1
|
Lobos P, Vega-Vásquez I, Bruna B, Gleitze S, Toledo J, Härtel S, Hidalgo C, Paula-Lima A. Amyloid β-Oligomers Inhibit the Nuclear Ca 2+ Signals and the Neuroprotective Gene Expression Induced by Gabazine in Hippocampal Neurons. Antioxidants (Basel) 2023; 12:1972. [PMID: 38001825 PMCID: PMC10669355 DOI: 10.3390/antiox12111972] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/31/2023] [Accepted: 11/04/2023] [Indexed: 11/26/2023] Open
Abstract
Hippocampal neuronal activity generates dendritic and somatic Ca2+ signals, which, depending on stimulus intensity, rapidly propagate to the nucleus and induce the expression of transcription factors and genes with crucial roles in cognitive functions. Soluble amyloid-beta oligomers (AβOs), the main synaptotoxins engaged in the pathogenesis of Alzheimer's disease, generate aberrant Ca2+ signals in primary hippocampal neurons, increase their oxidative tone and disrupt structural plasticity. Here, we explored the effects of sub-lethal AβOs concentrations on activity-generated nuclear Ca2+ signals and on the Ca2+-dependent expression of neuroprotective genes. To induce neuronal activity, neuron-enriched primary hippocampal cultures were treated with the GABAA receptor blocker gabazine (GBZ), and nuclear Ca2+ signals were measured in AβOs-treated or control neurons transfected with a genetically encoded nuclear Ca2+ sensor. Incubation (6 h) with AβOs significantly reduced the nuclear Ca2+ signals and the enhanced phosphorylation of cyclic AMP response element-binding protein (CREB) induced by GBZ. Likewise, incubation (6 h) with AβOs significantly reduced the GBZ-induced increases in the mRNA levels of neuronal Per-Arnt-Sim domain protein 4 (Npas4), brain-derived neurotrophic factor (BDNF), ryanodine receptor type-2 (RyR2), and the antioxidant enzyme NADPH-quinone oxidoreductase (Nqo1). Based on these findings we propose that AβOs, by inhibiting the generation of activity-induced nuclear Ca2+ signals, disrupt key neuroprotective gene expression pathways required for hippocampal-dependent learning and memory processes.
Collapse
Affiliation(s)
- Pedro Lobos
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (P.L.); (I.V.-V.); (S.G.); (S.H.)
- Advanced Clinical Research Center, Clinical Hospital, Universidad de Chile, Santiago 8380456, Chile; (B.B.); (J.T.)
| | - Ignacio Vega-Vásquez
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (P.L.); (I.V.-V.); (S.G.); (S.H.)
- Advanced Scientific Equipment Network (REDECA), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Barbara Bruna
- Advanced Clinical Research Center, Clinical Hospital, Universidad de Chile, Santiago 8380456, Chile; (B.B.); (J.T.)
| | - Silvia Gleitze
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (P.L.); (I.V.-V.); (S.G.); (S.H.)
| | - Jorge Toledo
- Advanced Clinical Research Center, Clinical Hospital, Universidad de Chile, Santiago 8380456, Chile; (B.B.); (J.T.)
- Advanced Scientific Equipment Network (REDECA), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Steffen Härtel
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (P.L.); (I.V.-V.); (S.G.); (S.H.)
- Laboratory for Scientific Image Analysis, Center for Medical Informatics and Telemedicine, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile
- Anatomy and Biology of Development Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile
| | - Cecilia Hidalgo
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (P.L.); (I.V.-V.); (S.G.); (S.H.)
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile
- Physiology and Biophysics Program, Institute of Biomedical Sciences and Center for Exercise, Metabolism and Cancer Studies, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile
| | - Andrea Paula-Lima
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (P.L.); (I.V.-V.); (S.G.); (S.H.)
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile
- Interuniversity Center for Healthy Aging (CIES), Santiago 8380000, Chile
- Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, Universidad de Chile, Santiago 8380544, Chile
| |
Collapse
|
2
|
Yang J, Johnson CH. Bioluminescent Sensors for Ca ++ Flux Imaging and the Introduction of a New Intensity-Based Ca ++ Sensor. Front Bioeng Biotechnol 2021; 9:773353. [PMID: 34778237 PMCID: PMC8578923 DOI: 10.3389/fbioe.2021.773353] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/13/2021] [Indexed: 11/13/2022] Open
Abstract
Sensitive detection of biological events is a goal for the design and characterization of sensors that can be used in vitro and in vivo. One important second messenger is Ca++ which has been a focus of using genetically encoded Ca++ indicators (GECIs) within living cells or intact organisms in vivo. An ideal GECI would exhibit high signal intensity, excellent signal-to-noise ratio (SNR), rapid kinetics, a large dynamic range within relevant physiological conditions, and red-shifted emission. Most available GECIs are based on fluorescence, but bioluminescent GECIs have potential advantages in terms of avoiding tissue autofluorescence, phototoxicity, photobleaching, and spectral overlap, as well as enhancing SNR. Here, we summarize current progress in the development of bioluminescent GECIs and introduce a new and previously unpublished biosensor. Because these biosensors require a substrate, we also describe the pros and cons of various substrates used with these sensors. The novel GECI that is introduced here is called CalBiT, and it is a Ca++ indicator based on the functional complementation of NanoBiT which shows a high dynamic change in response to Ca++ fluxes. Here, we use CalBiT for the detection of Ca++ fluctuations in cultured cells, including its ability for real-time imaging in living cells.
Collapse
Affiliation(s)
- Jie Yang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
| | - Carl Hirschie Johnson
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| |
Collapse
|
3
|
Galla L, Vajente N, Pendin D, Pizzo P, Pozzan T, Greotti E. Generation and Characterization of a New FRET-Based Ca 2+ Sensor Targeted to the Nucleus. Int J Mol Sci 2021; 22:ijms22189945. [PMID: 34576104 PMCID: PMC8467696 DOI: 10.3390/ijms22189945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/09/2021] [Accepted: 09/12/2021] [Indexed: 12/17/2022] Open
Abstract
Calcium (Ca2+) exerts a pivotal role in controlling both physiological and detrimental cellular processes. This versatility is due to the existence of a cell-specific molecular Ca2+ toolkit and its fine subcellular compartmentalization. Study of the role of Ca2+ in cellular physiopathology greatly benefits from tools capable of quantitatively measuring its dynamic concentration ([Ca2+]) simultaneously within organelles and in the cytosol to correlate localized and global [Ca2+] changes. To this aim, as nucleoplasm Ca2+ changes mirror those of the cytosol, we generated a novel nuclear-targeted version of a Föster resonance energy transfer (FRET)-based Ca2+ probe. In particular, we modified the previously described nuclear Ca2+ sensor, H2BD3cpv, by substituting the donor ECFP with mCerulean3, a brighter and more photostable fluorescent protein. The thorough characterization of this sensor in HeLa cells demonstrated that it significantly improved the brightness and photostability compared to the original probe, thus obtaining a probe suitable for more accurate quantitative Ca2+ measurements. The affinity for Ca2+ was determined in situ. Finally, we successfully applied the new probe to confirm that cytoplasmic and nucleoplasmic Ca2+ levels were similar in both resting conditions and upon cell stimulation. Examples of simultaneous monitoring of Ca2+ signal dynamics in different subcellular compartments in the very same cells are also presented.
Collapse
Affiliation(s)
- Luisa Galla
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; (L.G.); (N.V.); (D.P.); (P.P.); (T.P.)
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Nicola Vajente
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; (L.G.); (N.V.); (D.P.); (P.P.); (T.P.)
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Diana Pendin
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; (L.G.); (N.V.); (D.P.); (P.P.); (T.P.)
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Paola Pizzo
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; (L.G.); (N.V.); (D.P.); (P.P.); (T.P.)
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Tullio Pozzan
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; (L.G.); (N.V.); (D.P.); (P.P.); (T.P.)
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
- Venetian Institute of Molecular Medicine (VIMM), 35131 Padua, Italy
| | - Elisa Greotti
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; (L.G.); (N.V.); (D.P.); (P.P.); (T.P.)
