1
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Yang W, Mei FC, Lin W, White MA, Li L, Li Y, Pan S, Cheng X. Protein SUMOylation promotes cAMP-independent EPAC1 activation. Cell Mol Life Sci 2024; 81:283. [PMID: 38963422 DOI: 10.1007/s00018-024-05315-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/20/2024] [Accepted: 06/12/2024] [Indexed: 07/05/2024]
Abstract
Protein SUMOylation is a prevalent stress-response posttranslational modification crucial for maintaining cellular homeostasis. Herein, we report that protein SUMOylation modulates cellular signaling mediated by cAMP, an ancient and universal stress-response second messenger. We identify K561 as a primary SUMOylation site in exchange protein directly activated by cAMP (EPAC1) via site-specific mapping of SUMOylation using mass spectrometry. Sequence and site-directed mutagenesis analyses reveal that a functional SUMO-interacting motif in EPAC1 is required for the binding of SUMO-conjugating enzyme UBC9, formation of EPAC1 nuclear condensate, and EPAC1 cellular SUMOylation. Heat shock-induced SUMO modification of EPAC1 promotes Rap1/2 activation in a cAMP-independent manner. Structural modeling and molecular dynamics simulation studies demonstrate that SUMO substituent on K561 of EPAC1 promotes Rap1 interaction by increasing the buried surface area between the SUMOylated receptor and its effector. Our studies identify a functional SUMOylation site in EPAC1 and unveil a novel mechanism in which SUMOylation of EPAC1 leads to its autonomous activation. The findings of SUMOylation-mediated activation of EPAC1 not only provide new insights into our understanding of cellular regulation of EPAC1 but also will open up a new field of experimentation concerning the cross-talk between cAMP/EPAC1 signaling and protein SUMOylation, two major cellular stress response pathways, during cellular homeostasis.
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Affiliation(s)
- Wenli Yang
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Fang C Mei
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Wei Lin
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Mark A White
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Li Li
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Yue Li
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Cell Therapy Manufacturing Center, 2130 W Holcombe Blvd, Houston, TX, 77030, USA
| | - Sheng Pan
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, TX, USA.
- Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX, USA.
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, USA.
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2
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Zhang T, Dolga AM, Eisel ULM, Schmidt M. Novel crosstalk mechanisms between GluA3 and Epac2 in synaptic plasticity and memory in Alzheimer's disease. Neurobiol Dis 2024; 191:106389. [PMID: 38142840 DOI: 10.1016/j.nbd.2023.106389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease which accounts for the most cases of dementia worldwide. Impaired memory, including acquisition, consolidation, and retrieval, is one of the hallmarks in AD. At the cellular level, dysregulated synaptic plasticity partly due to reduced long-term potentiation (LTP) and enhanced long-term depression (LTD) underlies the memory deficits in AD. GluA3 containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are one of key receptors involved in rapid neurotransmission and synaptic plasticity. Recent studies revealed a novel form of GluA3 involved in neuronal plasticity that is dependent on cyclic adenosine monophosphate (cAMP), rather than N-methyl-d-aspartate (NMDA). However, this cAMP-dependent GluA3 pathway is specifically and significantly impaired by amyloid beta (Aβ), a pathological marker of AD. cAMP is a key second messenger that plays an important role in modulating memory and synaptic plasticity. We previously reported that exchange protein directly activated by cAMP 2 (Epac2), acting as a main cAMP effector, plays a specific and time-limited role in memory retrieval. From electrophysiological perspective, Epac2 facilities the maintenance of LTP, a cellular event closely associated with memory retrieval. Additionally, Epac2 was found to be involved in the GluA3-mediated plasticity. In this review, we comprehensively summarize current knowledge regarding the specific roles of GluA3 and Epac2 in synaptic plasticity and memory, and their potential association with AD.
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Affiliation(s)
- Tong Zhang
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747 AG, Netherlands
| | - Amalia M Dolga
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Ulrich L M Eisel
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747 AG, Netherlands
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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3
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Yang W, Mei FC, Lin W, White MA, Li L, Li Y, Pan S, Cheng X. Protein SUMOylation promotes cAMP-independent EPAC1 activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.08.574738. [PMID: 38260470 PMCID: PMC10802480 DOI: 10.1101/2024.01.08.574738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Exchange protein directly activated by cAMP (EPAC1) mediates the intracellular functions of a critical stress-response second messenger, cAMP. Herein, we report that EPAC1 is a cellular substrate of protein SUMOylation, a prevalent stress-response posttranslational modification. Site-specific mapping of SUMOylation by mass spectrometer leads to identifying K561 as a primary SUMOylation site in EPAC1. Sequence and site-directed mutagenesis analyses reveal a functional SUMO-interacting motif required for cellular SUMOylation of EPAC1. SUMO modification of EPAC1 mediates its heat shock-induced Rap1/2 activation in a cAMP-independent manner. Structural modeling and molecular dynamics simulation studies demonstrate that SUMO substituent on K561 of EPAC1 promotes Rap1 interaction by increasing the buried surface area between the SUMOylated receptor and its effector. Our studies identify a functional SUMOylation site in EPAC1 and unveil a novel mechanism in which SUMOylation of EPAC1 leads to its autonomous activation. The findings of SUMOylation-mediated activation of EPAC1 not only provide new insights into our understanding of cellular regulation of EPAC1 but also will open up a new field of experimentation concerning the cross-talk between cAMP/EPAC1 signaling and protein SUMOylation, two major cellular stress response pathways, during cellular homeostasis.
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4
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Iannucci LF, D'Erchia AM, Picardi E, Bettio D, Conca F, Surdo NC, Di Benedetto G, Musso D, Arrigoni C, Lolicato M, Vismara M, Grisan F, Salviati L, Milanesi L, Pesole G, Lefkimmiatis K. Cyclic AMP induces reversible EPAC1 condensates that regulate histone transcription. Nat Commun 2023; 14:5521. [PMID: 37684224 PMCID: PMC10491619 DOI: 10.1038/s41467-023-41088-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
The second messenger cyclic AMP regulates many nuclear processes including transcription, pre-mRNA splicing and mitosis. While most functions are attributed to protein kinase A, accumulating evidence suggests that not all nuclear cyclic AMP-dependent effects are mediated by this kinase, implying that other effectors may be involved. Here we explore the nuclear roles of Exchange Protein Activated by cyclic AMP 1. We find that it enters the nucleus where forms reversible biomolecular condensates in response to cyclic AMP. This phenomenon depends on intrinsically disordered regions present at its amino-terminus and is independent of protein kinase A. Finally, we demonstrate that nuclear Exchange Protein Activated by cyclic AMP 1 condensates assemble at genomic loci on chromosome 6 in the proximity of Histone Locus Bodies and promote the transcription of a histone gene cluster. Collectively, our data reveal an unexpected mechanism through which cyclic AMP contributes to nuclear spatial compartmentalization and promotes the transcription of specific genes.
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Affiliation(s)
- Liliana Felicia Iannucci
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- Veneto Institute of Molecular Medicine, 35129, Padova, Italy
| | - Anna Maria D'Erchia
- Department of Biosciences, Biotechnologies and Environment, University of Bari "Aldo Moro", Bari, Italy
| | - Ernesto Picardi
- Department of Biosciences, Biotechnologies and Environment, University of Bari "Aldo Moro", Bari, Italy
| | - Daniela Bettio
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Filippo Conca
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- Veneto Institute of Molecular Medicine, 35129, Padova, Italy
| | - Nicoletta Concetta Surdo
- Veneto Institute of Molecular Medicine, 35129, Padova, Italy
- Institute of Neuroscience (IN-CNR), National Research Council of Italy, Padova, Italy
| | - Giulietta Di Benedetto
- Veneto Institute of Molecular Medicine, 35129, Padova, Italy
- Institute of Neuroscience (IN-CNR), National Research Council of Italy, Padova, Italy
| | - Deborah Musso
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | | | - Marco Lolicato
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Mauro Vismara
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- Veneto Institute of Molecular Medicine, 35129, Padova, Italy
| | | | - Leonardo Salviati
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Luciano Milanesi
- Institute of Biomedical Technologies, National Research Council of Italy, Milan, Italy
| | - Graziano Pesole
- Department of Biosciences, Biotechnologies and Environment, University of Bari "Aldo Moro", Bari, Italy
| | - Konstantinos Lefkimmiatis
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.
- Veneto Institute of Molecular Medicine, 35129, Padova, Italy.
- Institute of Neuroscience (IN-CNR), National Research Council of Italy, Padova, Italy.
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5
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Veth TS, Francavilla C, Heck AJR, Altelaar M. Elucidating Fibroblast Growth Factor-Induced Kinome Dynamics Using Targeted Mass Spectrometry and Dynamic Modeling. Mol Cell Proteomics 2023; 22:100594. [PMID: 37328066 PMCID: PMC10368922 DOI: 10.1016/j.mcpro.2023.100594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/02/2023] [Accepted: 06/12/2023] [Indexed: 06/18/2023] Open
Abstract
Fibroblast growth factors (FGFs) are paracrine or endocrine signaling proteins that, activated by their ligands, elicit a wide range of health and disease-related processes, such as cell proliferation and the epithelial-to-mesenchymal transition. The detailed molecular pathway dynamics that coordinate these responses have remained to be determined. To elucidate these, we stimulated MCF-7 breast cancer cells with either FGF2, FGF3, FGF4, FGF10, or FGF19. Following activation of the receptor, we quantified the kinase activity dynamics of 44 kinases using a targeted mass spectrometry assay. Our system-wide kinase activity data, supplemented with (phospho)proteomics data, reveal ligand-dependent distinct pathway dynamics, elucidate the involvement of not earlier reported kinases such as MARK, and revise some of the pathway effects on biological outcomes. In addition, logic-based dynamic modeling of the kinome dynamics further verifies the biological goodness-of-fit of the predicted models and reveals BRAF-driven activation upon FGF2 treatment and ARAF-driven activation upon FGF4 treatment.
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Affiliation(s)
- Tim S Veth
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Chiara Francavilla
- Division of Molecular and Cellular Function, School of Biological Science, and Manchester Breast Centre, Manchester Cancer Research Centre, Faculty of Biology Medicine and Health (FBMH), The University of Manchester, Manchester, UK
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands.
