. In contrast, mRNA levels of the synapse pruning factor C1q-c were increased in neurons expressing PV.NLS-mC, causing a reduction in the density and size of dendritic spines. Our results establish a close link between nuclear calcium buffering capacity and the transcription of genes that determine neuronal structure. They suggest that the development of cognitive deficits observed in neurological conditions associated with CaBP deregulation may reflect the loss of necessary structural features of dendrites and spines.
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Affiliation(s)
- Daniela Mauceri
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Anna M Hagenston
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Kathrin Schramm
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Ursula Weiss
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Hilmar Bading
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
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22
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Gonzalez WG, Arango AS, Miksovska J. Amphiphilic Residues 29–44 of DREAM N-Termini Mediate Calmodulin:DREAM Complex Formation. Biochemistry 2015; 54:4391-403. [DOI: 10.1021/acs.biochem.5b00251] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Walter G. Gonzalez
- Department
of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Andres S. Arango
- Department
of Physics, Florida International University, Miami, Florida 33199, United States
| | - Jaroslava Miksovska
- Department
of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
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23
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Chae PS, Bae HE, Ehsan M, Hussain H, Kim JW. New ganglio-tripod amphiphiles (TPAs) for membrane protein solubilization and stabilization: implications for detergent structure-property relationships. Org Biomol Chem 2015; 12:8480-7. [PMID: 25227873 DOI: 10.1039/c4ob01375a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Detergents are widely used for membrane protein research; however, membrane proteins encapsulated in micelles formed by conventional detergents tend to undergo structural degradation, necessitating the development of new agents with enhanced efficacy. Here we prepared several hydrophobic variants of ganglio-tripod amphiphiles (TPAs) derived from previously reported TPAs and evaluated for a multi-subunit, pigment protein superassembly. In this study, TPA-16 was found to be most efficient in protein solubilization while TPA-15 proved most favourable in long-term protein stability. The current study combined with previous TPA studies enabled us to elaborate on a few detergent structure-property relationships that could provide useful guidelines for novel amphiphile design.
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Affiliation(s)
- Pil Seok Chae
- Department of Bionanotechnology, Hanyang University, Ansan, 426-791, Korea.
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24
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Bae HE, Gotfryd K, Thomas J, Hussain H, Ehsan M, Go J, Loland CJ, Byrne B, Chae PS. Deoxycholate-Based Glycosides (DCGs) for Membrane Protein Stabilisation. Chembiochem 2015; 16:1454-9. [PMID: 25953685 DOI: 10.1002/cbic.201500151] [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: 03/23/2015] [Indexed: 12/16/2022]
Abstract
Detergents are an absolute requirement for studying the structure of membrane proteins. However, many conventional detergents fail to stabilise denaturation-sensitive membrane proteins, such as eukaryotic proteins and membrane protein complexes. New amphipathic agents with enhanced efficacy in stabilising membrane proteins will be helpful in overcoming the barriers to studying membrane protein structures. We have prepared a number of deoxycholate-based amphiphiles with carbohydrate head groups, designated deoxycholate-based glycosides (DCGs). These DCGs are the hydrophilic variants of previously reported deoxycholate-based N-oxides (DCAOs). Membrane proteins in these agents, particularly the branched diglucoside-bearing amphiphiles DCG-1 and DCG-2, displayed favourable behaviour compared to previously reported parent compounds (DCAOs) and conventional detergents (LDAO and DDM). Given their excellent properties, these agents should have significant potential for membrane protein studies.
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Affiliation(s)
- Hyoung Eun Bae
- Department of Bionanotechnology, Hanyang University, Hanyangdaehak-ro, Ansan, 426-791 (Korea)
| | - Kamil Gotfryd
- Department of Neuroscience and Pharmacology, University of Copenhagen, Nørre Alle 20, 2200 Copenhagen (Denmark).,Present address: Department of Biomedical Sciences, University of Copenhagen, Nørre Alle 20, 2200 Copenhagen (Denmark)
| | - Jennifer Thomas
- Present address: MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 OQH (UK).,Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ (UK)
| | - Hazrat Hussain
- Department of Bionanotechnology, Hanyang University, Hanyangdaehak-ro, Ansan, 426-791 (Korea)
| | - Muhammad Ehsan
- Department of Bionanotechnology, Hanyang University, Hanyangdaehak-ro, Ansan, 426-791 (Korea)
| | - Juyeon Go
- Department of Bionanotechnology, Hanyang University, Hanyangdaehak-ro, Ansan, 426-791 (Korea)
| | - Claus J Loland
- Department of Neuroscience and Pharmacology, University of Copenhagen, Nørre Alle 20, 2200 Copenhagen (Denmark)
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ (UK)
| | - Pil Seok Chae
- Department of Bionanotechnology, Hanyang University, Hanyangdaehak-ro, Ansan, 426-791 (Korea).