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
- Correspondence:
| |
Collapse
|
4
|
Pirayesh N, Giridhar M, Ben Khedher A, Vothknecht UC, Chigri F. Organellar calcium signaling in plants: An update. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:118948. [PMID: 33421535 DOI: 10.1016/j.bbamcr.2021.118948] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/13/2022]
Abstract
Calcium ion (Ca2+) is a versatile signaling transducer in all eukaryotic organisms. In plants, intracellular changes in free Ca2+ levels act as regulators in many growth and developmental processes. Ca2+ also mediates the cellular responses to environmental stimuli and thus plays an important role in providing stress tolerance to plants. Ca2+ signals are decoded by a tool kit of various families of Ca2+-binding proteins and their downstream targets, which mediate the transformation of the Ca2+ signal into appropriate cellular response. Early interest and research on Ca2+ signaling focused on its function in the cytosol, however it has become evident that this important regulatory pathway also exists in organelles such as nucleus, chloroplast, mitochondria, peroxisomes and the endomembrane system. In this review, we give an overview on the knowledge about organellar Ca2+ signaling with a focus on recent advances and developments.
Collapse
Affiliation(s)
- Niloufar Pirayesh
- Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Maya Giridhar
- Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Ahlem Ben Khedher
- Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Ute C Vothknecht
- Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany.
| | - Fatima Chigri
- Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany.
| |
Collapse
|
5
|
Pratt SJP, Hernández-Ochoa E, Martin SS. Calcium signaling: breast cancer's approach to manipulation of cellular circuitry. Biophys Rev 2020; 12:1343-1359. [PMID: 33569087 PMCID: PMC7755621 DOI: 10.1007/s12551-020-00771-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/29/2020] [Indexed: 12/11/2022] Open
Abstract
Calcium is a versatile element that participates in cell signaling for a wide range of cell processes such as death, cell cycle, division, migration, invasion, metabolism, differentiation, autophagy, transcription, and others. Specificity of calcium in each of these processes is achieved through modulation of intracellular calcium concentrations by changing the characteristics (amplitude/frequency modulation) or location (spatial modulation) of the signal. Breast cancer utilizes calcium signaling as an advantage for survival and progression. This review integrates evidence showing that increases in expression of calcium channels, GPCRs, pumps, effectors, and enzymes, as well as resulting intracellular calcium signals, lead to high calcium and/or an elevated calcium- mobilizing capacity necessary for malignant functions such as migratory, invasive, proliferative, tumorigenic, or metastatic capacities.
Collapse
Affiliation(s)
- Stephen J P Pratt
- Program in Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD USA.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD USA.,Marlene and Stewart Greenebaum NCI Comprehensive Cancer Center, University of Maryland School of Medicine, 655 W. Baltimore Street, Bressler Research Building, Rm 10-020 D, Baltimore, MD 21201 USA
| | - Erick Hernández-Ochoa
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD USA
| | - Stuart S Martin
- Program in Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD USA.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD USA.,Marlene and Stewart Greenebaum NCI Comprehensive Cancer Center, University of Maryland School of Medicine, 655 W. Baltimore Street, Bressler Research Building, Rm 10-020 D, Baltimore, MD 21201 USA
| |
Collapse
|
6
|
Werley CA, Boccardo S, Rigamonti A, Hansson EM, Cohen AE. Multiplexed Optical Sensors in Arrayed Islands of Cells for multimodal recordings of cellular physiology. Nat Commun 2020; 11:3881. [PMID: 32753572 PMCID: PMC7403318 DOI: 10.1038/s41467-020-17607-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 07/07/2020] [Indexed: 11/29/2022] Open
Abstract
Cells typically respond to chemical or physical perturbations via complex signaling cascades which can simultaneously affect multiple physiological parameters, such as membrane voltage, calcium, pH, and redox potential. Protein-based fluorescent sensors can report many of these parameters, but spectral overlap prevents more than ~4 modalities from being recorded in parallel. Here we introduce the technique, MOSAIC, Multiplexed Optical Sensors in Arrayed Islands of Cells, where patterning of fluorescent sensor-encoding lentiviral vectors with a microarray printer enables parallel recording of multiple modalities. We demonstrate simultaneous recordings from 20 sensors in parallel in human embryonic kidney (HEK293) cells and in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), and we describe responses to metabolic and pharmacological perturbations. Together, these results show that MOSAIC can provide rich multi-modal data on complex physiological responses in multiple cell types.
Collapse
Affiliation(s)
- Christopher A Werley
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
- Q-State Biosciences, Cambridge, MA, 02139, USA
| | - Stefano Boccardo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
- Nobel Biocare AG, Kloten, Switzerland
| | - Alessandra Rigamonti
- Integrated Cardio Metabolic Centre, Department of Medicine Huddinge, Karolinska Institute, Huddinge, Sweden
| | - Emil M Hansson
- Integrated Cardio Metabolic Centre, Department of Medicine Huddinge, Karolinska Institute, Huddinge, Sweden
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Adam E Cohen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA.
| |
Collapse
|
7
|
Abstract
Calcium ion (Ca2+) is a ubiquitous intracellular messenger able to generate versatile intracellular signals that modulate a large variety of functions in virtually every cell type. Chemical and genetic biosensors, targeted to different subcellular compartments, have been developed and continuously improved to monitor Ca2+ dynamics in living cells. Here we describe the usage of Förster resonance energy transfer (FRET)-based Cameleon probes to investigate Ca2+ influx across the plasma membrane (PM) or Ca2+ release from the main intracellular Ca2+ store, the endoplasmic reticulum (ER).
Collapse
|
8
|
High-Throughput Screening Using Photoluminescence Probe to Measure Intracellular Calcium Levels. Methods Mol Biol 2019; 1925:1-14. [PMID: 30674012 DOI: 10.1007/978-1-4939-9018-4_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Aequorin, a 22 kDa protein produced by the jellyfish Aequorea victoria, was the first probe used to measure Ca2+ concentrations ([Ca2+]) of specific intracellular organelles in intact cells. After the binding of Ca2+ to three high-affinity binding sites, an irreversible reaction occurs leading to the emission of photons that is proportional to [Ca2+]. While native aequorin is suitable for measuring cytosolic [Ca2+] after cell stimulation in a range from 0.5 to 10 μM, it cannot be used in organelles where [Ca2+] is much higher, such as in the lumen of endoplasmic/sarcoplasmic reticulum (ER/SR) and mitochondria. However, some modifications made on aequorin itself or on coelenterazine, its lipophilic prosthetic luminophore, and the addition of targeting sequences or the fusion with resident proteins allowed the specific organelle localization and the measurements of intra-organelle Ca2+ levels. In the last years, the development of multiwell plate readers has opened the possibility to perform aequorin-based high-throughput screenings and has overcome some limitation of the standard method. Here we present the procedure for expressing, targeting, and reconstituting aequorin in intact cells and for measuring Ca2+ in the bulk cytosol, mitochondria, and ER by a high-throughput screening system.
Collapse
|
9
|
Maturation and fertilization of echinoderm eggs: Role of actin cytoskeleton dynamics. Biochem Biophys Res Commun 2018; 506:361-371. [DOI: 10.1016/j.bbrc.2018.09.084] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 09/13/2018] [Indexed: 01/31/2023]
|
10
|
Shi S, Li S, Asim M, Mao J, Xu D, Ullah Z, Liu G, Wang Q, Liu H. The Arabidopsis Calcium-Dependent Protein Kinases (CDPKs) and Their Roles in Plant Growth Regulation and Abiotic Stress Responses. Int J Mol Sci 2018; 19:E1900. [PMID: 29958430 PMCID: PMC6073581 DOI: 10.3390/ijms19071900] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 06/21/2018] [Indexed: 02/06/2023] Open
Abstract
As a ubiquitous secondary messenger in plant signaling systems, calcium ions (Ca2+) play essential roles in plant growth and development. Within the cellular signaling network, the accurate decoding of diverse Ca2+ signal is a fundamental molecular event. Calcium-dependent protein kinases (CDPKs), identified commonly in plants, are a kind of vital regulatory protein deciphering calcium signals triggered by various developmental and environmental stimuli. This review chiefly introduces Ca2+ distribution in plant cells, the classification of Arabidopsis thaliana CDPKs (AtCDPKs), the identification of the Ca2+-AtCDPK signal transduction mechanism and AtCDPKs’ functions involved in plant growth regulation and abiotic stress responses. The review presents a comprehensive overview of AtCDPKs and may contribute to the research of CDPKs in other plants.
