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Wang M, Li Z, Song Y, Sun Q, Deng L, Lin Z, Zeng Y, Qiu C, Lin J, Guo H, Chen J, Guo W. Genetic tagging of the adenosine A2A receptor reveals its heterogeneous expression in brain regions. Front Neuroanat 2022; 16:978641. [PMID: 36059431 PMCID: PMC9434489 DOI: 10.3389/fnana.2022.978641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 07/29/2022] [Indexed: 11/22/2022] Open
Abstract
The adenosine A2A receptor (A2AR), a G protein-coupled receptor, is involved in numerous and varied physiological and pathological processes, including inflammation, immune responses, blood flow, and neurotransmission. Accordingly, it has become an important drug target for the treatment of neuropsychiatric disorders. However, the exact brain distribution of A2AR in regions outside the striatum that display relatively low levels of endogenous A2AR expression has hampered the exploration of A2AR functions under both physiological and pathological conditions. To further study the detailed distribution of the A2AR in low-expression regions, we have generated A2AR knock-in mice in which the 3xHA-2xMyc epitope tag sequence was fused to the C-terminus of A2AR (A2AR-tag mice) via CRISPR/Cas9 technology. Here, using CRISPR/Cas9 technology, we have generated A2AR knock-in mice in which the 3xHA-2xMyc epitope tag sequence was fused to the C-terminus of A2AR (A2AR-tag mice). The A2AR-tag mice exhibited normal locomotor activity and emotional state. Consistent with previous studies, A2AR fluorescence was widely detected in the striatum, nucleus accumbens, and olfactory tubercles, with numerous labeled cells being evident in these regions in the A2AR-tag mouse. Importantly, we also identified the presence of a few but clearly labeled cells in heterogeneous brain regions where A2AR expression has not previously been unambiguously detected, including the lateral septum, hippocampus, amygdala, cerebral cortex, and gigantocellular reticular nucleus. The A2AR-tag mouse represents a novel useful genetic tool for monitoring the expression of A2AR and dissecting its functions in brain regions other than the striatum.
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Affiliation(s)
- Muran Wang
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Zewen Li
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Yue Song
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Qiuqin Sun
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Lu Deng
- Department of Neurology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- Key Laboratory of Structural Malformations in Children of Zhejiang Province, Wenzhou, China
| | - Zhiqing Lin
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Yang Zeng
- Shanghai Pregen Biotechnology Co., Ltd., Shanghai, China
| | - Chunhong Qiu
- Shanghai Pregen Biotechnology Co., Ltd., Shanghai, China
| | - Jingjing Lin
- Department of Neurology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- Key Laboratory of Structural Malformations in Children of Zhejiang Province, Wenzhou, China
| | - Hui Guo
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Jiangfan Chen
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
- Jiangfan Chen,
| | - Wei Guo
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
- *Correspondence: Wei Guo,
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Skopál A, Kéki T, Tóth PÁ, Csóka B, Koscsó B, Németh ZH, Antonioli L, Ivessa A, Ciruela F, Virág L, Haskó G, Kókai E. Cathepsin D interacts with adenosine A 2A receptors in mouse macrophages to modulate cell surface localization and inflammatory signaling. J Biol Chem 2022; 298:101888. [PMID: 35367412 PMCID: PMC9065627 DOI: 10.1016/j.jbc.2022.101888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/21/2022] [Accepted: 03/23/2022] [Indexed: 11/30/2022] Open
Abstract
Adenosine A2A receptor (A2AR)–dependent signaling in macrophages plays a key role in the regulation of inflammation. However, the processes regulating A2AR targeting to the cell surface and degradation in macrophages are incompletely understood. For example, the C-terminal domain of the A2AR and proteins interacting with it are known to regulate receptor recycling, although it is unclear what role potential A2AR-interacting partners have in macrophages. Here, we aimed to identify A2AR-interacting partners in macrophages that may effect receptor trafficking and activity. To this end, we performed a yeast two-hybrid screen using the C-terminal tail of A2AR as the “bait” and a macrophage expression library as the “prey.” We found that the lysosomal protease cathepsin D (CtsD) was a robust hit. The A2AR–CtsD interaction was validated in vitro and in cellular models, including RAW 264.7 and mouse peritoneal macrophage (IPMΦ) cells. We also demonstrated that the A2AR is a substrate of CtsD and that the blockade of CtsD activity increases the density and cell surface targeting of A2AR in macrophages. Conversely, we demonstrate that A2AR activation prompts the maturation and enzymatic activity of CtsD in macrophages. In summary, we conclude that CtsD is a novel A2AR-interacting partner and thus describe molecular and functional interplay that may be crucial for adenosine-mediated macrophage regulation in inflammatory processes.