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25
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Pham K, Dhulipala G, Gonzalez WG, Gerstman BS, Regmi C, Chapagain PP, Miksovska J. Ca2+ and Mg2+ modulate conformational dynamics and stability of downstream regulatory element antagonist modulator. Protein Sci 2015; 24:741-51. [PMID: 25627705 DOI: 10.1002/pro.2646] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 01/25/2015] [Indexed: 11/09/2022]
Abstract
Downstream Regulatory Element Antagonist Modulator (DREAM) belongs to the family of neuronal calcium sensors (NCS) that transduce the intracellular changes in Ca(2+) concentration into a variety of responses including gene expression, regulation of Kv channel activity, and calcium homeostasis. Despite the significant sequence and structural similarities with other NCS members, DREAM shows several features unique among NCS such as formation of a tetramer in the apo-state, and interactions with various intracellular biomacromolecules including DNA, presenilin, Kv channels, and calmodulin. Here we use spectroscopic techniques in combination with molecular dynamics simulation to study conformational changes induced by Ca(2+) /Mg(2+) association to DREAM. Our data indicate a minor impact of Ca(2+) association on the overall structure of the N- and C-terminal domains, although Ca(2+) binding decreases the conformational heterogeneity as evident from the decrease in the fluorescence lifetime distribution in the Ca(2+) bound forms of the protein. Time-resolved fluorescence data indicate that Ca(2+) binding triggers a conformational transition that is characterized by more efficient quenching of Trp residue. The unfolding of DREAM occurs through an partially unfolded intermediate that is stabilized by Ca(2+) association to EF-hand 3 and EF-hand 4. The native state is stabilized with respect to the partially unfolded state only in the presence of both Ca(2+) and Mg(2+) suggesting that, under physiological conditions, Ca(2+) free DREAM exhibits a high conformational flexibility that may facilitate its physiological functions.
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Affiliation(s)
- Khoa Pham
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, 33199
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26
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Ruiz-DeDiego I, Mellstrom B, Vallejo M, Naranjo JR, Moratalla R. Activation of DREAM (downstream regulatory element antagonistic modulator), a calcium-binding protein, reduces L-DOPA-induced dyskinesias in mice. Biol Psychiatry 2015; 77:95-105. [PMID: 24857398 DOI: 10.1016/j.biopsych.2014.03.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 03/05/2014] [Accepted: 03/20/2014] [Indexed: 12/26/2022]
Abstract
BACKGROUND Previous studies have implicated the cyclic adenosine monophosphate/protein kinase A pathway as well as FosB and dynorphin-B expression mediated by dopamine D1 receptor stimulation in the development of 3,4-dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia. The magnitude of these molecular changes correlates with the intensity of dyskinesias. The calcium-binding protein downstream regulatory element antagonistic modulator (DREAM) binds to regulatory element sites called DRE in the DNA and represses transcription of target genes such as c-fos, fos-related antigen-2 (fra-2), and prodynorphin. This repression is released by calcium and protein kinase A activation. Dominant-active DREAM transgenic mice (daDREAM) and DREAM knockout mice (DREAM(-/-)) were used to define the involvement of DREAM in dyskinesias. METHODS Dyskinesias were evaluated twice a week in mice with 6-hydroxydopamine lesions during long-term L-DOPA (25 mg/kg) treatment. The impact of DREAM on L-DOPA efficacy was evaluated using the rotarod and the cylinder test after the establishment of dyskinesia and the molecular changes by immunohistochemistry and Western blot. RESULTS In daDREAM mice, L-DOPA-induced dyskinesia was decreased throughout the entire treatment. In correlation with these behavioral results, daDREAM mice showed a decrease in FosB, phosphoacetylated histone H3, dynorphin-B, and phosphorylated glutamate receptor subunit, type 1 expression. Conversely, genetic inactivation of DREAM potentiated the intensity of dyskinesia, and DREAM(-/-) mice exhibited an increase in expression of molecular markers associated with dyskinesias. The DREAM modifications did not affect the kinetic profile or antiparkinsonian efficacy of L-DOPA therapy. CONCLUSIONS The protein DREAM decreases development of L-DOPA-induced dyskinesia in mice and reduces L-DOPA-induced expression of FosB, phosphoacetylated histone H3, and dynorphin-B in the striatum. These data suggest that therapeutic approaches that activate DREAM may be useful to alleviate L-DOPA-induced dyskinesia without interfering with the therapeutic motor effects of L-DOPA.
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Affiliation(s)
- Irene Ruiz-DeDiego
- Cajal Institute, Madrid, Spain; Centro Nacional de Biotecnología, Madrid, Spain
| | - Britt Mellstrom
- Centro Nacional de Biotecnología, Madrid, Spain; Instituto de Investigaciones Biomédicas Alberto Sols all part of Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Mario Vallejo
- CIBERNED, Madrid, Spain; CIBERDEM, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Jose R Naranjo
- Centro Nacional de Biotecnología, Madrid, Spain; Instituto de Investigaciones Biomédicas Alberto Sols all part of Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Rosario Moratalla
- Cajal Institute, Madrid, Spain; Centro Nacional de Biotecnología, Madrid, Spain.
