1
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Lohse MJ, Bock A, Zaccolo M. G Protein-Coupled Receptor Signaling: New Insights Define Cellular Nanodomains. Annu Rev Pharmacol Toxicol 2024; 64:387-415. [PMID: 37683278 DOI: 10.1146/annurev-pharmtox-040623-115054] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
G protein-coupled receptors are the largest and pharmacologically most important receptor family and are involved in the regulation of most cell functions. Most of them reside exclusively at the cell surface, from where they signal via heterotrimeric G proteins to control the production of second messengers such as cAMP and IP3 as well as the activity of several ion channels. However, they may also internalize upon agonist stimulation or constitutively reside in various intracellular locations. Recent evidence indicates that their function differs depending on their precise cellular localization. This is because the signals they produce, notably cAMP and Ca2+, are mostly bound to cell proteins that significantly reduce their mobility, allowing the generation of steep concentration gradients. As a result, signals generated by the receptors remain confined to nanometer-sized domains. We propose that such nanometer-sized domains represent the basic signaling units in a cell and a new type of target for drug development.
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Affiliation(s)
- Martin J Lohse
- ISAR Bioscience Institute, Planegg/Munich, Germany;
- Rudolf Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Andreas Bock
- Rudolf Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics and National Institute for Health and Care Research Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom;
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2
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Wong A, Chi W, Yu J, Bi C, Tian X, Yang Y, Gehring C. Plant adenylate cyclases have come full circle. NATURE PLANTS 2023; 9:1389-1397. [PMID: 37709954 DOI: 10.1038/s41477-023-01486-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 07/07/2023] [Indexed: 09/16/2023]
Abstract
In bacteria, fungi and animals, 3'-5'-cyclic adenosine monophosphate (cAMP) and adenylate cyclases (ACs), enzymes that catalyse the formation of 3',5'-cAMP from ATP, are recognized as key signalling components. In contrast, the presence of cAMP and its biological roles in higher plants have long been a matter of controversy due to the generally lower amounts in plant tissues compared with that in animal and bacterial cells, and a lack of clarity on the molecular nature of the generating and degrading enzymes, as well as downstream effectors. While treatment with 3',5'-cAMP elicited many plant responses, ACs were, however, somewhat elusive. This changed when systematic searches with amino acid motifs deduced from the conserved catalytic centres of annotated ACs from animals and bacteria identified candidate proteins in higher plants that were subsequently shown to have AC activities in vitro and in vivo. The identification of active ACs moonlighting within complex multifunctional proteins is consistent with their roles as molecular tuners and regulators of cellular and physiological functions. Furthermore, the increasing number of ACs identified as part of proteins with different domain architectures suggests that there are many more hidden ACs in plant proteomes and they may affect a multitude of mechanisms and processes at the molecular and systems levels.
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Affiliation(s)
- Aloysius Wong
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, Zhejiang Province, China.
- Wenzhou Municipal Key Lab for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang Province, China.
- Zhejiang Bioinformatics Internatiosnal Science and Technology Cooperation Center, Wenzhou, Zhejiang Province, China.
| | - Wei Chi
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, Zhejiang Province, China
| | - Jia Yu
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, Zhejiang Province, China
| | - Chuyun Bi
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, Zhejiang Province, China
- Wenzhou Municipal Key Lab for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang Province, China
- Zhejiang Bioinformatics Internatiosnal Science and Technology Cooperation Center, Wenzhou, Zhejiang Province, China
| | - Xuechen Tian
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, Zhejiang Province, China
- Wenzhou Municipal Key Lab for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang Province, China
- Zhejiang Bioinformatics Internatiosnal Science and Technology Cooperation Center, Wenzhou, Zhejiang Province, China
| | - Yixin Yang
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, Zhejiang Province, China
- Wenzhou Municipal Key Lab for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang Province, China
- Zhejiang Bioinformatics Internatiosnal Science and Technology Cooperation Center, Wenzhou, Zhejiang Province, China
| | - Chris Gehring
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy.
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3
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Karagyaur M, Primak A, Efimenko A, Skryabina M, Tkachuk V. The Power of Gene Technologies: 1001 Ways to Create a Cell Model. Cells 2022; 11:cells11203235. [PMID: 36291103 PMCID: PMC9599997 DOI: 10.3390/cells11203235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/01/2022] [Accepted: 10/12/2022] [Indexed: 12/04/2022] Open
Abstract
Modern society faces many biomedical challenges that require urgent solutions. Two of the most important include the elucidation of mechanisms of socially significant diseases and the development of prospective drug treatments for these diseases. Experimental cell models are a convenient tool for addressing many of these problems. The power of cell models is further enhanced when combined with gene technologies, which allows the examination of even more subtle changes within the structure of the genome and permits testing of proteins in a native environment. The list and possibilities of these recently emerging technologies are truly colossal, which requires a rethink of a number of approaches for obtaining experimental cell models. In this review, we analyze the possibilities and limitations of promising gene technologies for obtaining cell models, and also give recommendations on the development and creation of relevant models. In our opinion, this review will be useful for novice cell biologists, as it provides some reference points in the rapidly growing universe of gene and cell technologies.