Collapse
Affiliation(s)
- Sujuan Shi
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Shugui Li
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
- College of Agriculture, Qingdao Agricultural University, Qingdao 266109, China.
| | - Muhammad Asim
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Jingjing Mao
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Dizhi Xu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Zia Ullah
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Guanshan Liu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Qian Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Haobao Liu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| |
Collapse
|
11
|
Murata A, Itoh Y, Mano E, Kanbayashi S, Igarashi C, Takahashi H, Takahashi S, Kamagata K. One-Dimensional Search Dynamics of Tumor Suppressor p53 Regulated by a Disordered C-Terminal Domain. Biophys J 2017; 112:2301-2314. [PMID: 28591603 DOI: 10.1016/j.bpj.2017.04.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 04/06/2017] [Accepted: 04/25/2017] [Indexed: 11/15/2022] Open
Abstract
Tumor suppressor p53 slides along DNA and finds its target sequence in drastically different and changing cellular conditions. To elucidate how p53 maintains efficient target search at different concentrations of divalent cations such as Ca2+ and Mg2+, we prepared two mutants of p53, each possessing one of its two DNA-binding domains, the CoreTet mutant having the structured core domain plus the tetramerization (Tet) domain, and the TetCT mutant having Tet plus the disordered C-terminal domain. We investigated their equilibrium and kinetic dissociation from DNA and search dynamics along DNA at various [Mg2+]. Although binding of CoreTet to DNA becomes markedly weaker at higher [Mg2+], binding of TetCT depends slightly on [Mg2+]. Single-molecule fluorescence measurements revealed that the one-dimensional diffusion of CoreTet along DNA consists of fast and slow search modes, the ratio of which depends strongly on [Mg2+]. In contrast, diffusion of TetCT consisted of only the fast mode. The disordered C-terminal domain can associate with DNA irrespective of [Mg2+], and can maintain an equilibrium balance of the two search modes and the p53 search distance. These results suggest that p53 modulates the quaternary structure of the complex between p53 and DNA under different [Mg2+] and that it maintains the target search along DNA.
Collapse
Affiliation(s)
- Agato Murata
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
| | - Yuji Itoh
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
| | - Eriko Mano
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
| | - Saori Kanbayashi
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
| | - Chihiro Igarashi
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
| | - Hiroto Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
| | - Satoshi Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan.
| | - Kiyoto Kamagata
- Institute of Multidisciplinary Research for Advanced Materials, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan.
| |
Collapse
|
12
|
Je HJ, Kim MG, Kwon HJ. Bioluminescence Assays for Monitoring Chondrogenic Differentiation and Cartilage Regeneration. SENSORS 2017; 17:s17061306. [PMID: 28587284 PMCID: PMC5492100 DOI: 10.3390/s17061306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 05/24/2017] [Accepted: 06/02/2017] [Indexed: 02/06/2023]
Abstract
Since articular cartilage has a limited regeneration potential, for developing biological therapies for cartilage regeneration it is important to study the mechanisms underlying chondrogenesis of stem cells. Bioluminescence assays can visualize a wide range of biological phenomena such as gene expression, signaling, metabolism, development, cellular movements, and molecular interactions by using visible light and thus contribute substantially to elucidation of their biological functions. This article gives a concise review to introduce basic principles of bioluminescence assays and applications of the technology to visualize the processes of chondrogenesis and cartilage regeneration. Applications of bioluminescence assays have been highlighted in the methods of real-time monitoring of gene expression and intracellular levels of biomolecules and noninvasive cell tracking within animal models. This review suggests that bioluminescence assays can be applied towards a visual understanding of chondrogenesis and cartilage regeneration.
Collapse
Affiliation(s)
- Hyeon Jeong Je
- Department of Physical Therapy and Rehabilitation Science, College of Health Science, Eulji University, Gyeonggi 13135, Korea.
| | - Min Gu Kim
- Department of Physical Therapy and Rehabilitation Science, College of Health Science, Eulji University, Gyeonggi 13135, Korea.
| | - Hyuck Joon Kwon
- Department of Physical Therapy and Rehabilitation Science, College of Health Science, Eulji University, Gyeonggi 13135, Korea.
| |
Collapse
|
13
|
Alonso MT, Rodríguez-Prados M, Navas-Navarro P, Rojo-Ruiz J, García-Sancho J. Using aequorin probes to measure Ca 2+ in intracellular organelles. Cell Calcium 2017; 64:3-11. [PMID: 28214023 DOI: 10.1016/j.ceca.2017.01.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 01/11/2017] [Indexed: 11/28/2022]
Abstract
Aequorins are excellent tools for measuring intra-organellar Ca2+ and assessing its role in physiological and pathological functions. Here we review targeting strategies to express aequorins in various organelles. We address critical topics such as probe affinity tuning as well as normalization and calibration of the signal. We also focus on bioluminescent Ca2+ imaging in nucleus or mitochondria of living cells. Finally, recent advances with a new chimeric GFP-aequorin protein (GAP), which can be used either as luminescent or fluorescent Ca2+ probe, are presented. GAP is robustly expressed in transgenic flies and mice, where it has proven to be a suitable Ca2+ indicator for monitoring physiological Ca2+ signaling ex vivo and in vivo.
Collapse
Affiliation(s)
- María Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain.
| | - Macarena Rodríguez-Prados
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
| | - Paloma Navas-Navarro
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
| | - Jonathan Rojo-Ruiz
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
| | - Javier García-Sancho
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain.
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Martins TV, Evans MJ, Wysham DB, Morris RJ. Nuclear pores enable sustained perinuclear calcium oscillations. BMC SYSTEMS BIOLOGY 2016; 10:55. [PMID: 27449670 PMCID: PMC4957432 DOI: 10.1186/s12918-016-0289-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 06/14/2016] [Indexed: 11/16/2022]
Abstract
Background Calcium signalling relies on the flux of calcium ions across membranes yet how signals in different compartments are related remains unclear. In particular, similar calcium signals on both sides of the nuclear envelope have been reported and attributed to passive diffusion through nuclear pores. However, observed differing cytosolic and nucleosolic calcium signatures suggest that the signalling machinery in these compartments can act independently. Results We adapt the fire-diffuse-fire model to investigate the generation of perinuclear calcium oscillations. We demonstrate that autonomous spatio-temporal calcium patterns are still possible in the presence of nuclear and cytosolic coupling via nuclear pores. The presence or absence of this autonomy is dependent upon the strength of the coupling and the maximum firing rate of an individual calcium channel. In all cases, coupling through the nuclear pores enables robust signalling with respect to changes in the diffusion constant. Conclusions We show that contradictory interpretations of experimental data with respect to the autonomy of nuclear calcium oscillations can be reconciled within one model, with different observations being a consequence of varying nuclear pore permeabilities for calcium and refractory conditions of channels. Furthermore, our results provide an explanation for why calcium oscillations on both sides of the nuclear envelope may be beneficial for sustained perinuclear signaling. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0289-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Teresa Vaz Martins
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK.
| | - Matthew J Evans
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK
| | - Derin B Wysham
- Mathematics Department, Wenatchee Valley College, Wenatchee, USA
| | - Richard J Morris
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK
| |
Collapse
|
16
|
Abstract
The hypothalamic suprachiasmatic nucleus (SCN) has a pivotal role in the mammalian circadian clock. SCN neurons generate circadian rhythms in action potential firing frequencies and neurotransmitter release, and the core oscillation is thought to be driven by “clock gene” transcription-translation feedback loops. Cytosolic Ca2+mobilization followed by stimulation of various receptors has been shown to reset the gene transcription cycles in SCN neurons, whereas contribution of steady-state cytosolic Ca2+levels to the rhythm generation is unclear. Recently, circadian rhythms in cytosolic Ca2+levels have been demonstrated in cultured SCN neurons. The circadian Ca2+rhythms are driven by the release of Ca2+from ryanodine-sensitive internal stores and resistant to the blockade of action potentials. These results raise the possibility that gene translation/transcription loops may interact with autonomous Ca2+oscillations in the production of circadian rhythms in SCN neurons.
