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Gao N, Raduka A, Rezaee F. Vitamin D 3 protects against respiratory syncytial virus-induced barrier dysfunction in airway epithelial cells via PKA signaling pathway. Eur J Cell Biol 2023; 102:151336. [PMID: 37354621 PMCID: PMC10773979 DOI: 10.1016/j.ejcb.2023.151336] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 06/26/2023] Open
Abstract
Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection in infants and young children globally and is responsible for hospitalization and mortality in the elderly population. Virus-induced airway epithelial barrier damage is a critical step during RSV infection, and emerging studies suggest that RSV disrupts the tight junctions (TJs) and adherens junctions (AJs) between epithelial cells, increasing the permeability of the airway epithelial barrier. The lack of commercially available vaccines and effective antiviral drugs for RSV emphasizes the need for new management strategies. Vitamin D3 is a promising intervention for viral infection due to its critical role in modulating innate immune responses. However, there is limited evidence on the effect of vitamin D3 on RSV pathogenies. Here, we investigated the impact of vitamin D3 on RSV-induced epithelial barrier dysfunction and the underlying mechanisms. We found that pre-incubation with 1,25(OH)2D3, the active form of vitamin D3, alleviated RSV-induced epithelial barrier disruption in a dose-dependent manner without affecting viability in 16HBE cells. 1,25(OH)2D3 induced minor changes in the protein expression level of TJ/AJ proteins in RSV-infected cells. We observed increased CREB phosphorylation at Ser133 during 1,25(OH)2D3 exposure, indicating that vitamin D3 triggered protein kinase A (PKA) activity in 16HBE. PKA inhibitors modified the restoration of barrier function by 1,25(OH)2D3 in RSV-infected cells, implying that PKA signaling is responsible for the protective effects of vitamin D3 against RSV-induced barrier dysfunction in airway epithelial cells. Our findings suggest vitamin D3 as a prophylactic intervention to protect the respiratory epithelium during RSV infections.
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Affiliation(s)
- Nannan Gao
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Andjela Raduka
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Fariba Rezaee
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; Center for Pediatric Pulmonary Medicine, Cleveland Clinic Children's, Cleveland, OH, USA.
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2
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Lin D, Chen Y, Koksal AR, Dash S, Aydin Y. Targeting ER stress/PKA/GSK-3β/β-catenin pathway as a potential novel strategy for hepatitis C virus-infected patients. Cell Commun Signal 2023; 21:102. [PMID: 37158967 PMCID: PMC10165818 DOI: 10.1186/s12964-023-01081-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 02/13/2023] [Indexed: 05/10/2023] Open
Abstract
BACKGROUND Chronic hepatitis C virus (HCV) infection causes hepatocellular carcinoma (HCC). The HCC risk, while decreased compared with active HCV infection, persists in HCV-cured patients by direct-acting antiviral agents (DAA). We previously demonstrated that Wnt/β-catenin signaling remained activated after DAA-mediated HCV eradication. Developing therapeutic strategies to both eradicate HCV and reverse Wnt/β-catenin signaling is needed. METHODS Cell-based HCV long term infection was established. Chronically HCV infected cells were treated with DAA, protein kinase A (PKA) inhibitor H89 and endoplasmic reticulum (ER) stress inhibitor tauroursodeoxycholic acid (TUDCA). Western blotting analysis and fluorescence microscopy were performed to determine HCV levels and component levels involved in ER stress/PKA/glycogen synthase kinase-3β (GSK-3β)/β-catenin pathway. Meanwhile, the effects of H89 and TUDCA were determined on HCV infection. RESULTS Both chronic HCV infection and replicon-induced Wnt/β-catenin signaling remained activated after HCV and replicon eradication by DAA. HCV infection activated PKA activity and PKA/GSK-3β-mediated Wnt/β-catenin signaling. Inhibition of PKA with H89 both repressed HCV and replicon replication and reversed PKA/GSK-3β-mediated Wnt/β-catenin signaling in both chronic HCV infection and replicon. Both chronic HCV infection and replicon induced ER stress. Inhibition of ER stress with TUDCA both repressed HCV and replicon replication and reversed ER stress/PKA/GSK-3β-dependent Wnt/β-catenin signaling. Inhibition of either PKA or ER stress both inhibited extracellular HCV infection. CONCLUSION Targeting ER stress/PKA/GSK-3β-dependent Wnt/β-catenin signaling with PKA inhibitor could be a novel therapeutic strategy for HCV-infected patients to overcomes the issue of remaining activated Wnt/β-catenin signaling by DAA treatment. Video Abstract.
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Affiliation(s)
- Dong Lin
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, LA, 70112, USA.
| | - Yijia Chen
- The College of Liberal Arts and Sciences, Arizona State University, Tempe, AZ, 85281, USA
| | - Ali Riza Koksal
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Srikanta Dash
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Yucel Aydin
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, LA, 70112, USA.
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3
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Chau AK, Bracken K, Bai L, Pham D, Good L, Maillard RA. Conformational changes in Protein Kinase A along its activation cycle are rooted in the folding energetics of cyclic-nucleotide binding domains. J Biol Chem 2023:104790. [PMID: 37150322 DOI: 10.1016/j.jbc.2023.104790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/09/2023] Open
Abstract
Cyclic-nucleotide binding (CNB) domains are structurally and evolutionarily conserved signaling modules that regulate proteins with diverse folds and functions. Despite a wealth of structural information, the mechanisms by which CNB domains couple cyclic-nucleotide binding to conformational changes involved in signal transduction remain unknown. Here we combined single-molecule and computational approaches to investigate the conformation and folding energetics of the two CNB domains of the regulatory subunit of protein kinase A (PKA). We found that the CNB domains exhibit different conformational and folding signatures in the apo state, when bound to cAMP, or when bound to the PKA catalytic subunit, underscoring their ability to adapt to different binding partners. Moreover, we show while the two CNB domains have near-identical structures, their thermodynamic coupling signatures are divergent, leading to distinct cAMP responses and differential mutational effects. Specifically, we demonstrate the mutation W260A exerts local and allosteric effects that impact multiple steps of the PKA activation cycle. Taken together, these results highlight the complex interplay between folding energetics, conformational dynamics, and thermodynamic signatures that underlies structurally conserved signaling modules in response to ligand binding and mutational effects.
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Affiliation(s)
- Amy K Chau
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
| | - Katherine Bracken
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
| | - Lihui Bai
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
| | - Dominic Pham
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
| | - Lydia Good
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
| | - Rodrigo A Maillard
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA.
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4
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Zhang X, Wang Q, Wang Z, Zhang H, Zhu F, Ma J, Wang W, Chen Z, Wang H. Interaction between A-kinase anchoring protein 5 and protein kinase A mediates CaMKII/HDAC signaling to inhibit cardiomyocyte hypertrophy after hypoxic reoxygenation. Cell Signal 2023; 103:110569. [PMID: 36565899 DOI: 10.1016/j.cellsig.2022.110569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
We reported that A-kinase anchoring protein 5 (AKAP5) played a role in cardiomyocyte apoptosis after hypoxia-reoxygenation (H/R). The role of AKAP5 in cardiomyocyte hypertrophy has not been fully elucidated. Herein we investigated whether AKAP5 regulates cardiomyocyte hypertrophy through calcium/calmodulin-dependent protein kinase II (CaMKII). After H/R, deficiency of AKAP5 in H9C2 cardiomyocytes and neonatal rat cardiac myocytes activated CaMKII and stimulated cardiomyocyte hypertrophy. AKAP5 upregulation limited this. Low expression of AKAP5 increased CaMKII interaction with histone deacetylases 4/5 (HDAC4/5) and increased nuclear export of HDAC4/5. In addition, AKAP5 interactions with protein kinase A (PKA) and phospholamban (PLN) were diminished. Moreover, the phosphorylation of PLN was decreased, and intracellular calcium increased. Interference of this process with St-Ht31 increased CaMKII signaling, decreased PLN phosphorylation and promoted post-H/R cell hypertrophy. And PKA-anchoring deficient AKAP5ΔPKA could not attenuate hypoxia-reoxygenation-induced cardiomyocyte hypertrophy, but AKAP5 could. Altogether, AKAP5 downregulation exacerbated H/R-induced hypertrophy in cardiomyocytes. This was due to, in part, to less in AKAP5-PKA interaction and the accumulation of intracellular Ca2+ with a subsequent increase in CaMKII activity.