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6
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Sartre C, Peurois F, Ley M, Kryszke MH, Zhang W, Courilleau D, Fischmeister R, Ambroise Y, Zeghouf M, Cianferani S, Ferrandez Y, Cherfils J. Membranes prime the RapGEF EPAC1 to transduce cAMP signaling. Nat Commun 2023; 14:4157. [PMID: 37438343 DOI: 10.1038/s41467-023-39894-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/30/2023] [Indexed: 07/14/2023] Open
Abstract
EPAC1, a cAMP-activated GEF for Rap GTPases, is a major transducer of cAMP signaling and a therapeutic target in cardiac diseases. The recent discovery that cAMP is compartmentalized in membrane-proximal nanodomains challenged the current model of EPAC1 activation in the cytosol. Here, we discover that anionic membranes are a major component of EPAC1 activation. We find that anionic membranes activate EPAC1 independently of cAMP, increase its affinity for cAMP by two orders of magnitude, and synergize with cAMP to yield maximal GEF activity. In the cell cytosol, where cAMP concentration is low, EPAC1 must thus be primed by membranes to bind cAMP. Examination of the cell-active chemical CE3F4 in this framework further reveals that it targets only fully activated EPAC1. Together, our findings reformulate previous concepts of cAMP signaling through EPAC proteins, with important implications for drug discovery.
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Affiliation(s)
- Candice Sartre
- Université Paris-Saclay, Ecole Normale Supérieure Paris-Saclay, CNRS, 91190, Gif-sur-Yvette, France
| | - François Peurois
- Université Paris-Saclay, Ecole Normale Supérieure Paris-Saclay, CNRS, 91190, Gif-sur-Yvette, France
| | - Marie Ley
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, IPHC, CNRS UMR 7178, Infrastructure Nationale de Protéomique ProFI - FR2048, 67087, Strasbourg, France
| | - Marie-Hélène Kryszke
- Université Paris-Saclay, Ecole Normale Supérieure Paris-Saclay, CNRS, 91190, Gif-sur-Yvette, France
| | - Wenhua Zhang
- Université Paris-Saclay, Ecole Normale Supérieure Paris-Saclay, CNRS, 91190, Gif-sur-Yvette, France
| | - Delphine Courilleau
- Université Paris-Saclay, IPSIT-CIBLOT, Inserm US31, CNRS UAR3679, 91400, Orsay, France
| | | | - Yves Ambroise
- Université Paris-Saclay, CEA, Service de Chimie Bioorganique et de Marquage, 91191, Gif-sur-Yvette, France
| | - Mahel Zeghouf
- Université Paris-Saclay, Ecole Normale Supérieure Paris-Saclay, CNRS, 91190, Gif-sur-Yvette, France
| | - Sarah Cianferani
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, IPHC, CNRS UMR 7178, Infrastructure Nationale de Protéomique ProFI - FR2048, 67087, Strasbourg, France
| | - Yann Ferrandez
- Université Paris-Saclay, Ecole Normale Supérieure Paris-Saclay, CNRS, 91190, Gif-sur-Yvette, France
| | - Jacqueline Cherfils
- Université Paris-Saclay, Ecole Normale Supérieure Paris-Saclay, CNRS, 91190, Gif-sur-Yvette, France.
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7
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Ramanadham S, Turk J, Bhatnagar S. Noncanonical Regulation of cAMP-Dependent Insulin Secretion and Its Implications in Type 2 Diabetes. Compr Physiol 2023; 13:5023-5049. [PMID: 37358504 PMCID: PMC10809800 DOI: 10.1002/cphy.c220031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Impaired glucose tolerance (IGT) and β-cell dysfunction in insulin resistance associated with obesity lead to type 2 diabetes (T2D). Glucose-stimulated insulin secretion (GSIS) from β-cells occurs via a canonical pathway that involves glucose metabolism, ATP generation, inactivation of K ATP channels, plasma membrane depolarization, and increases in cytosolic concentrations of [Ca 2+ ] c . However, optimal insulin secretion requires amplification of GSIS by increases in cyclic adenosine monophosphate (cAMP) signaling. The cAMP effectors protein kinase A (PKA) and exchange factor activated by cyclic-AMP (Epac) regulate membrane depolarization, gene expression, and trafficking and fusion of insulin granules to the plasma membrane for amplifying GSIS. The widely recognized lipid signaling generated within β-cells by the β-isoform of Ca 2+ -independent phospholipase A 2 enzyme (iPLA 2 β) participates in cAMP-stimulated insulin secretion (cSIS). Recent work has identified the role of a G-protein coupled receptor (GPCR) activated signaling by the complement 1q like-3 (C1ql3) secreted protein in inhibiting cSIS. In the IGT state, cSIS is attenuated, and the β-cell function is reduced. Interestingly, while β-cell-specific deletion of iPLA 2 β reduces cAMP-mediated amplification of GSIS, the loss of iPLA 2 β in macrophages (MØ) confers protection against the development of glucose intolerance associated with diet-induced obesity (DIO). In this article, we discuss canonical (glucose and cAMP) and novel noncanonical (iPLA 2 β and C1ql3) pathways and how they may affect β-cell (dys)function in the context of impaired glucose intolerance associated with obesity and T2D. In conclusion, we provide a perspective that in IGT states, targeting noncanonical pathways along with canonical pathways could be a more comprehensive approach for restoring β-cell function in T2D. © 2023 American Physiological Society. Compr Physiol 13:5023-5049, 2023.
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Affiliation(s)
- Sasanka Ramanadham
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Alabama, USA
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
| | - John Turk
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Sushant Bhatnagar
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
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8
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Slika H, Mansour H, Nasser SA, Shaito A, Kobeissy F, Orekhov AN, Pintus G, Eid AH. Epac as a tractable therapeutic target. Eur J Pharmacol 2023; 945:175645. [PMID: 36894048 DOI: 10.1016/j.ejphar.2023.175645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/09/2023]
Abstract
In 1957, cyclic adenosine monophosphate (cAMP) was identified as the first secondary messenger, and the first signaling cascade discovered was the cAMP-protein kinase A (PKA) pathway. Since then, cAMP has received increasing attention given its multitude of actions. Not long ago, a new cAMP effector named exchange protein directly activated by cAMP (Epac) emerged as a critical mediator of cAMP's actions. Epac mediates a plethora of pathophysiologic processes and contributes to the pathogenesis of several diseases such as cancer, cardiovascular disease, diabetes, lung fibrosis, neurological disorders, and others. These findings strongly underscore the potential of Epac as a tractable therapeutic target. In this context, Epac modulators seem to possess unique characteristics and advantages and hold the promise of providing more efficacious treatments for a wide array of diseases. This paper provides an in-depth dissection and analysis of Epac structure, distribution, subcellular compartmentalization, and signaling mechanisms. We elaborate on how these characteristics can be utilized to design specific, efficient, and safe Epac agonists and antagonists that can be incorporated into future pharmacotherapeutics. In addition, we provide a detailed portfolio for specific Epac modulators highlighting their discovery, advantages, potential concerns, and utilization in the context of clinical disease entities.
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Affiliation(s)
- Hasan Slika
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | - Hadi Mansour
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | | | - Abdullah Shaito
- Biomedical Research Center, Qatar University, Doha, P.O. Box: 2713, Qatar.
| | - Firas Kobeissy
- Department of Neurobiology and Neuroscience, Morehouse School of Medicine, Atlanta, Georgia, USA.
| | - Alexander N Orekhov
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, Institute of Human Morphology, 3 Tsyurupa Street, Moscow, 117418, Russia; Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow, 125315, Russia; Institute for Atherosclerosis Research, Skolkovo Innovative Center, Osennyaya Street 4-1-207, Moscow, 121609, Russia.
| | - Gianfranco Pintus
- Department of Biomedical Sciences, University of Sassari, 07100, Sassari, Italy.
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, P.O. Box 2713, Qatar.
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9
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Kilanowska A, Ziółkowska A, Stasiak P, Gibas-Dorna M. cAMP-Dependent Signaling and Ovarian Cancer. Cells 2022; 11:cells11233835. [PMID: 36497095 PMCID: PMC9738761 DOI: 10.3390/cells11233835] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/02/2022] Open
Abstract
cAMP-dependent pathway is one of the most significant signaling cascades in healthy and neoplastic ovarian cells. Working through its major effector proteins-PKA and EPAC-it regulates gene expression and many cellular functions. PKA promotes the phosphorylation of cAMP response element-binding protein (CREB) which mediates gene transcription, cell migration, mitochondrial homeostasis, cell proliferation, and death. EPAC, on the other hand, is involved in cell adhesion, binding, differentiation, and interaction between cell junctions. Ovarian cancer growth and metabolism largely depend on changes in the signal processing of the cAMP-PKA-CREB axis, often associated with neoplastic transformation, metastasis, proliferation, and inhibition of apoptosis. In addition, the intracellular level of cAMP also determines the course of other pathways including AKT, ERK, MAPK, and mTOR, that are hypo- or hyperactivated among patients with ovarian neoplasm. With this review, we summarize the current findings on cAMP signaling in the ovary and its association with carcinogenesis, multiplication, metastasis, and survival of cancer cells. Additionally, we indicate that targeting particular stages of cAMP-dependent processes might provide promising therapeutic opportunities for the effective management of patients with ovarian cancer.
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Affiliation(s)
- Agnieszka Kilanowska
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
- Correspondence: ; Tel.: +48-683-283-148
| | - Agnieszka Ziółkowska
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
| | - Piotr Stasiak
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
| | - Magdalena Gibas-Dorna
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
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10
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Sensitive genetically encoded sensors for population and subcellular imaging of cAMP in vivo. Nat Methods 2022; 19:1461-1471. [PMID: 36303019 PMCID: PMC10171401 DOI: 10.1038/s41592-022-01646-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 09/09/2022] [Indexed: 01/07/2023]
Abstract
Cyclic adenosine monophosphate (cAMP) signaling integrates information from diverse G-protein-coupled receptors, such as neuromodulator receptors, to regulate pivotal biological processes in a cellular-specific and subcellular-specific manner. However, in vivo cellular-resolution imaging of cAMP dynamics remains challenging. Here, we screen existing genetically encoded cAMP sensors and further develop the best performer to derive three improved variants, called cAMPFIREs. Compared with their parental sensor, these sensors exhibit up to 10-fold increased sensitivity to cAMP and a cytosolic distribution. cAMPFIREs are compatible with both ratiometric and fluorescence lifetime imaging and can detect cAMP dynamics elicited by norepinephrine at physiologically relevant, nanomolar concentrations. Imaging of cAMPFIREs in awake mice reveals tonic levels of cAMP in cortical neurons that are associated with wakefulness, modulated by opioids, and differentially regulated across subcellular compartments. Furthermore, enforced locomotion elicits neuron-specific, bidirectional cAMP dynamics. cAMPFIREs also function in Drosophila. Overall, cAMPFIREs may have broad applicability for studying intracellular signaling in vivo.