Collapse
Affiliation(s)
- Masayuki Ikeda
- Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Suita, Osaka, Japan.
| |
Collapse
|
17
|
Lim D, Bertoli A, Sorgato M, Moccia F. Generation and usage of aequorin lentiviral vectors for Ca2+ measurement in sub-cellular compartments of hard-to-transfect cells. Cell Calcium 2016; 59:228-39. [DOI: 10.1016/j.ceca.2016.03.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/01/2016] [Indexed: 12/18/2022]
|
18
|
Abstract
Calcium (Ca) is a universal second messenger involved in the regulation of various cellular processes, including electrical signaling, contraction, secretion, memory, gene transcription, and cell death. In heart, Ca governs cardiomyocyte contraction, is central in electrophysiological properties, and controls major signaling pathway implicated in gene transcription. How cardiomyocytes decode Ca signal to regulate gene expression without interfering with, or being controlled by, "contractile" Ca that floods the entire cytosol during each heartbeat is still elusive. In this review, we summarize recent findings on nuclear Ca regulation and its downstream signaling in cardiomyocytes. We will address difficulties in reliable quantification of nuclear Ca fluxes and discuss its role in the development and progression of cardiac hypertrophy and heart failure. We also point out key open questions to stimulate future work.
Collapse
|
19
|
Nasipak BT, Padilla-Benavides T, Green KM, Leszyk JD, Mao W, Konda S, Sif S, Shaffer SA, Ohkawa Y, Imbalzano AN. Opposing calcium-dependent signalling pathways control skeletal muscle differentiation by regulating a chromatin remodelling enzyme. Nat Commun 2015; 6:7441. [PMID: 26081415 PMCID: PMC4530624 DOI: 10.1038/ncomms8441] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 05/06/2015] [Indexed: 01/03/2023] Open
Abstract
Calcium signaling is important for differentiation-dependent gene expression, but is also involved in other cellular functions. Therefore mechanisms must exist to distinguish calcium signaling relevant to differentiation. Calcineurin is a calcium-regulated phosphatase that is required for myogenic gene expression and skeletal muscle differentiation. Here, we demonstrate that inhibition of calcineurin blocks chromatin remodeling and that the Brg1 ATPase of the SWI/SNF chromatin remodeling enzyme, which is required for the activation of myogenic gene expression, is a calcineurin substrate. Furthermore, we identify the calcium-regulated classical protein kinase C beta (PKCβ) as a repressor of myogenesis and as the enzyme that opposes calcineurin function. Replacement of endogenous Brg1 with a phosphomimetic mutant in primary myoblasts inhibits myogenesis, while replacement with a non-phosphorylatable mutant allows myogenesis despite inhibition of calcineurin signaling, demonstrating the functionality of calcineurin/PKC modified residues. Thus the Brg1 chromatin remodeling enzyme integrates two antagonistic calcium-dependent signaling pathways that control myogenic differentiation.
Collapse
Affiliation(s)
- Brian T Nasipak
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Teresita Padilla-Benavides
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Karin M Green
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - John D Leszyk
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Wenjie Mao
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Silvana Konda
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Saïd Sif
- Department of Internal Medicine, College of Medicine, Ohio State University, Columbus, Ohio 43210, USA.,Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, PO Box 2713, Doha, Qatar
| | - Scott A Shaffer
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Yasuyuki Ohkawa
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA.,Department Advanced Medical Initiatives, JST-CREST, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi Fukuoka 812-8582, Japan
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| |
Collapse
|
20
|
Oliveira AG, Guimarães ES, Andrade LM, Menezes GB, Fatima Leite M. Decoding calcium signaling across the nucleus. Physiology (Bethesda) 2015; 29:361-8. [PMID: 25180265 DOI: 10.1152/physiol.00056.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Calcium (Ca(2+)) is an important multifaceted second messenger that regulates a wide range of cellular events. A Ca(2+)-signaling toolkit has been shown to exist in the nucleus and to be capable of generating and modulating nucleoplasmic Ca(2+) transients. Within the nucleus, Ca(2+) controls cellular events that are different from those modulated by cytosolic Ca(2+). This review focuses on nuclear Ca(2+) signals and their role in regulating physiological and pathological processes.
Collapse
Affiliation(s)
- André G Oliveira
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Erika S Guimarães
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil; Molecular Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil; and
| | - Lídia M Andrade
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Gustavo B Menezes
- Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - M Fatima Leite
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil;
| |
Collapse
|
21
|
Ottolini D, Calì T, Brini M. Methods to measure intracellular Ca(2+) fluxes with organelle-targeted aequorin-based probes. Methods Enzymol 2015; 543:21-45. [PMID: 24924126 DOI: 10.1016/b978-0-12-801329-8.00002-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The photoprotein aequorin generates blue light upon binding of Ca(2+) ions. Together with its very low Ca(2+)-buffering capacity and the possibility to add specific targeting sequences, this property has rendered aequorin particularly suitable to monitor Ca(2+) concentrations in specific subcellular compartments. Recently, a new generation of genetically encoded Ca(2+) probes has been developed by fusing Ca(2+)-responsive elements with the green fluorescent protein (GFP). Aequorin has also been employed to this aim, resulting in an aequorin-GFP chimera with the Ca(2+) sensitivity of aequorin and the fluorescent properties of GFP. This setup has actually solved the major limitation of aequorin, for example, its poor ability to emit light, which rendered it inappropriate for the monitoring of Ca(2+) waves at the single-cell level by imaging. In spite of the numerous genetically encoded Ca(2+) indicators that are currently available, aequorin-based probes remain the method of election when an accurate quantification of Ca(2+) levels is required. Here, we describe currently available aequorin variants and their use for monitoring Ca(2+) waves in specific subcellular compartments. Among various applications, this method is relevant for the study of the alterations of Ca(2+) homeostasis that accompany oncogenesis, tumor progression, and response to therapy.
Collapse
Affiliation(s)
- Denis Ottolini
- Department of Biology, University of Padova, Padova, Italy
| | - Tito Calì
- Department of Biology, University of Padova, Padova, Italy
| | - Marisa Brini
- Department of Biology, University of Padova, Padova, Italy.
| |
Collapse
|
22
|
GAP, an aequorin-based fluorescent indicator for imaging Ca2+ in organelles. Proc Natl Acad Sci U S A 2014; 111:2584-9. [PMID: 24501126 DOI: 10.1073/pnas.1316539111] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Genetically encoded calcium indicators allow monitoring subcellular Ca(2+) signals inside organelles. Most genetically encoded calcium indicators are fusions of endogenous calcium-binding proteins whose functionality in vivo may be perturbed by competition with cellular partners. We describe here a novel family of fluorescent Ca(2+) sensors based on the fusion of two Aequorea victoria proteins, GFP and apo-aequorin (GAP). GAP exhibited a unique combination of features: dual-excitation ratiometric imaging, high dynamic range, good signal-to-noise ratio, insensitivity to pH and Mg(2+), tunable Ca(2+) affinity, uncomplicated calibration, and targetability to five distinct organelles. Moreover, transgenic mice for endoplasmic reticulum-targeted GAP exhibited a robust long-term expression that correlated well with its reproducible performance in various neural tissues. This biosensor fills a gap in the actual repertoire of Ca(2+) indicators for organelles and becomes a valuable tool for in vivo Ca(2+) imaging applications.
Collapse
|
23
|
Granatiero V, Patron M, Tosatto A, Merli G, Rizzuto R. Using targeted variants of aequorin to measure Ca2+ levels in intracellular organelles. Cold Spring Harb Protoc 2014; 2014:86-93. [PMID: 24371314 DOI: 10.1101/pdb.prot072843] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Aequorin is a Ca(2+)-sensitive photoprotein isolated from the jellyfish Aequorea victoria. It is an ideal probe for measuring Ca(2+) concentration ([Ca(2+)]) in intracellular organelles because it can be modified to include specific targeting sequences. On the binding of Ca(2+) to three high-affinity sites in aequorin, an irreversible reaction occurs in which the prosthetic group coelenterazine is released and a photon is emitted. This protocol presents procedures for expressing, targeting, and reconstituting aequorin in intact and permeabilized mammalian cells and describes how to use this photoprotein to measure intracellular [Ca(2+)] in various subcellular compartments.