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Dopamine midbrain neurons in health and Parkinson’s disease: Emerging roles of voltage-gated calcium channels and ATP-sensitive potassium channels. Neuroscience 2015; 284:798-814. [DOI: 10.1016/j.neuroscience.2014.10.037] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 10/20/2014] [Accepted: 10/22/2014] [Indexed: 12/14/2022]
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Néant I, Mellström B, Gonzalez P, Naranjo JR, Moreau M, Leclerc C. Kcnip1 a Ca²⁺-dependent transcriptional repressor regulates the size of the neural plate in Xenopus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:2077-85. [PMID: 25499267 DOI: 10.1016/j.bbamcr.2014.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 11/28/2014] [Accepted: 12/03/2014] [Indexed: 12/30/2022]
Abstract
In amphibian embryos, our previous work has demonstrated that calcium transients occurring in the dorsal ectoderm at the onset of gastrulation are necessary and sufficient to engage the ectodermal cells into a neural fate by inducing neural specific genes. Some of these genes are direct targets of calcium. Here we search for a direct transcriptional mechanism by which calcium signals are acting. The only known mechanism responsible for a direct action of calcium on gene transcription involves an EF-hand Ca²⁺ binding protein which belongs to a group of four proteins (Kcnip1 to 4). Kcnip protein can act in a Ca²⁺-dependent manner as a transcriptional repressor by binding to a specific DNA sequence, the Downstream Regulatory Element (DRE) site. In Xenopus, among the four kcnips, we show that only kcnip1 is timely and spatially present in the presumptive neural territories and is able to bind DRE sites in a Ca²⁺-dependent manner. The loss of function of kcnip1 results in the expansion of the neural plate through an increased proliferation of neural progenitors. Later on, this leads to an impairment in the development of anterior neural structures. We propose that, in the embryo, at the onset of neurogenesis Kcnip1 is the Ca²⁺-dependent transcriptional repressor that controls the size of the neural plate. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.
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Affiliation(s)
- Isabelle Néant
- Université Toulouse 3, Centre de Biologie du Développement, 118 routes de Narbonne, F31062 Toulouse, Cedex 04, France; CNRS UMR5547, Toulouse F31062 France; GDRE CNRS, n° 731, Toulouse, France; Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain
| | - Britt Mellström
- Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain
| | - Paz Gonzalez
- Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain
| | - Jose R Naranjo
- GDRE CNRS, n° 731, Toulouse, France; Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain
| | - Marc Moreau
- Université Toulouse 3, Centre de Biologie du Développement, 118 routes de Narbonne, F31062 Toulouse, Cedex 04, France; CNRS UMR5547, Toulouse F31062 France; GDRE CNRS, n° 731, Toulouse, France
| | - Catherine Leclerc
- Université Toulouse 3, Centre de Biologie du Développement, 118 routes de Narbonne, F31062 Toulouse, Cedex 04, France; CNRS UMR5547, Toulouse F31062 France; GDRE CNRS, n° 731, Toulouse, France.
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Gonzalez WG, Pham K, Miksovska J. Modulation of the voltage-gated potassium channel (Kv4.3) and the auxiliary protein (KChIP3) interactions by the current activator NS5806. J Biol Chem 2014; 289:32201-32213. [PMID: 25228688 DOI: 10.1074/jbc.m114.577528] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
KChIP3 (potassium channel interacting protein 3) is a calcium-binding protein that binds at the N terminus of the Kv4 voltage-gated potassium channel through interactions at two contact sites and has been shown to regulate potassium current gating kinetics as well as channel trafficking in cardiac and neuronal cells. Using fluorescence spectroscopy, isothermal calorimetry, and docking simulations we show that the novel potassium current activator, NS5806, binds at a hydrophobic site on the C terminus of KChIP3 in a calcium-dependent manner, with an equilibrium dissociation constant of 2-5 μM in the calcium-bound form. We further determined that the association between KChIP3 and the hydrophobic N terminus of Kv4.3 is calcium-dependent, with an equilibrium dissociation constant in the apo-state of 70 ± 3 μM and 2.7 ± 0.1 μM in the calcium-bound form. NS5806 increases the affinity between KChIP3 and the N terminus of Kv4.3 (Kd = 1.9 ± 0.1 μM) in the presence and absence of calcium. Mutation of Tyr-174 or Phe-218 on KChIP3 abolished the enhancement of Kv4.3 site 1 binding in the apo-state, highlighting the role of these residues in drug and K4.3 binding. Kinetic studies show that NS5806 decreases the rate of dissociation between KChIP3 and the N terminus of KV4.3. Overall, these studies support the idea that NS5806 directly interacts with KChIP3 and modulates the interactions between this calcium-binding protein and the T1 domain of the Kv4.3 channels through reorientation of helix 10 on KChIP3.
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Affiliation(s)
- Walter G Gonzalez
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199
| | - Khoa Pham
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199.