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11
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Uttarkar A, Niranjan V. Brefeldin A variant via combinatorial screening acts as an effective antagonist inducing structural modification in EPAC2. MOLECULAR SIMULATION 2022. [DOI: 10.1080/08927022.2022.2110271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Akshay Uttarkar
- Department of Biotechnology, R V College of Engineering, Rashtreeya Sikshana Samithi Trust, Bengaluru, India
| | - Vidya Niranjan
- Department of Biotechnology, R V College of Engineering, Rashtreeya Sikshana Samithi Trust, Bengaluru, India
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12
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Identification of Core Allosteric Sites through Temperature- and Nucleus-Invariant Chemical Shift Covariance. Biophys J 2022; 121:2035-2045. [PMID: 35538664 DOI: 10.1016/j.bpj.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/11/2022] [Accepted: 05/04/2022] [Indexed: 11/22/2022] Open
Abstract
Allosteric regulation is essential to control biological function. In addition, allosteric sites offer a promising venue for selective drug targeting. However, accurate mapping of allosteric sites remains challenging since allostery relies on often subtle, yet functionally relevant, structural and dynamical changes. A viable approach proposed to overcome such challenge is the chemical shift covariance analysis (CHESCA). Although CHESCA offers an exhaustive map of allosteric networks, it is critical to define the core allosteric sites to be prioritized in subsequent functional studies or the design of allosteric drugs. Here we propose two new CHESCA-based methodologies, called temperature CHESCA (T-CHESCA) and CLASS-CHESCA, aimed at narrowing down allosteric maps to the core allosteric residues. Both T- and CLASS-CHESCAs rely on the invariance of core inter-residue correlations to changes in the chemical shifts of the active and inactive conformations interconverting in fast exchange. In the T-CHESCA the chemical shifts of such states are modulated through temperature changes, while in the CLASS-CHESCA through variations in the spin-active nuclei involved in pairwise correlations. The T- and CLASS-CHESCAs as well as complete-linkage CHESCA were applied to the cAMP-binding domain of the exchange protein directly activated by cAMP (EPAC), which serves as a prototypical allosteric switch. Residues consistently identified by the three CHESCA methods were found in previously identified EPAC allosteric core sites. Hence, the T-, CLASS- and CL-CHESCA provide a toolset to establish allosteric site hierarchy and triage allosteric sites to be further analyzed by mutations and functional assays. Furthermore, the core allosteric networks selectively revealed through T- and CLASS-CHESCA are expected to facilitate the mechanistic understanding of disease-related mutations and the design of selective allosteric modulators.
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Khamina M, Martinez Pomier K, Akimoto M, VanSchouwen B, Melacini G. Non-Canonical Allostery in Cyclic Nucleotide Dependent Kinases. J Mol Biol 2022; 434:167584. [DOI: 10.1016/j.jmb.2022.167584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 12/28/2022]
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14
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Franzoso M, Dokshokova L, Vitiello L, Zaglia T, Mongillo M. Tuning the Consonance of Microscopic Neuro-Cardiac Interactions Allows the Heart Beats to Play Countless Genres. Front Physiol 2022; 13:841740. [PMID: 35273522 PMCID: PMC8902305 DOI: 10.3389/fphys.2022.841740] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/01/2022] [Indexed: 12/12/2022] Open
Abstract
Different from skeletal muscle, the heart autonomously generates rhythmic contraction independently from neuronal inputs. However, speed and strength of the heartbeats are continuously modulated by environmental, physical or emotional inputs, delivered by cardiac innervating sympathetic neurons, which tune cardiomyocyte (CM) function, through activation of β-adrenoceptors (β-ARs). Given the centrality of such mechanism in heart regulation, β-AR signaling has been subject of intense research, which has reconciled the molecular details of the transduction pathway and the fine architecture of cAMP signaling in subcellular nanodomains, with its final effects on CM function. The importance of mechanisms keeping the elements of β-AR/cAMP signaling in good order emerges in pathology, when the loss of proper organization of the transduction pathway leads to detuned β-AR/cAMP signaling, with detrimental consequences on CM function. Despite the compelling advancements in decoding cardiac β-AR/cAMP signaling, most discoveries on the subject were obtained in isolated cells, somehow neglecting that complexity may encompass the means in which receptors are activated in the intact heart. Here, we outline a set of data indicating that, in the context of the whole myocardium, the heart orchestra (CMs) is directed by a closely interacting and continuously attentive conductor, represented by SNs. After a roundup of literature on CM cAMP regulation, we focus on the unexpected complexity and roles of cardiac sympathetic innervation, and present the recently discovered Neuro-Cardiac Junction, as the election site of "SN-CM" interaction. We further discuss how neuro-cardiac communication is based on the combination of extra- and intra-cellular signaling micro/nano-domains, implicating neuronal neurotransmitter exocytosis, β-ARs and elements of cAMP homeostasis in CMs, and speculate on how their dysregulation may reflect on dysfunctional neurogenic control of the heart in pathology.
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Affiliation(s)
- Mauro Franzoso
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lolita Dokshokova
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Tania Zaglia
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marco Mongillo
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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15
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Mohamed H, Shao H, Akimoto M, Darveau P, MacKinnon MR, Magolan J, Melacini G. QSAR models reveal new EPAC-selective allosteric modulators. RSC Chem Biol 2022; 3:1230-1239. [PMID: 36320893 PMCID: PMC9533425 DOI: 10.1039/d2cb00106c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 08/02/2022] [Indexed: 11/23/2022] Open
Abstract
Exchange proteins directly activated by cAMP (EPAC) are guanine nucleotide exchange factors for the small GTPases, Rap1 and Rap2. They regulate several physiological functions and mitigation of their activity has been suggested as a possible treatment for multiple diseases such as cardiomyopathy, diabetes, chronic pain, and cancer. Several EPAC-specific modulators have been developed, however studies that quantify their structure–activity relationships are still lacking. Here we propose a quantitative structure–activity relationship (QSAR) model for a series of EPAC-specific compounds. The model demonstrated high reproducibility and predictivity and the predictive ability of the model was tested against a series of compounds that were unknown to the model. The compound with the highest predicted affinity was validated experimentally through fluorescence-based competition assays and NMR experiments revealed its mode of binding and mechanism of action as a partial agonist. The proposed QSAR model can, therefore, serve as an effective screening tool to identify promising EPAC-selective drug leads with enhanced potency. QSAR models of EPAC-specific allosteric ligands predict the affinity of a promising analogue.![]()
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Affiliation(s)
- Hebatallah Mohamed
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Hongzhao Shao
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Madoka Akimoto
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Patrick Darveau
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Marc R. MacKinnon
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Jakob Magolan
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Giuseppe Melacini
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
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16
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Ni Z, Cheng X. Origin and Isoform Specific Functions of Exchange Proteins Directly Activated by cAMP: A Phylogenetic Analysis. Cells 2021; 10:cells10102750. [PMID: 34685730 PMCID: PMC8534922 DOI: 10.3390/cells10102750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/09/2021] [Accepted: 10/09/2021] [Indexed: 12/21/2022] Open
Abstract
Exchange proteins directly activated by cAMP (EPAC1 and EPAC2) are one of the several families of cellular effectors of the prototypical second messenger cAMP. To understand the origin and molecular evolution of EPAC proteins, we performed a comprehensive phylogenetic analysis of EPAC1 and EPAC2. Our study demonstrates that unlike its cousin PKA, EPAC proteins are only present in multicellular Metazoa. Within the EPAC family, EPAC1 is only associated with chordates, while EPAC2 spans the entire animal kingdom. Despite a much more contemporary origin, EPAC1 proteins show much more sequence diversity among species, suggesting that EPAC1 has undergone more selection and evolved faster than EPAC2. Phylogenetic analyses of the individual cAMP binding domain (CBD) and guanine nucleotide exchange (GEF) domain of EPACs, two most conserved regions between the two isoforms, further reveal that EPAC1 and EPAC2 are closely clustered together within both the larger cyclic nucleotide receptor and RAPGEF families. These results support the notion that EPAC1 and EPAC2 share a common ancestor resulting from a fusion between the CBD of PKA and the GEF from RAPGEF1. On the other hand, the two terminal extremities and the RAS-association (RA) domains show the most sequence diversity between the two isoforms. Sequence diversities within these regions contribute significantly to the isoform-specific functions of EPACs. Importantly, unique isoform-specific sequence motifs within the RA domain have been identified.
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Affiliation(s)
- Zhuofu Ni
- Department of Integrative Biology & Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
| | - Xiaodong Cheng
- Department of Integrative Biology & Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
- Texas Therapeutics Institute, Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-713-500-7487
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17
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Massengill CI, Day-Cooney J, Mao T, Zhong H. Genetically encoded sensors towards imaging cAMP and PKA activity in vivo. J Neurosci Methods 2021; 362:109298. [PMID: 34339753 PMCID: PMC8659126 DOI: 10.1016/j.jneumeth.2021.109298] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/22/2021] [Accepted: 07/29/2021] [Indexed: 12/26/2022]
Abstract
Cyclic adenosine monophosphate (cAMP) is a universal second messenger that plays a crucial role in diverse biological functions, ranging from transcription to neuronal plasticity, and from development to learning and memory. In the nervous system, cAMP integrates inputs from many neuromodulators across a wide range of timescales - from seconds to hours - to modulate neuronal excitability and plasticity in brain circuits during different animal behavioral states. cAMP signaling events are both cell-specific and subcellularly compartmentalized. The same stimulus may result in different, sometimes opposite, cAMP dynamics in different cells or subcellular compartments. Additionally, the activity of protein kinase A (PKA), a major cAMP effector, is also spatiotemporally regulated. For these reasons, many laboratories have made great strides toward visualizing the intracellular dynamics of cAMP and PKA. To date, more than 80 genetically encoded sensors, including original and improved variants, have been published. It is starting to become possible to visualize cAMP and PKA signaling events in vivo, which is required to study behaviorally relevant cAMP/PKA signaling mechanisms. Despite significant progress, further developments are needed to enhance the signal-to-noise ratio and practical utility of these sensors. This review summarizes the recent advances and challenges in genetically encoded cAMP and PKA sensors with an emphasis on in vivo imaging in the brain during behavior.