Collapse
Affiliation(s)
- Veronica Granatiero
- Department of Biomedical Sciences, University of Padua and CNR Neuroscience Institute, 35131 Padua, Italy
| | | | | | | | | |
Collapse
|
24
|
Granatiero V, Patron M, Tosatto A, Merli G, Rizzuto R. The use of aequorin and its variants for Ca2+ measurements. Cold Spring Harb Protoc 2014; 2014:9-16. [PMID: 24371311 DOI: 10.1101/pdb.top066118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Ca(2+)-sensitive photoproteins are ideal agents for measuring the Ca(2+) concentration ([Ca(2+)]) in intracellular organelles because they can be modified to include specific targeting sequences. Aequorin was the first Ca(2+)-sensitive photoprotein probe used to measure the [Ca(2+)] inside specific intracellular organelles in intact cells. Aequorin is a 22-kDa protein produced by the jellyfish Aequorea victoria. On the binding of Ca(2+) to three high-affinity sites in aequorin, an irreversible reaction occurs in which the prosthetic group is released and a photon is emitted. Aequorin has become widely used for intracellular Ca(2+) measurements because it offers many advantages: For example, it can be targeted with precision, functions over a wide range of [Ca(2+)], and shows low buffering capacity. In this article we describe the main characteristics of the aequorin probe and review the reasons why it is widely used to measure intracellular [Ca(2+)].
Collapse
Affiliation(s)
- Veronica Granatiero
- Department of Biomedical Sciences, University of Padua and CNR Neuroscience Institute, 35131 Padua, Italy
| | | | | | | | | |
Collapse
|
25
|
Abstract
Intracellular free Ca(2+) ([Ca(2+)]i) is a highly versatile second messenger that regulates a wide range of functions in every type of cell and tissue. To achieve this versatility, the Ca(2+) signaling system operates in a variety of ways to regulate cellular processes that function over a wide dynamic range. This is particularly well exemplified for Ca(2+) signals in the liver, which modulate diverse and specialized functions such as bile secretion, glucose metabolism, cell proliferation, and apoptosis. These Ca(2+) signals are organized to control distinct cellular processes through tight spatial and temporal coordination of [Ca(2+)]i signals, both within and between cells. This article will review the machinery responsible for the formation of Ca(2+) signals in the liver, the types of subcellular, cellular, and intercellular signals that occur, the physiological role of Ca(2+) signaling in the liver, and the role of Ca(2+) signaling in liver disease.
Collapse
Affiliation(s)
- Maria Jimena Amaya
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | | |
Collapse
|
26
|
Subcellular calcium measurements in mammalian cells using jellyfish photoprotein aequorin-based probes. Nat Protoc 2013; 8:2105-18. [DOI: 10.1038/nprot.2013.127] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
27
|
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.
Collapse
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
| |
Collapse
|
28
|
Resende RR, Andrade LM, Oliveira AG, Guimarães ES, Guatimosim S, Leite MF. Nucleoplasmic calcium signaling and cell proliferation: calcium signaling in the nucleus. Cell Commun Signal 2013; 11:14. [PMID: 23433362 PMCID: PMC3599436 DOI: 10.1186/1478-811x-11-14] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 02/12/2013] [Indexed: 01/19/2023] Open
Abstract
Calcium (Ca2+) is an essential signal transduction element involved in the regulation of several cellular activities and it is required at various key stages of the cell cycle. Intracellular Ca2+ is crucial for the orderly cell cycle progression and plays a vital role in the regulation of cell proliferation. Recently, it was demonstrated by in vitro and in vivo studies that nucleoplasmic Ca2+ regulates cell growth. Even though the mechanism by which nuclear Ca2+ regulates cell proliferation is not completely understood, there are reports demonstrating that activation of tyrosine kinase receptors (RTKs) leads to translocation of RTKs to the nucleus to generate localized nuclear Ca2+ signaling which are believed to modulate cell proliferation. Moreover, nuclear Ca2+ regulates the expression of genes involved in cell growth. This review will describe the nuclear Ca2+ signaling machinery and its role in cell proliferation. Additionally, the potential role of nuclear Ca2+ as a target in cancer therapy will be discussed.
Collapse
Affiliation(s)
- Rodrigo R Resende
- Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
| | | | | | | | | | | |
Collapse
|
29
|
|
30
|
Nanodomain Ca²⁺ of Ca²⁺ channels detected by a tethered genetically encoded Ca²⁺ sensor. Nat Commun 2012; 3:778. [PMID: 22491326 PMCID: PMC3615648 DOI: 10.1038/ncomms1777] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 03/07/2012] [Indexed: 12/29/2022] Open
Abstract
Coupling of excitation to secretion, contraction and transcription often relies on Ca(2+) computations within the nanodomain-a conceptual region extending tens of nanometers from the cytoplasmic mouth of Ca(2+) channels. Theory predicts that nanodomain Ca(2+) signals differ vastly from the slow submicromolar signals routinely observed in bulk cytoplasm. However, direct visualization of nanodomain Ca(2+) far exceeds optical resolution of spatially distributed Ca(2+) indicators. Here we couple an optical, genetically encoded Ca(2+) indicator (TN-XL) to the carboxy tail of Ca(V)2.2 Ca(2+) channels, enabling near-field imaging of the nanodomain. Under total internal reflection fluorescence microscopy, we detect Ca(2+) responses indicative of large-amplitude pulses. Single-channel electrophysiology reveals a corresponding Ca(2+) influx of only 0.085 pA, and fluorescence resonance energy transfer measurements estimate TN-XL distance to the cytoplasmic mouth at ~55 Å. Altogether, these findings raise the possibility that Ca(2+) exits the channel through the analogue of molecular portals, mirroring the crystallographic images of side windows in voltage-gated K channels.
Collapse
|
31
|
Zampese E, Pizzo P. Intracellular organelles in the saga of Ca2+ homeostasis: different molecules for different purposes? Cell Mol Life Sci 2012; 69:1077-104. [PMID: 21968921 PMCID: PMC11114864 DOI: 10.1007/s00018-011-0845-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/15/2011] [Accepted: 09/19/2011] [Indexed: 11/28/2022]
Abstract
An increase in the concentration of cytosolic free Ca(2+) is a key component regulating different cellular processes ranging from egg fertilization, active secretion and movement, to cell differentiation and death. The multitude of phenomena modulated by Ca(2+), however, do not simply rely on increases/decreases in its concentration, but also on specific timing, shape and sub-cellular localization of its signals that, combined together, provide a huge versatility in Ca(2+) signaling. Intracellular organelles and their Ca(2+) handling machineries exert key roles in this complex and precise mechanism, and this review will try to depict a map of Ca(2+) routes inside cells, highlighting the uniqueness of the different Ca(2+) toolkit components and the complexity of the interactions between them.
Collapse
Affiliation(s)
- Enrico Zampese
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
| |
Collapse
|
32
|
Stael S, Wurzinger B, Mair A, Mehlmer N, Vothknecht UC, Teige M. Plant organellar calcium signalling: an emerging field. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1525-42. [PMID: 22200666 PMCID: PMC3966264 DOI: 10.1093/jxb/err394] [Citation(s) in RCA: 207] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
This review provides a comprehensive overview of the established and emerging roles that organelles play in calcium signalling. The function of calcium as a secondary messenger in signal transduction networks is well documented in all eukaryotic organisms, but so far existing reviews have hardly addressed the role of organelles in calcium signalling, except for the nucleus. Therefore, a brief overview on the main calcium stores in plants-the vacuole, the endoplasmic reticulum, and the apoplast-is provided and knowledge on the regulation of calcium concentrations in different cellular compartments is summarized. The main focus of the review will be the calcium handling properties of chloroplasts, mitochondria, and peroxisomes. Recently, it became clear that these organelles not only undergo calcium regulation themselves, but are able to influence the Ca(2+) signalling pathways of the cytoplasm and the entire cell. Furthermore, the relevance of recent discoveries in the animal field for the regulation of organellar calcium signals will be discussed and conclusions will be drawn regarding potential homologous mechanisms in plant cells. Finally, a short overview on bacterial calcium signalling is included to provide some ideas on the question where this typically eukaryotic signalling mechanism could have originated from during evolution.
