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Bartošík V, Plucarová J, Laníková A, Janáčková Z, Padrta P, Jansen S, Vařečka V, Gruber T, Feller SM, Žídek L. Structural basis of binding the unique N-terminal domain of microtubule-associated protein 2c to proteins regulating kinases of signaling pathways. J Biol Chem 2024; 300:107551. [PMID: 39002671 DOI: 10.1016/j.jbc.2024.107551] [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: 04/23/2024] [Revised: 06/20/2024] [Accepted: 06/26/2024] [Indexed: 07/15/2024] Open
Abstract
Isoforms of microtubule-associated protein 2 (MAP2) differ from their homolog Tau in the sequence and interactions of the N-terminal region. Binding of the N-terminal region of MAP2c (N-MAP2c) to the dimerization/docking domains of the regulatory subunit RIIα of cAMP-dependent protein kinase (RIIDD2) and to the Src-homology domain 2 (SH2) of growth factor receptor-bound protein 2 (Grb2) have been described long time ago. However, the structural features of the complexes remained unknown due to the disordered nature of MAP2. Here, we provide structural description of the complexes. We have solved solution structure of N-MAP2c in complex with RIIDD2, confirming formation of an amphiphilic α-helix of MAP2c upon binding, defining orientation of the α-helix in the complex and showing that its binding register differs from previous predictions. Using chemical shift mapping, we characterized the binding interface of SH2-Grb2 and rat MAP2c phosphorylated by the tyrosine kinase Fyn in their complex and proposed a model explaining differences between SH2-Grb2 complexes with rat MAP2c and phosphopeptides with a Grb2-specific sequence. The results provide the structural basis of a potential role of MAP2 in regulating cAMP-dependent phosphorylation cascade via interactions with RIIDD2 and Ras signaling pathway via interactions with SH2-Grb2.
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Affiliation(s)
- Viktor Bartošík
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jitka Plucarová
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Alice Laníková
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Zuzana Janáčková
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Petr Padrta
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Séverine Jansen
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Vojtěch Vařečka
- Institute of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Tobias Gruber
- Institute of Molecular Medicine, Tumor Biology, Martin-Luther-University of Halle-Wittenberg, Germany; Institute of Physics, Biophysics, Martin-Luther-University of Halle-Wittenberg, Germany
| | - Stephan M Feller
- Institute of Molecular Medicine, Tumor Biology, Martin-Luther-University of Halle-Wittenberg, Germany
| | - Lukáš Žídek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
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2
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Lockwood C, Vo AS, Bellafard H, Carter AJR. More evidence for widespread antagonistic pleiotropy in polymorphic disease alleles. Front Genet 2024; 15:1404516. [PMID: 38952711 PMCID: PMC11215129 DOI: 10.3389/fgene.2024.1404516] [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: 03/21/2024] [Accepted: 05/29/2024] [Indexed: 07/03/2024] Open
Abstract
Introduction Many loci segregate alleles classified as "genetic diseases" due to their deleterious effects on health. However, some disease alleles have been reported to show beneficial effects under certain conditions or in certain populations. The beneficial effects of these antagonistically pleiotropic alleles may explain their continued prevalence, but the degree to which antagonistic pleiotropy is common or rare is unresolved. We surveyed the medical literature to identify examples of antagonistic pleiotropy to help determine whether antagonistic pleiotropy appears to be rare or common. Results We identified ten examples of loci with polymorphisms for which the presence of antagonistic pleiotropy is well supported by detailed genetic or epidemiological information in humans. One additional locus was identified for which the supporting evidence comes from animal studies. These examples complement over 20 others reported in other reviews. Discussion The existence of more than 30 identified antagonistically pleiotropic human disease alleles suggests that this phenomenon may be widespread. This poses important implications for both our understanding of human evolutionary genetics and our approaches to clinical treatment and disease prevention, especially therapies based on genetic modification.
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Affiliation(s)
| | | | | | - Ashley J. R. Carter
- California State University Long Beach, Department of Biological Sciences, Long Beach, CA, United States
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Collins KB, Scott JD. Phosphorylation, compartmentalization, and cardiac function. IUBMB Life 2023; 75:353-369. [PMID: 36177749 PMCID: PMC10049969 DOI: 10.1002/iub.2677] [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: 07/13/2022] [Accepted: 09/15/2022] [Indexed: 11/08/2022]
Abstract
Protein phosphorylation is a fundamental element of cell signaling. First discovered as a biochemical switch in glycogen metabolism, we now know that this posttranslational modification permeates all aspects of cellular behavior. In humans, over 540 protein kinases attach phosphate to acceptor amino acids, whereas around 160 phosphoprotein phosphatases remove phosphate to terminate signaling. Aberrant phosphorylation underlies disease, and kinase inhibitor drugs are increasingly used clinically as targeted therapies. Specificity in protein phosphorylation is achieved in part because kinases and phosphatases are spatially organized inside cells. A prototypic example is compartmentalization of the cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase A through association with A-kinase anchoring proteins. This configuration creates autonomous signaling islands where the anchored kinase is constrained in proximity to activators, effectors, and selected substates. This article primarily focuses on A kinase anchoring protein (AKAP) signaling in the heart with an emphasis on anchoring proteins that spatiotemporally coordinate excitation-contraction coupling and hypertrophic responses.
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Affiliation(s)
- Kerrie B. Collins
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
| | - John D. Scott
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
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Wan L, Chen R, Zhu Y, Zhang W, Mu W. Interaction between the Anchoring Domain of A-Kinase Anchoring Proteins and the Dimerization and Docking Domain of Protein Kinase A: A Potent Tool for Synthetic Biology. ACS Synth Biol 2022; 11:3154-3162. [PMID: 36197832 DOI: 10.1021/acssynbio.2c00443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Nature is enriched with specific interactions between receptor proteins and their cognate ligands. These interacting pairs can be exploited and applied for the construction of well-ordered multicomponent assemblies with multivalency and multifunctionality. One of the research hotspots of this area is the formation of multienzyme complexes with stable and tunable architectures, which may bear the potential to facilitate cascade biocatalysis and/or strengthen metabolic fluxes. Here we focus on a special interacting pair, the anchoring domain (AD) derived from A-kinase anchoring protein and its interacting dimerization and docking domain (DDD) derived from cyclic AMP-dependent protein kinase, which has potential to be an effective and powerful synthetic biology tool for the construction of multienzyme assemblies. We review the origin and interaction mechanism of AD-DDD, followed by the application of this so-called dock-and-lock pair to form various bioconjugates with multivalency and multispecificity. Then several recent studies related to the construction of multienzyme complexes using AD-DDD, and more specifically, the RIAD-RIDD interacting pair, are presented. Finally, we also discuss the great biotechnology potential and perspectives of AD-DDD as a potent synthetic biology tool for post-translational modifications.