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Affiliation(s)
| | - Julian Day-Cooney
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Tianyi Mao
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Haining Zhong
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA.
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18
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Khegay II. Vasopressin Receptors in Blood Vessels and Proliferation of Endotheliocytes. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2021. [DOI: 10.1134/s1068162021040129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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19
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Sakai Y, Tsunekawa M, Ohta K, Shimizu T, Pastuhov S, Hanafusa H, Hisamoto N, Matsumoto K. The Integrin Signaling Network Promotes Axon Regeneration via the Src-Ephexin-RhoA GTPase Signaling Axis. J Neurosci 2021; 41:4754-4767. [PMID: 33963050 PMCID: PMC8260174 DOI: 10.1523/jneurosci.2456-20.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022] Open
Abstract
Axon regeneration is an evolutionarily conserved process essential for restoring the function of damaged neurons. In Caenorhabditis elegans hermaphrodites, initiation of axon regeneration is regulated by the RhoA GTPase-ROCK (Rho-associated coiled-coil kinase)-regulatory nonmuscle myosin light-chain phosphorylation signaling pathway. However, the upstream mechanism that activates the RhoA pathway remains unknown. Here, we show that axon injury activates TLN-1/talin via the cAMP-Epac (exchange protein directly activated by cAMP)-Rap GTPase cascade and that TLN-1 induces multiple downstream events, one of which is integrin inside-out activation, leading to the activation of the RhoA-ROCK signaling pathway. We found that the nonreceptor tyrosine kinase Src, a key mediator of integrin signaling, activates the Rho guanine nucleotide exchange factor EPHX-1/ephexin by phosphorylating the Tyr-568 residue in the autoinhibitory domain. Our results suggest that the C. elegans integrin signaling network regulates axon regeneration via the Src-RhoGEF-RhoA axis.SIGNIFICANCE STATEMENT The ability of axons to regenerate after injury is governed by cell-intrinsic regeneration pathways. We have previously demonstrated that the Caenorhabditis elegans RhoA GTPase-ROCK (Rho-associated coiled-coil kinase) pathway promotes axon regeneration by inducing MLC-4 phosphorylation. In this study, we found that axon injury activates TLN-1/talin through the cAMP-Epac (exchange protein directly activated by cAMP)-Rap GTPase cascade, leading to integrin inside-out activation, which promotes axonal regeneration by activating the RhoA signaling pathway. In this pathway, SRC-1/Src acts downstream of integrin activation and subsequently activates EPHX-1/ephexin RhoGEF by phosphorylating the Tyr-568 residue in the autoinhibitory domain. Our results suggest that the C. elegans integrin signaling network regulates axon regeneration via the Src-RhoGEF-RhoA axis.
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Affiliation(s)
- Yoshiki Sakai
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Mayuka Tsunekawa
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Kohei Ohta
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Tatsuhiro Shimizu
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Strahil Pastuhov
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Hiroshi Hanafusa
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Naoki Hisamoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Kunihiro Matsumoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
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20
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Yarwood SJ. Special Issue on "New Advances in Cyclic AMP Signalling"-An Editorial Overview. Cells 2020; 9:cells9102274. [PMID: 33053803 PMCID: PMC7599692 DOI: 10.3390/cells9102274] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 10/10/2020] [Indexed: 02/07/2023] Open
Abstract
The cyclic nucleotides 3′,5′-adenosine monophosphate (cyclic AMP) signalling system underlies the control of many biological events and disease processes in man. Cyclic AMP is synthesised by adenylate cyclase (AC) enzymes in order to activate effector proteins and it is then degraded by phosphodiesterase (PDE) enzymes. Research in recent years has identified a range of cell-type-specific cyclic AMP effector proteins, including protein kinase A (PKA), exchange factor directly activated by cyclic AMP (EPAC), cyclic AMP responsive ion channels (CICs), and the Popeye domain containing (POPDC) proteins, which participate in different signalling mechanisms. In addition, recent advances have revealed new mechanisms of action for cyclic AMP signalling, including new effectors and new levels of compartmentalization into nanodomains, involving AKAP proteins and targeted adenylate cyclase and phosphodiesterase enzymes. This Special Issue contains 21 papers that highlight advances in our current understanding of the biology of compartmentlised cyclic AMP signalling. This ranges from issues of pathogenesis and associated molecular pathways, functional assessment of novel nanodomains, to the development of novel tool molecules and new techniques for imaging cyclic AMP compartmentilisation. This editorial aims to summarise these papers within the wider context of cyclic AMP signalling.
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Affiliation(s)
- Stephen John Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK
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21
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Qureshi U, Khan MI, Ashraf S, Hameed A, Hafizur RM, Rafique R, Khan KM, Ul-Haq Z. Identification of novel Epac2 antagonists through in silico and in vitro analyses. Eur J Pharm Sci 2020; 153:105492. [PMID: 32730843 DOI: 10.1016/j.ejps.2020.105492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/18/2020] [Accepted: 07/27/2020] [Indexed: 11/26/2022]
Abstract
cAMP-dependent guanine nucleotide exchange factor (Epac) is a key regulator in signal transduction and represents an excellent drug target to be investigated against various diseases. To date, very few modulators selective for Epac are available; however, there is still an unmet need of isoform-selective inhibitors. In the present study, ligand-based pharmacophores were designed to investigating structurally diverse molecules as Epac2 inhibitors. Pharmacophore models were developed using reported allosteric site inhibitors. The developed models were used to screen 95 thousand compounds from the National Cancer Institute (NCI), Maybride, and our in-house ICCBS Database. The binding mode and efficiency of the screened hits was investigated using molecular docking simulation on the allosteric site of Epac2 apo-protein (PDB ID: 2BYV) followed by ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) profiling Furthermore, obtained in silico screened hits were subjected to in vitro assay for insulin secretion. We identified, three lead molecules RDR02145, AAK-399, and AAD-026 reducing, insulin secretion. Remarkably, a higher inhibitory effect on insulin secretion was observed in AAK-399, and AAD-026 as compared to that of standard Epac2 non-competitive allosteric site inhibitor, MAY0132. Furthermore, Dynamic simulation studies of lead compounds proved the structural stability of the Epac2 auto-inhibited state. These findings underline the potential of these compounds as valuable pharmacological tools for designing future selective probes to inhibit the Epac-mediated signaling pathway.
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Affiliation(s)
- Urooj Qureshi
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - M Israr Khan
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Sajda Ashraf
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Abdul Hameed
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Rahman M Hafizur
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Rafaila Rafique
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Zaheer Ul-Haq
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
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22
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Formoso K, Lezoualc'h F, Mialet-Perez J. Role of EPAC1 Signalosomes in Cell Fate: Friends or Foes? Cells 2020; 9:E1954. [PMID: 32854274 PMCID: PMC7563956 DOI: 10.3390/cells9091954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/21/2020] [Accepted: 08/22/2020] [Indexed: 02/06/2023] Open
Abstract
The compartmentation of signaling processes is accomplished by the assembly of protein complexes called signalosomes. These signaling platforms colocalize enzymes, substrates, and anchoring proteins into specific subcellular compartments. Exchange protein directly activated by cAMP 1 (EPAC1) is an effector of the second messenger, 3',5'-cyclic adenosine monophosphate (cAMP) that is associated with multiple roles in several pathologies including cardiac diseases. Both EPAC1 intracellular localization and molecular partners are key players in the regulation of cell fate, which may have important therapeutic potential. In this review, we summarize the recent findings on EPAC1 structure, regulation, and pharmacology. We describe the importance of EPAC1 subcellular distribution in its biological action, paying special attention to its nuclear localization and mechanism of action leading to cardiomyocyte hypertrophy. In addition, we discuss the role of mitochondrial EPAC1 in the regulation of cell death. Depending on the cell type and stress condition, we present evidence that supports either a protective or detrimental role of EPAC1 activation.
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Affiliation(s)
- Karina Formoso
- INSERM UMR-1048, Institute of Metabolic and Cardiovascular Diseases, and Université de Toulouse III-Paul Sabatier, 31432 Toulouse, France
| | - Frank Lezoualc'h
- INSERM UMR-1048, Institute of Metabolic and Cardiovascular Diseases, and Université de Toulouse III-Paul Sabatier, 31432 Toulouse, France
| | - Jeanne Mialet-Perez
- INSERM UMR-1048, Institute of Metabolic and Cardiovascular Diseases, and Université de Toulouse III-Paul Sabatier, 31432 Toulouse, France
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23
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Modeling Epac1 interactions with the allosteric inhibitor AM-001 by co-solvent molecular dynamics. J Comput Aided Mol Des 2020; 34:1171-1179. [PMID: 32700175 PMCID: PMC7533256 DOI: 10.1007/s10822-020-00332-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022]
Abstract
The exchange proteins activated by cAMP (EPAC) are implicated in a large variety of physiological processes and they are considered as promising targets for a wide range of therapeutic applications. Several recent reports provided evidence for the therapeutic effectiveness of the inhibiting EPAC1 activity cardiac diseases. In that context, we recently characterized a selective EPAC1 antagonist named AM-001. This compound was featured by a non-competitive mechanism of action but the localization of its allosteric site to EPAC1 structure has yet to be investigated. Therefore, we performed cosolvent molecular dynamics with the aim to identify a suitable allosteric binding site. Then, the docking and molecular dynamics were used to determine the binding of the AM-001 to the regions highlighted by cosolvent molecular dynamics for EPAC1. These analyses led us to the identification of a suitable allosteric AM-001 binding pocket at EPAC1. As a model validation, we also evaluated the binding poses of the available AM-001 analogues, with a different biological potency. Finally, the complex EPAC1 with AM-001 bound at the putative allosteric site was further refined by molecular dynamics. The principal component analysis led us to identify the protein motion that resulted in an inactive like conformation upon the allosteric inhibitor binding.