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Affiliation(s)
- Adrienn Skopál
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Kéki
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Á Tóth
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Csóka
- Department of Anesthesiology, Columbia University, New York, New York, USA
| | - Balázs Koscsó
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Zoltán H Németh
- Department of Anesthesiology, Columbia University, New York, New York, USA; Department of Surgery, Morristown Medical Center, Morristown, New Jersey, USA
| | - Luca Antonioli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Andreas Ivessa
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Francisco Ciruela
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain; Neuropharmacology and Pain Group, Neuroscience Program, Bellvitge Institute for Biomedical Research, L'Hospitalet de Llobregat, Barcelona, Spain
| | - László Virág
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; MTA-DE Cell Biology and Signaling Research Group, University of Debrecen, Debrecen, Hungary
| | - György Haskó
- Department of Anesthesiology, Columbia University, New York, New York, USA.
| | - Endre Kókai
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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Maula T, Vahvelainen N, Tossavainen H, Koivunen T, T. Pöllänen M, Johansson A, Permi P, Ihalin R. Decreased temperature increases the expression of a disordered bacterial late embryogenesis abundant (LEA) protein that enhances natural transformation. Virulence 2021; 12:1239-1257. [PMID: 33939577 PMCID: PMC8096337 DOI: 10.1080/21505594.2021.1918497] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/22/2021] [Accepted: 04/03/2021] [Indexed: 11/02/2022] Open
Abstract
Late embryogenesis abundant (LEA) proteins are important players in the management of responses to stressful conditions, such as drought, high salinity, and changes in temperature. Many LEA proteins do not have defined three-dimensional structures, so they are intrinsically disordered proteins (IDPs) and are often highly hydrophilic. Although LEA-like sequences have been identified in bacterial genomes, the functions of bacterial LEA proteins have been studied only recently. Sequence analysis of outer membrane interleukin receptor I (BilRI) from the oral pathogen Aggregatibacter actinomycetemcomitans indicated that it shared sequence similarity with group 3/3b/4 LEA proteins. Comprehensive nuclearcgq magnetic resonance (NMR) studies confirmed its IDP nature, and expression studies in A. actinomycetemcomitans harboring a red fluorescence reporter protein-encoding gene revealed that bilRI promoter expression was increased at decreased temperatures. The amino acid backbone of BilRI did not stimulate either the production of reactive oxygen species from human leukocytes or the production of interleukin-6 from human macrophages. Moreover, BilRI-specific IgG antibodies could not be detected in the sera of A. actinomycetemcomitans culture-positive periodontitis patients. Since the bilRI gene is located near genes involved in natural competence (i.e., genes associated with the uptake of extracellular (eDNA) and its incorporation into the genome), we also investigated the role of BilRI in these events. Compared to wild-type cells, the ΔbilRI mutants showed a lower transformation efficiency, which indicates either a direct or indirect role in natural competence. In conclusion, A. actinomycetemcomitans might express BilRI, especially outside the host, to survive under stressful conditions and improve its transmission potential.
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Affiliation(s)
- Terhi Maula
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Nelli Vahvelainen
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Helena Tossavainen
- Department of Biological and Environmental Sciences, Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland
| | - Tuuli Koivunen
- Department of Life Technologies, University of Turku, Turku, Finland
| | | | - Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Perttu Permi
- Department of Biological and Environmental Sciences, Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland
- Department of Chemistry, Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland
| | - Riikka Ihalin
- Department of Life Technologies, University of Turku, Turku, Finland
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Calmodulin and Its Binding Proteins in Parkinson's Disease. Int J Mol Sci 2021; 22:ijms22063016. [PMID: 33809535 PMCID: PMC8001340 DOI: 10.3390/ijms22063016] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 02/07/2023] Open
Abstract
Parkinson’s disease (PD) is a neurodegenerative disorder that manifests with rest tremor, muscle rigidity and movement disturbances. At the microscopic level it is characterized by formation of specific intraneuronal inclusions, called Lewy bodies (LBs), and by a progressive loss of dopaminergic neurons in the striatum and substantia nigra. All living cells, among them neurons, rely on Ca2+ as a universal carrier of extracellular and intracellular signals that can initiate and control various cellular processes. Disturbances in Ca2+ homeostasis and dysfunction of Ca2+ signaling pathways may have serious consequences on cells and even result in cell death. Dopaminergic neurons are particularly sensitive to any changes in intracellular Ca2+ level. The best known and studied Ca2+ sensor in eukaryotic cells is calmodulin. Calmodulin binds Ca2+ with high affinity and regulates the activity of a plethora of proteins. In the brain, calmodulin and its binding proteins play a crucial role in regulation of the activity of synaptic proteins and in the maintenance of neuronal plasticity. Thus, any changes in activity of these proteins might be linked to the development and progression of neurodegenerative disorders including PD. This review aims to summarize published results regarding the role of calmodulin and its binding proteins in pathology and pathogenesis of PD.