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Affiliation(s)
- Li Wan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Roulin Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yingying Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wenli Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China
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5
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Soundararajan R, Hernández-Cuervo H, Stearns TM, Griswold AJ, Patil SS, Fukumoto J, Narala VR, Galam L, Lockey R, Kolliputi N. A-Kinase Anchor Protein 1 deficiency causes mitochondrial dysfunction in mouse model of hyperoxia induced acute lung injury. Front Pharmacol 2022; 13:980723. [PMID: 36263130 PMCID: PMC9574061 DOI: 10.3389/fphar.2022.980723] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Critically ill patients on supplemental oxygen therapy eventually develop acute lung injury (ALI). Reactive oxygen species (ROS) produced during ALI perturbs the mitochondrial dynamics resulting in cellular damage. Genetic deletion of the mitochondrial A-kinase anchoring protein 1 (Akap1) in mice resulted in mitochondrial damage, Endoplasmic reticulum (ER) stress, increased expression of mitophagy proteins and pro-inflammatory cytokines, exacerbating hyperoxia-induced Acute Lung Injury (HALI).Objective: Despite a strong causal link between mitochondrial dysfunction and HALI, the mechanisms governing the disease progression at the transcriptome level is unknown.Methods: In this study, RNA sequencing (RNA-seq) analysis was carried out using the lungs of Akap1 knockout (Akap1−/−) mice exposed to normoxia or 48 h of hyperoxia followed by quantitative real time PCR and Ingenuity pathway analysis (IPA). Western blot analysis assessed mitochondrial dysfunction, OXPHOS complex (I-V), apoptosis and antioxidant proteins. Mitochondrial enzymatic assays was used to measure the aconitase, fumarase, citrate synthase activities in isolated mitochondria from Akap1−/− vs. Wt mice exposed to hyperoxia.Results: Transcriptome analysis of Akap1−/− exposed to hyperoxia reveals increases in transcripts encoding electron transport chain (ETC) and tricarboxylic acid cycle (TCA) proteins. Ingenuity pathway analysis (IPA) shows enrichment of mitochondrial dysfunction and oxidative phosphorylation in Akap1−/− mice. Loss of AKAP1, coupled with oxidant injury, significantly decreases the activities of TCA enzymes. Mechanistically, a significant loss of dynamin-related protein 1 (Drp1) phosphorylation at the protein kinase A (PKA) site Serine 637 (Ser637), decreases in Akt phosphorylation at Serine 437 (Ser47) and increase in the expression of pro-apoptotic protein Bax indicate mitochondrial dysfunction. Heme oxygenase-1 (HO-1) levels significantly increased in CD68 positive alveolar macrophages in Akap1−/− lungs, suggesting a strong antioxidant response to hyperoxia.Conclusion: Overall these results suggest that AKAP1 overexpression and modulation of Drp1 phosphorylation at Ser637 is an important therapeutic strategy for acute lung injury.
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Affiliation(s)
- Ramani Soundararajan
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Helena Hernández-Cuervo
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
- University of South Florida, Department of Molecular Medicine, Morsani College of Medicine, Tampa, FL, United States
| | | | - Anthony J Griswold
- John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Sahebgowda Sidramagowda Patil
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Jutaro Fukumoto
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | | | - Lakshmi Galam
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Richard Lockey
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Narasaiah Kolliputi
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
- University of South Florida, Department of Molecular Medicine, Morsani College of Medicine, Tampa, FL, United States
- *Correspondence: Narasaiah Kolliputi,
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Phosphorylation and acetylation of mitochondrial transcription factor A promote transcription processivity without compromising initiation or DNA compaction. J Biol Chem 2022; 298:101815. [PMID: 35278431 PMCID: PMC9006650 DOI: 10.1016/j.jbc.2022.101815] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/27/2022] [Accepted: 02/28/2022] [Indexed: 11/15/2022] Open
Abstract
Mitochondrial transcription factor A (TFAM) plays important roles in mitochondrial DNA compaction, transcription initiation, and in the regulation of processes like transcription and replication processivity. It is possible that TFAM is locally regulated within the mitochondrial matrix via such mechanisms as phosphorylation by protein kinase A and nonenzymatic acetylation by acetyl-CoA. Here, we demonstrate that DNA-bound TFAM is less susceptible to these modifications. We confirmed using EMSAs that phosphorylated or acetylated TFAM compacted circular double-stranded DNA just as well as unmodified TFAM and provide an in-depth analysis of acetylated sites on TFAM. We show that both modifications of TFAM increase the processivity of mitochondrial RNA polymerase during transcription through TFAM-imposed barriers on DNA, but that TFAM bearing either modification retains its full activity in transcription initiation. We conclude that TFAM phosphorylation by protein kinase A and nonenzymatic acetylation by acetyl-CoA are unlikely to occur at the mitochondrial DNA and that modified free TFAM retains its vital functionalities like compaction and transcription initiation while enhancing transcription processivity.
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Byrne DP, Omar MH, Kennedy EJ, Eyers PA, Scott JD. Biochemical Analysis of AKAP-Anchored PKA Signaling Complexes. Methods Mol Biol 2022; 2483:297-317. [PMID: 35286684 PMCID: PMC9518671 DOI: 10.1007/978-1-0716-2245-2_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Generation of the prototypic second messenger cAMP instigates numerous signaling events. A major intracellular target of cAMP is Protein kinase A (PKA), a Ser/Thr protein kinase. Where and when this enzyme is activated inside the cell has profound implications on the functional impact of PKA. It is now well established that PKA signaling is focused locally into subcellular signaling "islands" or "signalosomes." The A-Kinase Anchoring Proteins (AKAPs) play a critical role in this process by dictating spatial and temporal aspects of PKA action. Genetically encoded biosensors, small molecule and peptide-based disruptors of PKA signaling are valuable tools for rigorous investigation of local PKA action at the biochemical level. This chapter focuses on approaches to evaluate PKA signaling islands, including a simple assay for monitoring the interaction of an AKAP with a tunable PKA holoenzyme. The latter approach evaluates the composition of PKA holoenzymes, in which regulatory subunits and catalytic subunits can be visualized in the presence of test compounds and small-molecule inhibitors.
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Affiliation(s)
- Dominic P Byrne
- Department of Biochemistry and Systems Biology, ISMIB, University of Liverpool, Liverpool, UK
| | - Mitchell H Omar
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Patrick A Eyers
- Department of Biochemistry and Systems Biology, ISMIB, University of Liverpool, Liverpool, UK.
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, WA, USA.
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Chaanine AH. Metabolic Remodeling and Implicated Calcium and Signal Transduction Pathways in the Pathogenesis of Heart Failure. Int J Mol Sci 2021; 22:ijms221910579. [PMID: 34638917 PMCID: PMC8508915 DOI: 10.3390/ijms221910579] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 11/16/2022] Open
Abstract
The heart is an organ with high-energy demands in which the mitochondria are most abundant. They are considered the powerhouse of the cell and occupy a central role in cellular metabolism. The intermyofibrillar mitochondria constitute the majority of the three-mitochondrial subpopulations in the heart. They are also considered to be the most important in terms of their ability to participate in calcium and cellular signaling, which are critical for the regulation of mitochondrial function and adenosine triphosphate (ATP) production. This is because they are located in very close proximity with the endoplasmic reticulum (ER), and for the presence of tethering complexes enabling interorganelle crosstalk via calcium signaling. Calcium is an important second messenger that regulates mitochondrial function. It promotes ATP production and cellular survival under physiological changes in cardiac energetic demand. This is accomplished in concert with signaling pathways that regulate both calcium cycling and mitochondrial function. Perturbations in mitochondrial homeostasis and metabolic remodeling occupy a central role in the pathogenesis of heart failure. In this review we will discuss perturbations in ER-mitochondrial crosstalk and touch on important signaling pathways and molecular mechanisms involved in the dysregulation of calcium homeostasis and mitochondrial function in heart failure.