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Affiliation(s)
- Maxim Karagyaur
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, 27/10, Lomonosovsky Ave., 119192 Moscow, Russia
- Faculty of Medicine, Lomonosov Moscow State University, 27/1, Lomonosovsky Ave., 119192 Moscow, Russia
- Correspondence:
| | - Alexandra Primak
- Faculty of Medicine, Lomonosov Moscow State University, 27/1, Lomonosovsky Ave., 119192 Moscow, Russia
| | - Anastasia Efimenko
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, 27/10, Lomonosovsky Ave., 119192 Moscow, Russia
- Faculty of Medicine, Lomonosov Moscow State University, 27/1, Lomonosovsky Ave., 119192 Moscow, Russia
| | - Mariya Skryabina
- Faculty of Medicine, Lomonosov Moscow State University, 27/1, Lomonosovsky Ave., 119192 Moscow, Russia
| | - Vsevolod Tkachuk
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, 27/10, Lomonosovsky Ave., 119192 Moscow, Russia
- Faculty of Medicine, Lomonosov Moscow State University, 27/1, Lomonosovsky Ave., 119192 Moscow, Russia
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4
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Wang L, Wu C, Peng W, Zhou Z, Zeng J, Li X, Yang Y, Yu S, Zou Y, Huang M, Liu C, Chen Y, Li Y, Ti P, Liu W, Gao Y, Zheng W, Zhong H, Gao S, Lu Z, Ren PG, Ng HL, He J, Chen S, Xu M, Li Y, Chu J. A high-performance genetically encoded fluorescent indicator for in vivo cAMP imaging. Nat Commun 2022; 13:5363. [PMID: 36097007 PMCID: PMC9468011 DOI: 10.1038/s41467-022-32994-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/24/2022] [Indexed: 11/25/2022] Open
Abstract
cAMP is a key second messenger that regulates diverse cellular functions including neural plasticity. However, the spatiotemporal dynamics of intracellular cAMP in intact organisms are largely unknown due to low sensitivity and/or brightness of current genetically encoded fluorescent cAMP indicators. Here, we report the development of the new circularly permuted GFP (cpGFP)-based cAMP indicator G-Flamp1, which exhibits a large fluorescence increase (a maximum ΔF/F0 of 1100% in HEK293T cells), decent brightness, appropriate affinity (a Kd of 2.17 μM) and fast response kinetics (an association and dissociation half-time of 0.20 and 0.087 s, respectively). Furthermore, the crystal structure of the cAMP-bound G-Flamp1 reveals one linker connecting the cAMP-binding domain to cpGFP adopts a distorted β-strand conformation that may serve as a fluorescence modulation switch. We demonstrate that G-Flamp1 enables sensitive monitoring of endogenous cAMP signals in brain regions that are implicated in learning and motor control in living organisms such as fruit flies and mice.
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Affiliation(s)
- Liang Wang
- grid.9227.e0000000119573309Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Chunling Wu
- grid.11135.370000 0001 2256 9319PKU-IDG–McGovern Institute for Brain Research, Beijing, 100871 China ,grid.9227.e0000000119573309State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Wanling Peng
- grid.9227.e0000000119573309Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031 China
| | - Ziliang Zhou
- grid.12981.330000 0001 2360 039XMolecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, 519000 China ,grid.410737.60000 0000 8653 1072Department of Oral Emergency and General Dentistry, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, 510182 Guangdong China
| | - Jianzhi Zeng
- grid.11135.370000 0001 2256 9319PKU-IDG–McGovern Institute for Brain Research, Beijing, 100871 China
| | - Xuelin Li
- grid.11135.370000 0001 2256 9319PKU-IDG–McGovern Institute for Brain Research, Beijing, 100871 China
| | - Yini Yang
- grid.11135.370000 0001 2256 9319PKU-IDG–McGovern Institute for Brain Research, Beijing, 100871 China
| | - Shuguang Yu
- grid.9227.e0000000119573309State Key Laboratory of Neuroscience, Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031 China
| | - Ye Zou
- grid.36567.310000 0001 0737 1259Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, 66506 KS USA
| | - Mian Huang
- grid.36567.310000 0001 0737 1259Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, 66506 KS USA
| | - Chang Liu
- grid.9227.e0000000119573309Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Yefei Chen
- grid.9227.e0000000119573309Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Yi Li
- grid.33199.310000 0004 0368 7223Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Panpan Ti
- grid.33199.310000 0004 0368 7223Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Wenfeng Liu
- grid.9227.e0000000119573309Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Yufeng Gao
- grid.9227.e0000000119573309Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Wei Zheng
- grid.9227.e0000000119573309Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Haining Zhong
- grid.5288.70000 0000 9758 5690Vollum Institute, Oregon Health and Science University, Portland, 97239 OR USA