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Liebl MP, Kaya AM, Tenzer S, Mittenzwei R, Koziollek-Drechsler I, Schild H, Moosmann B, Behl C, Clement AM. Dimerization of visinin-like protein 1 is regulated by oxidative stress and calcium and is a pathological hallmark of amyotrophic lateral sclerosis. Free Radic Biol Med 2014; 72:41-54. [PMID: 24742816 DOI: 10.1016/j.freeradbiomed.2014.04.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 04/04/2014] [Accepted: 04/05/2014] [Indexed: 11/28/2022]
Abstract
Redox control of proteins that form disulfide bonds upon oxidative challenge is an emerging topic in the physiological and pathophysiological regulation of protein function. We have investigated the role of the neuronal calcium sensor protein visinin-like protein 1 (VILIP-1) as a novel redox sensor in a cellular system. We have found oxidative stress to trigger dimerization of VILIP-1 within a cellular environment and identified thioredoxin reductase as responsible for facilitating the remonomerization of the dimeric protein. Dimerization is modulated by calcium and not dependent on the myristoylation of VILIP-1. Furthermore, we show by site-directed mutagenesis that dimerization is exclusively mediated by Cys187. As a functional consequence, VILIP-1 dimerization modulates the sensitivity of cells to an oxidative challenge. We have investigated whether dimerization of VILIP-1 occurs in two different animal models of amyotrophic lateral sclerosis (ALS) and detected soluble VILIP-1 dimers to be significantly enriched in the spinal cord from phenotypic disease onset onwards. Moreover, VILIP-1 is part of the ALS-specific protein aggregates. We show for the first time that the C-terminus of VILIP-1, containing Cys187, might represent a novel redox-sensitive motif and that VILIP-1 dimerization and aggregation are hallmarks of ALS. This suggests that VILIP-1 dimers play a functional role in integrating the cytosolic calcium concentration and the oxidative status of the cell. Furthermore, a loss of VILIP-1 function owing to protein aggregation in ALS could be relevant in the pathophysiology of the disease.
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Affiliation(s)
- Martina P Liebl
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Ali M Kaya
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Stefan Tenzer
- Institute for Immunology, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Romy Mittenzwei
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Ingrid Koziollek-Drechsler
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Hansjörg Schild
- Institute for Immunology, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Bernd Moosmann
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Christian Behl
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Albrecht M Clement
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University, D-55099 Mainz, Germany.
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Application of ANS fluorescent probes to identify hydrophobic sites on the surface of DREAM. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1472-80. [PMID: 24854592 DOI: 10.1016/j.bbapap.2014.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 05/01/2014] [Accepted: 05/12/2014] [Indexed: 11/23/2022]
Abstract
DREAM (calsenilin or KChIP-3) is a calcium sensor involved in regulation of diverse physiological processes by interactions with multiple intracellular partners including DNA, Kv4 channels, and presenilin, however the detailed mechanism of the recognition of the intracellular partners remains unclear. To identify the surface hydrophobic surfaces on apo and Ca(2+)DREAM as a possible interaction sites for target proteins and/or specific regulators of DREAM function the binding interactions of 1,8-ANS and 2,6-ANS with DREAM were characterized by fluorescence and docking studies. Emission intensity of ANS-DREAM complexes increases upon Ca(2+) association which is consistent with an overall decrease in surface polarity. The dissociation constants for ANS binding to apoDREAM and Ca(2+)DREAM were determined to be 195±20μM and 62±4μM, respectively. Fluorescence lifetime measurements indicate that two ANS molecules bind in two independent binding sites on DREAM monomer. One site is near the exiting helix of EF-4 and the second site is located in the hydrophobic crevice between EF-3 and EF-4. 1,8-ANS displacement studies using arachidonic acid demonstrate that the hydrophobic crevice between EF-3 and EF-4 serves as a binding site for fatty acids that modulate functional properties of Kv4 channel:KChIP complexes. Thus, the C-terminal hydrophobic crevice may be involved in DREAM interactions with small hydrophobic ligands as well as other intracellular proteins.
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Abstract
The electrical output of neurons relies critically on voltage- and calcium-gated ion channels. The traditional view of ion channels is that they operate independently of each other in the plasma membrane in a manner that could be predicted according to biophysical characteristics of the isolated current. However, there is increasing evidence that channels interact with each other not just functionally but also physically. This is exemplified in the case of Cav3 T-type calcium channels, where new work indicates the ability to form signaling complexes with different types of calcium-gated and even voltage-gated potassium channels. The formation of a Cav3-K complex provides the calcium source required to activate KCa1.1 or KCa3.1 channels and, furthermore, to bestow a calcium-dependent regulation of Kv4 channels via associated KChIP proteins. Here, we review these interactions and discuss their significance in the context of neuronal firing properties.
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DREAM controls the on/off switch of specific activity-dependent transcription pathways. Mol Cell Biol 2013; 34:877-87. [PMID: 24366545 DOI: 10.1128/mcb.00360-13] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Changes in nuclear Ca(2+) homeostasis activate specific gene expression programs and are central to the acquisition and storage of information in the brain. DREAM (downstream regulatory element antagonist modulator), also known as calsenilin/KChIP-3 (K(+) channel interacting protein 3), is a Ca(2+)-binding protein that binds DNA and represses transcription in a Ca(2+)-dependent manner. To study the function of DREAM in the brain, we used transgenic mice expressing a Ca(2+)-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). Using genome-wide analysis, we show that DREAM regulates the expression of specific activity-dependent transcription factors in the hippocampus, including Npas4, Nr4a1, Mef2c, JunB, and c-Fos. Furthermore, DREAM regulates its own expression, establishing an autoinhibitory feedback loop to terminate activity-dependent transcription. Ablation of DREAM does not modify activity-dependent transcription because of gene compensation by the other KChIP family members. The expression of daDREAM in the forebrain resulted in a complex phenotype characterized by loss of recurrent inhibition and enhanced long-term potentiation (LTP) in the dentate gyrus and impaired learning and memory. Our results indicate that DREAM is a major master switch transcription factor that regulates the on/off status of specific activity-dependent gene expression programs that control synaptic plasticity, learning, and memory.