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Chen JY, Zhu Q, Cai CZ, Luo HB, Lu JH. α-mangostin derivative 4e as a PDE4 inhibitor promote proteasomal degradation of alpha-synuclein in Parkinson's disease models through PKA activation. Phytomedicine 2022; 101:154125. [PMID: 35525236 DOI: 10.1016/j.phymed.2022.154125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 03/25/2022] [Accepted: 04/17/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Parkinson's disease (PD) is a multi-factorial neurodegenerative disease affecting motor function of patients. The hall markers of PD are dopaminergic neuron loss in the midbrain and the presence of intra-neuronal inclusion bodies mainly composed of aggregation-prone protein alpha-synuclein (α-syn). Ubiquitin-proteasome system (UPS) is a multi-step reaction process responsible for more than 80% intracellular protein degradation. Impairment of UPS function has been observed in the brain tissue of PD patients. PDE4 inhibitors have been shown to activate cAMP-PKA pathway and promote UPS activity in Alzheimer's disease model. α-mangostin is a natural xanthonoid with broad biological activities, such as antioxidant, antimicrobial and antitumour activities. Structure-based optimizations based on α-mangostin produced a potent PDE4 inhibitor, 4e. Herein, we studied whether 4e could promote proteasomal degradation of α-syn in Parkinson's disease models through PKA activation. METHODS cAMP Assay was conducted to quantify cAMP levels in samples. Model UPS substrates (Ub-G76V-GFP and Ub-R-GFP) were used to monitor UPS-dependent activity. Proteasome activity was investigated by short peptide substrate, Suc-LLVY-AMC, cleavage of which by the proteasome increases fluorescence sensitivity. Tet-on WT, A30P, and A53T α-syn-inducible PC12 cells and primary mouse cortical neurons from A53T transgenic mice were used to evaluate the effect of 4e against α-syn in vitro. Heterozygous A53T transgenic mice were employed to assess the effect of 4e on the clearance of α-syn in vivo, and further validations were applied by western blotting and immunohistochemistry. RESULTS Taken together, α-mangostin derivative 4e, a PDE4 inhibitor, efficiently activated the cAMP/PKA pathway in neuronal cells, and promoted UPS activity as evidenced by enhanced degradation of UPS substrate Ub-G76V-GFP and Ub-R-GFP, as well as elevated proteasomal enzyme activity. Interestingly, 4e dramatically accelerated degradation of inducibly-expressed WT and mutant α-syn in PC12 cells, in a UPS dependent manner. Besides, 4e consistently activated PKA in primary neuron and A53T mice brain, restored UPS inhibition and alleviated α-syn accumulation in the A53T mice brain. CONCLUSIONS 4e is a natural compound derived highly potent PDE4 inhibitor. We revealed its potential effect in promoting UPS activity to degrade pathogenic proteins associated with PD.
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Affiliation(s)
- Jia-Yue Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Qi Zhu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Cui-Zan Cai
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Hai-Bin Luo
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, Hainan 570228, China.
| | - Jia-Hong Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China.
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Kanassatega RS, Bunch TA, Lepak VC, Wang C, Colson BA. Human cardiac myosin-binding protein C phosphorylation- and mutation-dependent structural dynamics monitored by time-resolved FRET. J Mol Cell Cardiol 2022; 166:116-126. [PMID: 35227736 PMCID: PMC9067379 DOI: 10.1016/j.yjmcc.2022.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/31/2022] [Accepted: 02/21/2022] [Indexed: 11/27/2022]
Abstract
Cardiac myosin-binding protein C (cMyBP-C) is a thick filament-associated protein of the sarcomere and a potential therapeutic target for treating contractile dysfunction in heart failure. Mimicking the structural dynamics of phosphorylated cMyBP-C by small-molecule drug binding could lead to therapies that modulate cMyBP-C conformational states, and thereby function, to improve contractility. We have developed a human cMyBP-C biosensor capable of detecting intramolecular structural changes due to phosphorylation and mutation. Using site-directed mutagenesis and time-resolved fluorescence resonance energy transfer (TR-FRET), we substituted cysteines in cMyBP-C N-terminal domains C0 through C2 (C0-C2) for thiol-reactive fluorescent probe labeling to examine C0-C2 structure. We identified a cysteine pair that upon donor-acceptor labeling reports phosphorylation-sensitive structural changes between the C1 domain and the tri-helix bundle of the M-domain that links C1 to C2. Phosphorylation reduced FRET efficiency by ~18%, corresponding to a ~11% increase in the distance between probes and a ~30% increase in disorder between them. The magnitude and precision of phosphorylation-mediated TR-FRET changes, as quantified by the Z'-factor, demonstrate the assay's potential for structure-based high-throughput screening of compounds for cMyBP-C-targeted therapies to improve cardiac performance in heart failure. Additionally, by probing C1's spatial positioning relative to the tri-helix bundle, these findings provide new molecular insight into the structural dynamics of phosphoregulation as well as mutations in cMyBP-C. Biosensor sensitivity to disease-relevant mutations in C0-C2 was demonstrated by examination of the hypertrophic cardiomyopathy mutation R282W. The results presented here support a screening platform to identify small molecules that regulate N-terminal cMyBP-C conformational states.
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Affiliation(s)
- Rhye-Samuel Kanassatega
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Thomas A Bunch
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Victoria C Lepak
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Christopher Wang
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Brett A Colson
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America.
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Byrne DP, Omar MH, Kennedy EJ, Eyers PA, Scott JD. Biochemical Analysis of AKAP-Anchored PKA Signaling Complexes. Methods Mol Biol 2022; 2483:297-317. [PMID: 35286684 PMCID: PMC9518671 DOI: 10.1007/978-1-0716-2245-2_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Generation of the prototypic second messenger cAMP instigates numerous signaling events. A major intracellular target of cAMP is Protein kinase A (PKA), a Ser/Thr protein kinase. Where and when this enzyme is activated inside the cell has profound implications on the functional impact of PKA. It is now well established that PKA signaling is focused locally into subcellular signaling "islands" or "signalosomes." The A-Kinase Anchoring Proteins (AKAPs) play a critical role in this process by dictating spatial and temporal aspects of PKA action. Genetically encoded biosensors, small molecule and peptide-based disruptors of PKA signaling are valuable tools for rigorous investigation of local PKA action at the biochemical level. This chapter focuses on approaches to evaluate PKA signaling islands, including a simple assay for monitoring the interaction of an AKAP with a tunable PKA holoenzyme. The latter approach evaluates the composition of PKA holoenzymes, in which regulatory subunits and catalytic subunits can be visualized in the presence of test compounds and small-molecule inhibitors.
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Affiliation(s)
- Dominic P Byrne
- Department of Biochemistry and Systems Biology, ISMIB, University of Liverpool, Liverpool, UK
| | - Mitchell H Omar
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Patrick A Eyers
- Department of Biochemistry and Systems Biology, ISMIB, University of Liverpool, Liverpool, UK.
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, WA, USA.
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Walker-Gray R, Pallien T, Miller DC, Oder A, Neuenschwander M, von Kries JP, Diecke S, Klussmann E. Disruptors of AKAP-Dependent Protein-Protein Interactions. Methods Mol Biol 2022; 2483:117-139. [PMID: 35286673 DOI: 10.1007/978-1-0716-2245-2_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A-kinase anchoring proteins (AKAPs) are a family of multivalent scaffolding proteins. They engage in direct protein-protein interactions with protein kinases, kinase substrates and further signaling molecules. Each AKAP interacts with a specific set of protein interaction partners and such sets can vary between different cellular compartments and cells. Thus, AKAPs can coordinate signal transduction processes spatially and temporally in defined cellular environments. AKAP-dependent protein-protein interactions are involved in a plethora of physiological processes, including processes in the cardiovascular, nervous, and immune system. Dysregulation of AKAPs and their interactions is associated with or causes widespread diseases, for example, cardiac diseases such as heart failure. However, there are profound shortcomings in understanding functions of specific AKAP-dependent protein-protein interactions. In part, this is due to the lack of agents for specifically targeting defined protein-protein interactions. Peptidic and non-peptidic inhibitors are invaluable molecular tools for elucidating the functions of AKAP-dependent protein-protein interactions. In addition, such interaction disruptors may pave the way to new concepts for the treatment of diseases where AKAP-dependent protein-protein interactions constitute potential drug targets.Here we describe screening approaches for the identification of small molecule disruptors of AKAP-dependent protein-protein interactions. Examples include interactions of AKAP18 and protein kinase A (PKA) and of AKAP-Lbc and RhoA. We discuss a homogenous time-resolved fluorescence (HTRF) and an AlphaScreen® assay for small molecule library screening and human induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs) as a cell system for the characterization of identified hits.