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Affiliation(s)
- Antoine H. Chaanine
- Department of Medicine, Heart and Vascular Institute, Tulane University, New Orleans, LA 70112, USA; ; Tel.: +1-(504)-988-1612
- Department of Physiology, Tulane University, New Orleans, LA 70112, USA
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9
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Sherpa RT, Fiore C, Moshal KS, Wadsworth A, Rudokas MW, Agarwal SR, Harvey RD. Mitochondrial A-kinase anchoring proteins in cardiac ventricular myocytes. Physiol Rep 2021; 9:e15015. [PMID: 34514737 PMCID: PMC8436057 DOI: 10.14814/phy2.15015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 12/30/2022] Open
Abstract
Compartmentation of cAMP signaling is a critical factor for maintaining the integrity of receptor-specific responses in cardiac myocytes. This phenomenon relies on various factors limiting cAMP diffusion. Our previous work in adult rat ventricular myocytes (ARVMs) indicates that PKA regulatory subunits anchored to the outer membrane of mitochondria play a key role in buffering the movement of cytosolic cAMP. PKA can be targeted to discrete subcellular locations through the interaction of both type I and type II regulatory subunits with A-kinase anchoring proteins (AKAPs). The purpose of this study is to identify which AKAPs and PKA regulatory subunit isoforms are associated with mitochondria in ARVMs. Quantitative PCR data demonstrate that mRNA for dual specific AKAP1 and 2 (D-AKAP1 & D-AKAP2), acyl-CoA-binding domain-containing 3 (ACBD3), optic atrophy 1 (OPA1) are most abundant, while Rab32, WAVE-1, and sphingosine kinase type 1 interacting protein (SPHKAP) were barely detectable. Biochemical and immunocytochemical analysis suggests that D-AKAP1, D-AKAP2, and ACBD3 are the predominant mitochondrial AKAPs exposed to the cytosolic compartment in these cells. Furthermore, we show that both type I and type II regulatory subunits of PKA are associated with mitochondria. Taken together, these data suggest that D-AKAP1, D-AKAP2, and ACBD3 may be responsible for tethering both type I and type II PKA regulatory subunits to the outer mitochondrial membrane in ARVMs. In addition to regulating PKA-dependent mitochondrial function, these AKAPs may play an important role by buffering the movement of cAMP necessary for compartmentation.
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Affiliation(s)
| | - Chase Fiore
- Department of PharmacologyUniversity of NevadaRenoNevadaUSA
| | | | - Adam Wadsworth
- Department of PharmacologyUniversity of NevadaRenoNevadaUSA
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10
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Dahlin HR, Zheng N, Scott JD. Beyond PKA: Evolutionary and structural insights that define a docking and dimerization domain superfamily. J Biol Chem 2021; 297:100927. [PMID: 34256050 PMCID: PMC8339350 DOI: 10.1016/j.jbc.2021.100927] [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: 05/20/2021] [Revised: 06/18/2021] [Accepted: 06/28/2021] [Indexed: 01/26/2023] Open
Abstract
Protein-interaction domains can create unique macromolecular complexes that drive evolutionary innovation. By combining bioinformatic and phylogenetic analyses with structural approaches, we have discovered that the docking and dimerization (D/D) domain of the PKA regulatory subunit is an ancient and conserved protein fold. An archetypal function of this module is to interact with A-kinase-anchoring proteins (AKAPs) that facilitate compartmentalization of this key cell-signaling enzyme. Homology searching reveals that D/D domain proteins comprise a superfamily with 18 members that function in a variety of molecular and cellular contexts. Further in silico analyses indicate that D/D domains segregate into subgroups on the basis of their similarity to type I or type II PKA regulatory subunits. The sperm autoantigenic protein 17 (SPA17) is a prototype of the type II or R2D2 subgroup that is conserved across metazoan phyla. We determined the crystal structure of an extended D/D domain from SPA17 (amino acids 1-75) at 1.72 Å resolution. This revealed a four-helix bundle-like configuration featuring terminal β-strands that can mediate higher order oligomerization. In solution, SPA17 forms both homodimers and tetramers and displays a weak affinity for AKAP18. Quantitative approaches reveal that AKAP18 binding occurs at nanomolar affinity when SPA17 heterodimerizes with the ropporin-1-like D/D protein. These findings expand the role of the D/D fold as a versatile protein-interaction element that maintains the integrity of macromolecular architectures within organelles such as motile cilia.
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Affiliation(s)
- Heather R Dahlin
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, Washington, USA; Howard Hughes Medical Institute, University of Washington, Seattle, Washington, USA.
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, Washington, USA.
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Banerjee TD, Reihl K, Swain M, Torres M, Dagda RK. Mitochondrial PKA Is Neuroprotective in a Cell Culture Model of Alzheimer's Disease. Mol Neurobiol 2021; 58:3071-3083. [PMID: 33624140 PMCID: PMC8260456 DOI: 10.1007/s12035-021-02333-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 02/15/2021] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive decline. In hippocampal neurons, the pathological features of AD include the accumulation of extracellular amyloid-beta peptide (Aβ) accompanied by oxidative stress, mitochondrial dysfunction, and neuron loss. A decrease in neuroprotective Protein Kinase A (PKA) signaling contributes to mitochondrial fragmentation and neurodegeneration in AD. By associating with the protein scaffold Dual-Specificity Anchoring Protein 1 (D-AKAP1), PKA is targeted to mitochondria to promote mitochondrial fusion by phosphorylating the fission modulator dynamin-related protein 1 (Drp1). We hypothesized that (1) a decrease in the endogenous level of endogenous D-AKAP1 contributes to decreased PKA signaling in mitochondria and that (2) restoring PKA signaling in mitochondria can reverse neurodegeneration and mitochondrial fragmentation in neurons in AD models. Through immunohistochemistry, we showed that endogenous D-AKAP1, but not other mitochondrial proteins, is significantly reduced in primary neurons treated with Aβ42 peptide (10μM, 24 h), and in the hippocampus and cortex from asymptomatic and symptomatic AD mice (5X-FAD). Transiently expressing wild-type, but not a PKA-binding deficient mutant of D-AKAP1, was able to reduce mitochondrial fission, dendrite retraction, and apoptosis in primary neurons treated with Aβ42. Mechanistically, the protective effects of D-AKAP1/PKA are moderated through PKA-mediated phosphorylation of Drp1, as transiently expressing a PKA phosphomimetic mutant of Drp1 (Drp1-S656D) phenocopies D-AKAP1's ability to reduce Aβ42-mediated apoptosis and mitochondrial fission. Overall, our data suggest that a loss of D-AKAP1/PKA contributes to mitochondrial pathology and neurodegeneration in an in vitro cell culture model of AD.
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Affiliation(s)
- Tania Das Banerjee
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Kelly Reihl
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Maryann Swain
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Mariana Torres
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Ruben K Dagda
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA.
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12
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Sholokh A, Klussmann E. Local cyclic adenosine monophosphate signalling cascades-Roles and targets in chronic kidney disease. Acta Physiol (Oxf) 2021; 232:e13641. [PMID: 33660401 DOI: 10.1111/apha.13641] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/20/2022]
Abstract
The molecular mechanisms underlying chronic kidney disease (CKD) are poorly understood and treatment options are limited, a situation underpinning the need for elucidating the causative molecular mechanisms and for identifying innovative treatment options. It is emerging that cyclic 3',5'-adenosine monophosphate (cAMP) signalling occurs in defined cellular compartments within nanometre dimensions in processes whose dysregulation is associated with CKD. cAMP compartmentalization is tightly controlled by a specific set of proteins, including A-kinase anchoring proteins (AKAPs) and phosphodiesterases (PDEs). AKAPs such as AKAP18, AKAP220, AKAP-Lbc and STUB1, and PDE4 coordinate arginine-vasopressin (AVP)-induced water reabsorption by collecting duct principal cells. However, hyperactivation of the AVP system is associated with kidney damage and CKD. Podocyte injury involves aberrant AKAP signalling. cAMP signalling in immune cells can be local and slow the progression of inflammatory processes typical for CKD. A major risk factor of CKD is hypertension. cAMP directs the release of the blood pressure regulator, renin, from juxtaglomerular cells, and plays a role in Na+ reabsorption through ENaC, NKCC2 and NCC in the kidney. Mutations in the cAMP hydrolysing PDE3A that cause lowering of cAMP lead to hypertension. Another major risk factor of CKD is diabetes mellitus. AKAP18 and AKAP150 and several PDEs are involved in insulin release. Despite the increasing amount of data, an understanding of functions of compartmentalized cAMP signalling with relevance for CKD is fragmentary. Uncovering functions will improve the understanding of physiological processes and identification of disease-relevant aberrations may guide towards new therapeutic concepts for the treatment of CKD.