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Abstract
Synaptic activity initiates biochemical processes that have various outcomes, including the formation of memories, increases in neuronal survival and the development of chronic pain and addiction. Virtually all activity-induced, long-lasting adaptations of brain functions require a dialogue between synapses and the nucleus that results in changes in gene expression. Calcium signals that are induced by synaptic activity and propagate into the nucleus are a major route for synapse-to-nucleus communication. Recent findings indicate that diverse forms of neuroadaptation require calcium transients in the nucleus to switch on the necessary genomic programme. Deficits in nuclear calcium signalling as a result of a reduction in synaptic activity or increased extrasynaptic NMDA receptor signalling may underlie the aetiologies of various diseases, including neurodegeneration and cognitive dysfunction.
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Affiliation(s)
- Hilmar Bading
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany. Hilmar.Bading@ uni-hd.de
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35
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Chae PS, Wander MJ, Cho KH, Laible PD, Gellman SH. Carbohydrate-containing Triton X-100 analogues for membrane protein solubilization and stabilization. MOLECULAR BIOSYSTEMS 2013; 9:626-9. [PMID: 23377371 PMCID: PMC3593792 DOI: 10.1039/c3mb25584k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Membrane protein manipulation is a challenging task owing to limited tertiary and quaternary structural stability once the protein has been removed from a lipid bilayer. Such instability can be overcome by embedding membrane proteins in detergent micelles formed from amphiphiles with carefully tuned properties. This study introduces a class of easy-to-synthesize amphiphiles, which are designated CGT (Chae's Glyco-Triton) detergents. Some of the agents are well suited for membrane protein solubilization and stabilization.
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Affiliation(s)
- Pil Seok Chae
- Department of Bionano Engineering, Hanyang University, Ansan, 426-791, Korea
| | - Marc J. Wander
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Kyung Ho Cho
- Department of Bionano Engineering, Hanyang University, Ansan, 426-791, Korea
| | - Philip D. Laible
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Samuel H. Gellman
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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36
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DREAM regulates insulin promoter activity through newly identified DRE element. Open Life Sci 2013. [DOI: 10.2478/s11535-013-0123-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AbstractDownstream regulatory element antagonist modulator (DREAM) protein is a 31 kDa Ca2+-regulated transcriptional repressor. It functions as a silencer of the gene transcription. In low intracellular free Ca2+ concentration DREAM tightly binds to the downstream regulatory element (DRE) of gene promoter and impedes the transcription. In higher Ca2+ concentrations DREAM binds Ca2+ and disconnects from DRE of the gene promoter enabling transcription. We report that DREAM is expressed in different human tissues including the pancreas, where it is located in the islets of Langerhans. Location of DREAM in RIN-F5 cells in cultures is restricted to the nucleus and membranes and changes after increased Ca2+-levels. The proteins dissociate from dimmers to monomers and translocate out of the nucleus. The expression of DREAM in β-cells in the islets of Langerhans regulates the promoter activity of the insulin gene by directly interacting with the sequence located between +52 bp and +81 bp downstream of the transcriptional start site of the promoter. Our results provide evidence for the existence of DRE sequence in the insulin gene promoter. It is suggested that DREAM is a repressor of insulin gene transcription, whose effect is mediated by direct binding to DRE sequence.
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37
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Ramachandran PL, Craig TA, Atanasova EA, Cui G, Owen BA, Bergen HR, Mer G, Kumar R. The potassium channel interacting protein 3 (DREAM/KChIP3) heterodimerizes with and regulates calmodulin function. J Biol Chem 2012; 287:39439-48. [PMID: 23019329 DOI: 10.1074/jbc.m112.398495] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Downstream regulatory element antagonistic modulator (DREAM/KChIP3), a neuronal EF-hand protein, modulates pain, potassium channel activity, and binds presenilin 1. Using affinity capture of neuronal proteins by immobilized DREAM/KChIP3 in the presence and absence of calcium (Ca(2+)) followed by mass spectroscopic identification of interacting proteins, we demonstrate that in the presence of Ca(2+), DREAM/KChIP3 interacts with the EF-hand protein, calmodulin (CaM). The interaction of DREAM/KChIP3 with CaM does not occur in the absence of Ca(2+). In the absence of Ca(2+), DREAM/KChIP3 binds the EF-hand protein, calcineurin subunit-B. Ca(2+)-bound DREAM/KChIP3 binds CaM with a dissociation constant of ∼3 μM as assessed by changes in DREAM/KChIP3 intrinsic protein fluorescence in the presence of CaM. Two-dimensional (1)H,(15)N heteronuclear single quantum coherence spectra reveal changes in chemical shifts and line broadening upon the addition of CaM to (15)N DREAM/KChIP3. The amino-terminal portion of DREAM/KChIP3 is required for its binding to CaM because a construct of DREAM/KChIP3 lacking the first 94 amino-terminal residues fails to bind CaM as assessed by fluorescence spectroscopy. The addition of Ca(2+)-bound DREAM/KChIP3 increases the activation of calcineurin (CN) by calcium CaM. A DREAM/KChIP3 mutant incapable of binding Ca(2+) also stimulates calmodulin-dependent CN activity. The shortened form of DREAM/KChIP3 lacking the NH(2)-terminal amino acids fails to activate CN in the presence of calcium CaM. Our data demonstrate the interaction of DREAM/KChIP3 with the important EF-hand protein, CaM, and show that the interaction alters CN activity.