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Affiliation(s)
- Ryan Walker-Gray
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Tamara Pallien
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Duncan C Miller
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany
| | - Andreas Oder
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | | | | | - Sebastian Diecke
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany
| | - Enno Klussmann
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany.
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Dyla M, Kjaergaard M. Intrinsic disorder in protein kinase A anchoring proteins signaling complexes. Prog Mol Biol Transl Sci 2021; 183:271-94. [PMID: 34656331 DOI: 10.1016/bs.pmbts.2021.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Protein kinase A (PKA) is regulated by a diverse class of anchoring proteins known as AKAPs that target PKA to subsets of its activators and substrates. Recently, it was reported that PKA can remain bound to its regulatory subunit after activation in contrast to classical model of activation-by-dissociation. This implies that PKA remains bound to the AKAPs and its substrates, and thus suggest many phosphorylation reactions occur while PKA is physically connected to its substrate. Intra-complex reactions are sensitive to the architecture of the signaling complex, but generally concentration independent. We show that most AKAPs have long intrinsically disordered regions, and suggest that they represent an adaptation for intra-complex phosphorylation. Based on polymer models of the disordered proteins, we predict that the effective concentrations of tethered substrates range from the low millimolar range to tens of micromolar. Based on recent models for intra-complex enzyme reactions, we suggest that the structure of the AKAP signaling complex is likely to be source of allosteric regulation of PKA signaling.
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Liu L, Jiang Y, Steinle JJ. Forskolin regulates retinal endothelial cell permeability through TLR4 actions in vitro. Mol Cell Biochem 2021; 476:4487-4492. [PMID: 34499321 DOI: 10.1007/s11010-021-04252-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/20/2021] [Indexed: 01/09/2023]
Abstract
To investigate whether forskolin, a protein kinase A agonist, regulates toll-like receptor 4 actions on retinal endothelial cell permeability in vitro. We also evaluated whether PKA could regulate TLR4 signaling independent of exchange protein activated by cAMP in REC in culture. REC were grown in normal (5 mM) or high (25 mM) glucose. Cells were treated with forskolin to increase PKA levels, siRNA against TLR4, siRNA against myeloid differentiation primary response 88, siRNA against translocating chain associated membrane protein 1, siRNA against epac1, or scrambled siRNA, or a combination of these treatments. Western blotting was done for zonula occludens 1 and occludin protein levels, as well as TLR4 signaling cascade proteins. Permeability measurements were done for REC in culture following inhibition of TLR4 or its signaling cascades. Forskolin restored high glucose-associated decreases in ZO-1 and occludin, which was associated with improved in vitro permeability levels. Both forskolin and TLR4 inhibition reduced high glucose-induced increases in REC permeability, but the actions were not cooperative. Forskolin regulated both MyD88-dependent and -independent signaling pathways, independent of Epac1. Finally, blockade of MyD88 or TRAM1 reduced permeability in REC grown in high glucose. A PKA agonist regulated TLR4 signaling independent of Epac1. PKA agonism or TLR4 inhibition is effective at reducing high glucose-induced permeability in REC in vitro. These studies offer new avenues for therapeutic development.
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Affiliation(s)
- Li Liu
- Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Youde Jiang
- Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Jena J Steinle
- Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, USA.
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Chaimana R, Teerapornpuntakit J, Jantarajit W, Lertsuwan K, Krungchanuchat S, Panupinthu N, Krishnamra N, Charoenphandhu N. CFTR-mediated anion secretion in parathyroid hormone-treated Caco-2 cells is associated with PKA and PI3K phosphorylation but not intracellular pH changes or Na +/K +-ATPase abundance. Biochem Biophys Rep 2021; 27:101054. [PMID: 34189282 PMCID: PMC8220001 DOI: 10.1016/j.bbrep.2021.101054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/27/2021] [Accepted: 06/09/2021] [Indexed: 02/07/2023] Open
Abstract
Parathyroid hormone (PTH) has previously been shown to enhance the transepithelial secretion of Cl− and HCO3− across the intestinal epithelia including Caco-2 monolayer, but the underlying cellular mechanisms are not completely understood. Herein, we identified the major signaling pathways that possibly mediated the PTH action to its known target anion channel, i.e., cystic fibrosis transmembrane conductance regulator anion channel (CFTR). Specifically, PTH was able to induce phosphorylation of protein kinase A and phosphoinositide 3-kinase. Since the apical HCO3− efflux through CFTR often required the intracellular H+/HCO3− production and/or the Na+-dependent basolateral HCO3− uptake, the intracellular pH (pHi) balance might be disturbed, especially as a consequence of increased endogenous H+ and HCO3− production. However, measurement of pHi by a pH-sensitive dye suggested that the PTH-exposed Caco-2 cells were able to maintain normal pH despite robust HCO3− transport. In addition, although the plasma membrane Na+/K+-ATPase (NKA) is normally essential for basolateral HCO3− uptake and other transporters (e.g., NHE1), PTH did not induce insertion of new NKA molecules into the basolateral membrane as determined by membrane protein biotinylation technique. Thus, together with our previous data, we concluded that the PTH action on Caco-2 cells is dependent on PKA and PI3K with no detectable change in pHi or NKA abundance on cell membrane. Intestinal epithelial-like Caco-2 cells expressed CFTR and PTH1R. PTH increased anion transport across Caco-2 monolayer as suggested by Vt change. PTH induced phosphorylation of PKA and PI3K in Caco-2 cells. Intracellular pH was unaltered despite the presence of PTH-induced HCO3− efflux. PTH did not change Na+/K+-ATPase abundance in the plasma membrane.
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Affiliation(s)
- Rattana Chaimana
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Jarinthorn Teerapornpuntakit
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Walailak Jantarajit
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Kornkamon Lertsuwan
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Saowalak Krungchanuchat
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Nattapon Panupinthu
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Nateetip Krishnamra
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Narattaphol Charoenphandhu
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand.,Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.,The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
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Helmstadter KG, Ljubojevic-Holzer S, Wood BM, Taheri KD, Sedej S, Erickson JR, Bossuyt J, Bers DM. CaMKII and PKA-dependent phosphorylation co-regulate nuclear localization of HDAC4 in adult cardiomyocytes. Basic Res Cardiol 2021; 116:11. [PMID: 33590335 DOI: 10.1007/s00395-021-00850-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023]
Abstract
Nuclear histone deacetylase 4 (HDAC4) represses MEF2-mediated transcription, implicated in the development of heart failure. CaMKII-dependent phosphorylation drives nucleus-to-cytoplasm HDAC4 shuttling, but protein kinase A (PKA) is also linked to HDAC4 translocation. However, the interplay of CaMKII and PKA in regulating adult cardiomyocyte HDAC4 translocation is unclear. Here we sought to determine the interplay of PKA- and CaMKII-dependent HDAC4 phosphorylation and translocation in adult mouse, rabbit and human ventricular myocytes. Confocal imaging and protein analyses revealed that inhibition of CaMKII-but not PKA, PKC or PKD-raised nucleo-to-cytoplasmic HDAC4 fluorescence ratio (FNuc/FCyto) by ~ 50%, indicating baseline CaMKII activity that limits HDAC4 nuclear localization. Further CaMKII activation (via increased extracellular [Ca2+], high pacing frequencies, angiotensin II or overexpression of CaM or CaMKIIδC) led to significant HDAC4 nuclear export. In contrast, PKA activation by isoproterenol or forskolin drove HDAC4 into the nucleus (raising FNuc/FCyto by > 60%). These PKA-mediated effects were abolished in cells pretreated with PKA inhibitors and in cells expressing mutant HDAC4 in S265/266A mutant. In physiological conditions where both kinases are active, PKA-dependent nuclear accumulation of HDAC4 was predominant in the very early response, while CaMKII-dependent HDAC4 export prevailed upon prolonged stimuli. This orchestrated co-regulation was shifted in failing cardiomyocytes, where CaMKII-dependent effects predominated over PKA-dependent response. Importantly, human cardiomyocytes showed similar CaMKII- and PKA-dependent HDAC4 shifts. Collectively, CaMKII limits nuclear localization of HDAC4, while PKA favors HDAC4 nuclear retention and S265/266 is essential for PKA-mediated regulation. These pathways thus compete in HDAC4 nuclear localization and transcriptional regulation in cardiac signaling.