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Affiliation(s)
- Anastasiia Sholokh
- Max‐Delbrück‐Center for Molecular Medicine (MDC) Helmholtz Association Berlin Germany
| | - Enno Klussmann
- Max‐Delbrück‐Center for Molecular Medicine (MDC) Helmholtz Association Berlin Germany
- DZHK (German Centre for Cardiovascular Research) Berlin Germany
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13
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Regulation of Cardiac PKA Signaling by cAMP and Oxidants. Antioxidants (Basel) 2021; 10:antiox10050663. [PMID: 33923287 PMCID: PMC8146537 DOI: 10.3390/antiox10050663] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 12/31/2022] Open
Abstract
Pathologies, such as cancer, inflammatory and cardiac diseases are commonly associated with long-term increased production and release of reactive oxygen species referred to as oxidative stress. Thereby, protein oxidation conveys protein dysfunction and contributes to disease progression. Importantly, trials to scavenge oxidants by systemic antioxidant therapy failed. This observation supports the notion that oxidants are indispensable physiological signaling molecules that induce oxidative post-translational modifications in target proteins. In cardiac myocytes, the main driver of cardiac contractility is the activation of the β-adrenoceptor-signaling cascade leading to increased cellular cAMP production and activation of its main effector, the cAMP-dependent protein kinase (PKA). PKA-mediated phosphorylation of substrate proteins that are involved in excitation-contraction coupling are responsible for the observed positive inotropic and lusitropic effects. PKA-actions are counteracted by cellular protein phosphatases (PP) that dephosphorylate substrate proteins and thus allow the termination of PKA-signaling. Both, kinase and phosphatase are redox-sensitive and susceptible to oxidation on critical cysteine residues. Thereby, oxidation of the regulatory PKA and PP subunits is considered to regulate subcellular kinase and phosphatase localization, while intradisulfide formation of the catalytic subunits negatively impacts on catalytic activity with direct consequences on substrate (de)phosphorylation and cardiac contractile function. This review article attempts to incorporate the current perception of the functionally relevant regulation of cardiac contractility by classical cAMP-dependent signaling with the contribution of oxidant modification.
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14
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Colombe AS, Pidoux G. Cardiac cAMP-PKA Signaling Compartmentalization in Myocardial Infarction. Cells 2021; 10:cells10040922. [PMID: 33923648 PMCID: PMC8073060 DOI: 10.3390/cells10040922] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/02/2021] [Accepted: 04/13/2021] [Indexed: 02/07/2023] Open
Abstract
Under physiological conditions, cAMP signaling plays a key role in the regulation of cardiac function. Activation of this intracellular signaling pathway mirrors cardiomyocyte adaptation to various extracellular stimuli. Extracellular ligand binding to seven-transmembrane receptors (also known as GPCRs) with G proteins and adenylyl cyclases (ACs) modulate the intracellular cAMP content. Subsequently, this second messenger triggers activation of specific intracellular downstream effectors that ensure a proper cellular response. Therefore, it is essential for the cell to keep the cAMP signaling highly regulated in space and time. The temporal regulation depends on the activity of ACs and phosphodiesterases. By scaffolding key components of the cAMP signaling machinery, A-kinase anchoring proteins (AKAPs) coordinate both the spatial and temporal regulation. Myocardial infarction is one of the major causes of death in industrialized countries and is characterized by a prolonged cardiac ischemia. This leads to irreversible cardiomyocyte death and impairs cardiac function. Regardless of its causes, a chronic activation of cardiac cAMP signaling is established to compensate this loss. While this adaptation is primarily beneficial for contractile function, it turns out, in the long run, to be deleterious. This review compiles current knowledge about cardiac cAMP compartmentalization under physiological conditions and post-myocardial infarction when it appears to be profoundly impaired.
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15
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Di Benedetto G, Iannucci LF, Surdo NC, Zanin S, Conca F, Grisan F, Gerbino A, Lefkimmiatis K. Compartmentalized Signaling in Aging and Neurodegeneration. Cells 2021; 10:464. [PMID: 33671541 PMCID: PMC7926881 DOI: 10.3390/cells10020464] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/12/2022] Open
Abstract
The cyclic AMP (cAMP) signalling cascade is necessary for cell homeostasis and plays important roles in many processes. This is particularly relevant during ageing and age-related diseases, where drastic changes, generally decreases, in cAMP levels have been associated with the progressive decline in overall cell function and, eventually, the loss of cellular integrity. The functional relevance of reduced cAMP is clearly supported by the finding that increases in cAMP levels can reverse some of the effects of ageing. Nevertheless, despite these observations, the molecular mechanisms underlying the dysregulation of cAMP signalling in ageing are not well understood. Compartmentalization is widely accepted as the modality through which cAMP achieves its functional specificity; therefore, it is important to understand whether and how this mechanism is affected during ageing and to define which is its contribution to this process. Several animal models demonstrate the importance of specific cAMP signalling components in ageing, however, how age-related changes in each of these elements affect the compartmentalization of the cAMP pathway is largely unknown. In this review, we explore the connection of single components of the cAMP signalling cascade to ageing and age-related diseases whilst elaborating the literature in the context of cAMP signalling compartmentalization.
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Affiliation(s)
- Giulietta Di Benedetto
- Neuroscience Institute, National Research Council of Italy (CNR), 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
| | - Liliana F. Iannucci
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Nicoletta C. Surdo
- Neuroscience Institute, National Research Council of Italy (CNR), 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
| | - Sofia Zanin
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Filippo Conca
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Biology, University of Padova, 35122 Padova, Italy
| | - Francesca Grisan
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Biology, University of Padova, 35122 Padova, Italy
| | - Andrea Gerbino
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, 70121 Bari, Italy;
| | - Konstantinos Lefkimmiatis
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
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16
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Omar MH, Scott JD. AKAP Signaling Islands: Venues for Precision Pharmacology. Trends Pharmacol Sci 2020; 41:933-946. [PMID: 33082006 DOI: 10.1016/j.tips.2020.09.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/19/2022]
Abstract
Regulatory enzymes often have different roles in distinct subcellular compartments. Yet, most drugs indiscriminately saturate the cell. Thus, subcellular drug-delivery holds promise as a means to reduce off-target pharmacological effects. A-kinase anchoring proteins (AKAPs) sequester combinations of signaling enzymes within subcellular microdomains. Targeting drugs to these 'signaling islands' offers an opportunity for more precise delivery of therapeutics. Here, we review mechanisms that bestow protein kinase A (PKA) versatility inside the cell, appraise recent advances in exploiting AKAPs as platforms for precision pharmacology, and explore the impact of methodological innovations on AKAP research.
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Affiliation(s)
- Mitchell H Omar
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA.
