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Liese A, Eichstädt B, Lederer S, Schulz P, Oehlschläger J, Matschi S, Feijó JA, Schulze WX, Konrad KR, Romeis T. Imaging of plant calcium-sensor kinase conformation monitors real time calcium-dependent decoding in planta. THE PLANT CELL 2024; 36:276-297. [PMID: 37433056 PMCID: PMC11210078 DOI: 10.1093/plcell/koad196] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/14/2023] [Accepted: 07/10/2023] [Indexed: 07/13/2023]
Abstract
Changes in cytosolic calcium (Ca2+) concentration are among the earliest reactions to a multitude of stress cues. While a plethora of Ca2+-permeable channels may generate distinct Ca2+ signatures and contribute to response specificities, the mechanisms by which Ca2+ signatures are decoded are poorly understood. Here, we developed a genetically encoded Förster resonance energy transfer (FRET)-based reporter that visualizes the conformational changes in Ca2+-dependent protein kinases (CDPKs/CPKs). We focused on two CDPKs with distinct Ca2+-sensitivities, highly Ca2+-sensitive Arabidopsis (Arabidopsis thaliana) AtCPK21 and rather Ca2+-insensitive AtCPK23, to report conformational changes accompanying kinase activation. In tobacco (Nicotiana tabacum) pollen tubes, which naturally display coordinated spatial and temporal Ca2+ fluctuations, CPK21-FRET, but not CPK23-FRET, reported oscillatory emission ratio changes mirroring cytosolic Ca2+ changes, pointing to the isoform-specific Ca2+-sensitivity and reversibility of the conformational change. In Arabidopsis guard cells, CPK21-FRET-monitored conformational dynamics suggest that CPK21 serves as a decoder of signal-specific Ca2+ signatures in response to abscisic acid and the flagellin peptide flg22. Based on these data, CDPK-FRET is a powerful approach for tackling real-time live-cell Ca2+ decoding in a multitude of plant developmental and stress responses.
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Affiliation(s)
- Anja Liese
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Bernadette Eichstädt
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Sarah Lederer
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Philipp Schulz
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Jan Oehlschläger
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Susanne Matschi
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - José A Feijó
- Department of Cell Biology & Molecular Genetics, University of Maryland, 2136 Bioscience Research Bldg, College Park, MD 20742-5815, USA
| | - Waltraud X Schulze
- Plant Systems Biology, Universität Hohenheim, D-70593 Stuttgart, Germany
| | - Kai R Konrad
- Julius-Von-Sachs Institute for Biosciences, Julius Maximilians Universität Würzburg, D-97082 Würzburg, Germany
| | - Tina Romeis
- Department for Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, D-14195 Berlin, Germany
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2
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Aslam M, Ladilov Y. Editorial: Advances in cAMP signaling research: basic and translational aspects. Front Physiol 2023; 14:1266718. [PMID: 37727656 PMCID: PMC10505720 DOI: 10.3389/fphys.2023.1266718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 08/22/2023] [Indexed: 09/21/2023] Open
Affiliation(s)
- Muhammad Aslam
- Experimental Cardiology, Department of Internal Medicine I, Justus Liebig University, Giessen, Germany
- Department of Cardiology, Kerckhoff Clinic GmbH, Bad Nauheim, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Rhein-Main, Bad Nauheim, Germany
| | - Yury Ladilov
- Department of Cardiovascular Surgery, Heart Center Brandenburg, Brandenburg Medical School Theodor Fontane, Bernau bei Berlin, Germany
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3
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Paolocci E, Zaccolo M. Compartmentalised cAMP signalling in the primary cilium. Front Physiol 2023; 14:1187134. [PMID: 37256063 PMCID: PMC10226274 DOI: 10.3389/fphys.2023.1187134] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/25/2023] [Indexed: 06/01/2023] Open
Abstract
cAMP is a universal second messenger that relies on precise spatio-temporal regulation to control varied, and often opposing, cellular functions. This is achieved via selective activation of effectors embedded in multiprotein complexes, or signalosomes, that reside at distinct subcellular locations. cAMP is also one of many pathways known to operate within the primary cilium. Dysfunction of ciliary signaling leads to a class of diseases known as ciliopathies. In Autosomal Dominant Polycystic Kidney Disease (ADPKD), a ciliopathy characterized by the formation of fluid-filled kidney cysts, upregulation of cAMP signaling is known to drive cystogenesis. For decades it has been debated whether the primary cilium is an independent cAMP sub-compartment, or whether it shares a diffusible pool of cAMP with the cell body. Recent studies now suggest it is a specific pool of cAMP generated in the cilium that propels cyst formation in ADPKD, supporting the notion that this antenna-like organelle is a compartment within which cAMP signaling occurs independently from cAMP signaling in the bulk cytosol. Here we present examples of cAMP function in the cilium which suggest this mysterious organelle is home to more than one cAMP signalosome. We review evidence that ciliary membrane localization of G-Protein Coupled Receptors (GPCRs) determines their downstream function and discuss how optogenetic tools have contributed to establish that cAMP generated in the primary cilium can drive cystogenesis.