| | - Shangbang Gao
- grid.33199.310000 0004 0368 7223Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Zhonghua Lu
- grid.9227.e0000000119573309Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Pei-Gen Ren
- grid.9227.e0000000119573309Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Ho Leung Ng
- grid.36567.310000 0001 0737 1259Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, 66506 KS USA
| | - Jie He
- grid.9227.e0000000119573309State Key Laboratory of Neuroscience, Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031 China
| | - Shoudeng Chen
- grid.12981.330000 0001 2360 039XMolecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, 519000 China ,grid.12981.330000 0001 2360 039XDepartment of Experimental Medicine, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, 519000 China
| | - Min Xu
- grid.9227.e0000000119573309Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031 China
| | - Yulong Li
- grid.11135.370000 0001 2256 9319PKU-IDG–McGovern Institute for Brain Research, Beijing, 100871 China
| | - Jun Chu
- grid.9227.e0000000119573309Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China ,grid.458489.c0000 0001 0483 7922Shenzhen-Hong Kong Institute of Brain Science, and Shenzhen Institute of Synthetic Biology, Shenzhen, 518055 China ,grid.9227.e0000000119573309CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
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5
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Kawata S, Yamamoto Y, Saitoh N. Spectra analysis and live-neuron imaging of cyclic AMP binding domain fusing circularly permutated GFP: Data for violet light excitable cyclic AMP indicator. Data Brief 2022; 43:108441. [PMID: 35845098 PMCID: PMC9283500 DOI: 10.1016/j.dib.2022.108441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 06/29/2022] [Accepted: 06/29/2022] [Indexed: 11/20/2022] Open
Abstract
Cyclic adenosine monophosphate (cyclic AMP) is a second messenger, which is involved in the regulation of various cellular processes, including neuronal firing rate, synaptic plasticity, axon formation and axon elongation in brain. Although the main molecules in the cAMP-mediated signaling pathway are well studied, the spatio-temporal dynamics of the cAMP remain to be elucidated. Live imaging is an informative tool to investigate the cell signaling dynamics. It allows continuous monitoring of a specific cell over a period of time. Thus, optical probes for cAMP are important tools for studying the dynamics of cAMP signaling. Multiple genetically encoded cAMP probes are available [1], [2], including Förster resonance energy transfer (FRET) based or circular permutated fluorescent protein (cpFP) based probes. cpFP-based probes have an advantage of easier handling than FRET-based probes caused by monomeric detection and smaller molecular size. However, there is no cAMP probe compatible with violet light excitation. Therefore, we fused violet light excitable cpGFP to cyclic nucleotide binding domain (CBD) in E. coli cAMP receptor protein. This construct successfully responded to cAMP concentration changes. We show here the spectra data and live-cell imaging data of the violet light excitable cAMP probe which can be used for multi-signal fluorescence imaging.
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6
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Green fluorescent cAMP indicator of high speed and specificity suitable for neuronal live-cell imaging. Proc Natl Acad Sci U S A 2022; 119:e2122618119. [PMID: 35867738 DOI: 10.1073/pnas.2122618119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a canonical intracellular messenger playing diverse roles in cell functions. In neurons, cAMP promotes axonal growth during early development, and mediates sensory transduction and synaptic plasticity after maturation. The molecular cascades of cAMP are well documented, but its spatiotemporal profiles associated with neuronal functions remain hidden. Hence, we developed a genetically encoded cAMP indicator based on a bacterial cAMP-binding protein. This indicator "gCarvi" monitors [cAMP]i at 0.2 to 20 µM with a subsecond time resolution and a high specificity over cyclic guanosine monophosphate (cGMP). gCarvi can be converted to a ratiometric probe for [cAMP]i quantification and its expression can be specifically targeted to various subcellular compartments. Monomeric gCarvi also enables simultaneous multisignal monitoring in combination with other indicators. As a proof of concept, simultaneous cAMP/Ca2+ imaging in hippocampal neurons revealed a tight linkage of cAMP to Ca2+ signals. In cerebellar presynaptic boutons, forskolin induced nonuniform cAMP elevations among boutons, which positively correlated with subsequent increases in the size of the recycling pool of synaptic vesicles assayed using FM dye. Thus, the cAMP domain in presynaptic boutons is an important determinant of the synaptic strength.