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17
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Gabrovsek L, Collins KB, Aggarwal S, Saunders LM, Lau HT, Suh D, Sancak Y, Trapnell C, Ong SE, Smith FD, Scott JD. A-kinase-anchoring protein 1 (dAKAP1)-based signaling complexes coordinate local protein synthesis at the mitochondrial surface. J Biol Chem 2020; 295:10749-10765. [PMID: 32482893 PMCID: PMC7397098 DOI: 10.1074/jbc.ra120.013454] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/20/2020] [Indexed: 12/30/2022] Open
Abstract
Compartmentalization of macromolecules is a ubiquitous molecular mechanism that drives numerous cellular functions. The appropriate organization of enzymes in space and time enables the precise transmission and integration of intracellular signals. Molecular scaffolds constrain signaling enzymes to influence the regional modulation of these physiological processes. Mitochondrial targeting of protein kinases and protein phosphatases provides a means to locally control the phosphorylation status and action of proteins on the surface of this organelle. Dual-specificity protein kinase A anchoring protein 1 (dAKAP1) is a multivalent binding protein that targets protein kinase A (PKA), RNAs, and other signaling enzymes to the outer mitochondrial membrane. Many AKAPs recruit a diverse set of binding partners that coordinate a broad range of cellular processes. Here, results of MS and biochemical analyses reveal that dAKAP1 anchors additional components, including the ribonucleoprotein granule components La-related protein 4 (LARP4) and polyadenylate-binding protein 1 (PABPC1). Local translation of mRNAs at organelles is a means to spatially control the synthesis of proteins. RNA-Seq data demonstrate that dAKAP1 binds mRNAs encoding proteins required for mitochondrial metabolism, including succinate dehydrogenase. Functional studies suggest that the loss of dAKAP1-RNA interactions reduces mitochondrial electron transport chain activity. Hence, dAKAP1 plays a previously unappreciated role as a molecular interface between second messenger signaling and local protein synthesis machinery.
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Affiliation(s)
- Laura Gabrovsek
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
- Program in Molecular and Cellular Biology, University of Washington, Seattle, Washington, USA
| | - Kerrie B Collins
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - Stacey Aggarwal
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - Lauren M Saunders
- Program in Molecular and Cellular Biology, University of Washington, Seattle, Washington, USA
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Ho-Tak Lau
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - Danny Suh
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - Yasemin Sancak
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Shao-En Ong
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - F Donelson Smith
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
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18
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Bucko PJ, Scott JD. Drugs That Regulate Local Cell Signaling: AKAP Targeting as a Therapeutic Option. Annu Rev Pharmacol Toxicol 2020; 61:361-379. [PMID: 32628872 DOI: 10.1146/annurev-pharmtox-022420-112134] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells respond to environmental cues by mobilizing signal transduction cascades that engage protein kinases and phosphoprotein phosphatases. Correct organization of these enzymes in space and time enables the efficient and precise transmission of chemical signals. The cyclic AMP-dependent protein kinase A is compartmentalized through its association with A-kinase anchoring proteins (AKAPs). AKAPs are a family of multivalent scaffolds that constrain signaling enzymes and effectors at subcellular locations to drive essential physiological events. More recently, it has been recognized that defective signaling in certain endocrine disorders and cancers proceeds through pathological AKAP complexes. Consequently, pharmacologically targeting these macromolecular complexes unlocks new therapeutic opportunities for a growing number of clinical indications. This review highlights recent findings on AKAP signaling in disease, particularly in certain cancers, and offers an overview of peptides and small molecules that locally regulate AKAP-binding partners.
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Affiliation(s)
- Paula J Bucko
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
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19
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van der Horst J, Greenwood IA, Jepps TA. Cyclic AMP-Dependent Regulation of Kv7 Voltage-Gated Potassium Channels. Front Physiol 2020; 11:727. [PMID: 32695022 PMCID: PMC7338754 DOI: 10.3389/fphys.2020.00727] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/04/2020] [Indexed: 01/08/2023] Open
Abstract
Voltage-gated Kv7 potassium channels, encoded by KCNQ genes, have major physiological impacts cardiac myocytes, neurons, epithelial cells, and smooth muscle cells. Cyclic adenosine monophosphate (cAMP), a well-known intracellular secondary messenger, can activate numerous downstream effector proteins, generating downstream signaling pathways that regulate many functions in cells. A role for cAMP in ion channel regulation has been established, and recent findings show that cAMP signaling plays a role in Kv7 channel regulation. Although cAMP signaling is recognized to regulate Kv7 channels, the precise molecular mechanism behind the cAMP-dependent regulation of Kv7 channels is complex. This review will summarize recent research findings that support the mechanisms of cAMP-dependent regulation of Kv7 channels.
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Affiliation(s)
- Jennifer van der Horst
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iain A Greenwood
- Molecular and Clinical Sciences Institute, St. George's University of London, London, United Kingdom
| | - Thomas A Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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20
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A-Kinase Anchoring Protein 1: Emerging Roles in Regulating Mitochondrial Form and Function in Health and Disease. Cells 2020; 9:cells9020298. [PMID: 31991888 PMCID: PMC7072574 DOI: 10.3390/cells9020298] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/1970] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 01/01/2023] Open
Abstract
Best known as the powerhouse of the cell, mitochondria have many other important functions such as buffering intracellular calcium and reactive oxygen species levels, initiating apoptosis and supporting cell proliferation and survival. Mitochondria are also dynamic organelles that are constantly undergoing fission and fusion to meet specific functional needs. These processes and functions are regulated by intracellular signaling at the mitochondria. A-kinase anchoring protein 1 (AKAP1) is a scaffold protein that recruits protein kinase A (PKA), other signaling proteins, as well as RNA to the outer mitochondrial membrane. Hence, AKAP1 can be considered a mitochondrial signaling hub. In this review, we discuss what is currently known about AKAP1's function in health and diseases. We focus on the recent literature on AKAP1's roles in metabolic homeostasis, cancer and cardiovascular and neurodegenerative diseases. In healthy tissues, AKAP1 has been shown to be important for driving mitochondrial respiration during exercise and for mitochondrial DNA replication and quality control. Several recent in vivo studies using AKAP1 knockout mice have elucidated the role of AKAP1 in supporting cardiovascular, lung and neuronal cell survival in the stressful post-ischemic environment. In addition, we discuss the unique involvement of AKAP1 in cancer tumor growth, metastasis and resistance to chemotherapy. Collectively, the data indicate that AKAP1 promotes cell survival throug regulating mitochondrial form and function. Lastly, we discuss the potential of targeting of AKAP1 for therapy of various disorders.
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21
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Zhu YR, Jiang XX, Zheng Y, Xiong J, Wei D, Zhang DM. Cardiac function modulation depends on the A-kinase anchoring protein complex. J Cell Mol Med 2019; 23:7170-7179. [PMID: 31512389 PMCID: PMC6815827 DOI: 10.1111/jcmm.14659] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/27/2019] [Accepted: 08/06/2019] [Indexed: 12/26/2022] Open
Abstract
The A‐kinase anchoring proteins (AKAPs) are a group of structurally diverse proteins identified in various species and tissues. These proteins are able to anchor protein kinase and other signalling proteins to regulate cardiac function. Acting as a scaffold protein, AKAPs ensure specificity in signal transduction by enzymes close to their appropriate effectors and substrates. Over the decades, more than 70 different AKAPs have been discovered. Accumulative evidence indicates that AKAPs play crucial roles in the functional regulation of cardiac diseases, including cardiac hypertrophy, myofibre contractility dysfunction and arrhythmias. By anchoring different partner proteins (PKA, PKC, PKD and LTCCs), AKAPs take part in different regulatory pathways to function as regulators in the heart, and a damaged structure can influence the activities of these complexes. In this review, we highlight recent advances in AKAP‐associated protein complexes, focusing on local signalling events that are perturbed in cardiac diseases and their roles in interacting with ion channels and their regulatory molecules. These new findings suggest that AKAPs might have potential therapeutic value in patients with cardiac diseases, particularly malignant rhythm.