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4
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Burton JC, Okalova J, Grimsey NJ. Fluorescence resonance energy transfer (FRET) spatiotemporal mapping of atypical P38 reveals an endosomal and cytosolic spatial bias. Sci Rep 2023; 13:7477. [PMID: 37156828 PMCID: PMC10167256 DOI: 10.1038/s41598-023-33953-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) p38 is a central regulator of intracellular signaling, driving physiological and pathological pathways. With over 150 downstream targets, it is predicted that spatial positioning and the availability of cofactors and substrates determines kinase signaling specificity. The subcellular localization of p38 is highly dynamic to facilitate the selective activation of spatially restricted substrates. However, the spatial dynamics of atypical p38 inflammatory signaling are understudied. We utilized subcellular targeted fluorescence resonance energy transfer (FRET) p38 activity biosensors to map the spatial profile of kinase activity. Through comparative analysis of plasma membrane, cytosolic, nuclear, and endosomal compartments, we confirm a characteristic profile of nuclear bias for mitogen-activated kinase kinase 3/6 (MKK3/6) dependent p38 activation. Conversely, atypical p38 activation via thrombin-mediated protease-activated receptor 1 (PAR1) activity led to enhanced p38 activity at the endosome and cytosol, limiting nuclear p38 activity, a profile conserved for prostaglandin E2 activation of p38. Conversely, perturbation of receptor endocytosis led to spatiotemporal switching of thrombin signaling, reducing endosomal and cytosolic p38 activity and increasing nuclear activity. The data presented reveal the spatiotemporal dynamics of p38 activity and provide critical insight into how atypical p38 signaling drives differential signaling responses through spatial sequestration of kinase activity.
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Affiliation(s)
- Jeremy C Burton
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Pharmacy South Rm 414, Athens, 30602, USA
| | - Jennifer Okalova
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Pharmacy South Rm 414, Athens, 30602, USA
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Neil J Grimsey
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Pharmacy South Rm 414, Athens, 30602, USA.
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5
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Molin M, Logg K, Bodvard K, Peeters K, Forsmark A, Roger F, Jörhov A, Mishra N, Billod JM, Amir S, Andersson M, Eriksson LA, Warringer J, Käll M, Blomberg A. Protein kinase A controls yeast growth in visible light. BMC Biol 2020; 18:168. [PMID: 33198745 PMCID: PMC7667738 DOI: 10.1186/s12915-020-00867-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/09/2020] [Indexed: 01/07/2023] Open
Abstract
Background A wide variety of photosynthetic and non-photosynthetic species sense and respond to light, having developed protective mechanisms to adapt to damaging effects on DNA and proteins. While the biology of UV light-induced damage has been well studied, cellular responses to stress from visible light (400–700 nm) remain poorly understood despite being a regular part of the life cycle of many organisms. Here, we developed a high-throughput method for measuring growth under visible light stress and used it to screen for light sensitivity in the yeast gene deletion collection. Results We found genes involved in HOG pathway signaling, RNA polymerase II transcription, translation, diphthamide modifications of the translational elongation factor eEF2, and the oxidative stress response to be required for light resistance. Reduced nuclear localization of the transcription factor Msn2 and lower glycogen accumulation indicated higher protein kinase A (cAMP-dependent protein kinase, PKA) activity in many light-sensitive gene deletion strains. We therefore used an ectopic fluorescent PKA reporter and mutants with constitutively altered PKA activity to show that repression of PKA is essential for resistance to visible light. Conclusion We conclude that yeast photobiology is multifaceted and that protein kinase A plays a key role in the ability of cells to grow upon visible light exposure. We propose that visible light impacts on the biology and evolution of many non-photosynthetic organisms and have practical implications for how organisms are studied in the laboratory, with or without illumination.