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Wang P, Luchowska-Stańska U, van Basten B, Chen H, Liu Z, Wiejak J, Whelan P, Morgan D, Lochhead E, Barker G, Rehmann H, Yarwood SJ, Zhou J. Synthesis and Biochemical Evaluation of Noncyclic Nucleotide Exchange Proteins Directly Activated by cAMP 1 (EPAC1) Regulators. J Med Chem 2020; 63:5159-5184. [PMID: 32340447 DOI: 10.1021/acs.jmedchem.9b02094] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Exchange proteins directly activated by cAMP (EPAC) play a central role in various biological functions, and activation of the EPAC1 protein has shown potential benefits for the treatment of various human diseases. Herein, we report the synthesis and biochemical evaluation of a series of noncyclic nucleotide EPAC1 activators. Several potent EPAC1 binders were identified including 25g, 25q, 25n, 25u, 25e, and 25f, which promote EPAC1 guanine nucleotide exchange factor activity in vitro. These agonists can also activate EPAC1 protein in cells, where they exhibit excellent selectivity toward EPAC over protein kinase A and G protein-coupled receptors. Moreover, 25e, 25f, 25n, and 25u exhibited improved selectivity toward activation of EPAC1 over EPAC2 in cells. Of these, 25u was found to robustly inhibit IL-6-activated signal transducer and activator of transcription 3 (STAT3) and subsequent induction of the pro-inflammatory vascular cell adhesion molecule 1 (VCAM1) cell-adhesion protein. These novel EPAC1 activators may therefore act as useful pharmacological tools for elucidation of EPAC function and promising drug leads for the treatment of relevant human diseases.
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Affiliation(s)
- Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Boy van Basten
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jolanta Wiejak
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Padraic Whelan
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - David Morgan
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Emma Lochhead
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Holger Rehmann
- Department of Molecular Cancer Research, Centre of Biomedical Genetics and Cancer Genomics Centre, University Medical Centre Utrecht, Utrecht 3584 CX, Netherlands
| | - Stephen J Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
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25
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Shao H, Mohamed H, Boulton S, Huang J, Wang P, Chen H, Zhou J, Luchowska-Stańska U, Jentsch NG, Armstrong AL, Magolan J, Yarwood S, Melacini G. Mechanism of Action of an EPAC1-Selective Competitive Partial Agonist. J Med Chem 2020; 63:4762-4775. [PMID: 32297742 DOI: 10.1021/acs.jmedchem.9b02151] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The exchange protein activated by cAMP (EPAC) is a promising drug target for a wide disease range, from neurodegeneration and infections to cancer and cardiovascular conditions. A novel partial agonist of the EPAC isoform 1 (EPAC1), I942, was recently discovered, but its mechanism of action remains poorly understood. Here, we utilize NMR spectroscopy to map the I942-EPAC1 interactions at atomic resolution and propose a mechanism for I942 partial agonism. We found that I942 interacts with the phosphate binding cassette (PBC) and base binding region (BBR) of EPAC1, similar to cyclic adenosine monophosphate (cAMP). These results not only reveal the molecular basis for the I942 vs cAMP mimicry and competition, but also suggest that the partial agonism of I942 arises from its ability to stabilize an inhibition-incompetent activation intermediate distinct from both active and inactive EPAC1 states. The mechanism of action of I942 may facilitate drug design for EPAC-related diseases.
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Affiliation(s)
| | | | | | | | - Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
| | | | | | | | - Stephen Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
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26
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Canault M, Alessi MC. RasGRP2 Structure, Function and Genetic Variants in Platelet Pathophysiology. Int J Mol Sci 2020; 21:E1075. [PMID: 32041177 PMCID: PMC7037602 DOI: 10.3390/ijms21031075] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 12/18/2022] Open
Abstract
RasGRP2 is calcium and diacylglycerol-regulated guanine nucleotide exchange factor I that activates Rap1, which is an essential signaling-knot in "inside-out" αIIbβ3 integrin activation in platelets. Inherited platelet function disorder caused by variants of RASGRP2 represents a new congenital bleeding disorder referred to as platelet-type bleeding disorder-18 (BDPLT18). We review here the structure of RasGRP2 and its functions in the pathophysiology of platelets and of the other cellular types that express it. We will also examine the different pathogenic variants reported so far as well as strategies for the diagnosis and management of patients with BDPLT18.
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Affiliation(s)
- Matthias Canault
- Aix Marseille University, INSERM, INRAE, C2VN, 13005 Marseille, France
| | - Marie-Christine Alessi
- Aix Marseille University, INSERM, INRAE, C2VN, 13005 Marseille, France
- Hematology laboratory, APHM, CHU Timone, 13005 Marseille, France
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27
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White MA, Tsalkova T, Mei FC, Cheng X. Conformational States of Exchange Protein Directly Activated by cAMP (EPAC1) Revealed by Ensemble Modeling and Integrative Structural Biology. Cells 2019; 9:cells9010035. [PMID: 31877746 PMCID: PMC7016869 DOI: 10.3390/cells9010035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 02/08/2023] Open
Abstract
Exchange proteins directly activated by cAMP (EPAC1 and EPAC2) are important allosteric regulators of cAMP-mediated signal transduction pathways. To understand the molecular mechanism of EPAC activation, we performed detailed Small-Angle X-ray Scattering (SAXS) analysis of EPAC1 in its apo (inactive), cAMP-bound, and effector (Rap1b)-bound states. Our study demonstrates that we can model the solution structures of EPAC1 in each state using ensemble analysis and homology models derived from the crystal structures of EPAC2. The N-terminal domain of EPAC1, which is not conserved between EPAC1 and EPAC2, appears folded and interacts specifically with another component of EPAC1 in each state. The apo-EPAC1 state is a dynamic mixture of a compact (Rg = 32.9 Å, 86%) and a more extended (Rg = 38.5 Å, 13%) conformation. The cAMP-bound form of EPAC1 in the absence of Rap1 forms a dimer in solution; but its molecular structure is still compatible with the active EPAC1 conformation of the ternary complex model with cAMP and Rap1. Herein, we show that SAXS can elucidate the conformational states of EPAC1 activation as it proceeds from the compact, inactive apo conformation through a previously unknown intermediate-state, to the extended cAMP-bound form, and then binds to its effector (Rap1b) in a ternary complex.
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Affiliation(s)
- Mark Andrew White
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555, USA
- Correspondence: (M.A.W.); (X.C.); Tel.: +409-747-4747 (M.A.W.); +713-500-7487 (X.C.)
| | - Tamara Tsalkova
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX 77555, USA;
| | - Fang C. Mei
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
- Texas Therapeutics Institute, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Xiaodong Cheng
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
- Texas Therapeutics Institute, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Correspondence: (M.A.W.); (X.C.); Tel.: +409-747-4747 (M.A.W.); +713-500-7487 (X.C.)
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28
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Xu Y, Schwede F, Wienk H, Tengholm A, Rehmann H. A Membrane Permeable Prodrug of S223 for Selective Epac2 Activation in Living Cells. Cells 2019; 8:cells8121589. [PMID: 31817822 PMCID: PMC6952820 DOI: 10.3390/cells8121589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 12/22/2022] Open
Abstract
Signalling by cyclic adenosine monophosphate (cAMP) occurs via various effector proteins, notably protein kinase A and the guanine nucleotide exchange factors Epac1 and Epac2. These proteins are activated by cAMP binding to conserved cyclic nucleotide binding domains. The specific roles of the effector proteins in various processes in different types of cells are still not well defined, but investigations have been facilitated by the development of cyclic nucleotide analogues with distinct selectivity profiles towards a single effector protein. A remaining challenge in the development of such analogues is the poor membrane permeability of nucleotides, which limits their applicability in intact living cells. Here, we report the synthesis and characterisation of S223-AM, a cAMP analogue designed as an acetoxymethyl ester prodrug to overcome limitations of permeability. Using total internal reflection imaging with various fluorescent reporters, we show that S223-AM selectively activates Epac2, but not Epac1 or protein kinase A, in intact insulin-secreting β-cells, and that this effect was associated with pronounced activation of the small G-protein Rap. A comparison of the effects of different cAMP analogues in pancreatic islet cells deficient in Epac1 and Epac2 demonstrates that cAMP-dependent Rap activity at the β-cell plasma membrane is exclusively dependent on Epac2. With its excellent selectivity and permeability properties, S223-AM should get broad utility in investigations of cAMP effector involvement in many different types of cells.
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Affiliation(s)
- Yunjian Xu
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Frank Schwede
- BIOLOG Life Science Institute, Flughafendamm 9a, 28199 Bremen, Germany;
| | - Hans Wienk
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands;
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Holger Rehmann
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
- Correspondence:
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29
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The Epac1 Protein: Pharmacological Modulators, Cardiac Signalosome and Pathophysiology. Cells 2019; 8:cells8121543. [PMID: 31795450 PMCID: PMC6953115 DOI: 10.3390/cells8121543] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/22/2019] [Accepted: 11/24/2019] [Indexed: 12/11/2022] Open
Abstract
The second messenger 3′,5′-cyclic adenosine monophosphate (cAMP) is one of the most important signalling molecules in the heart as it regulates many physiological and pathophysiological processes. In addition to the classical protein kinase A (PKA) signalling route, the exchange proteins directly activated by cAMP (Epac) mediate the intracellular functions of cAMP and are now emerging as a new key cAMP effector in cardiac pathophysiology. In this review, we provide a perspective on recent advances in the discovery of new chemical entities targeting the Epac1 isoform and illustrate their use to study the Epac1 signalosome and functional characterisation in cardiac cells. We summarize the role of Epac1 in different subcompartments of the cardiomyocyte and discuss how cAMP–Epac1 specific signalling networks may contribute to the development of cardiac diseases. We also highlight ongoing work on the therapeutic potential of Epac1-selective small molecules for the treatment of cardiac disorders.
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30
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Ahmed A, Boulton S, Shao H, Akimoto M, Natarajan A, Cheng X, Melacini G. Recent Advances in EPAC-Targeted Therapies: A Biophysical Perspective. Cells 2019; 8:cells8111462. [PMID: 31752286 PMCID: PMC6912387 DOI: 10.3390/cells8111462] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 02/07/2023] Open
Abstract
The universal second messenger cAMP regulates diverse intracellular processes by interacting with ubiquitously expressed proteins, such as Protein Kinase A (PKA) and the Exchange Protein directly Activated by cAMP (EPAC). EPAC is implicated in multiple pathologies, thus several EPAC-specific inhibitors have been identified in recent years. However, the mechanisms and molecular interactions underlying the EPAC inhibition elicited by such compounds are still poorly understood. Additionally, being hydrophobic low molecular weight species, EPAC-specific inhibitors are prone to forming colloidal aggregates, which result in non-specific aggregation-based inhibition (ABI) in aqueous systems. Here, we review from a biophysical perspective the molecular basis of the specific and non-specific interactions of two EPAC antagonists—CE3F4R, a non-competitive inhibitor, and ESI-09, a competitive inhibitor of EPAC. Additionally, we discuss the value of common ABI attenuators (e.g., TX and HSA) to reduce false positives at the expense of introducing false negatives when screening aggregation-prone compounds. We hope this review provides the EPAC community effective criteria to evaluate similar compounds, aiding in the optimization of existing drug leads, and informing the development of the next generation of EPAC-specific inhibitors.