Collapse
Affiliation(s)
- Simon Stael
- Department of Biochemistry and Cell Biology, MFPL, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Bernhard Wurzinger
- Department of Biochemistry and Cell Biology, MFPL, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Andrea Mair
- Department of Biochemistry and Cell Biology, MFPL, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Norbert Mehlmer
- Department of Biology I, Botany, LMU Munich, Großhaderner Str. 2, D-82152 Planegg-Martinsried, Germany
| | - Ute C. Vothknecht
- Department of Biology I, Botany, LMU Munich, Großhaderner Str. 2, D-82152 Planegg-Martinsried, Germany
- Center for Integrated Protein Science (Munich) at the Department of Biology of the LMU Munich, D-81377 Munich, Germany
| | - Markus Teige
- Department of Biochemistry and Cell Biology, MFPL, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
- To whom correspondence should be addressed.
| |
Collapse
|
33
|
|
34
|
Mazars C, Brière C, Bourque S, Thuleau P. Nuclear calcium signaling: an emerging topic in plants. Biochimie 2011; 93:2068-74. [PMID: 21683118 DOI: 10.1016/j.biochi.2011.05.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 05/31/2011] [Indexed: 01/02/2023]
Abstract
The calcium ion is probably one of the most studied second messenger both in plant and animal fields. A large number of reviews have browsed the diversity of cytosolic calcium signatures and evaluated their pleiotropic roles in plant and animal cells. In the recent years, an increasing number of reviews has focused on nuclear calcium, especially on the possible roles of nuclear calcium concentration variations on nuclear activities. Experiments initially performed on animal cells gave conflicting results that brought about a controversy about the ability of the nucleus to generate its own calcium signals and to regulate its calcium level. But in plant cells, several converging scientific pieces of evidence support the hypothesis of nucleus autonomy. The present review briefly summarizes data supporting this hypothesis and tries to put forward some possible roles for these nucleus-generated calcium signals in controlling nuclear activity.
Collapse
Affiliation(s)
- Christian Mazars
- Université de Toulouse, Université Paul Sabatier, Laboratoire de Recherche en Sciences végétales, Castanet-Tolosan, France.
| | | | | | | |
Collapse
|
35
|
Bengtson CP, Freitag HE, Weislogel JM, Bading H. Nuclear calcium sensors reveal that repetition of trains of synaptic stimuli boosts nuclear calcium signaling in CA1 pyramidal neurons. Biophys J 2011; 99:4066-77. [PMID: 21156150 DOI: 10.1016/j.bpj.2010.10.044] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 10/13/2010] [Accepted: 10/22/2010] [Indexed: 10/18/2022] Open
Abstract
Nuclear calcium is a key signal in the dialogue between synapse and nucleus that controls the genomic responses required for persistent adaptations, including memory and acquired neuroprotection. The amplitude and duration of nuclear calcium transients specify activity-induced transcriptional changes. However, the precise relationship between synaptic input and nuclear calcium output is unknown. Here, we used stereotaxic delivery to the rat brain of recombinant adeno-associated viruses encoding nuclear-targeted calcium sensors to assess nuclear calcium transients in CA1 pyramidal neurons after stimulation of the Schaffer collaterals. We show that in acute hippocampal slices, a burst of synaptic activity elicits a nuclear calcium signal with a regenerative component at above-threshold stimulation intensities. Using classical stimulation paradigms (i.e., high-frequency stimulation (HFS) and θ burst stimulation (TBS)) to induce early LTP (E-LTP) and transcription-dependent late LTP (L-LTP), we found that the magnitude of nuclear calcium signals and the number of action potentials activated by synaptic stimulation trains are greatly amplified by their repetition. Nuclear calcium signals and action potential generation were reduced by blockade of either NMDA receptors or L-type voltage-gated calcium channels, but not by procedures that lead to internal calcium store depletion or by blockade of metabotropic glutamate receptors. These findings identify a repetition-induced switch in nuclear calcium signaling that correlates with the transition from E-LTP to L-LTP, and may explain why the transcription-dependent phase of L-LTP is not induced by a single HFS or TBS but requires repeated trains of activity. Recombinant, nuclear-targeted indicators may prove useful for further analysis of nuclear calcium signaling in vivo.
Collapse
Affiliation(s)
- C Peter Bengtson
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
| | | | | | | |
Collapse
|
36
|
Alonso MT, García-Sancho J. Nuclear Ca(2+) signalling. Cell Calcium 2010; 49:280-9. [PMID: 21146212 DOI: 10.1016/j.ceca.2010.11.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 10/30/2010] [Accepted: 11/08/2010] [Indexed: 10/18/2022]
Abstract
Ca(2+) signalling is important for controlling gene transcription. Changes of the cytosolic Ca(2+) ([Ca(2+)](C)) may promote migration of transcription factors or transcriptional regulators to the nucleus. Changes of the nucleoplasmic Ca(2+) ([Ca(2+)](N)) can also regulate directly gene expression. [Ca(2+)](N) may change by propagation of [Ca(2+)](C) changes through the nuclear envelope or by direct release of Ca(2+) inside the nucleus. In the last case nuclear and cytosolic signalling can be dissociated. Phosphatidylinositol bisphosphate, phospholipase C and cyclic ADP-ribosyl cyclase are present inside the nucleus. Inositol trisphosphate receptors (IP(3)R) and ryanodine receptors (RyR) have also been found in the nucleus and can be activated by agonists. Furthermore, nuclear location of the synthesizing enzymes and receptors may be atypical, not associated to the nuclear envelope or other membranes. The possible role of nuclear subdomains such as speckles, nucleoplasmic reticulum, multi-macromolecular complexes and nuclear nanovesicles is discussed.
Collapse
Affiliation(s)
- Maria Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
| | | |
Collapse
|
37
|
Salozhin SV, Bol'shakov AP. Transfection of nerve cells. NEUROSCIENCE AND BEHAVIORAL PHYSIOLOGY 2010; 40:269-77. [PMID: 20146014 DOI: 10.1007/s11055-010-9254-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Accepted: 06/09/2008] [Indexed: 11/29/2022]
Abstract
Transfection is a method of transforming cells based on the introduction into living cells of plasmids encoding a particular protein or RNA. This review describes the main methods of transfection and considers their advantages and disadvantages. Most attention is paid to lentivirus transduction as one of the most efficient methods for transforming nerve cells. The development of current transfection systems based on lentivirus vectors is described and a brief review of studies performed using in vivo and in vitro lentivirus transfection of nerve cells is presented.
Collapse
Affiliation(s)
- S V Salozhin
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
| | | |
Collapse
|
38
|
Webb SE, Rogers KL, Karplus E, Miller AL. The use of aequorins to record and visualize Ca(2+) dynamics: from subcellular microdomains to whole organisms. Methods Cell Biol 2010; 99:263-300. [PMID: 21035690 DOI: 10.1016/b978-0-12-374841-6.00010-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this chapter, we describe the practical aspects of measuring [Ca(2+)] transients that are generated in a particular cytoplasmic domain, or within a specific organelle or its periorganellar environment, using bioluminescent, genetically encoded and targeted Ca(2+) reporters, especially those based on apoaequorin. We also list examples of the organisms, tissues, and cells that have been transfected with apoaequorin or an apoaequorin-BRET complex, as well as of the organelles and subcellular domains that have been specifically targeted with these bioluminescent Ca(2+) reporters. In addition, we summarize the various techniques used to load the apoaequorin cofactor, coelenterazine, and its analogs into cells, tissues, and intact organisms, and we describe recent advances in the detection and imaging technologies that are currently being used to measure and visualize the luminescence generated by the aequorin-Ca(2+) reaction within these various cytoplasmic domains and subcellular compartments.