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O’Day DH. Calmodulin Binding Proteins and Alzheimer's Disease: Biomarkers, Regulatory Enzymes and Receptors That Are Regulated by Calmodulin. Int J Mol Sci 2020; 21:ijms21197344. [PMID: 33027906 PMCID: PMC7582761 DOI: 10.3390/ijms21197344] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/02/2020] [Accepted: 10/03/2020] [Indexed: 12/19/2022] Open
Abstract
The integral role of calmodulin in the amyloid pathway and neurofibrillary tangle formation in Alzheimer’s disease was first established leading to the “Calmodulin Hypothesis”. Continued research has extended our insight into the central function of the small calcium sensor and effector calmodulin and its target proteins in a multitude of other events associated with the onset and progression of this devastating neurodegenerative disease. Calmodulin’s involvement in the contrasting roles of calcium/CaM-dependent kinase II (CaMKII) and calcineurin (CaN) in long term potentiation and depression, respectively, and memory impairment and neurodegeneration are updated. The functions of the proposed neuronal biomarker neurogranin, a calmodulin binding protein also involved in long term potentiation and depression, is detailed. In addition, new discoveries into calmodulin’s role in regulating glutamate receptors (mGluR, NMDAR) are overviewed. The interplay between calmodulin and amyloid beta in the regulation of PMCA and ryanodine receptors are prime examples of how the buildup of classic biomarkers can underly the signs and symptoms of Alzheimer’s. The role of calmodulin in the function of stromal interaction molecule 2 (STIM2) and adenosine A2A receptor, two other proteins linked to neurodegenerative events, is discussed. Prior to concluding, an analysis of how targeting calmodulin and its binding proteins are viable routes for Alzheimer’s therapy is presented. In total, calmodulin and its binding proteins are further revealed to be central to the onset and progression of Alzheimer’s disease.
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Affiliation(s)
- Danton H. O’Day
- Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada;
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
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6
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GPCR drug discovery: integrating solution NMR data with crystal and cryo-EM structures. Nat Rev Drug Discov 2018; 18:59-82. [PMID: 30410121 DOI: 10.1038/nrd.2018.180] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The 826 G protein-coupled receptors (GPCRs) in the human proteome regulate key physiological processes and thus have long been attractive drug targets. With the crystal structures of more than 50 different human GPCRs determined over the past decade, an initial platform for structure-based rational design has been established for drugs that target GPCRs, which is currently being augmented with cryo-electron microscopy (cryo-EM) structures of higher-order GPCR complexes. Nuclear magnetic resonance (NMR) spectroscopy in solution is one of the key approaches for expanding this platform with dynamic features, which can be accessed at physiological temperature and with minimal modification of the wild-type GPCR covalent structures. Here, we review strategies for the use of advanced biochemistry and NMR techniques with GPCRs, survey projects in which crystal or cryo-EM structures have been complemented with NMR investigations and discuss the impact of this integrative approach on GPCR biology and drug discovery.
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7
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La Verde V, Dominici P, Astegno A. Towards Understanding Plant Calcium Signaling through Calmodulin-Like Proteins: A Biochemical and Structural Perspective. Int J Mol Sci 2018; 19:E1331. [PMID: 29710867 PMCID: PMC5983762 DOI: 10.3390/ijms19051331] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 11/17/2022] Open
Abstract
Ca2+ ions play a key role in a wide variety of environmental responses and developmental processes in plants, and several protein families with Ca2+-binding domains have evolved to meet these needs, including calmodulin (CaM) and calmodulin-like proteins (CMLs). These proteins have no catalytic activity, but rather act as sensor relays that regulate downstream targets. While CaM is well-studied, CMLs remain poorly characterized at both the structural and functional levels, even if they are the largest class of Ca2+ sensors in plants. The major structural theme in CMLs consists of EF-hands, and variations in these domains are predicted to significantly contribute to the functional versatility of CMLs. Herein, we focus on recent advances in understanding the features of CMLs from biochemical and structural points of view. The analysis of the metal binding and structural properties of CMLs can provide valuable insight into how such a vast array of CML proteins can coexist, with no apparent functional redundancy, and how these proteins contribute to cellular signaling while maintaining properties that are distinct from CaM and other Ca2+ sensors. An overview of the principal techniques used to study the biochemical properties of these interesting Ca2+ sensors is also presented.