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Affiliation(s)
- Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden. .,Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
| | - Katarina Logg
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.,Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Kristofer Bodvard
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Ken Peeters
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Annabelle Forsmark
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Friederike Roger
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Anna Jörhov
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Neha Mishra
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.,Horizon Discovery, Cambridge, CB25 9TL, UK
| | - Jean-Marc Billod
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.,Bio-Me A/S, Oslo Science Park, Gaustadalléen, 210349, Oslo, Norway
| | - Sabiha Amir
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mikael Andersson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Leif A Eriksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Jonas Warringer
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mikael Käll
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Anders Blomberg
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
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6
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Roger F, Picazo C, Reiter W, Libiad M, Asami C, Hanzén S, Gao C, Lagniel G, Welkenhuysen N, Labarre J, Nyström T, Grøtli M, Hartl M, Toledano MB, Molin M. Peroxiredoxin promotes longevity and H 2O 2-resistance in yeast through redox-modulation of protein kinase A. eLife 2020; 9:e60346. [PMID: 32662770 PMCID: PMC7392609 DOI: 10.7554/elife.60346] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 07/08/2020] [Indexed: 12/16/2022] Open
Abstract
Peroxiredoxins are H2O2 scavenging enzymes that also carry out H2O2 signaling and chaperone functions. In yeast, the major cytosolic peroxiredoxin, Tsa1 is required for both promoting resistance to H2O2 and extending lifespan upon caloric restriction. We show here that Tsa1 effects both these functions not by scavenging H2O2, but by repressing the nutrient signaling Ras-cAMP-PKA pathway at the level of the protein kinase A (PKA) enzyme. Tsa1 stimulates sulfenylation of cysteines in the PKA catalytic subunit by H2O2 and a significant proportion of the catalytic subunits are glutathionylated on two cysteine residues. Redox modification of the conserved Cys243 inhibits the phosphorylation of a conserved Thr241 in the kinase activation loop and enzyme activity, and preventing Thr241 phosphorylation can overcome the H2O2 sensitivity of Tsa1-deficient cells. Results support a model of aging where nutrient signaling pathways constitute hubs integrating information from multiple aging-related conduits, including a peroxiredoxin-dependent response to H2O2.
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Affiliation(s)
- Friederike Roger
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Cecilia Picazo
- Department of Biology and Biological Engineering, Chalmers University of TechnologyGothenburgSweden
| | - Wolfgang Reiter
- Mass Spectrometry Facility, Department of Biochemistry, Max F. Perutz Laboratories, University of Vienna, Vienna BioCenterViennaAustria
| | - Marouane Libiad
- Oxidative Stress and Cancer Laboratory, Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC)Gif sur YvetteFrance
| | - Chikako Asami
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Sarah Hanzén
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Chunxia Gao
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Gilles Lagniel
- Oxidative Stress and Cancer Laboratory, Integrative Biology and Molecular Genetics Unit (SBIGEM)CEA SaclayFrance
| | - Niek Welkenhuysen
- Department of Mathematical Sciences, Chalmers University of Technology and University of GothenburgGothenburgSweden
| | - Jean Labarre
- Oxidative Stress and Cancer Laboratory, Integrative Biology and Molecular Genetics Unit (SBIGEM)CEA SaclayFrance
| | - Thomas Nyström
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, University of GothenburgGothenburgSweden
| | - Morten Grøtli
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Markus Hartl
- Mass Spectrometry Facility, Department of Biochemistry, Max F. Perutz Laboratories, University of Vienna, Vienna BioCenterViennaAustria
| | - Michel B Toledano
- Oxidative Stress and Cancer Laboratory, Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC)Gif sur YvetteFrance
| | - Mikael Molin
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
- Department of Biology and Biological Engineering, Chalmers University of TechnologyGothenburgSweden
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7
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Pendin D, Greotti E, Lefkimmiatis K, Pozzan T. Exploring cells with targeted biosensors. J Gen Physiol 2016; 149:1-36. [PMID: 28028123 PMCID: PMC5217087 DOI: 10.1085/jgp.201611654] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/26/2016] [Accepted: 12/01/2016] [Indexed: 01/10/2023] Open
Abstract
Cellular signaling networks are composed of multiple pathways, often interconnected, that form complex networks with great potential for cross-talk. Signal decoding depends on the nature of the message as well as its amplitude, temporal pattern, and spatial distribution. In addition, the existence of membrane-bound organelles, which are both targets and generators of messages, add further complexity to the system. The availability of sensors that can localize to specific compartments in live cells and monitor their targets with high spatial and temporal resolution is thus crucial for a better understanding of cell pathophysiology. For this reason, over the last four decades, a variety of strategies have been developed, not only to generate novel and more sensitive probes for ions, metabolites, and enzymatic activity, but also to selectively deliver these sensors to specific intracellular compartments. In this review, we summarize the principles that have been used to target organic or protein sensors to different cellular compartments and their application to cellular signaling.