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7
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Arena DT, Hofer AM. Imaging the cAMP Signaling Microdomain of the Primary Cilium Using Targeted FRET-Based Biosensors. Methods Mol Biol 2022; 2483:77-92. [PMID: 35286670 DOI: 10.1007/978-1-0716-2245-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Optical approaches have revolutionized our view of second messenger signaling in organelles, allowing precise time-resolved assessment of soluble signaling molecules in situ. Among the most challenging of subcellular signaling microdomains to assay is the primary cilium. A petite but visually arresting organelle, the primary cilium extends from the cell surface of most non-dividing cells. Recently, the concept of the primary cilium as an independent cAMP signaling organelle has attracted substantial interest. The cilium sequesters a very specific subset of ciliary cAMP-linked GPCRs in its membrane (e.g., 5-HT6, D1R, MCR4, FFAR4, TGR5), as well as other key components of the cAMP signaling machinery that include adenylyl cyclases, GNAS, phosphodiesterases, PKA holoenzyme, and biologically important PKA targets. Here we provide a practical guide to assessing ciliary cAMP signals in live cells using targeted genetically encoded FRET biosensors. Key experimental difficulties include gathering sufficient signal from such a small, photon-limited volume, and the susceptibility of cilia to movement artifacts. Other challenges are associated with the fidelity of sensor targeting and the difficulties in distinguishing between cAMP signals produced exclusively within the cilium vs. those that emanate from the cell body. Here we describe ratio imaging approaches used in our lab for time-resolved visualization of ciliary cAMP in cultured renal cells. These methods can be readily adapted to other cell types and microscopy platforms according to the needs of the user.
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Affiliation(s)
- Danielle T Arena
- VA Boston Healthcare System and the Department of Surgery, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Aldebaran M Hofer
- VA Boston Healthcare System and the Department of Surgery, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA.
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8
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Dietrich P, Moeder W, Yoshioka K. Plant Cyclic Nucleotide-Gated Channels: New Insights on Their Functions and Regulation. PLANT PHYSIOLOGY 2020; 184:27-38. [PMID: 32576644 PMCID: PMC7479878 DOI: 10.1104/pp.20.00425] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/17/2020] [Indexed: 05/02/2023]
Abstract
Recent advances of plant cyclic nucleotide-gated channels give new insight into their molecular functions focusing on regulation, subunit assembly, and phosphorylation.
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Affiliation(s)
- Petra Dietrich
- Molecular Plant Physiology, Friedrich-Alexander University Erlangen-Nuremberg, 91058 Erlangen, Germany
| | - Wolfgang Moeder
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Keiko Yoshioka
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Center for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
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9
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Blanco E, Fortunato S, Viggiano L, de Pinto MC. Cyclic AMP: A Polyhedral Signalling Molecule in Plants. Int J Mol Sci 2020; 21:E4862. [PMID: 32660128 PMCID: PMC7402341 DOI: 10.3390/ijms21144862] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 02/07/2023] Open
Abstract
The cyclic nucleotide cAMP (3',5'-cyclic adenosine monophosphate) is nowadays recognised as an important signalling molecule in plants, involved in many molecular processes, including sensing and response to biotic and abiotic environmental stresses. The validation of a functional cAMP-dependent signalling system in higher plants has spurred a great scientific interest on the polyhedral role of cAMP, as it actively participates in plant adaptation to external stimuli, in addition to the regulation of physiological processes. The complex architecture of cAMP-dependent pathways is far from being fully understood, because the actors of these pathways and their downstream target proteins remain largely unidentified. Recently, a genetic strategy was effectively used to lower cAMP cytosolic levels and hence shed light on the consequences of cAMP deficiency in plant cells. This review aims to provide an integrated overview of the current state of knowledge on cAMP's role in plant growth and response to environmental stress. Current knowledge of the molecular components and the mechanisms of cAMP signalling events is summarised.
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Affiliation(s)
- Emanuela Blanco
- Institute of Biosciences and Bioresources, National Research Council, Via G. Amendola 165/A, 70126 Bari, Italy
| | - Stefania Fortunato
- Department of Biology, University of Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy; (S.F.); (L.V.)
| | - Luigi Viggiano
- Department of Biology, University of Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy; (S.F.); (L.V.)
| | - Maria Concetta de Pinto
- Department of Biology, University of Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy; (S.F.); (L.V.)
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10
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Rational Design of a Protein Kinase A Nuclear-cytosol Translocation Reporter. Sci Rep 2020; 10:9365. [PMID: 32518322 PMCID: PMC7283302 DOI: 10.1038/s41598-020-66349-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 05/11/2020] [Indexed: 12/14/2022] Open
Abstract
Protein Kinase A (PKA) exists as a tetrameric holoenzyme which activates with increase of cAMP and plays an important role in many physiological processes including cardiac physiology, neuronal development, and adipocyte function. Although this kinase has been the subject of numerous biosensor designs, a single-fluorophore reporter that performs comparably to Förster resonance energy transfer (FRET) has not yet been reported. Here, we have used basic observations of electrostatic interactions in PKA substrate recognition mechanism and nucleus localization sequence motif to design a phosphorylation switch that shuttles between the cytosol and the nucleus, a strategy that should be generalizable to all basophilic kinases. The resulting reporter yielded comparable kinetics and dynamic range to the PKA FRET reporter, AKAR3EV. We also performed basic characterization and demonstrated its potential use in monitoring multiple signaling molecules inside cells using basic fluorescence microscopy. Due to the single-fluorophore nature of this reporter, we envision that this could find broad applications in studies involving single cell analysis of PKA activity.