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Affiliation(s)
- Alveena Ahmed
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.A.); (S.B.)
| | - Stephen Boulton
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.A.); (S.B.)
| | - Hongzhao Shao
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (H.S.); (M.A.)
| | - Madoka Akimoto
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (H.S.); (M.A.)
| | - Amarnath Natarajan
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Xiaodong Cheng
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
- Texas Therapeutics Institute, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Giuseppe Melacini
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.A.); (S.B.)
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (H.S.); (M.A.)
- Correspondence:
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31
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M. Beck E, Parnell E, Cowley A, Porter A, Gillespie J, Robinson J, Robinson L, Pannifer AD, Hamon V, Jones P, Morrison A, McElroy S, Timmerman M, Rutjes H, Mahajan P, Wiejak J, Luchowska-Stańska U, Morgan D, Barker G, Rehmann H, Yarwood SJ. Identification of A Novel Class of Benzofuran Oxoacetic Acid-Derived Ligands that Selectively Activate Cellular EPAC1. Cells 2019; 8:cells8111425. [PMID: 31726720 PMCID: PMC6912754 DOI: 10.3390/cells8111425] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 12/20/2022] Open
Abstract
Cyclic AMP promotes EPAC1 and EPAC2 activation through direct binding to a specific cyclic nucleotide-binding domain (CNBD) within each protein, leading to activation of Rap GTPases, which control multiple cell responses, including cell proliferation, adhesion, morphology, exocytosis, and gene expression. As a result, it has become apparent that directed activation of EPAC1 and EPAC2 with synthetic agonists may also be useful for the future treatment of diabetes and cardiovascular diseases. To identify new EPAC agonists we have developed a fluorescent-based, ultra-high-throughput screening (uHTS) assay that measures the displacement of binding of the fluorescent cAMP analogue, 8-NBD-cAMP to the EPAC1 CNBD. Triage of the output of an approximately 350,000 compound screens using this assay identified a benzofuran oxaloacetic acid EPAC1 binder (SY000) that displayed moderate potency using orthogonal assays (competition binding and microscale thermophoresis). We next generated a limited library of 91 analogues of SY000 and identified SY009, with modifications to the benzofuran ring associated with a 10-fold increase in potency towards EPAC1 over SY000 in binding assays. In vitro EPAC1 activity assays confirmed the agonist potential of these molecules in comparison with the known EPAC1 non-cyclic nucleotide (NCN) partial agonist, I942. Rap1 GTPase activation assays further demonstrated that SY009 selectively activates EPAC1 over EPAC2 in cells. SY009 therefore represents a novel class of NCN EPAC1 activators that selectively activate EPAC1 in cellulae.
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Affiliation(s)
- Elizabeth M. Beck
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Euan Parnell
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
| | - Angela Cowley
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Alison Porter
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Jonathan Gillespie
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - John Robinson
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Lindsay Robinson
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Andrew D. Pannifer
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Veronique Hamon
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Philip Jones
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Angus Morrison
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Stuart McElroy
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Martin Timmerman
- Pivot Park Screening Centre, Kloosterstraat 9, 5349 AB Oss, The Netherlands; (M.T.); (H.R.)
| | - Helma Rutjes
- Pivot Park Screening Centre, Kloosterstraat 9, 5349 AB Oss, The Netherlands; (M.T.); (H.R.)
| | - Pravin Mahajan
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK;
| | - Jolanta Wiejak
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK; (J.W.); (U.L.-S.)
| | - Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK; (J.W.); (U.L.-S.)
| | - David Morgan
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK; (D.M.); (G.B.)
| | - Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK; (D.M.); (G.B.)
| | - Holger Rehmann
- Department of Molecular Cancer Research, Centre of Biomedical Genetics and Cancer Genomics Centre, University Medical Centre Utrecht, 3508 TC Utrecht, The Netherlands;
| | - Stephen J. Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK; (J.W.); (U.L.-S.)
- Correspondence:
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32
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Luchowska-Stańska U, Morgan D, Yarwood SJ, Barker G. Selective small-molecule EPAC activators. Biochem Soc Trans 2019; 47:1415-1427. [PMID: 31671184 PMCID: PMC6824682 DOI: 10.1042/bst20190254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/22/2019] [Accepted: 08/27/2019] [Indexed: 02/06/2023]
Abstract
The cellular signalling enzymes, EPAC1 and EPAC2, have emerged as key intracellular sensors of the secondary messenger cyclic 3',5'-adenosine monophosphate (cyclic adenosine monophosphate) alongside protein kinase A. Interest has been galvanised in recent years thanks to the emergence of these species as potential targets for new cardiovascular disease therapies, including vascular inflammation and insulin resistance in vascular endothelial cells. We herein summarise the current state-of-the-art in small-molecule EPAC activity modulators, including cyclic nucleotides, sulphonylureas, and N-acylsulphonamides.
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Affiliation(s)
- Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics, and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - David Morgan
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Stephen J. Yarwood
- Institute of Biological Chemistry, Biophysics, and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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33
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Reverte-Salisa L, Sanyal A, Pfeifer A. Role of cAMP and cGMP Signaling in Brown Fat. Handb Exp Pharmacol 2019; 251:161-182. [PMID: 29633180 DOI: 10.1007/164_2018_117] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cold-induced activation of brown adipose tissue (BAT) is mediated by norepinephrine and adenosine that are released during sympathetic nerve activation. Both signaling molecules induce an increase in intracellular levels of 3',5'-cyclic adenosine monophosphate (cAMP) in murine and human BAT. In brown adipocytes, cAMP plays a central role, because it activates lipolysis, glucose uptake, and thermogenesis. Another well-studied intracellular second messenger is 3',5'-cyclic guanosine monophosphate (cGMP), which closely resembles cAMP. Several studies have shown that intact cGMP signaling is essential for normal adipogenic differentiation and BAT-mediated thermogenesis in mice. This chapter highlights recent observations, demonstrating the physiological significance of cyclic nucleotide signaling in BAT as well as their potential to induce browning of white adipose tissue (WAT) in mice and humans.
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Affiliation(s)
- Laia Reverte-Salisa
- Institute of Pharmacology and Toxicology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Abhishek Sanyal
- Institute of Pharmacology and Toxicology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Alexander Pfeifer
- Institute of Pharmacology and Toxicology, University Hospital Bonn, University of Bonn, Bonn, Germany.
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Swan AH, Gruscheski L, Boland LA, Brand T. The Popeye domain containing gene family encoding a family of cAMP-effector proteins with important functions in striated muscle and beyond. J Muscle Res Cell Motil 2019; 40:169-183. [PMID: 31197601 PMCID: PMC6726836 DOI: 10.1007/s10974-019-09523-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 06/11/2019] [Indexed: 12/14/2022]
Abstract
The Popeye domain containing (POPDC) gene family encodes a novel class of membrane-bound cyclic AMP effector proteins. POPDC proteins are abundantly expressed in cardiac and skeletal muscle. Consistent with its predominant expression in striated muscle, Popdc1 and Popdc2 null mutants in mouse and zebrafish develop cardiac arrhythmia and muscular dystrophy. Likewise, mutations in POPDC genes in patients have been associated with cardiac arrhythmia and muscular dystrophy phenotypes. A membrane trafficking function has been identified in this context. POPDC proteins have also been linked to tumour formation. Here, POPDC1 plays a role as a tumour suppressor by limiting c-Myc and WNT signalling. Currently, a common functional link between POPDC’s role in striated muscle and as a tumour suppressor is lacking. We also discuss several alternative working models to better understand POPDC protein function.
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Affiliation(s)
- Alexander H Swan
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK.,Institute of Chemical Biology, Imperial College London, London, UK
| | - Lena Gruscheski
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK
| | - Lauren A Boland
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK
| | - Thomas Brand
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK.
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35
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Boulton S, Selvaratnam R, Ahmed R, Van K, Cheng X, Melacini G. Mechanisms of Specific versus Nonspecific Interactions of Aggregation-Prone Inhibitors and Attenuators. J Med Chem 2019; 62:5063-5079. [PMID: 31074269 PMCID: PMC7255057 DOI: 10.1021/acs.jmedchem.9b00258] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A common source of false positives in drug discovery is ligand self-association into large colloidal assemblies that nonspecifically inhibit target proteins. However, the mechanisms of aggregation-based inhibition (ABI) and ABI-attenuation by additives, such as Triton X-100 (TX) and human serum albumin (HSA), are not fully understood. Here, we investigate the molecular basis of ABI and ABI-attenuation through the lens of NMR and coupled thermodynamic cycles. We unexpectedly discover a new class of aggregating ligands that exhibit negligible interactions with proteins but act as competitive sinks for the free inhibitor, resulting in bell-shaped dose-response curves. TX attenuates ABI by converting inhibitory, protein-binding aggregates into nonbinding coaggregates, whereas HSA minimizes nonspecific ligand interactions by functioning as a reservoir for free inhibitor and preventing self-association. Hence, both TX and HSA are useful tools to minimize false positives arising from nonspecific binding but at the cost of potentially introducing false negatives due to suppression of specific interactions.
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Affiliation(s)
- Stephen Boulton
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Rajeevan Selvaratnam
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4L8, Canada
- Department of Laboratory Medicine, University Health Network, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - Rashik Ahmed
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Katherine Van
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology and Texas Therapeutics Institute, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, United States
| | - Giuseppe Melacini
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4L8, Canada
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36
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Patel A, Perrin AJ, Flynn HR, Bisson C, Withers-Martinez C, Treeck M, Flueck C, Nicastro G, Martin SR, Ramos A, Gilberger TW, Snijders AP, Blackman MJ, Baker DA. Cyclic AMP signalling controls key components of malaria parasite host cell invasion machinery. PLoS Biol 2019; 17:e3000264. [PMID: 31075098 PMCID: PMC6530879 DOI: 10.1371/journal.pbio.3000264] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/22/2019] [Accepted: 04/26/2019] [Indexed: 01/01/2023] Open
Abstract
Cyclic AMP (cAMP) is an important signalling molecule across evolution, but its role in malaria parasites is poorly understood. We have investigated the role of cAMP in asexual blood stage development of Plasmodium falciparum through conditional disruption of adenylyl cyclase beta (ACβ) and its downstream effector, cAMP-dependent protein kinase (PKA). We show that both production of cAMP and activity of PKA are critical for erythrocyte invasion, whilst key developmental steps that precede invasion still take place in the absence of cAMP-dependent signalling. We also show that another parasite protein with putative cyclic nucleotide binding sites, Plasmodium falciparum EPAC (PfEpac), does not play an essential role in blood stages. We identify and quantify numerous sites, phosphorylation of which is dependent on cAMP signalling, and we provide mechanistic insight as to how cAMP-dependent phosphorylation of the cytoplasmic domain of the essential invasion adhesin apical membrane antigen 1 (AMA1) regulates erythrocyte invasion.