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13
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Schoijet AC, Sternlieb T, Alonso GD. Methods to Investigate Signal Transduction Pathways in Trypanosoma cruzi: Cyclic Nucleotide Phosphodiesterases Assay Protocols. Methods Mol Biol 2021; 2116:523-534. [PMID: 32221940 DOI: 10.1007/978-1-0716-0294-2_31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Intracellular levels of cyclic nucleotide second messengers are regulated predominantly by a large superfamily of phosphodiesterases (PDEs). Most of the different PDE variants play specific physiological functions; in fact, PDEs can associate with other proteins allowing them to be strategically anchored throughout the cell. In this regard, precise cellular expression and compartmentalization of these enzymes produce the specific control of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) gradients in cells and enable their integration with other signaling pathways.In trypanosomatids, some PDEs are essential for their survival and play fundamental roles in the adaptation of these parasites to different environmental stresses, as well as in the differentiation between their different life cycle forms. Given that these enzymes not only are similar to human PDEs but also have differential biochemical properties, and due to the great knowledge of drugs that target human PDEs, trypanosomatid PDEs could be postulated as important therapeutic targets through the repositioning of drugs.In this chapter, we describe a simple and sensitive radioisotope-based method to measure cyclic 3',5'-nucleotide phosphodiesterase using [3H]cAMP.
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Affiliation(s)
- Alejandra C Schoijet
- Laboratorio de Señalización y Mecanismos Adaptativos en Tripanosomátidos, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Buenos Aires, Argentina
| | - Tamara Sternlieb
- Laboratorio de Señalización y Mecanismos Adaptativos en Tripanosomátidos, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Buenos Aires, Argentina
| | - Guillermo D Alonso
- Laboratorio de Señalización y Mecanismos Adaptativos en Tripanosomátidos, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Buenos Aires, Argentina.
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14
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Nishimori S, Wein MN, Kronenberg HM. PTHrP targets salt-inducible kinases, HDAC4 and HDAC5, to repress chondrocyte hypertrophy in the growth plate. Bone 2021; 142:115709. [PMID: 33148508 PMCID: PMC7744326 DOI: 10.1016/j.bone.2020.115709] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 10/21/2020] [Indexed: 12/17/2022]
Abstract
Hypertrophy of chondrocytes is a crucial step in the endochondral bone formation process that drives bone lengthening and the transition to endochondral bone formation. Both Parathyroid hormone-related protein (PTHrP) and Histone deacetylase 4 (HDAC4) inhibit chondrocyte hypertrophy. Use of multiple mouse genetics models reveals how PTHrP and HDAC4 participate in a pathway that regulates chondrocyte hypertrophy. PTHrP/cAMP/protein kinase A (PKA) signaling pathway phosphorylates the PKA-target sites on salt-inducible kinase 3 (Sik3), which leads to inhibition of Sik3 kinase activity. Inhibition of Sik3 kinase activity decreases phosphorylation of HDAC4 by Sik3 at binding sites for 14-3-3; lower levels of HDAC4 phosphorylation then allow HDAC4 nuclear translocation. In the nucleus, the transcription factor, Myocyte Enhancer Factor 2 (Mef2), activates Runt-related transcription factor 2 (Runx2), and together these two transcription factors drive the hypertrophic process. HDAC4 binds both Mef2 and Runx2 and blocks their activities. There are genetic redundancies in this pathway. Sik1 and Sik2 also mediate PTHrP/cAMP/PKA signaling when Sik3 activity is low. HDAC5 also mediates PTHrP signaling when HDAC4 expression is low. Thus, PTHrP triggers a kinase cascade that leads to inhibition of the key transcription factors (Mef2 and Runx2) that promote chondrocyte hypertrophy.
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Affiliation(s)
- Shigeki Nishimori
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Department of Biochemistry, Teikyo University School of Medicine, Tokyo, Japan
| | - Marc N Wein
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Henry M Kronenberg
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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15
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Baro Graf C, Ritagliati C, Stival C, Luque GM, Gentile I, Buffone MG, Krapf D. Everything you ever wanted to know about PKA regulation and its involvement in mammalian sperm capacitation. Mol Cell Endocrinol 2020; 518:110992. [PMID: 32853743 DOI: 10.1016/j.mce.2020.110992] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 12/29/2022]
Abstract
The 3', 5'-cyclic adenosine monophosphate (cAMP) dependent protein kinase (PKA) is a tetrameric holoenzyme comprising a set of two regulatory subunits (PKA-R) and two catalytic (PKA-C) subunits. The PKA-R subunits act as sensors of cAMP and allow PKA-C activity. One of the first signaling events observed during mammalian sperm capacitation is PKA activation. Thus, understanding how PKA activity is restricted in space and time is crucial to decipher the critical steps of sperm capacitation. It is widely accepted that PKA specificity depends on several levels of regulation. Anchoring proteins play a pivotal role in achieving proper localization signaling, subcellular targeting and cAMP microdomains. These multi-factorial regulation steps are necessary for a precise spatio-temporal activation of PKA. Here we discuss recent understanding of regulatory mechanisms of PKA in mammalian sperm, such as post-translational modifications, in the context of its role as the master orchestrator of molecular events conducive to capacitation.
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Affiliation(s)
- Carolina Baro Graf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina; Laboratorio de Medicina Reproductiva (LMR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Carla Ritagliati
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Cintia Stival
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Guillermina M Luque
- Laboratory of Cellular and Molecular Reproductive Biology, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
| | - Iñaki Gentile
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Mariano G Buffone
- Laboratory of Cellular and Molecular Reproductive Biology, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
| | - Dario Krapf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina; Laboratorio de Medicina Reproductiva (LMR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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16
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Wang L, Han L, Xue P, Hu X, Wong SW, Deng M, Tseng HC, Huang BW, Ko CC. Dopamine suppresses osteoclast differentiation via cAMP/PKA/CREB pathway. Cell Signal 2020; 78:109847. [PMID: 33242564 DOI: 10.1016/j.cellsig.2020.109847] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/08/2020] [Accepted: 11/20/2020] [Indexed: 01/08/2023]
Abstract
How the nervous system regulates bone remodeling is an exciting area of emerging research in bone biology. Accumulating evidence suggest that neurotransmitter-mediated inputs from neurons may act directly on osteoclasts. Dopamine is a neurotransmitter that can be released by hypothalamic neurons to regulate bone metabolism through the hypothalamic-pituitary-gonadal axis. Dopamine is also present in sympathetic nerves that penetrate skeletal structures throughout the body. It has been shown that dopamine suppresses osteoclast differentiation via a D2-like receptors (D2R)-dependent manner, but the intracellular secondary signaling pathway has not been elucidated. In this study, we found that cAMP-response element binding protein (CREB) activity responds to dopamine treatment during osteoclastogenesis. Considering the critical role of CREB in osteoclastogenesis, we hypothesize that CREB may be a critical target in dopamine's regulation of osteoclast differentiation. We confirmed that D2R is also present in RAW cells and activated by dopamine. Binding of dopamine to D2R inhibits the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway which ultimately decreases CREB phosphorylation during osteoclastogenesis. This was also associated with diminished expression of osteoclast markers that are downstream of CREB. Pharmacological activation of adenylate cyclase (to increase cAMP production) and PKA reverses the effect of dopamine on CREB activity and osteoclastogenesis. Therefore, we have identified D2R/cAMP/PKA/CREB as a candidate pathway that mediates dopamine's inhibition of osteoclast differentiation. These findings will contribute to our understanding of how the nervous and skeletal systems interact to regulate bone remodeling. This will enable future work toward elucidating the role of the nervous system in bone development, repair, aging, and degenerative disease.