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11
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Sensing Senses: Optical Biosensors to Study Gustation. SENSORS 2020; 20:s20071811. [PMID: 32218129 PMCID: PMC7180777 DOI: 10.3390/s20071811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/19/2020] [Accepted: 03/21/2020] [Indexed: 12/11/2022]
Abstract
The five basic taste modalities, sweet, bitter, umami, salty and sour induce changes of Ca2+ levels, pH and/or membrane potential in taste cells of the tongue and/or in neurons that convey and decode gustatory signals to the brain. Optical biosensors, which can be either synthetic dyes or genetically encoded proteins whose fluorescence spectra depend on levels of Ca2+, pH or membrane potential, have been used in primary cells/tissues or in recombinant systems to study taste-related intra- and intercellular signaling mechanisms or to discover new ligands. Taste-evoked responses were measured by microscopy achieving high spatial and temporal resolution, while plate readers were employed for higher throughput screening. Here, these approaches making use of fluorescent optical biosensors to investigate specific taste-related questions or to screen new agonists/antagonists for the different taste modalities were reviewed systematically. Furthermore, in the context of recent developments in genetically encoded sensors, 3D cultures and imaging technologies, we propose new feasible approaches for studying taste physiology and for compound screening.
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12
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Imaging cAMP nanodomains in the heart. Biochem Soc Trans 2020; 47:1383-1392. [PMID: 31670375 PMCID: PMC6824676 DOI: 10.1042/bst20190245] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 01/13/2023]
Abstract
3′-5′-cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger that modulates multiple cellular functions. It is now well established that cAMP can mediate a plethora of functional effects via a complex system of local regulatory mechanisms that result in compartmentalized signalling. The use of fluorescent probes to monitor cAMP in intact, living cells have been instrumental in furthering our appreciation of this ancestral and ubiquitous pathway and unexpected details of the nano-architecture of the cAMP signalling network are starting to emerge. Recent evidence shows that sympathetic control of cardiac contraction and relaxation is achieved via generation of multiple, distinct pools of cAMP that lead to differential phosphorylation of target proteins localized only tens of nanometres apart. The specific local control at these nanodomains is enabled by a distinct signalosome where effectors, targets, and regulators of the cAMP signal are clustered. In this review, we focus on recent advances using targeted fluorescent reporters for cAMP and how they have contributed to our current understanding of nanodomain cAMP signalling in the heart. We briefly discuss how this information can be exploited to design novel therapies and we highlight some of the questions that remain unanswered.
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13
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Bers DM, Xiang YK, Zaccolo M. Whole-Cell cAMP and PKA Activity are Epiphenomena, Nanodomain Signaling Matters. Physiology (Bethesda) 2020; 34:240-249. [PMID: 31165682 DOI: 10.1152/physiol.00002.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Novel targeted fluorescent biosensors provide key insights into very local nanodomains of cAMP and PKA activity, and how they respond differently to β-adrenergic activation in cardiac myocytes. This unique spatiotemporal detail in living cells is not available with biochemical measurements of total cellular cAMP and PKA, and provides unique physiological insights.
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Affiliation(s)
- Donald M Bers
- Department of Pharmacology, University of California , Davis, California
| | - Yang K Xiang
- Department of Pharmacology, University of California , Davis, California
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford , Oxford , United Kingdom
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14
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Tschaikner P, Enzler F, Torres-Quesada O, Aanstad P, Stefan E. Hedgehog and Gpr161: Regulating cAMP Signaling in the Primary Cilium. Cells 2020; 9:cells9010118. [PMID: 31947770 PMCID: PMC7017137 DOI: 10.3390/cells9010118] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/20/2019] [Accepted: 12/29/2019] [Indexed: 12/14/2022] Open
Abstract
Compartmentalization of diverse types of signaling molecules contributes to the precise coordination of signal propagation. The primary cilium fulfills this function by acting as a spatiotemporally confined sensory signaling platform. For the integrity of ciliary signaling, it is mandatory that the ciliary signaling pathways are constantly attuned by alterations in both oscillating small molecules and the presence or absence of their sensor/effector proteins. In this context, ciliary G protein-coupled receptor (GPCR) pathways participate in coordinating the mobilization of the diffusible second messenger molecule 3',5'-cyclic adenosine monophosphate (cAMP). cAMP fluxes in the cilium are primarily sensed by protein kinase A (PKA) complexes, which are essential for the basal repression of Hedgehog (Hh) signaling. Here, we describe the dynamic properties of underlying signaling circuits, as well as strategies for second messenger compartmentalization. As an example, we summarize how receptor-guided cAMP-effector pathways control the off state of Hh signaling. We discuss the evidence that a macromolecular, ciliary-localized signaling complex, composed of the orphan GPCR Gpr161 and type I PKA holoenzymes, is involved in antagonizing Hh functions. Finally, we outline how ciliary cAMP-linked receptor pathways and cAMP-sensing signalosomes may become targets for more efficient combinatory therapy approaches to counteract dysregulation of Hh signaling.