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Affiliation(s)
- Diana Pendin
- Neuroscience Institute, National Research Council, Padua Section, 35121 Padua, Italy.,Department of Biomedical Sciences, University of Padua, 35121 Padua, Italy
| | - Elisa Greotti
- Neuroscience Institute, National Research Council, Padua Section, 35121 Padua, Italy.,Department of Biomedical Sciences, University of Padua, 35121 Padua, Italy
| | - Konstantinos Lefkimmiatis
- Neuroscience Institute, National Research Council, Padua Section, 35121 Padua, Italy.,Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Tullio Pozzan
- Neuroscience Institute, National Research Council, Padua Section, 35121 Padua, Italy.,Venetian Institute of Molecular Medicine, 35129 Padua, Italy.,Department of Biomedical Sciences, University of Padua, 35121 Padua, Italy
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8
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Cilia have high cAMP levels that are inhibited by Sonic Hedgehog-regulated calcium dynamics. Proc Natl Acad Sci U S A 2016; 113:13069-13074. [PMID: 27799542 DOI: 10.1073/pnas.1602393113] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Protein kinase A (PKA) phosphorylates Gli proteins, acting as a negative regulator of the Hedgehog pathway. PKA was recently detected within the cilium, and PKA activity specifically in cilia regulates Gli processing. Using a cilia-targeted genetically encoded sensor, we found significant basal PKA activity. Using another targeted sensor, we measured basal ciliary cAMP that is fivefold higher than whole-cell cAMP. The elevated basal ciliary cAMP level is a result of adenylyl cyclase 5 and 6 activity that depends on ciliary phosphatidylinositol (3,4,5)-trisphosphate (PIP3), not stimulatory G protein (Gαs), signaling. Sonic Hedgehog (SHH) reduces ciliary cAMP levels, inhibits ciliary PKA activity, and increases Gli1. Remarkably, SHH regulation of ciliary cAMP and downstream signals is not dependent on inhibitory G protein (Gαi/o) signaling but rather Ca2+ entry through a Gd3+-sensitive channel. Therefore, PIP3 sustains high basal cAMP that maintains PKA activity in cilia and Gli repression. SHH activates Gli by inhibiting cAMP through a G protein-independent mechanism that requires extracellular Ca2+ entry.
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González-Vera JA, Morris MC. Fluorescent Reporters and Biosensors for Probing the Dynamic Behavior of Protein Kinases. Proteomes 2015; 3:369-410. [PMID: 28248276 PMCID: PMC5217393 DOI: 10.3390/proteomes3040369] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/30/2015] [Accepted: 10/23/2015] [Indexed: 12/20/2022] Open
Abstract
Probing the dynamic activities of protein kinases in real-time in living cells constitutes a major challenge that requires specific and sensitive tools tailored to meet the particular demands associated with cellular imaging. The development of genetically-encoded and synthetic fluorescent biosensors has provided means of monitoring protein kinase activities in a non-invasive fashion in their native cellular environment with high spatial and temporal resolution. Here, we review existing technologies to probe different dynamic features of protein kinases and discuss limitations where new developments are required to implement more performant tools, in particular with respect to infrared and near-infrared fluorescent probes and strategies which enable improved signal-to-noise ratio and controlled activation of probes.