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Affiliation(s)
- Lufei Wang
- Division of Oral and Craniofacial Health Sciences, University of North Carolina Adams School of Dentistry, Chapel Hill, NC, United States
| | - Lichi Han
- Department of Oral Medicine, Medical College, Dalian University, Dalian, China
| | - Peng Xue
- Division of Oral and Craniofacial Health Sciences, University of North Carolina Adams School of Dentistry, Chapel Hill, NC, United States
| | - Xiangxiang Hu
- Division of Oral and Craniofacial Health Sciences, University of North Carolina Adams School of Dentistry, Chapel Hill, NC, United States
| | - Sing-Wai Wong
- Division of Comprehensive Oral Health, University of North Carolina Adams School of Dentistry, Chapel Hill, NC, United States
| | - Meng Deng
- Division of Craniofacial and Surgical Care, University of North Carolina Adams School of Dentistry, Chapel Hill, NC, United States
| | - Henry C Tseng
- Duke Eye Center and Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States
| | - Bo-Wen Huang
- Division of Orthodontics, The Ohio State University College of Dentistry, Columbus, OH, United States
| | - Ching-Chang Ko
- Division of Orthodontics, The Ohio State University College of Dentistry, Columbus, OH, United States.
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17
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Cui LN, Sun N, Li BX, Wang LF, Zhang XY, Qiu DL, Chu CP. Noradrenaline inhibits complex spikes activity via the presynaptic PKA signaling pathway in mouse cerebellar slices. Neurosci Lett 2020; 729:135008. [PMID: 32344107 DOI: 10.1016/j.neulet.2020.135008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/10/2020] [Accepted: 04/20/2020] [Indexed: 10/24/2022]
Abstract
Norepinephrine (NA) is an important neurotransmitter of the cerebellum that regulates synaptic transmission, motor regulation and motor learning under certain conditions via adrenergic receptors (ARs). We previously found that NA depressed cerebellar climbing fiber-Purkinje cell (CF-PC) synaptic transmission via α2-ARs in vivo in mice. We here investigated the mechanisms of NA inhibited CF-PC synaptic transmission in acute cerebellar slices using the whole-cell recording technique and pharmacological methods. Bath application of NA (10 μM) depressed CF-PC synaptic transmission, which exhibited a time-dependent decrease in amplitude of excitatory postsynaptic currents (N1), accompanied by an increase in the paired-pulse ratio (PPR). The NA-induced depression of CF-PC synaptic transmission was significantly prevented by inhibition of protein kinase A (PKA) with either H-89 or KT5720. Furthermore, the NA-induced inhibition of CF-PC synaptic transmission was rescued by activation adenylate cyclase (AC), and the AC-induced enhancement of CF-PC synaptic transmission was depressed by NA. Moreover, inhibition of AC with SQ22536, produced a significant depression of CF-PC synaptic transmission and abrogated the NA-induced depression of CF-PC synaptic transmission. However, the NA-induced depression of CF-PC synaptic transmission was not blocked by intracellular inhibition of PKA with a cell impermeable PKA inhibitor, PKI, or by extracellular inhibition of protein kinase C. These results indicate that NA activates presynaptic α2-AR, resulting in a depression of mouse cerebellar CF-PC synaptic transmission through the AC-PKA signaling pathway.
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Affiliation(s)
- Li-Na Cui
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China; Department of Acupuncture, Affiliated Hospital of Yanbian University, Yanji, Jilin, China
| | - Na Sun
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Bing-Xue Li
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Li-Fei Wang
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Xin-Yuan Zhang
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - De-Lai Qiu
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China.
| | - Chun-Ping Chu
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China.
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18
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Nemer A, Azab AN, Rimon G, Lamprecht S, Ben-Menahem D. Different roles of cAMP/PKA and PKC signaling in regulating progesterone and PGE 2 levels in immortalized rat granulosa cell cultures. Gen Comp Endocrinol 2018; 269:88-95. [PMID: 30144443 DOI: 10.1016/j.ygcen.2018.08.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/14/2018] [Accepted: 08/21/2018] [Indexed: 10/28/2022]
Abstract
Follicular cells from various species secrete steroids and prostaglandins, which are crucial for reproduction, in response to gonadotropins. Here, we examined prostaglandin E2 (PGE2) secretion from immortalized rat granulosa cells derived from preovulaotry follicles expressing the rat follicle stimulating hormone receptor (denoted as FSHR cells) that produce progesterone in response to gonadotropins. The cells were stimulated with a) pregnant mare's serum gonadotropin (PMSG; a rat FSH receptor agonist), b) activators of the protein kinase A (PKA) pathway (forskolin and a cell permeable cAMP analog Dibutyryl-cAMP (DB-cAMP)) and c) protein kinase C (PKC) (12-O-tetradecanoylphorbol 13-acetate; TPA), alone and in combination for 24 h. Thereafter, PGE2 and progesterone levels in the culture media were determined. In accordance with previous studies, while PMSG and the PKA pathway activators induced progesterone accumulation in the media, TPA did not. In contrast, our data indicate that TPA, but neither PMSG, forskolin and DB-cAMP evoked PGE2 accumulation in the media. Western Blot analysis of cell lysate showed a drastic TPA induced increase of COX-2 levels, which was not seen with neither PMSG nor forskolin treatment. This association between the COX-2 and PGE2 levels suggests that the enzyme activity is the likely factor that determines the synthesis and levels of the prostaglandin in the culture media of the granulosa-derived cells. The addition of the PKA inhibitor H-89 to the FSHR cultures suppressed the gonadotropin and forskolin induction of progesterone secretion. Incubation in the presence of GF109203X (a PKC inhibitor) attenuated the TPA induced PGE2 accumulation in the culture media of the cells (a dose dependent reduction of 40-70%). In addition, while TPA inhibited the PMSG and forskolin induced-accumulation of progesterone in the media, the gonadotropin and forskolin inhibited the elevation of PGE2 levels evoked by TPA (a dose dependent decrease of 35-55%). These data suggest that cAMP/PKA and PKC signaling have opposite effects on PGE2 and progesterone synthesis in FSHR cells. We propose that this PKA and PKC interplay on progesterone and PGE2 may be advantageous for the coordination of these key mediators for successful ovulation and luteinization.