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Affiliation(s)
- Yan-Rong Zhu
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Xiao-Xin Jiang
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Yaguo Zheng
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Jing Xiong
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Dongping Wei
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Dai-Min Zhang
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
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22
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Aggarwal S, Gabrovsek L, Langeberg LK, Golkowski M, Ong SE, Smith FD, Scott JD. Depletion of dAKAP1-protein kinase A signaling islands from the outer mitochondrial membrane alters breast cancer cell metabolism and motility. J Biol Chem 2018; 294:3152-3168. [PMID: 30598507 DOI: 10.1074/jbc.ra118.006741] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/21/2018] [Indexed: 01/23/2023] Open
Abstract
Breast cancer screening and new precision therapies have led to improved patient outcomes. Yet, a positive prognosis is less certain when primary tumors metastasize. Metastasis requires a coordinated program of cellular changes that promote increased survival, migration, and energy consumption. These pathways converge on mitochondrial function, where distinct signaling networks of kinases, phosphatases, and metabolic enzymes regulate these processes. The protein kinase A-anchoring protein dAKAP1 compartmentalizes protein kinase A (PKA) and other signaling enzymes at the outer mitochondrial membrane and thereby controls mitochondrial function and dynamics. Modulation of these processes occurs in part through regulation of dynamin-related protein 1 (Drp1). Here, we report an inverse relationship between the expression of dAKAP1 and mesenchymal markers in breast cancer. Molecular, cellular, and in silico analyses of breast cancer cell lines confirmed that dAKAP1 depletion is associated with impaired mitochondrial function and dynamics, as well as with increased glycolytic potential and invasiveness. Furthermore, disruption of dAKAP1-PKA complexes affected cell motility and mitochondrial movement toward the leading edge in invasive breast cancer cells. We therefore propose that depletion of dAKAP1-PKA "signaling islands" from the outer mitochondrial membrane augments progression toward metastatic breast cancer.
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Affiliation(s)
- Stacey Aggarwal
- From the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Laura Gabrovsek
- From the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Lorene K Langeberg
- From the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Martin Golkowski
- From the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Shao-En Ong
- From the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - F Donelson Smith
- From the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - John D Scott
- From the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
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23
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Single nucleotide polymorphisms alter kinase anchoring and the subcellular targeting of A-kinase anchoring proteins. Proc Natl Acad Sci U S A 2018; 115:E11465-E11474. [PMID: 30455320 DOI: 10.1073/pnas.1816614115] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A-kinase anchoring proteins (AKAPs) shape second-messenger signaling responses by constraining protein kinase A (PKA) at precise intracellular locations. A defining feature of AKAPs is a helical region that binds to regulatory subunits (RII) of PKA. Mining patient-derived databases has identified 42 nonsynonymous SNPs in the PKA-anchoring helices of five AKAPs. Solid-phase RII binding assays confirmed that 21 of these amino acid substitutions disrupt PKA anchoring. The most deleterious side-chain modifications are situated toward C-termini of AKAP helices. More extensive analysis was conducted on a valine-to-methionine variant in the PKA-anchoring helix of AKAP18. Molecular modeling indicates that additional density provided by methionine at position 282 in the AKAP18γ isoform deflects the pitch of the helical anchoring surface outward by 6.6°. Fluorescence polarization measurements show that this subtle topological change reduces RII-binding affinity 8.8-fold and impairs cAMP responsive potentiation of L-type Ca2+ currents in situ. Live-cell imaging of AKAP18γ V282M-GFP adducts led to the unexpected discovery that loss of PKA anchoring promotes nuclear accumulation of this polymorphic variant. Targeting proceeds via a mechanism whereby association with the PKA holoenzyme masks a polybasic nuclear localization signal on the anchoring protein. This led to the discovery of AKAP18ε: an exclusively nuclear isoform that lacks a PKA-anchoring helix. Enzyme-mediated proximity-proteomics reveal that compartment-selective variants of AKAP18 associate with distinct binding partners. Thus, naturally occurring PKA-anchoring-defective AKAP variants not only perturb dissemination of local second-messenger responses, but also may influence the intracellular distribution of certain AKAP18 isoforms.
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24
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Mitochondrial cAMP-PKA signaling: What do we really know? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:868-877. [PMID: 29694829 DOI: 10.1016/j.bbabio.2018.04.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/06/2018] [Accepted: 04/18/2018] [Indexed: 12/22/2022]
Abstract
Mitochondria are key organelles for cellular homeostasis. They generate the most part of ATP that is used by cells through oxidative phosphorylation. They also produce reactive oxygen species, neurotransmitters and other signaling molecules. They are important for calcium homeostasis and apoptosis. Considering the role of this organelle, it is not surprising that most mitochondrial dysfunctions are linked to the development of pathologies. Various mechanisms adjust mitochondrial activity according to physiological needs. The cAMP-PKA signaling emerged in recent years as a direct and powerful mean to regulate mitochondrial functions. Multiple evidence demonstrates that such pathway can be triggered from cytosol or directly within mitochondria. Notably, specific anchor proteins target PKA to mitochondria whereas enzymes necessary for generation and degradation of cAMP are found directly in these organelles. Mitochondrial PKA targets proteins localized in different compartments of mitochondria, and related to various functions. Alterations of mitochondrial cAMP-PKA signaling affect the development of several physiopathological conditions, including neurodegenerative diseases. It is however difficult to discriminate between the effects of cAMP-PKA signaling triggered from cytosol or directly in mitochondria. The specific roles of PKA localized in different mitochondrial compartments are also not completely understood. The aim of this work is to review the role of cAMP-PKA signaling in mitochondrial (patho)physiology.
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25
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Ercu M, Klussmann E. Roles of A-Kinase Anchoring Proteins and Phosphodiesterases in the Cardiovascular System. J Cardiovasc Dev Dis 2018; 5:jcdd5010014. [PMID: 29461511 PMCID: PMC5872362 DOI: 10.3390/jcdd5010014] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/16/2018] [Accepted: 02/18/2018] [Indexed: 12/13/2022] Open
Abstract
A-kinase anchoring proteins (AKAPs) and cyclic nucleotide phosphodiesterases (PDEs) are essential enzymes in the cyclic adenosine 3′-5′ monophosphate (cAMP) signaling cascade. They establish local cAMP pools by controlling the intensity, duration and compartmentalization of cyclic nucleotide-dependent signaling. Various members of the AKAP and PDE families are expressed in the cardiovascular system and direct important processes maintaining homeostatic functioning of the heart and vasculature, e.g., the endothelial barrier function and excitation-contraction coupling. Dysregulation of AKAP and PDE function is associated with pathophysiological conditions in the cardiovascular system including heart failure, hypertension and atherosclerosis. A number of diseases, including autosomal dominant hypertension with brachydactyly (HTNB) and type I long-QT syndrome (LQT1), result from mutations in genes encoding for distinct members of the two classes of enzymes. This review provides an overview over the AKAPs and PDEs relevant for cAMP compartmentalization in the heart and vasculature and discusses their pathophysiological role as well as highlights the potential benefits of targeting these proteins and their protein-protein interactions for the treatment of cardiovascular diseases.
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Affiliation(s)
- Maria Ercu
- Max Delbrück Center for Molecular Medicine Berlin (MDC), Berlin 13125, Germany.
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine Berlin (MDC), Berlin 13125, Germany.
- DZHK (German Centre for Cardiovascular Research), partner site Berlin 13347, Germany.