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Affiliation(s)
- Juan A González-Vera
- Cell Cycle Biosensors & Inhibitors, Department of Amino Acids, Peptides and Proteins, Institute of Biomolecules Max Mousseron (IBMM) CNRS-UMR 5247, 15 Avenue Charles Flahault, Montpellier 34093, France.
| | - May C Morris
- Cell Cycle Biosensors & Inhibitors, Department of Amino Acids, Peptides and Proteins, Institute of Biomolecules Max Mousseron (IBMM) CNRS-UMR 5247, 15 Avenue Charles Flahault, Montpellier 34093, France.
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10
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Huang PC, Hsiao YT, Kao SY, Chen CF, Chen YC, Chiang CW, Lee CF, Lu JC, Chern Y, Wang CT. Adenosine A(2A) receptor up-regulates retinal wave frequency via starburst amacrine cells in the developing rat retina. PLoS One 2014; 9:e95090. [PMID: 24777042 PMCID: PMC4002430 DOI: 10.1371/journal.pone.0095090] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 03/23/2014] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Developing retinas display retinal waves, the patterned spontaneous activity essential for circuit refinement. During the first postnatal week in rodents, retinal waves are mediated by synaptic transmission between starburst amacrine cells (SACs) and retinal ganglion cells (RGCs). The neuromodulator adenosine is essential for the generation of retinal waves. However, the cellular basis underlying adenosine's regulation of retinal waves remains elusive. Here, we investigated whether and how the adenosine A(2A) receptor (A(2A)R) regulates retinal waves and whether A(2A)R regulation of retinal waves acts via presynaptic SACs. METHODOLOGY/PRINCIPAL FINDINGS We showed that A(2A)R was expressed in the inner plexiform layer and ganglion cell layer of the developing rat retina. Knockdown of A(2A)R decreased the frequency of spontaneous Ca²⁺ transients, suggesting that endogenous A(2A)R may up-regulate wave frequency. To investigate whether A(2A)R acts via presynaptic SACs, we targeted gene expression to SACs by the metabotropic glutamate receptor type II promoter. Ca²⁺ transient frequency was increased by expressing wild-type A(2A)R (A2AR-WT) in SACs, suggesting that A(2A)R may up-regulate retinal waves via presynaptic SACs. Subsequent patch-clamp recordings on RGCs revealed that presynaptic A(2A)R-WT increased the frequency of wave-associated postsynaptic currents (PSCs) or depolarizations compared to the control, without changing the RGC's excitability, membrane potentials, or PSC charge. These findings suggest that presynaptic A(2A)R may not affect the membrane properties of postsynaptic RGCs. In contrast, by expressing the C-terminal truncated A(2A)R mutant (A(2A)R-ΔC) in SACs, the wave frequency was reduced compared to the A(2A)R-WT, but was similar to the control, suggesting that the full-length A(2A)R in SACs is required for A(2A)R up-regulation of retinal waves. CONCLUSIONS/SIGNIFICANCE A(2A)R up-regulates the frequency of retinal waves via presynaptic SACs, requiring its full-length protein structure. Thus, by coupling with the downstream intracellular signaling, A(2A)R may have a great capacity to modulate patterned spontaneous activity during neural circuit refinement.
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Affiliation(s)
- Pin-Chien Huang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yu-Tien Hsiao
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Shao-Yen Kao
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Feng Chen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yu-Chieh Chen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Chung-Wei Chiang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Chien-fei Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Juu-Chin Lu
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Yijuang Chern
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chih-Tien Wang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan
- * E-mail:
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11
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Using a genetically encoded FRET-based reporter to visualize calcineurin phosphatase activity in living cells. Methods Mol Biol 2014; 1071:139-49. [PMID: 24052386 DOI: 10.1007/978-1-62703-622-1_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Calcineurin is an evolutionarily conserved, ubiquitously expressed protein phosphatase that serves as a major effector of Ca(2+) signals, regulating diverse biological processes such as gene expression, tissue differentiation, immune responses, and neural plasticity. The following method describes how to monitor real-time calcineurin activity in cultured mammalian cells using a fluorescence resonance energy transfer (FRET)-based activity reporter.
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12
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Nhu Ngoc Van T, Morris MC. Fluorescent Sensors of Protein Kinases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 113:217-74. [DOI: 10.1016/b978-0-12-386932-6.00006-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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