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Affiliation(s)
- Ala Nemer
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Abed N Azab
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Gilad Rimon
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Sergio Lamprecht
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - David Ben-Menahem
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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19
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Ranieri A, Kemp E, Burgoyne JR, Avkiran M. β-Adrenergic regulation of cardiac type 2A protein phosphatase through phosphorylation of regulatory subunit B56δ at S573. J Mol Cell Cardiol 2017; 115:20-31. [PMID: 29294329 PMCID: PMC5823843 DOI: 10.1016/j.yjmcc.2017.12.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 12/19/2017] [Accepted: 12/29/2017] [Indexed: 11/18/2022]
Abstract
Background Type 2A protein phosphatase (PP2A) enzymes are serine/threonine phosphatases which comprise a scaffold A subunit, a regulatory B subunit and a catalytic C subunit, and have been implicated in the dephosphorylation of multiple cardiac phosphoproteins. B subunits determine subcellular targeting, substrate specificity and catalytic activity, and can themselves be regulated by post-translational modifications. We explored potential β-adrenergic regulation of PP2A in cardiomyocytes through phosphorylation of the regulatory B subunit isoform B56δ. Methods and results Phosphate affinity SDS-PAGE and immunoblot analysis revealed increased phosphorylation of B56δ in adult rat ventricular myocytes (ARVM) exposed to the β-adrenergic receptor (βAR) agonist isoprenaline (ISO). Phosphorylation of B56δ occurred at S573, primarily through stimulation of the β1AR subtype, and was dependent on PKA activity. The functional role of the phosphorylation was explored in ARVM transduced with adenoviruses expressing wild type (WT) or non-phosphorylatable (S573A) B56δ, fused to GFP at the N-terminus. C subunit expression was increased in ARVM expressing GFP-B56δ-WT or GFP-B56δ-S573A, both of which co-immunoprecipitated with endogenous C and A subunits. PP2A activity in cell lysates was increased in response to ISO in ARVM expressing GFP-B56δ-WT but not GFP-B56δ-S573A. Immunoblot analysis of the phosphoproteome in ARVM expressing GFP-B56δ-WT or GFP-B56δ-S573A with antibodies detecting (i) phospho-serine/threonine residues in distinct kinase substrate motifs or (ii) specific phosphorylated residues of functional importance in selected proteins revealed a comparable phosphorylation profile in the absence or presence of ISO stimulation. Conclusions In cardiomyocytes, βAR stimulation induces PKA-mediated phosphorylation of the PP2A regulatory subunit isoform B56δ at S573, which increases associated PP2A catalytic activity. This is likely to regulate the phosphorylation status of specific B56δ-PP2A substrates, which remain to be identified. PP2A subunit B56δ is phosphorylated on β-adrenergic stimulation of cardiomyocytes. Phosphorylation occurs at Ser573 and increases B56δ-PP2A catalytic activity. Response is mediated by the β1-adrenoceptor subtype and protein kinase A. Phosphorylated B56δ abundance is increased in pathological cardiac hypertrophy.
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Affiliation(s)
- Antonella Ranieri
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Elizabeth Kemp
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Joseph R Burgoyne
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Metin Avkiran
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom.
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20
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García-Morales V, Luaces-Regueira M, Campos-Toimil M. The cAMP effectors PKA and Epac activate endothelial NO synthase through PI3K/Akt pathway in human endothelial cells. Biochem Pharmacol 2017; 145:94-101. [PMID: 28912066 DOI: 10.1016/j.bcp.2017.09.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/07/2017] [Indexed: 02/05/2023]
Abstract
3',5'-Cyclic adenosine monophosphate (cAMP) exerts an endothelium-dependent vasorelaxant action by stimulating endothelial NO synthase (eNOS) activity, and the subsequent NO release, through cAMP protein kinase (PKA) and exchange protein directly activated by cAMP (Epac) activation in endothelial cells. Here, we have investigated the mechanism by which the cAMP-Epac/PKA pathway activates eNOS. cAMP-elevating agents (forskolin and dibutyryl-cAMP) and the joint activation of PKA (6-Bnz-cAMP) and Epac (8-pCPT-2'-O-Me-cAMP) increased cytoplasmic Ca2+ concentration ([Ca2+]c) in ≤30% of fura-2-loaded isolated human umbilical vein endothelial cells (HUVEC). However, these drugs did not modify [Ca2+]c in fluo-4-loaded HUVEC monolayers. In DAF-2-loaded HUVEC monolayers, forskolin, PKA and Epac activators significantly increased NO release, and the forskolin effect was reduced by inhibition of PKA (Rp-cAMPs), Epac (ESI-09), eNOS (L-NAME) or phosphoinositide 3-kinase (PI3K; LY-294,002). On the other hand, inhibition of CaMKII (KN-93), AMPK (Compound C), or total absence of Ca2+, was without effect. In Western blot experiments, Serine 1177 phosphorylated-eNOS was significantly increased in HUVEC by cAMP-elevating agents and PKA or Epac activators. In isolated rat aortic rings LY-294,002, but not KN-93 or Compound C, significantly reduced the vasorelaxant effects of forskolin in the presence of endothelium. Our results suggest that Epac and PKA activate eNOS via Ser 1177 phosphorylation by activating the PI3K/Akt pathway, and independently of AMPK or CaMKII activation or [Ca2+]c increase. This action explains, in part, the endothelium-dependent vasorelaxant effect of cAMP.
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Affiliation(s)
- Verónica García-Morales
- Pharmacology of Chronic Diseases (CD Pharma), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - María Luaces-Regueira
- Pharmacology of Chronic Diseases (CD Pharma), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Manuel Campos-Toimil
- Pharmacology of Chronic Diseases (CD Pharma), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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21
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Li L, Fan X, Zhang XT, Yue SQ, Sun ZY, Zhu JQ, Zhang JH, Gao XM, Zhang H. The effects of Chinese medicines on cAMP/PKA signaling in central nervous system dysfunction. Brain Res Bull 2017; 132:109-17. [PMID: 28438669 DOI: 10.1016/j.brainresbull.2017.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 04/11/2017] [Indexed: 01/06/2023]
Abstract
Neuropathological injury in the mammalian adult central nervous system (CNS) may cause axon disruption, neuronal death and lasting neurological deficits. Failure of axon regeneration is one of the major challenges for CNS functional recovery. Recently, the cAMP/PKA signaling pathway has been proven to be a critical regulator for neuronal regeneration, neuroplasticity, learning and memory. Also, previous studies have shown the effects of Chinese medicines on the prevention and treatment of CNS dysfunction mediated in part by cAMP/PKA signaling. In this review, the authors discuss current knowledge of the role of cAMP/PKA signaling pathway in neuronal regeneration and provide an overview of the Chinese medicines that may enable CNS functional recovery via this signaling pathway.
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22
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Chiaradonna F, Pirola Y, Ricciardiello F, Palorini R. Transcriptional profiling of immortalized and K-ras-transformed mouse fibroblasts upon PKA stimulation by forskolin in low glucose availability. Genom Data 2016; 9:100-4. [PMID: 27486565 PMCID: PMC4957573 DOI: 10.1016/j.gdata.2016.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 07/06/2016] [Indexed: 01/28/2023]
Abstract
Forskolin (FSK) induces activation of protein kinase A (PKA). This activation protects specifically some cancer cells from death induced by glucose starvation. Cell effects upon FSK treatment prompted us to investigate in detail the physiological role of PKA in the activation of pro-survival mechanisms in glucose starvation. In this regard we performed a microarray analysis of normal NIH3T3 and transformed NIH3T3-K-ras mouse fibroblasts cultured at 1 mM glucose and daily treated or not with 10 μM FSK until 72 h of growth, when the samples were collected. The microarray is deposited into Gene Expression Omnibus under Series GSE68266. The microarray data revealed that the activation of PKA regulates the expression of genes involved in metabolic, stress-response and pro-survival processes, like glutamine metabolism, autophagy and unfolded protein response, preventing cancer cell death in glucose starvation. Altogether these findings suggest that PKA activation, by inducing a complex transcriptional program, leads to cancer survival in nutrient stress, a typical feature of developing tumor. These transcriptional data, identifying this important role of PKA, will be useful to identify novel target in cancer therapy.
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Affiliation(s)
- Ferdinando Chiaradonna
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Yuri Pirola
- Department of Informatics Systems and Communication (DISCo), University of Milano-Bicocca, Viale Sarca 336, 20126 Milan, Italy
| | - Francesca Ricciardiello
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Roberta Palorini
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
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23
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Diviani D, Reggi E, Arambasic M, Caso S, Maric D. Emerging roles of A-kinase anchoring proteins in cardiovascular pathophysiology. Biochim Biophys Acta 2015; 1863:1926-36. [PMID: 26643253 DOI: 10.1016/j.bbamcr.2015.11.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/20/2015] [Accepted: 11/23/2015] [Indexed: 01/08/2023]
Abstract
Heart and blood vessels ensure adequate perfusion of peripheral organs with blood and nutrients. Alteration of the homeostatic functions of the cardiovascular system can cause hypertension, atherosclerosis, and coronary artery disease leading to heart injury and failure. A-kinase anchoring proteins (AKAPs) constitute a family of scaffolding proteins that are crucially involved in modulating the function of the cardiovascular system both under physiological and pathological conditions. AKAPs assemble multifunctional signaling complexes that ensure correct targeting of the cAMP-dependent protein kinase (PKA) as well as other signaling enzymes to precise subcellular compartments. This allows local regulation of specific effector proteins that control the function of vascular and cardiac cells. This review will focus on recent advances illustrating the role of AKAPs in cardiovascular pathophysiology. The accent will be mainly placed on the molecular events linked to the control of vascular integrity and blood pressure as well as on the cardiac remodeling process associated with heart failure. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Dario Diviani
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland.