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26
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Narala VR, Fukumoto J, Hernández-Cuervo H, Patil SS, Krishnamurthy S, Breitzig M, Galam L, Soundararajan R, Lockey RF, Kolliputi N. Akap1 genetic deletion increases the severity of hyperoxia-induced acute lung injury in mice. Am J Physiol Lung Cell Mol Physiol 2018; 314:L860-L870. [PMID: 29388469 DOI: 10.1152/ajplung.00365.2017] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Critically ill patients are commonly treated with high levels of oxygen, hyperoxia, for prolonged periods of time. Unfortunately, extended exposure to hyperoxia can exacerbate respiratory failure and lead to a high mortality rate. Mitochondrial A-kinase anchoring protein (Akap) has been shown to regulate mitochondrial function. It has been reported that, under hypoxic conditions, Akap121 undergoes proteolytic degradation and promotes cardiac injury. However, the role of Akap1 in hyperoxia-induced acute lung injury (ALI) is largely unknown. To address this gap in our understanding of Akap1, we exposed wild-type ( wt) and Akap1-/- mice to 100% oxygen for 48 h, a time point associated with lung damage in the murine model of ALI. We found that under hyperoxia, Akap1-/- mice display increased levels of proinflammatory cytokines, immune cell infiltration, and protein leakage in lungs, as well as increased alveolar capillary permeability compared with wt controls. Further analysis revealed that Akap1 deletion enhances lung NF-κB p65 activity as assessed by immunoblotting and DNA-binding assay and mitochondrial autophagy-related markers, PINK1 and Parkin. Ultrastructural analysis using electron microscopy revealed that Akap1 deletion was associated with remarkably aberrant mitochondria and lamellar bodies in type II alveolar epithelial cells. Taken together, these results demonstrate that Akap1 genetic deletion increases the severity of hyperoxia-induced acute lung injury in mice.
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Affiliation(s)
- Venkata Ramireddy Narala
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida.,Department of Zoology, Yogi Vemana University, Kadapa, India
| | - Jutaro Fukumoto
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Helena Hernández-Cuervo
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Sahebgowda Sidramagowda Patil
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Sudarshan Krishnamurthy
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Mason Breitzig
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Lakshmi Galam
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Ramani Soundararajan
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Richard F Lockey
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
| | - Narasaiah Kolliputi
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida
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27
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Chung J, Wittig JG, Ghamari A, Maeda M, Dailey TA, Bergonia H, Kafina MD, Coughlin EE, Minogue CE, Hebert AS, Li L, Kaplan J, Lodish HF, Bauer DE, Orkin SH, Cantor AB, Maeda T, Phillips JD, Coon JJ, Pagliarini DJ, Dailey HA, Paw BH. Erythropoietin signaling regulates heme biosynthesis. eLife 2017; 6. [PMID: 28553927 PMCID: PMC5478267 DOI: 10.7554/elife.24767] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 05/28/2017] [Indexed: 11/13/2022] Open
Abstract
Heme is required for survival of all cells, and in most eukaryotes, is produced through a series of eight enzymatic reactions. Although heme production is critical for many cellular processes, how it is coupled to cellular differentiation is unknown. Here, using zebrafish, murine, and human models, we show that erythropoietin (EPO) signaling, together with the GATA1 transcriptional target, AKAP10, regulates heme biosynthesis during erythropoiesis at the outer mitochondrial membrane. This integrated pathway culminates with the direct phosphorylation of the crucial heme biosynthetic enzyme, ferrochelatase (FECH) by protein kinase A (PKA). Biochemical, pharmacological, and genetic inhibition of this signaling pathway result in a block in hemoglobin production and concomitant intracellular accumulation of protoporphyrin intermediates. Broadly, our results implicate aberrant PKA signaling in the pathogenesis of hematologic diseases. We propose a unifying model in which the erythroid transcriptional program works in concert with post-translational mechanisms to regulate heme metabolism during normal development. DOI:http://dx.doi.org/10.7554/eLife.24767.001 Heme is an iron-containing compound that is important for all living things, from bacteria to humans. Our red blood cells use heme to carry oxygen and deliver it throughout the body. The amount of heme that is produced must be tightly regulated. Too little or too much heme in a person’s red blood cells can lead to blood-related diseases such as anemia and porphyria. Yet, while scientists knew the enzymes needed to make heme, they did not know how these enzymes were controlled. Now, Chung et al. show that an important signaling molecule called erythropoietin controls how much heme is produced when red blood cells are made. The experiments used a combination of red blood cells from humans and mice as well as zebrafish, which are useful model organisms because their blood develops in a similar way to humans. When Chung et al. inhibited components of erythropoietin signaling, heme production was blocked too and the red blood cells could not work properly. These new findings pave the way to look at human patients with blood-related disorders to determine if they have defects in the erythropoietin signaling cascade. In the future, this avenue of research might lead to better treatments for a variety of blood diseases in humans. DOI:http://dx.doi.org/10.7554/eLife.24767.002
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Affiliation(s)
- Jacky Chung
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - Johannes G Wittig
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - Alireza Ghamari
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, United States
| | - Manami Maeda
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - Tamara A Dailey
- Department of Microbiology, University of Georgia, Athens, United States.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, United States
| | - Hector Bergonia
- Division of Hematology and Hematologic Malignancies, University of Utah School of Medicine, Salt Lake City, United States
| | - Martin D Kafina
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | | | - Catherine E Minogue
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | | | - Liangtao Li
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, United States
| | - Jerry Kaplan
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, United States
| | - Harvey F Lodish
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, United States
| | - Daniel E Bauer
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, United States.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, United States
| | - Stuart H Orkin
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, United States.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, United States
| | - Alan B Cantor
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, United States.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, United States
| | - Takahiro Maeda
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - John D Phillips
- Division of Hematology and Hematologic Malignancies, University of Utah School of Medicine, Salt Lake City, United States
| | - Joshua J Coon
- Genome Center of Wisconsin, Madison, United States.,Department of Chemistry, University of Wisconsin-Madison, Madison, United States.,Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, United States
| | - David J Pagliarini
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States
| | - Harry A Dailey
- Department of Microbiology, University of Georgia, Athens, United States.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, United States
| | - Barry H Paw
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, United States.,Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, United States.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, United States
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28
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Ilouz R, Lev-Ram V, Bushong EA, Stiles TL, Friedmann-Morvinski D, Douglas C, Goldberg JL, Ellisman MH, Taylor SS. Isoform-specific subcellular localization and function of protein kinase A identified by mosaic imaging of mouse brain. eLife 2017; 6:17681. [PMID: 28079521 PMCID: PMC5300705 DOI: 10.7554/elife.17681] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 01/03/2017] [Indexed: 01/26/2023] Open
Abstract
Protein kinase A (PKA) plays critical roles in neuronal function that are mediated by different regulatory (R) subunits. Deficiency in either the RIβ or the RIIβ subunit results in distinct neuronal phenotypes. Although RIβ contributes to synaptic plasticity, it is the least studied isoform. Using isoform-specific antibodies, we generated high-resolution large-scale immunohistochemical mosaic images of mouse brain that provided global views of several brain regions, including the hippocampus and cerebellum. The isoforms concentrate in discrete brain regions, and we were able to zoom-in to show distinct patterns of subcellular localization. RIβ is enriched in dendrites and co-localizes with MAP2, whereas RIIβ is concentrated in axons. Using correlated light and electron microscopy, we confirmed the mitochondrial and nuclear localization of RIβ in cultured neurons. To show the functional significance of nuclear localization, we demonstrated that downregulation of RIβ, but not of RIIβ, decreased CREB phosphorylation. Our study reveals how PKA isoform specificity is defined by precise localization. DOI:http://dx.doi.org/10.7554/eLife.17681.001
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Affiliation(s)
- Ronit Ilouz
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| | - Varda Lev-Ram
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| | - Eric A Bushong
- Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, San Diego, United States
| | - Travis L Stiles
- Department of Ophthalmology, Shiley Eye Center, University of California, San Diego, La Jolla, United States
| | - Dinorah Friedmann-Morvinski
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, United States.,Department of Biochemistry and Molecular Biology, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Christopher Douglas
- Department of Ophthalmology, Shiley Eye Center, University of California, San Diego, La Jolla, United States
| | - Jeffrey L Goldberg
- Department of Ophthalmology, Shiley Eye Center, University of California, San Diego, La Jolla, United States
| | - Mark H Ellisman
- Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, San Diego, United States.,Department of Neurosciences, University of California, San Diego School of Medicine, La Jolla, United States
| | - Susan S Taylor
- Department of Pharmacology, University of California, San Diego, La Jolla, United States.,Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, United States
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29
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Zhang F, Zhang L, Qi Y, Xu H. Mitochondrial cAMP signaling. Cell Mol Life Sci 2016; 73:4577-4590. [PMID: 27233501 PMCID: PMC5097110 DOI: 10.1007/s00018-016-2282-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/25/2016] [Accepted: 05/20/2016] [Indexed: 12/19/2022]
Abstract
Cyclic adenosine 3, 5'-monophosphate (cAMP) is a ubiquitous second messenger regulating many biological processes, such as cell migration, differentiation, proliferation and apoptosis. cAMP signaling functions not only on the plasma membrane, but also in the nucleus and in organelles such as mitochondria. Mitochondrial cAMP signaling is an indispensable part of the cytoplasm-mitochondrion crosstalk that maintains mitochondrial homeostasis, regulates mitochondrial dynamics, and modulates cellular stress responses and other signaling pathways. Recently, the compartmentalization of mitochondrial cAMP signaling has attracted great attentions. This new input should be carefully taken into account when we interpret the findings of mitochondrial cAMP signaling. In this review, we summarize previous and recent progress in our understanding of mitochondrial cAMP signaling, including the components of the signaling cascade, and the function and regulation of this signaling pathway in different mitochondrial compartments.