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Affiliation(s)
- Valentina La Verde
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Paola Dominici
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Alessandra Astegno
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
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8
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Piirainen H, Taura J, Kursula P, Ciruela F, Jaakola VP. Calcium modulates calmodulin/α-actinin 1 interaction with and agonist-dependent internalization of the adenosine A 2A receptor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:674-686. [PMID: 28130124 DOI: 10.1016/j.bbamcr.2017.01.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 01/14/2017] [Accepted: 01/23/2017] [Indexed: 10/20/2022]
Abstract
Adenosine receptors are G protein-coupled receptors that sense extracellular adenosine to transmit intracellular signals. One of the four adenosine receptor subtypes, the adenosine A2A receptor (A2AR), has an exceptionally long intracellular C terminus (A2AR-ct) that mediates interactions with a large array of proteins, including calmodulin and α-actinin. Here, we aimed to ascertain the α-actinin 1/calmodulin interplay whilst binding to A2AR and the role of Ca2+ in this process. First, we studied the A2AR-α-actinin 1 interaction by means of native polyacrylamide gel electrophoresis, isothermal titration calorimetry, and surface plasmon resonance, using purified recombinant proteins. α-Actinin 1 binds the A2AR-ct through its distal calmodulin-like domain in a Ca2+-independent manner with a dissociation constant of 5-12μM, thus showing an ~100 times lower affinity compared to the A2AR-calmodulin/Ca2+ complex. Importantly, calmodulin displaced α-actinin 1 from the A2AR-ct in a Ca2+-dependent fashion, disrupting the A2AR-α-actinin 1 complex. Finally, we assessed the impact of Ca2+ on A2AR internalization in living cells, a function operated by the A2AR-α-actinin 1 complex. Interestingly, while Ca2+ influx did not affect constitutive A2AR endocytosis, it abolished agonist-dependent internalization. In addition, we demonstrated that the A2AR/α-actinin interaction plays a pivotal role in receptor internalization and function. Overall, our results suggest that the interplay of A2AR with calmodulin and α-actinin 1 is fine-tuned by Ca2+, a fact that might power agonist-mediated receptor internalization and function.
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Affiliation(s)
- Henni Piirainen
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Finland
| | - Jaume Taura
- Unitat de Farmacologia, Departament Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL, Universitat de Barcelona, Spain; Institut de Neurociències, Universitat de Barcelona, Spain
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Finland; Department of Biomedicine, University of Bergen, Norway
| | - Francisco Ciruela
- Unitat de Farmacologia, Departament Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL, Universitat de Barcelona, Spain; Institut de Neurociències, Universitat de Barcelona, Spain.
| | - Veli-Pekka Jaakola
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Finland.