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Affiliation(s)
- Philipp Tschaikner
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria; (P.T.); (F.E.); (O.T.-Q.)
- Institute of Molecular Biology, University of Innsbruck, 6020 Innsbruck, Austria;
| | - Florian Enzler
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria; (P.T.); (F.E.); (O.T.-Q.)
| | - Omar Torres-Quesada
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria; (P.T.); (F.E.); (O.T.-Q.)
| | - Pia Aanstad
- Institute of Molecular Biology, University of Innsbruck, 6020 Innsbruck, Austria;
| | - Eduard Stefan
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria; (P.T.); (F.E.); (O.T.-Q.)
- Correspondence: ; Tel.: +43-512-507-57531; Fax: +43-512-507-57599
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Studying β 1 and β 2 adrenergic receptor signals in cardiac cells using FRET-based sensors. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 154:30-38. [PMID: 31266653 DOI: 10.1016/j.pbiomolbio.2019.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/10/2019] [Accepted: 06/17/2019] [Indexed: 12/17/2022]
Abstract
Cyclic 3'-5' adenosine monophosphate (cAMP) is a key modulator of cardiac function. Thanks to the sophisticated organization of its pathway in distinct functional units called microdomains, cAMP is involved in the regulation of both inotropy and chronotropy as well as transcription and cardiac death. While visualization of cAMP microdomains can be achieved thanks to cAMP-sensitive FRET-based sensors, the molecular mechanisms through which cAMP-generating stimuli are coupled to distinct functional outcomes are not well understood. One possibility is that each stimulus activates multiple microdomains in order to generate a spatiotemporal code that translates into function. To test this hypothesis here we propose a series of experimental protocols that allow to simultaneously follow cAMP or Protein Kinase A (PKA)-dependent phosphorylation in different subcellular compartments of living cells. We investigate the responses of β Adrenergic receptors (β1AR and β2AR) challenged with selective drugs that enabled us to measure the actions of each receptor independently. At the whole cell level, we used a combination of co-culture with selective βAR stimulation and were able to molecularly separate cardiac fibroblasts from neonatal rat ventricular myocytes based on their cAMP responses. On the other hand, at the subcellular level, these experimental protocols allowed us to dissect the relative weight of β1 and β2 adrenergic receptors on cAMP signalling at the cytosol and outer mitochondrial membrane of NRVMs. We propose that experimental procedures that allow the collection of multiparametric data are necessary in order to understand the molecular mechanisms underlying the coupling between extracellular signals and cellular responses.
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16
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Burke KJ, Bender KJ. Modulation of Ion Channels in the Axon: Mechanisms and Function. Front Cell Neurosci 2019; 13:221. [PMID: 31156397 PMCID: PMC6533529 DOI: 10.3389/fncel.2019.00221] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/01/2019] [Indexed: 12/11/2022] Open
Abstract
The axon is responsible for integrating synaptic signals, generating action potentials (APs), propagating those APs to downstream synapses and converting them into patterns of neurotransmitter vesicle release. This process is mediated by a rich assortment of voltage-gated ion channels whose function can be affected on short and long time scales by activity. Moreover, neuromodulators control the activity of these proteins through G-protein coupled receptor signaling cascades. Here, we review cellular mechanisms and signaling pathways involved in axonal ion channel modulation and examine how changes to ion channel function affect AP initiation, AP propagation, and the release of neurotransmitter. We then examine how these mechanisms could modulate synaptic function by focusing on three key features of synaptic information transmission: synaptic strength, synaptic variability, and short-term plasticity. Viewing these cellular mechanisms of neuromodulation from a functional perspective may assist in extending these findings to theories of neural circuit function and its neuromodulation.
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Affiliation(s)
- Kenneth J Burke
- Neuroscience Graduate Program and Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - Kevin J Bender
- Neuroscience Graduate Program and Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
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17
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Reuschlein AK, Jakobsen E, Mertz C, Bak LK. Aspects of astrocytic cAMP signaling with an emphasis on the putative power of compartmentalized signals in health and disease. Glia 2019; 67:1625-1636. [PMID: 31033018 DOI: 10.1002/glia.23622] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 12/17/2022]
Abstract
This review discusses aspects of known and putative compartmentalized 3',5'-cyclic adenosine monophosphate (cAMP) signaling in astrocytes, a cell type that has turned out to be a key player in brain physiology and pathology. cAMP has attracted less attention than Ca2+ in recent years, but could turn out to rival Ca2+ in its potential to drive cellular functions and responses to intra- and extracellular cues. Further, Ca2+ and cAMP are known to engage in extensive crosstalk and cAMP signals often take place within subcellular compartments revolving around multi-protein signaling complexes; however, we know surprisingly little about this in astrocytes. Here, we review aspects of astrocytic cAMP signaling, provide arguments for an increased interest in this subject, suggest possible future research directions within the field, and discuss putative drug targets.