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38
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Pruunsild P, Timmusk T. Subcellular localization and transcription regulatory potency of KCNIP/Calsenilin/DREAM/KChIP proteins in cultured primary cortical neurons do not provide support for their role in CRE-dependent gene expression. J Neurochem 2012; 123:29-43. [PMID: 22612322 DOI: 10.1111/j.1471-4159.2012.07796.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
KCNIP3/KChIP3 (voltage-dependent K+ channel interacting protein 3), alias Calsenilin and downstream regulatory element antagonist modulator (DREAM), is a multifunctional protein that modulates A-type potassium channels, affects processing of amyloid precursor protein and regulates transcription. KCNIP3 has been described to negatively influence the activity of CREB (cAMP/Ca(2+)-response element binding protein), an essential factor in neuronal activity-dependent gene expression regulation. However, reports on intracellular localization of KCNIP3 in neurons are diverse and necessitate additional analyses of distribution of KCNIPs in cells to clarify the potential of KCNIP3 to fulfill its functions in different cell compartments. Here, we examined localization of the entire family of highly similar KCNIP proteins in neuronal cells and show that over-expressed isoforms of KCNIP1/KChIP1, KCNIP2/KChIP2, KCNIP3/KChIP3, and KCNIP4/KChIP4 had varied, yet partially overlapping subcellular localization. In addition, although some of the over-expressed KCNIP isoforms localized to the nucleus, endogenous KCNIPs were not detected in nuclei of rat primary cortical neurons. Moreover, we analyzed the role of KCNIP proteins in cAMP/Ca(2+)-response element (CRE)-dependent transcription by luciferase reporter assay and electrophoretic mobility shift assay and report that our results do not support the role for KCNIPs, including DREAM/Calsenilin/KChIP3, in modulation of CREB-mediated transcription in neurons.
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Affiliation(s)
- Priit Pruunsild
- Department of Gene Technology, Tallinn University of Technology, Estonia.
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Dierssen M, Fedrizzi L, Gomez-Villafuertes R, de Lagran MM, Gutierrez-Adan A, Sahún I, Pintado B, Oliveros JC, Dopazo XM, Gonzalez P, Brini M, Mellström B, Carafoli E, Naranjo JR. Reduced Mid1 Expression and Delayed Neuromotor Development in daDREAM Transgenic Mice. Front Mol Neurosci 2012; 5:58. [PMID: 22563308 PMCID: PMC3342529 DOI: 10.3389/fnmol.2012.00058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 04/11/2012] [Indexed: 11/21/2022] Open
Abstract
Downstream regulatory element antagonist modulator (DREAM) is a Ca2+-binding protein that binds DNA and represses transcription in a Ca2+-dependent manner. Previous work has shown a role for DREAM in cerebellar function regulating the expression of the sodium/calcium exchanger 3 (NCX3) in cerebellar granular neurons to control Ca2+ homeostasis and survival of these neurons. To achieve a global view of the genes regulated by DREAM in the cerebellum, we performed a genome-wide analysis in transgenic cerebellum expressing a Ca2+-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). Here we show that DREAM regulates the expression of the midline 1 (Mid1) gene early after birth. As a consequence, daDREAM mice exhibit a significant shortening of the rostro-caudal axis of the cerebellum and a delay in neuromotor development early after birth. Our results indicate a role for DREAM in cerebellar function.
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Affiliation(s)
- Mara Dierssen
- Genomic Regulation Center, Parc de Recerca Biomèdica de Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Raras Barcelona, Spain
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Analysis of calcium signaling pathways in plants. Biochim Biophys Acta Gen Subj 2011; 1820:1283-93. [PMID: 22061997 DOI: 10.1016/j.bbagen.2011.10.012] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 10/19/2011] [Accepted: 10/21/2011] [Indexed: 11/20/2022]
Abstract
BACKGROUND Calcium serves as a versatile messenger in many adaptation and developmental processes in plants. Ca2+ signals are represented by stimulus-specific spatially and temporally defined Ca2+ signatures. These Ca2+ signatures are detected, decoded and transmitted to downstream responses by a complex toolkit of Ca2+ binding proteins that function as Ca2+ sensors. SCOPE OF REVIEW This review will reflect on advancements in monitoring Ca2+ dynamics in plants. Moreover, it will provide insights in the extensive and complex toolkit of plant Ca2+ sensor proteins that relay the information presented in the Ca2+ signatures into phosphorylation events, changes in protein-protein interaction or regulation of gene expression. MAJOR CONCLUSIONS Plants' response to signals is encoded by different Ca2+ signatures. The plant decoding Ca2+ toolkit encompasses different families of Ca2+ sensors like Calmodulins (CaM), Calmodulin-like proteins (CMLs), Ca2+-dependent protein kinases (CDPKs), Calcineurin B-like proteins (CBLs) and their interacting kinases (CIPKs). These Ca2+ sensors are encoded by complex gene families and form intricate signaling networks in plants that enable specific, robust and flexible information processing. GENERAL SIGNIFICANCE This review provides new insights about the biochemical regulation, physiological functions and of newly identified target proteins of the major plant Ca2+ sensor families. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signaling.