| | - Erica Reggi
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
| | - Miroslav Arambasic
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
| | - Stefania Caso
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
| | - Darko Maric
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
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24
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Gupte RP, Kadunganattil S, Shepherd AJ, Merrill R, Planer W, Bruchas MR, Strack S, Mohapatra DP. Convergent phosphomodulation of the major neuronal dendritic potassium channel Kv4.2 by pituitary adenylate cyclase-activating polypeptide. Neuropharmacology 2015; 101:291-308. [PMID: 26456351 DOI: 10.1016/j.neuropharm.2015.10.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 09/29/2015] [Accepted: 10/03/2015] [Indexed: 12/30/2022]
Abstract
The endogenous neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is secreted by both neuronal and non-neuronal cells in the brain and spinal cord, in response to pathological conditions such as stroke, seizures, chronic inflammatory and neuropathic pain. PACAP has been shown to exert various neuromodulatory and neuroprotective effects. However, direct influence of PACAP on the function of intrinsically excitable ion channels that are critical to both hyperexcitation as well as cell death, remain largely unexplored. The major dendritic K(+) channel Kv4.2 is a critical regulator of neuronal excitability, back-propagating action potentials in the dendrites, and modulation of synaptic inputs. We identified, cloned and characterized the downstream signaling originating from the activation of three PACAP receptor (PAC1) isoforms that are expressed in rodent hippocampal neurons that also exhibit abundant expression of Kv4.2 protein. Activation of PAC1 by PACAP leads to phosphorylation of Kv4.2 and downregulation of channel currents, which can be attenuated by inhibition of either PKA or ERK1/2 activity. Mechanistically, this dynamic downregulation of Kv4.2 function is a consequence of reduction in the density of surface channels, without any influence on the voltage-dependence of channel activation. Interestingly, PKA-induced effects on Kv4.2 were mediated by ERK1/2 phosphorylation of the channel at two critical residues, but not by direct channel phosphorylation by PKA, suggesting a convergent phosphomodulatory signaling cascade. Altogether, our findings suggest a novel GPCR-channel signaling crosstalk between PACAP/PAC1 and Kv4.2 channel in a manner that could lead to neuronal hyperexcitability.
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Affiliation(s)
- Raeesa P Gupte
- Department of Pharmacology, The University of Iowa Roy J. and Lucile A. Carver College of Medicine, Iowa City, IA 52242, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Suraj Kadunganattil
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Andrew J Shepherd
- Department of Pharmacology, The University of Iowa Roy J. and Lucile A. Carver College of Medicine, Iowa City, IA 52242, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ronald Merrill
- Department of Pharmacology, The University of Iowa Roy J. and Lucile A. Carver College of Medicine, Iowa City, IA 52242, USA
| | - William Planer
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael R Bruchas
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stefan Strack
- Department of Pharmacology, The University of Iowa Roy J. and Lucile A. Carver College of Medicine, Iowa City, IA 52242, USA
| | - Durga P Mohapatra
- Department of Pharmacology, The University of Iowa Roy J. and Lucile A. Carver College of Medicine, Iowa City, IA 52242, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, USA; Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, MO 63110, USA.
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25
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Graves J, Markman S, Alegranti Y, Gechtler J, Johnson RI, Cagan R, Ben-Menahem D. The LH/CG receptor activates canonical signaling pathway when expressed in Drosophila. Mol Cell Endocrinol 2015; 413:145-56. [PMID: 26112185 DOI: 10.1016/j.mce.2015.06.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 05/29/2015] [Accepted: 06/18/2015] [Indexed: 01/12/2023]
Abstract
G-protein coupled receptors (GPCRs) and their ligands provide precise tissue regulation and are therefore often restricted to specific animal phyla. For example, the gonadotropins and their receptors are crucial for vertebrate reproduction but absent from invertebrates. In mammals, LHR mainly couples to the PKA signaling pathway, and CREB is the major transcription factor of this pathway. Here we present the results of expressing elements of the human gonadotropin system in Drosophila. Specifically, we generated transgenic Drosophila expressing the human LH/CG receptor (denoted as LHR), a constitutively active form of LHR, and an hCG analog. We demonstrate activation-dependent signaling by LHR to direct Drosophila phenotypes including lethality and specific midline defects; these phenotypes were due to LHR activation of PKA/CREB pathway activity. That the LHR can act in an invertebrate demonstrates the conservation of factors required for GPCR function among phylogenetically distant organisms. This novel gonadotropin model may assist the identification of new modulators of mammalian fertility by exploiting the powerful genetic and pharmacological tools available in Drosophila.
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Affiliation(s)
- Justin Graves
- Dept. of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New-York, NY, USA
| | - Svetlana Markman
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yair Alegranti
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Jenia Gechtler
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ruth I Johnson
- Dept. of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New-York, NY, USA
| | - Ross Cagan
- Dept. of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New-York, NY, USA
| | - David Ben-Menahem
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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26
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Li X, Jiang L, Yang M, Wu Y, Sun S, Sun J. GLP-1 receptor agonist increases the expression of CTRP3, a novel adipokine, in 3T3-L1 adipocytes through PKA signal pathway. J Endocrinol Invest 2015; 38:73-9. [PMID: 25149084 DOI: 10.1007/s40618-014-0156-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 08/07/2014] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To investigate the effects of Exendin-4 (Ex-4), a glucagon-like peptide-1 (GLP-1) receptor agonist, on the expression of C1q/TNF-related protein-3 (CTRP3), a novel adipokine, in 3T3-L1 adipocytes. The role of protein kinase A (PKA) signal pathway in the effects was also investigated. METHODS The mRNA and protein expressions of CTRP3 in 3T3-L1 adiocytes were detected by real-time polymerase chain reaction and western blot, respectively. Exendin-fragment 9-39 (Ex-9), a specific GLP-1 receptor antagonist, and H89, a selective antagonist of PKA, were used to confirm the signal pathway of Ex-4 on CTRP3. RESULTS 2.5 or 5.0 nmol/l Ex-4 treatment for 8 h increased the expressions of CTRP3 mRNA and protein as well as PKA protein in 3T3-L1 adipocytes significantly, while Ex-9 or H89 blocked the up-regulation of CTRP3 expression induced by Ex-4 completely. CONCLUSION GLP-1 receptor agonist increases the expression of CTRP3 mRNA and protein in 3T3-L1 adipocytes via PKA signal pathway.
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Affiliation(s)
- X Li
- Department of Endocrinology, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China.
| | - L Jiang
- Department of Internal Medicine, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
| | - M Yang
- Department of Endocrinology, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
| | - Y Wu
- Department of Endocrinology, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
| | - S Sun
- Department of Endocrinology, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
| | - J Sun
- Department of Endocrinology, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
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27
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Pasyk S, Molinski S, Ahmadi S, Ramjeesingh M, Huan LJ, Chin S, Du K, Yeger H, Taylor P, Moran MF, Bear CE. The major cystic fibrosis causing mutation exhibits defective propensity for phosphorylation. Proteomics 2014; 15:447-61. [PMID: 25330774 DOI: 10.1002/pmic.201400218] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 09/24/2014] [Accepted: 10/16/2014] [Indexed: 11/11/2022]
Abstract
The major cystic fibrosis causing mutation, F508del-CFTR (where CFTR is cystic fibrosis transmembrane conductance regulator), impairs biosynthetic maturation of the CFTR protein, limiting its expression as a phosphorylation-dependent channel on the cell surface. The maturation defect can be partially rescued by low-temperature (27°C) cell culture conditions or small-molecule corrector compounds. Following its partial rescue, the open probability of F508del-CFTR is enhanced by the potentiator compound, VX-770. However, the channel activity of rescued F508del-CFTR remains less than that of the Wt-CFTR protein in the presence of VX-770. In this study, we asked if there are allosteric effects of F508del on the phosphorylation-regulated R domain. To identify defects in the R domain, we compared the phosphorylation status at protein kinase A sites in the R domain of Wt and F508del-CFTR. Here we show that phosphorylation of Ser-660, quantified by SRM-MS, is reduced in F508del-CFTR. Although the generation of a phosphomimic at this site (substituting aspartic acid for serine) did not modify the maturation defect, it did enhance F508del-CFTR channel function after pharmacological rescue with corrector VX-809, and treatment with the potentiator, VX-770. These findings support the concept that defective phosphorylation of F508del-CFTR partially accounts for its altered channel activity at the cell surface.