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Affiliation(s)
- Ann-Kathrin Reuschlein
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil Jakobsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christoffer Mertz
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lasse K Bak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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18
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Naim N, White AD, Reece JM, Wankhede M, Zhang X, Vilardaga JP, Altschuler DL. Luminescence-activated nucleotide cyclase regulates spatial and temporal cAMP synthesis. J Biol Chem 2018; 294:1095-1103. [PMID: 30559293 DOI: 10.1074/jbc.ac118.004905] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 12/12/2018] [Indexed: 12/15/2022] Open
Abstract
cAMP is a ubiquitous second messenger that regulates cellular proliferation, differentiation, attachment, migration, and several other processes. It has become increasingly evident that tight regulation of cAMP accumulation and localization confers divergent yet specific signaling to downstream pathways. Currently, few tools are available that have sufficient spatial and temporal resolution to study location-biased cAMP signaling. Here, we introduce a new fusion protein consisting of a light-activated adenylyl cyclase (bPAC) and luciferase (nLuc). This construct allows dual activation of cAMP production through temporally precise photostimulation or chronic chemical stimulation that can be fine-tuned to mimic physiological levels and duration of cAMP synthesis to trigger downstream events. By targeting this construct to different compartments, we show that cAMP produced in the cytosol and nucleus stimulates proliferation in thyroid cells. The bPAC-nLuc fusion construct adds a new reagent to the available toolkit to study cAMP-regulated processes in living cells.
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Affiliation(s)
- Nyla Naim
- Department of Pharmacology and Chemical Biology, Pittsburgh, Pennsylvania 15261; Molecular Pharmacology Training Program, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Alex D White
- Department of Pharmacology and Chemical Biology, Pittsburgh, Pennsylvania 15261; Molecular Pharmacology Training Program, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Jeff M Reece
- Department of Pharmacology and Chemical Biology, Pittsburgh, Pennsylvania 15261
| | - Mamta Wankhede
- Department of Pharmacology and Chemical Biology, Pittsburgh, Pennsylvania 15261
| | - Xuefeng Zhang
- Department of Pharmacology and Chemical Biology, Pittsburgh, Pennsylvania 15261
| | | | - Daniel L Altschuler
- Department of Pharmacology and Chemical Biology, Pittsburgh, Pennsylvania 15261.
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Filadi R, Basso E, Lefkimmiatis K, Pozzan T. Beyond Intracellular Signaling: The Ins and Outs of Second Messengers Microdomains. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 981:279-322. [PMID: 29594866 DOI: 10.1007/978-3-319-55858-5_12] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A typical characteristic of eukaryotic cells compared to prokaryotes is represented by the spatial heterogeneity of the different structural and functional components: for example, most of the genetic material is surrounded by a highly specific membrane structure (the nuclear membrane), continuous with, yet largely different from, the endoplasmic reticulum (ER); oxidative phosphorylation is carried out by organelles enclosed by a double membrane, the mitochondria; in addition, distinct domains, enriched in specific proteins, are present in the plasma membrane (PM) of most cells. Less obvious, but now generally accepted, is the notion that even the concentration of small molecules such as second messengers (Ca2+ and cAMP in particular) can be highly heterogeneous within cells. In the case of most organelles, the differences in the luminal levels of second messengers depend either on the existence on their membrane of proteins that allow the accumulation/release of the second messenger (e.g., in the case of Ca2+, pumps, exchangers or channels), or on the synthesis and degradation of the specific molecule within the lumen (the autonomous intramitochondrial cAMP system). It needs stressing that the existence of a surrounding membrane does not necessarily imply the existence of a gradient between the cytosol and the organelle lumen. For example, the nuclear membrane is highly permeable to both Ca2+ and cAMP (nuclear pores are permeable to solutes up to 50 kDa) and differences in [Ca2+] or [cAMP] between cytoplasm and nucleoplasm are not seen in steady state and only very transiently during cell activation. A similar situation has been observed, as far as Ca2+ is concerned, in peroxisomes.
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Affiliation(s)
- Riccardo Filadi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Emy Basso
- Institute of Neuroscience, Padova Section, National Research Council, Padova, Italy
| | - Konstantinos Lefkimmiatis
- Institute of Neuroscience, Padova Section, National Research Council, Padova, Italy
- Venetian Institute of Molecular Medicine, Padova, Italy
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
- Institute of Neuroscience, Padova Section, National Research Council, Padova, Italy.
- Venetian Institute of Molecular Medicine, Padova, Italy.