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Hradsky J, Raghuram V, Reddy PP, Navarro G, Hupe M, Casado V, McCormick PJ, Sharma Y, Kreutz MR, Mikhaylova M. Post-translational membrane insertion of tail-anchored transmembrane EF-hand Ca2+ sensor calneurons requires the TRC40/Asna1 protein chaperone. J Biol Chem 2011; 286:36762-76. [PMID: 21878631 DOI: 10.1074/jbc.m111.280339] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Calneuron-1 and -2 are neuronal EF-hand-type calcium sensor proteins that are prominently targeted to trans-Golgi network membranes and impose a calcium threshold at the Golgi for phosphatidylinositol 4-OH kinase IIIβ activation and the regulated local synthesis of phospholipids that are crucial for TGN-to-plasma membrane trafficking. In this study, we show that calneurons are nonclassical type II tail-anchored proteins that are post-translationally inserted into the endoplasmic reticulum membrane via an association of a 23-amino acid-long transmembrane domain (TMD) with the TRC40/Asna1 chaperone complex. Following trafficking to the Golgi, calneurons are probably retained in the TGN because of the length of the TMD and phosphatidylinositol 4-phosphate lipid binding. Both calneurons rapidly self-associate in vitro and in vivo via their TMD and EF-hand containing the N terminus. Although dimerization and potentially multimerization precludes TRC40/Asna1 binding and thereby membrane insertion, we found no evidence for a cytosolic pool of calneurons and could demonstrate that self-association of calneurons is restricted to membrane-inserted protein. The dimerization properties and the fact that they, unlike every other EF-hand calmodulin-like Ca(2+) sensor, are always associated with membranes of the secretory pathway, including vesicles and plasma membrane, suggests a high degree of spatial segregation for physiological target interactions.
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Affiliation(s)
- Johannes Hradsky
- Research Group Neuroplasticity, Leibniz-Institute for Neurobiology, 39118 Magdeburg, Germany
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Lyons MR, West AE. Mechanisms of specificity in neuronal activity-regulated gene transcription. Prog Neurobiol 2011; 94:259-95. [PMID: 21620929 PMCID: PMC3134613 DOI: 10.1016/j.pneurobio.2011.05.003] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 05/05/2011] [Accepted: 05/05/2011] [Indexed: 02/06/2023]
Abstract
The brain is a highly adaptable organ that is capable of converting sensory information into changes in neuronal function. This plasticity allows behavior to be accommodated to the environment, providing an important evolutionary advantage. Neurons convert environmental stimuli into long-lasting changes in their physiology in part through the synaptic activity-regulated transcription of new gene products. Since the neurotransmitter-dependent regulation of Fos transcription was first discovered nearly 25 years ago, a wealth of studies have enriched our understanding of the molecular pathways that mediate activity-regulated changes in gene transcription. These findings show that a broad range of signaling pathways and transcriptional regulators can be engaged by neuronal activity to sculpt complex programs of stimulus-regulated gene transcription. However, the shear scope of the transcriptional pathways engaged by neuronal activity raises the question of how specificity in the nature of the transcriptional response is achieved in order to encode physiologically relevant responses to divergent stimuli. Here we summarize the general paradigms by which neuronal activity regulates transcription while focusing on the molecular mechanisms that confer differential stimulus-, cell-type-, and developmental-specificity upon activity-regulated programs of neuronal gene transcription. In addition, we preview some of the new technologies that will advance our future understanding of the mechanisms and consequences of activity-regulated gene transcription in the brain.
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Affiliation(s)
- Michelle R Lyons
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
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Rivas M, Villar D, González P, Dopazo XM, Mellstrom B, Naranjo JR. Building the DREAM interactome. SCIENCE CHINA-LIFE SCIENCES 2011; 54:786-92. [DOI: 10.1007/s11427-011-4196-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 06/07/2011] [Indexed: 12/28/2022]
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Mikhaylova M, Hradsky J, Kreutz MR. Between promiscuity and specificity: novel roles of EF-hand calcium sensors in neuronal Ca2+ signalling. J Neurochem 2011; 118:695-713. [PMID: 21722133 DOI: 10.1111/j.1471-4159.2011.07372.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In recent years, substantial progress has been made towards an understanding of the physiological function of EF-hand calcium sensor proteins of the Calmodulin (CaM) superfamily in neurons. This deeper appreciation is based on the identification of novel target interactions, structural studies and the discovery of novel signalling mechanisms in protein trafficking and synaptic plasticity, in which CaM-like sensor proteins appear to play a role. However, not all interactions are of plausible physiological relevance and in many cases it is not yet clear how the CaM signaling network relates to the proposed function of other EF-hand sensors. In this review, we will summarize these findings and address some of the open questions on the functional role of EF-hand calcium binding proteins in neurons.