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Affiliation(s)
- Stan Pasyk
- Programme in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, The University of Toronto, Toronto, ON, Canada
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28
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Anekal PV, Yong J, Manser E. Arg kinase-binding protein 2 (ArgBP2) interaction with α-actinin and actin stress fibers inhibits cell migration. J Biol Chem 2014; 290:2112-25. [PMID: 25429109 DOI: 10.1074/jbc.m114.610725] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cell migration requires dynamic remodeling of the actomyosin network. We report here that an adapter protein, ArgBP2, is a component of α-actinin containing stress fibers and inhibits migration. ArgBP2 is undetectable in many commonly studied cancer-derived cell lines. COS-7 and HeLa cells express ArgBP2 (by Western analysis), but expression was detectable only in approximately half the cells by immunofluorescence. Short term clonal analysis demonstrated 0.2-0.3% of cells switch ArgBP2 expression (on or off) per cell division. ArgBP2 can have a fundamental impact on the actomyosin network: ArgBP2 positive COS-7 cells, for example, are clearly distinguishable by their denser actomyosin (stress fiber) network. ArgBP2γ binding to α-actinin appears to underlie its ability to localize to stress fibers and decrease cell migration. We map a small α-actinin binding region in ArgBP2 (residues 192-228) that is essential for these effects. Protein kinase A phosphorylation of ArgBP2γ at neighboring Ser-259 and consequent 14-3-3 binding blocks its interaction with α-actinin. ArgBP2 is known to be down-regulated in some aggressively metastatic cancers. Our work provides a biochemical explanation for the anti-migratory effect of ArgBP2.
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Affiliation(s)
- Praju Vikas Anekal
- From the sGSK Group Institute of Molecular and Cell Biology (IMCB), Proteos Building, 61 Biopolis Drive, 138673 Singapore
| | - Jeffery Yong
- From the sGSK Group Institute of Molecular and Cell Biology (IMCB), Proteos Building, 61 Biopolis Drive, 138673 Singapore
| | - Ed Manser
- From the sGSK Group Institute of Molecular and Cell Biology (IMCB), Proteos Building, 61 Biopolis Drive, 138673 Singapore, the Institute of Medical Biology (IMB), 8A Biomedical Grove, 06-06 Immunos Building, 138648 Singapore, and the Department of Pharmacology, National University of Singapore, 119077 Singapore
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29
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Dong Q, Giorgianni F, Deng X, Beranova-Giorgianni S, Bridges D, Park EA, Raghow R, Elam MB. Phosphorylation of sterol regulatory element binding protein-1a by protein kinase A (PKA) regulates transcriptional activity. Biochem Biophys Res Commun 2014; 449:449-54. [PMID: 24853806 DOI: 10.1016/j.bbrc.2014.05.046] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
Abstract
The counter-regulatory hormone glucagon inhibits lipogenesis via downregulation of sterol regulatory element binding protein 1 (SREBP-1). The effect of glucagon is mediated via protein kinase A (PKA). To determine if SREBP-1 is a direct phosphorylation target of PKA, we conducted mass spectrometry analysis of recombinant n-terminal SREBP-1a following PKA treatment in vitro. This analysis identified serines 331/332 as bona-fide phosphorylation targets of PKA. To determine the functional consequences of phosphorylation at these sites, we constructed mammalian expression vector for both nSREBP-1a and 1c isoforms in which the candidate PKA phosphorylation sites were mutated to active phosphomimetic or non-phosphorylatable amino acids. The transcriptional activity of SREBP was reduced by the phosphomimetic mutation of S332 of nSREBP-1a and the corresponding serine (S308) of nSREBP-1c. This site is a strong candidate for mediating the negative regulatory effect of glucagon on SREBP-1 and lipogenesis.
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Affiliation(s)
- Qingming Dong
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Francesco Giorgianni
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Xiong Deng
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN, USA; Research Service, Veteran's Affairs Medical Center, Memphis, TN, USA
| | - Sarka Beranova-Giorgianni
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Dave Bridges
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Edwards A Park
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Rajendra Raghow
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN, USA; Research Service, Veteran's Affairs Medical Center, Memphis, TN, USA
| | - Marshall B Elam
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN, USA; Research Service, Veteran's Affairs Medical Center, Memphis, TN, USA.
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30
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Dos Santos-Rodrigues A, Grañé-Boladeras N, Bicket A, Coe IR. Nucleoside transporters in the purinome. Neurochem Int 2014; 73:229-37. [PMID: 24704797 DOI: 10.1016/j.neuint.2014.03.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 03/23/2014] [Accepted: 03/24/2014] [Indexed: 01/20/2023]
Abstract
The purinome is a rich complex of proteins and cofactors that are involved in fundamental aspects of cellular homeostasis and cellular responses. The purinome is evolutionarily ancient and is made up of thousands of members. Our understanding of the mechanisms linking some parts of this complex network and the physiological relevance of the various connections is well advanced. However, our understanding of other parts of the purinome is less well developed. Our research focuses on the adenosine or nucleoside transporters (NTs), which are members of the membrane purinome. Nucleoside transporters are integral membrane proteins that are responsible for the flux of nucleosides, such as adenosine, and nucleoside analog drugs, used in a variety of anti-cancer, anti-viral and anti-parasite therapies, across cell membranes. Nucleoside transporters form the SLC28 and SLC29 families of solute carriers and the protein members of these families are widely distributed in human tissues including the central nervous system (CNS). NTs modulate purinergic signaling in the CNS primarily through their effects on modulating prevailing adenosine levels inside and outside the cell. By clearing the extracellular milieu of adenosine, NTs can terminate adenosine receptor-dependent signaling and this raises the possibility of regulatory feedback loops that tie together receptor signaling with transporter function. Despite the important role of NTs as modulators of purinergic signaling in the human body, very little is known about the nature or underlying mechanisms of regulation of either the SLC28 or SLC29 families, particularly within the context of the CNS purinome. Here we provide a brief overview of our current understanding of the regulation of members of the SLC29 family and highlight some interesting avenues for future research.
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Affiliation(s)
| | - Natalia Grañé-Boladeras
- Department of Chemistry and Biology, Faculty of Science, Ryerson University, Toronto, ON, Canada
| | - Alex Bicket
- Department of Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Imogen R Coe
- Department of Biology, Faculty of Science, York University, Toronto, ON, Canada; Department of Chemistry and Biology, Faculty of Science, Ryerson University, Toronto, ON, Canada.
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Abstract
Despite the simplicity of the yeast Saccharomyces cerevisiae, its basic cellular machinery tremendously mirrors that of higher eukaryotic counterparts. Thus, this unicellular organism turned out to be an invaluable model system to study the countless mechanisms that govern life of the cell. Recently, it has also enabled the deciphering of signalling pathways that control flux of mitochondrial proteins to the organelle according to metabolic requirements. For decades mitochondria were considered autonomous organelles that are only partially incorporated into cellular signalling networks. Consequently, only little has been known about the role of reversible phosphorylation as a meaningful mechanism that orchestrates mitochondrial biology accordingly to cellular needs. Therefore, research in this direction has been vastly neglected. However, findings over the past few years have changed this view and new exciting fields in mitochondrial biology have emerged. Here, we summarize recent discoveries in the yeast model system that point towards a vital role of reversible phosphorylation in regulation of mitochondrial protein import.
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Affiliation(s)
| | - Chris Meisinger
- Institut für Biochemie und Molekularbiologie, ZBMZ ; BIOSS Centre for Biological Signalling Studies
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