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20
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Arroyo-Olarte RD, Thurow L, Kozjak-Pavlovic V, Gupta N. Illuminating pathogen-host intimacy through optogenetics. PLoS Pathog 2018; 14:e1007046. [PMID: 30001435 PMCID: PMC6042787 DOI: 10.1371/journal.ppat.1007046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The birth and subsequent evolution of optogenetics has resulted in an unprecedented advancement in our understanding of the brain. Its outstanding success does usher wider applications; however, the tool remains still largely relegated to neuroscience. Here, we introduce selected aspects of optogenetics with potential applications in infection biology that will not only answer long-standing questions about intracellular pathogens (parasites, bacteria, viruses) but also broaden the dimension of current research in entwined models. In this essay, we illustrate how a judicious integration of optogenetics with routine methods can illuminate the host–pathogen interactions in a way that has not been feasible otherwise.
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Affiliation(s)
- Ruben Dario Arroyo-Olarte
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Laura Thurow
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Vera Kozjak-Pavlovic
- Department of Microbiology, Biocenter, Julius Maximilian University, Würzburg, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- * E-mail:
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Ohta Y, Furuta T, Nagai T, Horikawa K. Red fluorescent cAMP indicator with increased affinity and expanded dynamic range. Sci Rep 2018; 8:1866. [PMID: 29382930 PMCID: PMC5789972 DOI: 10.1038/s41598-018-20251-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/15/2018] [Indexed: 12/20/2022] Open
Abstract
cAMP is one of the most important second messengers in biological processes. Cellular dynamics of cAMP have been investigated using a series of fluorescent indicators; however, their sensitivity was sub-optimal for detecting cAMP dynamics at a low concentration range, due to a low ligand affinity and/or poor dynamic range. Seeking an indicator with improved detection sensitivity, we performed insertion screening of circularly permuted mApple, a red fluorescent protein, into the cAMP-binding motif of PKA regulatory subunit Iα and developed an improved cAMP indicator named R-FlincA (Red Fluorescent indicator for cAMP). Its increased affinity (Kd = 0.3 μM) and expanded dynamic range (860% at pH 7.2) allowed the detection of subtle changes in the cellular cAMP dynamics at sub-μM concentrations, which could not be easily observed with existing indicators. Increased detection sensitivity also strengthened the advantages of using R-FlincA as a red fluorescent indicator, as it permits a series of applications, including multi-channel/function imaging of multiple second messengers and combinatorial imaging with photo-manipulation. These results strongly suggest that R-FlincA is a promising tool that accelerates cAMP research by revealing unobserved cAMP dynamics at a low concentration range.
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Affiliation(s)
- Yusaku Ohta
- Department of Optical Imaging, The Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima City, Tokushima, 770-8503, Japan
| | - Toshiaki Furuta
- Department of Biomolecular Science, Toho University, 2-2-1 Miyama, Funabashi, 274-8510, Japan
| | - Takeharu Nagai
- Department of Biomolecular Science and Engineering, The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan
| | - Kazuki Horikawa
- Department of Optical Imaging, The Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima City, Tokushima, 770-8503, Japan.
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Musheshe N, Schmidt M, Zaccolo M. cAMP: From Long-Range Second Messenger to Nanodomain Signalling. Trends Pharmacol Sci 2017; 39:209-222. [PMID: 29289379 DOI: 10.1016/j.tips.2017.11.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/14/2017] [Accepted: 11/17/2017] [Indexed: 12/21/2022]
Abstract
How cAMP generates hormone-specific effects has been debated for many decades. Fluorescence resonance energy transfer (FRET)-based sensors for cAMP allow real-time imaging of the second messenger in intact cells with high spatiotemporal resolution. This technology has made it possible to directly demonstrate that cAMP signals are compartmentalised. The details of such signal compartmentalisation are still being uncovered, and recent findings reveal a previously unsuspected submicroscopic heterogeneity of intracellular cAMP. A model is emerging where specificity depends on compartmentalisation and where the physiologically relevant signals are those that occur within confined nanodomains, rather than bulk changes in cytosolic cAMP. These findings subvert the classical notion of cAMP signalling and provide a new framework for the development of targeted therapeutic approaches.
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Affiliation(s)
- Nshunge Musheshe
- Department of Molecular Pharmacology, University of Groningen, The Netherlands; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, The Netherlands; Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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Muallem S, Chung WY, Jha A, Ahuja M. Lipids at membrane contact sites: cell signaling and ion transport. EMBO Rep 2017; 18:1893-1904. [PMID: 29030479 DOI: 10.15252/embr.201744331] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/10/2017] [Accepted: 09/21/2017] [Indexed: 12/14/2022] Open
Abstract
Communication between organelles is essential to coordinate cellular functions and the cell's response to physiological and pathological stimuli. Organellar communication occurs at membrane contact sites (MCSs), where the endoplasmic reticulum (ER) membrane is tethered to cellular organelle membranes by specific tether proteins and where lipid transfer proteins and cell signaling proteins are located. MCSs have many cellular functions and are the sites of lipid and ion transfer between organelles and generation of second messengers. This review discusses several aspects of MCSs in the context of lipid transfer, formation of lipid domains, generation of Ca2+ and cAMP second messengers, and regulation of ion transporters by lipids.
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Affiliation(s)
- Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Woo Young Chung
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Archana Jha
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
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