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Affiliation(s)
- Marina Mikhaylova
- PG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg, Germany
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Sensing change: The emerging role of calcium sensors in neuronal disease. Semin Cell Dev Biol 2011; 22:530-5. [DOI: 10.1016/j.semcdb.2011.07.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 07/18/2011] [Indexed: 11/20/2022]
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Abstract
Background The transcriptional repressor DREAM (downstream regulatory element antagonist modulator) controls the expression of prodynorphin and has been involved in the modulation of endogenous responses to pain. To investigate the role of DREAM in central mechanisms of pain sensitization, we used a line of transgenic mice (L1) overexpressing a Ca2+- and cAMP-insensitive DREAM mutant in spinal cord and dorsal root ganglia. Results L1 DREAM transgenic mice showed reduced expression in the spinal cord of several genes related to pain, including prodynorphin and BDNF (brain-derived neurotrophic factor) and a state of basal hyperalgesia without change in A-type currents. Peripheral inflammation produced enhancement of spinal reflexes and increased expression of BDNF in wild type but not in DREAM transgenic mice. The enhancement of the spinal reflexes was reproduced in vitro by persistent electrical stimulation of C-fibers in wild type but not in transgenic mice. Exposure to exogenous BDNF produced a long-term enhancement of dorsal root-ventral root responses in transgenic mice. Conclusions Our results indicate that endogenous BDNF is involved in spinal sensitization following inflammation and that blockade of BDNF induction in DREAM transgenic mice underlies the failure to develop spinal sensitization.
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Palczewska M, Casafont I, Ghimire K, Rojas AM, Valencia A, Lafarga M, Mellström B, Naranjo JR. Sumoylation regulates nuclear localization of repressor DREAM. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1813:1050-8. [PMID: 21070824 DOI: 10.1016/j.bbamcr.2010.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 10/29/2010] [Accepted: 11/02/2010] [Indexed: 10/18/2022]
Abstract
DREAM is a Ca(2+)-binding protein with specific functions in different cell compartments. In the nucleus, DREAM acts as a transcriptional repressor, although the mechanism that controls its nuclear localization is unknown. Yeast two-hybrid assay revealed the interaction between DREAM and the SUMO-conjugating enzyme Ubc9 and bioinformatic analysis identified four sumoylation-susceptible sites in the DREAM sequence. Single K-to-R mutations at positions K26 and K90 prevented in vitro sumoylation of recombinant DREAM. DREAM sumoylation mutants retained the ability to bind to the DRE sequence but showed reduced nuclear localization and failed to regulate DRE-dependent transcription. In PC12 cells, sumoylated DREAM is present exclusively in the nucleus and neuronal differentiation induced nuclear accumulation of sumoylated DREAM. In fully differentiated trigeminal neurons, DREAM and SUMO-1 colocalized in nuclear domains associated with transcription. Our results show that sumoylation regulates the nuclear localization of DREAM in differentiated neurons. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
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Savignac M, Mellström B, Bébin AG, Oliveros JC, Delpy L, Pinaud E, Naranjo JR. Increased B cell proliferation and reduced Ig production in DREAM transgenic mice. THE JOURNAL OF IMMUNOLOGY 2010; 185:7527-36. [PMID: 21059893 DOI: 10.4049/jimmunol.1000152] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DREAM/KChIP-3 is a calcium-dependent transcriptional repressor highly expressed in immune cells. Transgenic mice expressing a dominant active DREAM mutant show reduced serum Ig levels. In vitro assays show that reduced Ig secretion is an intrinsic defect of transgenic B cells that occurs without impairment in plasma cell differentiation, class switch recombination, or Ig transcription. Surprisingly, transgenic B cells show an accelerated entry in cell division. Transcriptomic analysis of transgenic B cells revealed that hyperproliferative B cell response could be correlated with a reduced expression of Klf9, a cell-cycle regulator. Pulse-chase experiments demonstrated that the defect in Ig production is associated with reduced translation rather than with increased protein degradation. Importantly, transgenic B cells showed reduced expression of the Eif4g3 gene, which encodes a protein related to protein translation. Our results disclose, to our knowledge, a novel function of DREAM in proliferation and Ig synthesis in B lymphocytes.
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Affiliation(s)
- Magali Savignac
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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Jacob AL, Jordan BA, Weinberg RJ. Organization of amyloid-beta protein precursor intracellular domain-associated protein-1 in the rat brain. J Comp Neurol 2010; 518:3221-36. [PMID: 20575057 PMCID: PMC2894292 DOI: 10.1002/cne.22394] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sustained activity-dependent synaptic modifications require protein synthesis. Although proteins can be synthesized locally in dendrites, long-term changes also require nuclear signaling. Amyloid-beta protein precursor intracellular domain-associated protein-1 (AIDA-1), an abundant component of the biochemical postsynaptic density fraction, contains a nuclear localization sequence, making it a plausible candidate for synapse-to-nucleus signaling. We used immunohistochemistry to study the regional, cellular, and subcellular distribution of AIDA-1. Immunostaining was prominent in the hippocampus, cerebral cortex, and neostriatum. Along with diffuse staining of neuropil, fluorescence microscopy revealed immunostaining of excitatory synapses throughout the forebrain, and immunoreactive puncta within and directly outside the nucleus. Presynaptic staining was conspicuous in hippocampal mossy fibers. Electron microscopic analysis of material processed for postembedding immunogold revealed AIDA-1 label within postsynaptic densities in both hippocampus and cortex. Together with previous work, these data suggest that AIDA-1 serves as a direct signaling link between synapses and the nucleus in adult rat brain.
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Affiliation(s)
- Amanda L Jacob
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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