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Cunha RA. How does adenosine control neuronal dysfunction and neurodegeneration? J Neurochem 2016; 139:1019-1055. [PMID: 27365148 DOI: 10.1111/jnc.13724] [Citation(s) in RCA: 301] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/23/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022]
Abstract
The adenosine modulation system mostly operates through inhibitory A1 (A1 R) and facilitatory A2A receptors (A2A R) in the brain. The activity-dependent release of adenosine acts as a brake of excitatory transmission through A1 R, which are enriched in glutamatergic terminals. Adenosine sharpens salience of information encoding in neuronal circuits: high-frequency stimulation triggers ATP release in the 'activated' synapse, which is locally converted by ecto-nucleotidases into adenosine to selectively activate A2A R; A2A R switch off A1 R and CB1 receptors, bolster glutamate release and NMDA receptors to assist increasing synaptic plasticity in the 'activated' synapse; the parallel engagement of the astrocytic syncytium releases adenosine further inhibiting neighboring synapses, thus sharpening the encoded plastic change. Brain insults trigger a large outflow of adenosine and ATP, as a danger signal. A1 R are a hurdle for damage initiation, but they desensitize upon prolonged activation. However, if the insult is near-threshold and/or of short-duration, A1 R trigger preconditioning, which may limit the spread of damage. Brain insults also up-regulate A2A R, probably to bolster adaptive changes, but this heightens brain damage since A2A R blockade affords neuroprotection in models of epilepsy, depression, Alzheimer's, or Parkinson's disease. This initially involves a control of synaptotoxicity by neuronal A2A R, whereas astrocytic and microglia A2A R might control the spread of damage. The A2A R signaling mechanisms are largely unknown since A2A R are pleiotropic, coupling to different G proteins and non-canonical pathways to control the viability of glutamatergic synapses, neuroinflammation, mitochondria function, and cytoskeleton dynamics. Thus, simultaneously bolstering A1 R preconditioning and preventing excessive A2A R function might afford maximal neuroprotection. The main physiological role of the adenosine modulation system is to sharp the salience of information encoding through a combined action of adenosine A2A receptors (A2A R) in the synapse undergoing an alteration of synaptic efficiency with an increased inhibitory action of A1 R in all surrounding synapses. Brain insults trigger an up-regulation of A2A R in an attempt to bolster adaptive plasticity together with adenosine release and A1 R desensitization; this favors synaptotocity (increased A2A R) and decreases the hurdle to undergo degeneration (decreased A1 R). Maximal neuroprotection is expected to result from a combined A2A R blockade and increased A1 R activation. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
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Affiliation(s)
- Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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10
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Tossavainen H, Hellman M, Piirainen H, Jaakola VP, Permi P. H(N), N, C(α), C(β) and C' assignments of the intrinsically disordered C-terminus of human adenosine A2A receptor. BIOMOLECULAR NMR ASSIGNMENTS 2015; 9:403-406. [PMID: 25952762 DOI: 10.1007/s12104-015-9618-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/03/2015] [Indexed: 06/04/2023]
Abstract
The C-terminus of the human adenosine A2A receptor differs from the other human adenosine receptors by its exceptional length and lack of a canonical cysteine residue. We have previously structurally characterized this C-terminal domain and its interaction with calmodulin. It was shown to be structurally disordered and flexible, and to bind calmodulin with high affinity in a calcium-dependent manner. Interaction with calmodulin takes place at the N-terminal end of the A2A C-terminal domain without major conformational changes in the latter. NMR was one of the biophysical methods used in the study. Here we present the H(N), N, C(α), C(β) and C' chemical shift assignments of the free form of the C-terminus residues 293-412, used in the NMR spectroscopic characterization of the domain.
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Affiliation(s)
- Helena Tossavainen
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014, Helsinki, Finland
| | - Maarit Hellman
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014, Helsinki, Finland
| | - Henni Piirainen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Veli-Pekka Jaakola
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Perttu Permi
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014, Helsinki, Finland.
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Chukhlieb M, Raasakka A, Ruskamo S, Kursula P. The N-terminal cytoplasmic domain of neuregulin 1 type III is intrinsically disordered. Amino Acids 2015; 47:1567-77. [PMID: 25944317 DOI: 10.1007/s00726-015-1998-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 04/21/2015] [Indexed: 11/30/2022]
Abstract
Axonally expressed neuregulin 1 (NRG1) type III is a transmembrane protein involved in various neurodevelopmental processes, including myelination and Schwann cell migration. NRG1 type III has one transmembrane domain and a C-terminal extracellular segment, which contains an epidermal growth factor homology domain. Little is known, however, about the intracellular N terminus of NRG1 type III, and the structure-function relationships of this cytoplasmic domain have remained uncharacterized. In the current study, we carried out the first structural and functional studies on the NRG1 type III cytoplasmic domain. Based on sequence analyses, the domain is predicted to be largely disordered, while a strictly conserved region close to the transmembrane segment may contain helical structure and bind metal ions. As shown by synchrotron radiation circular dichroism spectroscopy, the recombinant NRG1 type III cytoplasmic domain was disordered in solution, but it was able to fold partially into a helical structure, especially when both metals and membrane-mimicking compounds were present. NRG1 cytoplasmic tail binding to metals was further confirmed by calorimetry. These results suggest that the juxtamembrane segment of the NRG1 type III cytoplasmic domain may fold onto the membrane surface upon metal binding. Using synchrotron small-angle X-ray scattering, we further proved that the NRG1 cytoplasmic domain is intrinsically disordered, highly elongated, and behaves like a random polymer. Our work provides the first biochemical and biophysical data on the previously unexplored cytoplasmic domain of NRG1 type III, which will help elucidate the detailed structure-function relationships of this domain.
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Affiliation(s)
- Maryna Chukhlieb
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
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