Collapse
Affiliation(s)
- Sarah E Webb
- Biochemistry and Cell Biology Section and State Key Laboratory of Molecular Neuroscience, Division of Life Science, HKUST, Clear Water Bay, Kowloon, Hong Kong, PR China
| | | | | | | |
Collapse
|
39
|
Bootman MD, Fearnley C, Smyrnias I, MacDonald F, Roderick HL. An update on nuclear calcium signalling. J Cell Sci 2009; 122:2337-50. [PMID: 19571113 DOI: 10.1242/jcs.028100] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Over the past 15 years or so, numerous studies have sought to characterise how nuclear calcium (Ca2+) signals are generated and reversed, and to understand how events that occur in the nucleoplasm influence cellular Ca2+ activity, and vice versa. In this Commentary, we describe mechanisms of nuclear Ca2+ signalling and discuss what is known about the origin and physiological significance of nuclear Ca2+ transients. In particular, we focus on the idea that the nucleus has an autonomous Ca2+ signalling system that can generate its own Ca2+ transients that modulate processes such as gene transcription. We also discuss the role of nuclear pores and the nuclear envelope in controlling ion flux into the nucleoplasm.
Collapse
Affiliation(s)
- Martin D Bootman
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham, Cambridge CB22 3AT, UK.
| | | | | | | | | |
Collapse
|
40
|
Eglen RM, Reisine T. Photoproteins: important new tools in drug discovery. Assay Drug Dev Technol 2009; 6:659-71. [PMID: 19035847 DOI: 10.1089/adt.2008.160] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The G protein-coupled receptor (GPCR) family is a major target for drug discovery, and most, if not all, GPCRs can couple to Ca2+ signaling. Consequently, there are a number of cellbased, primary, high-throughput screening (HTS) assays used for drug discovery that assess changes in intracellular Ca2+ as a functional readout of GPCR activation. Historically, changes in intracellular Ca2+ levels have been readily detected using fluorescent dyes that emit light in proportion to changes in intracellular Ca2+ concentration. An alternative approach to indirectly measure changes in Ca2+ concentrations involves the use of recombinantly expressed biosensor photoproteins, of which aequorin is a prototypic example. These biosensors have the advantage that they provide an intense luminescent signal in response to elevations in intracellular Ca2+. This exquisite sensitivity, the high signal-to-noise ratios, and the ability to target expression to discrete subcellular sites (in order to detect Ca2+ microdomains) have made photoproteins a principal choice in a wide range of GPCR drug discovery programs. Photoproteins are also finding increasing use in detecting activation of other molecular target classes such as ligand-gated ion channels and transporters. This review focuses upon the use of calcium photoproteins principally for use in GPCR drug discovery and HTS.
Collapse
Affiliation(s)
- Richard M Eglen
- Bio-discovery, PerkinElmer Life and Analytical Sciences, Waltham, MA 02451, USA.
| | | |
Collapse
|
41
|
Ribonucleotide reduction is a cytosolic process in mammalian cells independently of DNA damage. Proc Natl Acad Sci U S A 2008; 105:17801-6. [PMID: 18997010 DOI: 10.1073/pnas.0808198105] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Ribonucleotide reductase provides deoxynucleotides for nuclear and mitochondrial (mt) DNA replication and repair. The mammalian enzyme consists of a catalytic (R1) and a radical-generating (R2 or p53R2) subunit. During S-phase, a R1/R2 complex is the major provider of deoxynucleotides. p53R2 is induced by p53 after DNA damage and was proposed to supply deoxynucleotides for DNA repair after translocating from the cytosol to the cell nucleus. Similarly R1 and R2 were claimed to move to the nucleus during S-phase to provide deoxynucleotides for DNA replication. These models suggest translocation of ribonucleotide reductase subunits as a regulatory mechanism. In quiescent cells that are devoid of R2, R1/p53R2 synthesizes deoxynucleotides also in the absence of DNA damage. Mutations in human p53R2 cause severe mitochondrial DNA depletion demonstrating a vital function for p53R2 different from DNA repair and cast doubt on a nuclear localization of the protein. Here we use three independent methods to localize R1, R2, and p53R2 in fibroblasts during cell proliferation and after DNA damage: Western blotting after separation of cytosol and nuclei; immunofluorescence in intact cells; and transfection with proteins carrying fluorescent tags. We thoroughly validate each method, especially the specificity of antibodies. We find in all cases that ribonucleotide reductase resides in the cytosol suggesting that the deoxynucleotides produced by the enzyme diffuse into the nucleus or are transported into mitochondria and supporting a primary function of p53R2 for mitochondrial DNA replication.
Collapse
|
42
|
Brini M. Calcium-sensitive photoproteins. Methods 2008; 46:160-6. [DOI: 10.1016/j.ymeth.2008.09.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 09/12/2008] [Indexed: 12/28/2022] Open
|
43
|
Rimessi A, Giorgi C, Pinton P, Rizzuto R. The versatility of mitochondrial calcium signals: from stimulation of cell metabolism to induction of cell death. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:808-16. [PMID: 18573473 DOI: 10.1016/j.bbabio.2008.05.449] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 05/22/2008] [Accepted: 05/23/2008] [Indexed: 10/21/2022]
Abstract
Both the contribution of mitochondria to intracellular calcium (Ca(2+)) signalling and the role of mitochondrial Ca(2+) uptake in shaping the cytoplasmic response and controlling mitochondrial function are areas of intense investigation. These studies rely on the appropriate use of emerging techniques coupled with judicious data interpretation to a large extent. The development of targeted probes based on the molecular engineering of luminescent proteins has allowed the specific measurement of Ca(2+) concentration ([Ca(2+)]) and adenosine trisphosphate concentration ([ATP]) in intracellular organelles or cytoplasmic subdomains. This approach has given novel information on different aspects of mitochondrial homeostasis.
Collapse
Affiliation(s)
- Alessandro Rimessi
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation and Emilia Romagna Laboratory BioPharmaNet, University of Ferrara, Ferrara, Italy
| | | | | | | |
Collapse
|
44
|
Pozzan T, Rizzuto R. Imaging calcium dynamics using targeted recombinant aequorins. Cold Spring Harb Protoc 2008; 2008:pdb.top26. [PMID: 21356897 DOI: 10.1101/pdb.top26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
INTRODUCTIONAequorin is a small protein produced by the genus Aequorea that was widely used in the 1960s and 1970s as a probe to measure Ca(2+) in living cells. The invention of the carboxylate Ca(2+) indicators, which are much simpler to load into intact living cells and to calibrate and image at the single-cell level, has led most groups to abandon aequorin. Yet, this latter Ca(2+) indicator still offers some advantages over the fluorescent probes. In particular, the use of molecular biological techniques for expressing recombinant aequorin in mammalian cells, thus eliminating the need for microinjection, has opened new possibilities for this probe. Among the new uses of aequorin, one of the most interesting is the potential for targeting it specifically to different cellular locations, thus opening the possibility of monitoring selectively the dynamics of [Ca(2+)] with unprecedented spatial resolution. This article briefly discusses the problems concerned with targeting aequorin to different locations, the advantages and disadvantages offered by the steep dependence of luminescence on [Ca(2+)], and the instruments needed to obtain reliable measurements.
Collapse
|
45
|
Bezin S, Charpentier G, Lee HC, Baux G, Fossier P, Cancela JM. Regulation of nuclear Ca2+ signaling by translocation of the Ca2+ messenger synthesizing enzyme ADP-ribosyl cyclase during neuronal depolarization. J Biol Chem 2008; 283:27859-27870. [PMID: 18632662 DOI: 10.1074/jbc.m804701200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In neurons, voltage-gated Ca(2+) channels and nuclear Ca(2+) signaling play important roles, such as in the regulation of gene expression. However, the link between electrical activity and biochemical cascade activation involved in the generation of the nuclear Ca(2+) signaling is poorly understood. Here we show that depolarization of Aplysia neurons induces the translocation of ADP-ribosyl cyclase, a Ca(2+) messenger synthesizing enzyme, from the cytosol into the nucleus. The translocation is dependent on Ca(2+) influx mainly through the voltage-dependent L-type Ca(2+) channels. We report also that specific nucleoplasmic Ca(2+) signals can be induced by three different calcium messengers, cyclic ADP-ribose, nicotinic acid adenine dinucleotide phosphate (NAADP), both produced by the ADP-ribosyl cyclase, and inositol 1,4,5-trisphosphate (IP(3)). Moreover, our pharmacological data show that NAADP acts on its own receptor, which cooperates with the IP(3) and the ryanodine receptors to generate nucleoplasmic Ca(2+) oscillations. We propose a new model where voltage-dependent L-type Ca(2+) channel-induced nuclear translocation of the cytosolic cyclase is a crucial step in the fine tuning of nuclear Ca(2+) signals in neurons.