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Affiliation(s)
- Avnish Patel
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Abigail J. Perrin
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Helen R. Flynn
- Mass Spectrometry Proteomics Platform, The Francis Crick Institute, London, United Kingdom
| | - Claudine Bisson
- Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | | | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Christian Flueck
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Giuseppe Nicastro
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Stephen R. Martin
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Andres Ramos
- Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Tim W. Gilberger
- Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Ambrosius P. Snijders
- Mass Spectrometry Proteomics Platform, The Francis Crick Institute, London, United Kingdom
| | - Michael J. Blackman
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
| | - David A. Baker
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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37
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Lelle M, Otte M, Thon S, Bertinetti D, Herberg FW, Benndorf K. Chemical synthesis and biological activity of novel brominated 7-deazaadenosine-3',5'-cyclic monophosphate derivatives. Bioorg Med Chem 2019; 27:1704-1713. [PMID: 30879860 DOI: 10.1016/j.bmc.2019.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/09/2019] [Accepted: 03/11/2019] [Indexed: 11/19/2022]
Abstract
Synthetic derivatives of cyclic adenosine monophosphate, such as halogenated or other more hydrophobic analogs, are widely used compounds, to investigate diverse signal transduction pathways of eukaryotic cells. This inspired us to develop cyclic nucleotides, which exhibit chemical structures composed of brominated 7-deazaadenines and the phosphorylated ribosugar. The synthesized 8-bromo- and 7-bromo-7-deazaadenosine-3',5'-cyclic monophosphates rank among the most potent activators of cyclic nucleotide-regulated ion channels as well as cAMP-dependent protein kinase. Moreover, these substances bind tightly to exchange proteins directly activated by cAMP.
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Affiliation(s)
- Marco Lelle
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany
| | - Maik Otte
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany
| | - Susanne Thon
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany
| | - Daniela Bertinetti
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Friedrich W Herberg
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Klaus Benndorf
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany.
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Bandaru P, Kondo Y, Kuriyan J. The Interdependent Activation of Son-of-Sevenless and Ras. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a031534. [PMID: 29610148 DOI: 10.1101/cshperspect.a031534] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The guanine-nucleotide exchange factor (GEF) Son-of-Sevenless (SOS) plays a critical role in metazoan signaling by converting Ras•GDP (guanosine diphosphate) to Ras•GTP (guanosine triphosphate) in response to tyrosine kinase activation. Structural studies have shown that SOS differs from other Ras-specific GEFs in that SOS is itself activated by Ras•GTP binding to an allosteric site, distal to the site of nucleotide exchange. The activation of SOS involves membrane recruitment and conformational changes, triggered by lipid binding, that open the allosteric binding site for Ras•GTP. This is in contrast to other Ras-specific GEFs, which are activated by second messengers that more directly affect the active site. Allosteric Ras•GTP binding stabilizes SOS at the membrane, where it can turn over other Ras molecules processively, leading to an ultrasensitive response that is distinct from that of other Ras-specific GEFs.
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Affiliation(s)
- Pradeep Bandaru
- Department of Molecular and Cell Biology, California Institute for Quantitative Biosciences, Howard Hughes Medical Institute, University of California, Berkeley, California 94720
| | - Yasushi Kondo
- Department of Molecular and Cell Biology, California Institute for Quantitative Biosciences, Howard Hughes Medical Institute, University of California, Berkeley, California 94720
| | - John Kuriyan
- Departments of Molecular and Cell Biology and of Chemistry, California Institute for Quantitative Biosciences, Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Howard Hughes Medical Institute, University of California, Berkeley, California 94720
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39
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Ulens C. Structure of a transporter domain emerges. J Biol Chem 2018; 293:20008-20009. [PMID: 30593530 DOI: 10.1074/jbc.h118.006869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Magnesium homeostasis relies on transporters like the CNNM family, but little information on these proteins' structure and regulation limits our understanding of their biology and functions in disease. New characterization of a conserved cytoplasmic domain now confirms the presence of a self-liganded architecture that is indispensable for Mg2+ efflux and suggests a possible role for a dimeric assembly.
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Affiliation(s)
- Chris Ulens
- From the Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium.
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40
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Xu H, Yang Y, Chen Y, Mueller U, Iyer S, Presland J, Yang R, Kariv I. Determination of EPAC2 function using EPAC2 null Min6 sublines generated through CRISPR-Cas9 technology. Mol Cell Endocrinol 2018; 473:114-123. [PMID: 29407196 DOI: 10.1016/j.mce.2018.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 11/21/2022]
Abstract
Min6 cells, a mouse β cell line derived from transgenic mouse expressing the large T-antigen of SV40 in pancreatic beta cells, are commonly utilized as an in vitro cellular model for investigating targets involved in insulin secretion. Epac2, an exchange protein that can be directly activated by cyclic AMP (cAMP), is critical for pharmacologic stimuli-induced insulin secretion and has been hypothesized to be a direct target of sulfonylurea. Previous loss of function studies only specifically knocked out EPAC2 isoform A, leaving the other two isoforms intact. In this study, we investigated the function of EPAC2 in Min6 cells by generating EPAC2 knock-out sublines using CRISPR-Cas9 technology, by removing all three isoforms of EPAC2. Our results indicate that Min6 cells can be successfully cloned from a single cell after electroporation with plasmids expressing EPAC2 specific guide RNA, Cas9 and GFP, followed by sorting for GFP expressing single cells. Two clones were found to have a single nucleotide deletion in targeted site of EPAC2 gene by sequencing, therefore creating a frame shift in exon 13. The EPAC2 null clones have an unexpectedly increased secretion of insulin at basal level and an elevated total intracellular insulin content. However, EPAC2 deficiency impaires glucose and sulfonylurea induced insulin secretion without affecting sulfonylurea binding to cells. Potassium chloride induced insulin secretion remains intact. Interestingly, cAMP levels remained unchanged in EPAC2 null cells during these processes. To understand the global function of EPAC2, RNA Seq study was performed, which reveals that EPAC2 deficiency affects expression of multiple previously unrecognized genes, suggesting that EPAC2 can function through multiple pathways in addition to being a cAMP sensor.
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Affiliation(s)
- Haiyan Xu
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA.
| | - Yi Yang
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA
| | - Yiping Chen
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA
| | - Uwe Mueller
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA
| | - Sharanya Iyer
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA
| | - Jeremy Presland
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA
| | - Ruojing Yang
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA
| | - Ilona Kariv
- Department of Early Discovery Pharmacology, Cellular Pharmacology, Merck & Co., Inc., 33 Ave. Louis Pasteur, Boston, MA 02115, USA
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Abstract
Abstract Primary sensory neurons are responsible for transmitting sensory information from the peripheral to the central nervous system. Their responses to incoming stimulation become greatly enhanced and prolonged following inflammation, giving rise to exaggerated nociceptive responses and chronic pain. The inflammatory mediator, prostaglandin E2 (PGE2), released from the inflamed tissue surrounding the terminals of sensory neurons contributes to the abnormal pain responses. PGE2 acts on G protein-coupled EP receptors to activate adenylyl cyclase, which catalyzes the conversion of adenosine triphosphate to cyclic adenosine 3′,5′-monophosphate (cAMP). Under normal conditions, cAMP activates primarily protein kinase A. After inflammation, cAMP also activates the exchange proteins activated by cAMP (Epacs) to produce exaggerated PGE2-mediated hyperalgesia. The role of cAMP-Epac signaling in the generation of hypersensitivity is the topic of this review.
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Affiliation(s)
| | - Yanping Gu
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch Galveston, TX 77555-1069, USA
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42
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Boulton S, Selvaratnam R, Blondeau JP, Lezoualc'h F, Melacini G. Mechanism of Selective Enzyme Inhibition through Uncompetitive Regulation of an Allosteric Agonist. J Am Chem Soc 2018; 140:9624-9637. [PMID: 30016089 DOI: 10.1021/jacs.8b05044] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Classical uncompetitive inhibitors are potent pharmacological modulators of enzyme function. Since they selectively target enzyme-substrate complexes (E:S), their inhibitory potency is amplified by increasing substrate concentrations. Recently, an unconventional uncompetitive inhibitor, called CE3F4R, was discovered for the exchange protein activated by cAMP isoform 1 (EPAC1). Unlike conventional uncompetitive inhibitors, CE3F4R is uncompetitive with respect to an allosteric effector, cAMP, as opposed to the substrate (i.e., CE3F4R targets the E:cAMP rather than the E:S complex). However, the mechanism of CE3F4R as an uncompetitive inhibitor is currently unknown. Here, we elucidate the mechanism of CE3F4R's action using NMR spectroscopy. Due to limited solubility and line broadening, which pose major challenges for traditional structural determination approaches, we resorted to a combination of protein- and ligand-based NMR experiments to comparatively analyze EPAC mutations, inhibitor analogs, and cyclic nucleotide derivatives that trap EPAC at different stages of activation. We discovered that CE3F4R binds within the EPAC cAMP-binding domain (CBD) at a subdomain interface distinct from the cAMP binding site, acting as a wedge that stabilizes a cAMP-bound mixed-intermediate. The mixed-intermediate includes attributes of both the apo/inactive and cAMP-bound/active states. In particular, the intermediate targeted by CE3F4R traps a CBD's hinge helix in its inactive conformation, locking EPAC into a closed domain topology that restricts substrate access to the catalytic domain. The proposed mechanism of action also explains the isoform selectivity of CE3F4R in terms of a single EPAC1 versus EPAC2 amino acid difference that destabilizes the active conformation of the hinge helix.