Collapse
Affiliation(s)
- Stéphanie Bezin
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, UPR 9040, 1, Avenue de la Terrasse, 91198 Gif-Sur-Yvette Cedex, France
| | - Gilles Charpentier
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, UPR 9040, 1, Avenue de la Terrasse, 91198 Gif-Sur-Yvette Cedex, France; Université Bordeaux 1 Laboratoire DMPFCS, IECB, 2, Rue Robert Escarpit, 33607 Pessac, France
| | - Hon Cheung Lee
- Department of Physiology, University of Hong Kong, 4/F Lab Block, Faculty of Medicine Building, 21 Sassoon Road, Hong Kong
| | - Gérard Baux
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, UPR 9040, 1, Avenue de la Terrasse, 91198 Gif-Sur-Yvette Cedex, France
| | - Philippe Fossier
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, UPR 9040, 1, Avenue de la Terrasse, 91198 Gif-Sur-Yvette Cedex, France
| | - José-Manuel Cancela
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, UPR 9040, 1, Avenue de la Terrasse, 91198 Gif-Sur-Yvette Cedex, France.
| |
Collapse
|
46
|
Gerasimenko O, Tepikin A. How to measure Ca2+ in cellular organelles? Cell Calcium 2008; 38:201-11. [PMID: 16102822 DOI: 10.1016/j.ceca.2005.06.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 11/27/2022]
Abstract
The review will aim to briefly summarise information on calcium measurements in cellular organelles with emphases on studies conducted in live cells using optical probes. When appropriate we will try to compare the effectiveness of different indicators for intraorganellar calcium measurements. We will consider calcium measurements in endoplasmic reticulum, Golgi apparatus, endosomes/lysosomes, nucleoplasm, nuclear envelope, mitochondria and secretory granules.
Collapse
Affiliation(s)
- Oleg Gerasimenko
- The Physiological Laboratory, The University of Liverpool, Crown Street, P.O. Box 147, Liverpool L69 3BX, UK
| | | |
Collapse
|
47
|
Petersen OH. Ca2+ signalling and Ca2+-activated ion channels in exocrine acinar cells. Cell Calcium 2008; 38:171-200. [PMID: 16107275 DOI: 10.1016/j.ceca.2005.06.024] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 01/11/2023]
Abstract
The development of the calcium signalling field, from its early beginnings some 40 years ago to the present, is described. Calcium signalling in exocrine gland acinar cells and the effects of neurotransmitter- or hormone-elicited rises in the cytosolic calcium ion concentration on ion channel gating are reviewed. The highly polarized arrangement of the organelle systems in living acinar cells is described as well as its importance for the physiologically relevant local and polarized calcium signalling events.
Collapse
Affiliation(s)
- Ole H Petersen
- MRC Group, The Physiological Laboratory, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
| |
Collapse
|
48
|
Lasorsa FM, Pinton P, Palmieri L, Scarcia P, Rottensteiner H, Rizzuto R, Palmieri F. Peroxisomes as novel players in cell calcium homeostasis. J Biol Chem 2008; 283:15300-8. [PMID: 18364350 DOI: 10.1074/jbc.m800648200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ca2+ concentration in peroxisomal matrix ([Ca2+](perox)) has been monitored dynamically in mammalian cells expressing variants of Ca2+-sensitive aequorin specifically targeted to peroxisomes. Upon stimulation with agonists that induce Ca2+ release from intracellular stores, peroxisomes transiently take up Ca2+ reaching peak values in the lumen as high as 50-100 microm, depending on cell types. Also in resting cells, peroxisomes sustain a Ca2+ gradient, [Ca2+](perox) being approximately 20-fold higher than [Ca2+] in the cytosol ([Ca2+](cyt)). The properties of Ca2+ traffic across the peroxisomal membrane are different from those reported for other subcellular organelles. The sensitivity of peroxisomal Ca2+ uptake to agents dissipating H+ and Na+ gradients unravels the existence of a complex bioenergetic framework including V-ATPase, Ca2+/H+, and Ca2+/Na+ activities whose components are yet to be identified at a molecular level. The different [Ca2+](perox) of resting and stimulated cells suggest that Ca2+ could play an important role in the regulation of peroxisomal metabolism.
Collapse
Affiliation(s)
- Francesco Massimo Lasorsa
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari and CNR Institute of Biomembranes and Bioenergetics, Via Orabona 4, Bari, Italy
| | | | | | | | | | | | | |
Collapse
|
49
|
McCarron JG, Olson ML. A single luminally continuous sarcoplasmic reticulum with apparently separate Ca2+ stores in smooth muscle. J Biol Chem 2007; 283:7206-18. [PMID: 18096697 DOI: 10.1074/jbc.m708923200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Whether or not the sarcoplasmic reticulum (SR) is a continuous, interconnected network surrounding a single lumen or comprises multiple, separate Ca2+ pools was investigated in voltage-clamped single smooth muscle cells using local photolysis of caged compounds and Ca2+ imaging. The entire SR could be depleted or refilled from one small site via either inositol 1,4,5-trisphosphate receptors (IP3R) or ryanodine receptors (RyR) suggesting the SR is luminally continuous and that Ca2+ may diffuse freely throughout. Notwithstanding, regulation of the opening of RyR and IP3R, by the [Ca2+] within the SR, may create several apparent SR elements with various receptor arrangements. IP3R and RyR may appear to exist entirely on a single store, and there may seem to be additional SR elements that express either only RyR or only IP3R. The various SR receptor arrangements and apparently separate Ca2+ storage elements exist in a single luminally continuous SR entity.
Collapse
Affiliation(s)
- John G McCarron
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, John Arbuthnott Building, 27 Taylor Street, Glasgow G4 0NR, Scotland, United Kingdom.
| | | |
Collapse
|
50
|
Chamero P, Manjarres IM, García-Verdugo JM, Villalobos C, Alonso MT, García-Sancho J. Nuclear calcium signaling by inositol trisphosphate in GH3 pituitary cells. Cell Calcium 2007; 43:205-14. [PMID: 17583789 DOI: 10.1016/j.ceca.2007.05.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2007] [Revised: 05/01/2007] [Accepted: 05/08/2007] [Indexed: 11/28/2022]
Abstract
It has been proposed that nuclear and cytosolic Ca(2+) ([Ca(2+)](N) and [Ca(2+)](C)) may be regulated independently. We address here the issue of whether inositol trisphosphate (IP(3)) can, bypassing changes of [Ca(2+)](C), produce direct release of Ca(2+) into the nucleoplasm. We have used targeted aequorins to selectively measure and compare the changes in [Ca(2+)](C) and [Ca(2+)](N) induced by IP(3) in GH(3) pituitary cells. Heparin, an IP(3) inhibitor that does not permeate the nuclear pores, abolished the [Ca(2+)](C) peaks but inhibited only partly the [Ca(2+)](N) peaks. The permeant inhibitor 2-aminoethoxy-diphenyl-borate (2-APB) blocked both responses. Removal of ATP also inhibited more strongly the [Ca(2+)](C) than [Ca(2+)](N) peak. The [Ca(2+)](N) and [Ca(2+)](C) responses differed also in their sensitivity to IP(3), the nuclear response showing higher affinity. Among IP(3) receptors, type 2 (IP(3)R2) has a higher affinity for IP(3) and is not inactivated by ATP removal. We find that IP(3)R2 immunoreactivity is present inside the nucleus whereas the other IP(3)R subtypes are detected only in the cytoplasm. The nuclear envelope (NE) of GH(3) cells showed deep invaginations into the nucleoplasm, with cytosol and cytoplasmic organella inside. These results indicate that GH(3) pituitary cells possess mechanisms able to produce selective increases of [Ca(2+)](N).
Collapse
Affiliation(s)
- Pablo Chamero
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), Departamento de Fisiología y Bioquímica, Facultad de Medicina, E-47005 Valladolid, Spain
| | | | | | | | | | | |
Collapse
|