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Affiliation(s)
| | | | - Jean-Paul Blondeau
- Université Paris-Sud , Faculté de Pharmacie , 92296 Cedex Châtenay-Malabry , France
| | - Frank Lezoualc'h
- Inserm, UMR-1048, Institut des Maladies Métaboliques et Cardiovasculaires, Université de Toulouse III Paul Sabatier , 31432 Cedex 04 Toulouse , France
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43
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Balbach M, Beckert V, Hansen JN, Wachten D. Shedding light on the role of cAMP in mammalian sperm physiology. Mol Cell Endocrinol 2018; 468:111-120. [PMID: 29146556 DOI: 10.1016/j.mce.2017.11.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/10/2017] [Accepted: 11/10/2017] [Indexed: 12/24/2022]
Abstract
Mammalian fertilization relies on sperm finding the egg and penetrating the egg vestments. All steps in a sperm's lifetime crucially rely on changes in the second messenger cAMP (cyclic adenosine monophosphate). In recent years, it has become clear that signal transduction in sperm is not a continuum, but rather organized in subcellular domains, e.g. the sperm head and the sperm flagellum, with the latter being further separated into the midpiece, principal piece, and endpiece. To understand the underlying signaling pathways controlling sperm function in more detail, experimental approaches are needed that allow to study sperm signaling with spatial and temporal precision. Here, we will give a comprehensive overview on cAMP signaling in mammalian sperm, describing the molecular players involved in these pathways and the sperm functions that are controlled by cAMP. Furthermore, we will highlight recent advances in analyzing and manipulating sperm signaling with spatio-temporal precision using light.
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Affiliation(s)
- Melanie Balbach
- Center of Advanced European Studies and Research (caesar), Department of Molecular Sensory Systems, Bonn, Germany
| | - Vera Beckert
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany; Center of Advanced European Studies and Research (caesar), Minerva Max Planck Research Group, Molecular Physiology, Bonn, Germany.
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44
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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45
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Insights into exchange factor directly activated by cAMP (EPAC) as potential target for cancer treatment. Mol Cell Biochem 2018; 447:77-92. [PMID: 29417338 DOI: 10.1007/s11010-018-3294-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 01/19/2018] [Indexed: 01/02/2023]
Abstract
Cancer remains a global health problem and approximately 1.7 million new cancer cases are diagnosed every year worldwide. Although diverse molecules are currently being explored as targets for cancer therapy the tumor treatment and therapy is highly tricky. Secondary messengers are important for hormone-mediated signaling pathway. Cyclic AMP (cAMP), a secondary messenger responsible for various physiological processes regulates cell metabolism by activating Protein kinase A (PKA) and by targeting exchange protein directly activated by cAMP (EPAC). EPAC is present in two isoforms EPAC1 and EPAC2, which exhibit different tissue distribution and is involved in GDP/GTP exchange along with activating Rap1- and Rap2-mediated signaling pathways. EPAC is also known for its dual role in cancer as pro- and anti-proliferative in addition to metastasis. Results after perturbing EPAC activity suggests its involvement in cancer cell migration, proliferation, and cytoskeleton remodeling which makes it a potential therapeutic target for cancer treatments.
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46
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Abstract
Our laboratory has studied Ras and Ras-like proteins since the discovery of the Ras oncogene 35 years ago. In this review, I will give an account of what we have done in these 35 years and indicate the main papers that have guided our research. Our efforts started with the early analysis of mutant Ras in human tumors followed by deciphering of the role of Ras in signal transduction pathways. In an attempt to interfere in Ras signaling we turned to Rap proteins. These proteins are the closest relatives of Ras and were initially identified as Ras antagonists. However, our studies revealed that the Rap signaling network primarily is involved in spatiotemporal control of cell adhesion, in part through regulation of the actin cytoskeleton. More recently we returned to Ras, trying to interfere in Ras signaling by combinatorial drug testing using the organoid technology.
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Affiliation(s)
- Johannes L Bos
- Molecular Cancer Research, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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47
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Barker G, Parnell E, van Basten B, Buist H, Adams DR, Yarwood SJ. The Potential of a Novel Class of EPAC-Selective Agonists to Combat Cardiovascular Inflammation. J Cardiovasc Dev Dis 2017; 4:jcdd4040022. [PMID: 29367551 PMCID: PMC5753123 DOI: 10.3390/jcdd4040022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 11/23/2017] [Accepted: 11/30/2017] [Indexed: 02/07/2023] Open
Abstract
The cyclic 3′,5′-adenosine monophosphate (cAMP) sensor enzyme, EPAC1, is a candidate drug target in vascular endothelial cells (VECs) due to its ability to attenuate proinflammatory cytokine signalling normally associated with cardiovascular diseases (CVDs), including atherosclerosis. This is through the EPAC1-dependent induction of the suppressor of cytokine signalling gene, SOCS3, which targets inflammatory signalling proteins for ubiquitinylation and destruction by the proteosome. Given this important role for the EPAC1/SOCS3 signalling axis, we have used high throughput screening (HTS) to identify small molecule EPAC1 regulators and have recently isolated the first known non-cyclic nucleotide (NCN) EPAC1 agonist, I942. I942 therefore represents the first in class, isoform selective EPAC1 activator, with the potential to suppress pro-inflammatory cytokine signalling with a reduced risk of side effects associated with general cAMP-elevating agents that activate multiple response pathways. The development of augmented I942 analogues may therefore provide improved research tools to validate EPAC1 as a potential therapeutic target for the treatment of chronic inflammation associated with deadly CVDs.
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Affiliation(s)
- Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
| | - Euan Parnell
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Boy van Basten
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, UK.
| | - Hanna Buist
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, UK.
| | - David R Adams
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
| | - Stephen J Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, UK.
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48
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Czikora A, Kedei N, Kalish H, Blumberg PM. Importance of the REM (Ras exchange) domain for membrane interactions by RasGRP3. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2017; 1859:2350-2360. [PMID: 28912101 PMCID: PMC5659902 DOI: 10.1016/j.bbamem.2017.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 11/18/2022]
Abstract
RasGRP comprises a family of guanine nucleotide exchange factors, regulating the dissociation of GDP from Ras GTPases to enhance the formation of the active GTP-bound form. RasGRP1 possesses REM (Ras exchange), GEF (catalytic), EF-hand, C1, SuPT (suppressor of PT), and PT (plasma membrane-targeting) domains, among which the C1 domain drives membrane localization in response to diacylglycerol or phorbol ester and the PT domain recognizes phosphoinositides. The homologous family member RasGRP3 shows less plasma membrane localization. The objective of this study was to explore the role of the different domains of RasGRP3 in membrane translocation in response to phorbol esters. The full-length RasGRP3 shows limited translocation to the plasma membrane in response to PMA, even when the basic hydrophobic cluster in the PT domain, reported to be critical for RasGRP1 translocation to endogenous activators, is mutated to resemble that of RasGRP1. Moreover, exchange of the C-termini (SuPT-PT domain) of the two proteins had little effect on their plasma membrane translocation. On the other hand, while the C1 domain of RasGRP3 alone showed partial plasma membrane translocation, truncated RasGRP3 constructs, which contain the PT domain and are missing the REM, showed stronger translocation, indicating that the REM of RasGRP3 was a suppressor of its membrane interaction. The REM of RasGRP1 failed to show comparable suppression of RasGRP3 translocation. The marked differences between RasGRP3 and RasGRP1 in membrane interaction necessarily will contribute to their different behavior in cells and are relevant to the design of selective ligands as potential therapeutic agents.
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Affiliation(s)
- Agnes Czikora
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States
| | - Heather Kalish
- Trans-NIH Shared Resource on Biomedical Engineering and Physical Science (BEPS), National Institute of Biomedical Imaging and Bioengineering (NIBIB) National Institutes of Health, United States
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States.
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49
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Rehmann H. Interaction of Epac with Non-canonical Cyclic Nucleotides. Handb Exp Pharmacol 2017; 238:135-147. [PMID: 27900608 DOI: 10.1007/164_2015_37] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epac1 and Epac2 are cyclic nucleotide-binding (CNB) domain containing proteins, which were originally identified as cAMP-regulated guanine nucleotide exchange factors (GEFs) for the small G-protein Rap. Therefore, Epac proteins founded next to protein kinase A (PKA) and cyclic nucleotide-regulated ion channels the third group of cAMP-responsive proteins in higher organisms. Epac proteins are involved in the regulation of several physiological processes. In particular Epac1 mediates the regulation of molecular processes underlying cell adhesion and mobility. In the pancreas activation of Epac2 potentiates the release of glucose-induced insulin secretion and received attention as a putative target for antidiabetic treatment. While the regulation of Epac by cAMP has been analysed in structural and biochemical detail, less is known on the interaction of Epac with non-canonical cyclic nucleotides. This chapter will discuss to what extent other cyclic purines than cAMP or cyclic pyrimidine could act as Epac agonists or antagonists. The focus will be on the biophysical analysis of the interaction between Epac and these cyclic nucleotides.
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Affiliation(s)
- Holger Rehmann
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands.
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50
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Alenkvist I, Gandasi NR, Barg S, Tengholm A. Recruitment of Epac2A to Insulin Granule Docking Sites Regulates Priming for Exocytosis. Diabetes 2017; 66:2610-2622. [PMID: 28679628 DOI: 10.2337/db17-0050] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 06/20/2017] [Indexed: 11/13/2022]
Abstract
Epac is a cAMP-activated guanine nucleotide exchange factor that mediates cAMP signaling in various types of cells, including β-cells, where it is involved in the control of insulin secretion. Upon activation, the protein redistributes to the plasma membrane, but the underlying molecular mechanisms and functional consequences are unclear. Using quantitative high-resolution microscopy, we found that cAMP elevation caused rapid binding of Epac2A to the β-cell plasma membrane, where it accumulated specifically at secretory granules and rendered them more prone to undergo exocytosis. cAMP-dependent membrane binding required the high-affinity cyclic nucleotide-binding (CNB) and Ras association domains, but not the disheveled-Egl-10-pleckstrin domain. Although the N-terminal low-affinity CNB domain (CNB-A) was dispensable for the translocation to the membrane, it was critical for directing Epac2A to the granule sites. Epac1, which lacks the CNB-A domain, was recruited to the plasma membrane but did not accumulate at granules. We conclude that Epac2A controls secretory granule release by binding to the exocytosis machinery, an effect that is enhanced by prior cAMP-dependent accumulation of the protein at the plasma membrane.
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Affiliation(s)
- Ida Alenkvist
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Nikhil R Gandasi
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
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