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Affiliation(s)
- Fan Zhang
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Liping Zhang
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yun Qi
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Hong Xu
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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30
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Wehbi VL, Taskén K. Molecular Mechanisms for cAMP-Mediated Immunoregulation in T cells - Role of Anchored Protein Kinase A Signaling Units. Front Immunol 2016; 7:222. [PMID: 27375620 PMCID: PMC4896925 DOI: 10.3389/fimmu.2016.00222] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/23/2016] [Indexed: 12/20/2022] Open
Abstract
The cyclic AMP/protein kinase A (cAMP/PKA) pathway is one of the most common and versatile signal pathways in eukaryotic cells. A-kinase anchoring proteins (AKAPs) target PKA to specific substrates and distinct subcellular compartments providing spatial and temporal specificity for mediation of biological effects channeled through the cAMP/PKA pathway. In the immune system, cAMP is a potent negative regulator of T cell receptor-mediated activation of effector T cells (Teff) acting through a proximal PKA/Csk/Lck pathway anchored via a scaffold consisting of the AKAP Ezrin holding PKA, the linker protein EBP50, and the anchoring protein phosphoprotein associated with glycosphingolipid-enriched microdomains holding Csk. As PKA activates Csk and Csk inhibits Lck, this pathway in response to cAMP shuts down proximal T cell activation. This immunomodulating pathway in Teff mediates clinically important responses to regulatory T cell (Treg) suppression and inflammatory mediators, such as prostaglandins (PGs), adrenergic stimuli, adenosine, and a number of other ligands. A major inducer of T cell cAMP levels is PG E2 (PGE2) acting through EP2 and EP4 prostanoid receptors. PGE2 plays a crucial role in the normal physiological control of immune homeostasis as well as in inflammation and cancer immune evasion. Peripherally induced Tregs express cyclooxygenase-2, secrete PGE2, and elicit the immunosuppressive cAMP pathway in Teff as one tumor immune evasion mechanism. Moreover, a cAMP increase can also be induced by indirect mechanisms, such as intercellular transfer between T cells. Indeed, Treg, known to have elevated levels of intracellular cAMP, may mediate their suppressive function by transferring cAMP to Teff through gap junctions, which we speculate could also be regulated by PKA/AKAP complexes. In this review, we present an updated overview on the influence of cAMP-mediated immunoregulatory mechanisms acting through localized cAMP signaling and the therapeutical increasing prospects of AKAPs disruptors in T-cell immune function.
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Affiliation(s)
- Vanessa L. Wehbi
- Nordic EMBL Partnership, Centre for Molecular Medicine Norway, Oslo University Hospital, University of Oslo, Oslo, Norway
- Jebsen Inflammation Research Centre, Oslo University Hospital, Oslo, Norway
- Biotechnology Centre, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Kjetil Taskén
- Nordic EMBL Partnership, Centre for Molecular Medicine Norway, Oslo University Hospital, University of Oslo, Oslo, Norway
- Jebsen Inflammation Research Centre, Oslo University Hospital, Oslo, Norway
- Biotechnology Centre, Oslo University Hospital, University of Oslo, Oslo, Norway
- Jebsen Centre for Cancer Immunotherapy, Oslo University Hospital, Oslo, Norway
- Department of Infectious Diseases, Oslo University Hospital, Oslo, Norway
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31
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Burgers PP, Bruystens J, Burnley RJ, Nikolaev VO, Keshwani M, Wu J, Janssen BJC, Taylor SS, Heck AJR, Scholten A. Structure of smAKAP and its regulation by PKA-mediated phosphorylation. FEBS J 2016; 283:2132-48. [PMID: 27028580 DOI: 10.1111/febs.13726] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/04/2016] [Accepted: 03/29/2016] [Indexed: 12/27/2022]
Abstract
UNLABELLED The A-kinase anchoring protein (AKAP) smAKAP has three extraordinary features; it is very small, it is anchored directly to membranes by acyl motifs, and it interacts almost exclusively with the type I regulatory subunits (RI) of cAMP-dependent kinase (PKA). Here, we determined the crystal structure of smAKAP's A-kinase binding domain (smAKAP-AKB) in complex with the dimerization/docking (D/D) domain of RIα which reveals an extended hydrophobic interface with unique interaction pockets that drive smAKAP's high specificity for RI subunits. We also identify a conserved PKA phosphorylation site at Ser66 in the AKB domain which we predict would cause steric clashes and disrupt binding. This correlates with in vivo colocalization and fluorescence polarization studies, where Ser66 AKB phosphorylation ablates RI binding. Hydrogen/deuterium exchange studies confirm that the AKB helix is accessible and dynamic. Furthermore, full-length smAKAP as well as the unbound AKB is predicted to contain a break at the phosphorylation site, and circular dichroism measurements confirm that the AKB domain loses its helicity following phosphorylation. As the active site of PKA's catalytic subunit does not accommodate α-helices, we predict that the inherent flexibility of the AKB domain enables its phosphorylation by PKA. This represents a novel mechanism, whereby activation of anchored PKA can terminate its binding to smAKAP affecting the regulation of localized cAMP signaling events. DATABASE Structural data are available in the PDB under accession number 5HVZ.
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Affiliation(s)
- Pepijn P Burgers
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.,Netherlands Proteomics Centre, Utrecht, The Netherlands
| | - Jessica Bruystens
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, USA
| | - Rebecca J Burnley
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.,Netherlands Proteomics Centre, Utrecht, The Netherlands
| | | | - Malik Keshwani
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, USA
| | - Jian Wu
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, USA
| | - Bert J C Janssen
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
| | - Susan S Taylor
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, USA.,Department of Pharmacology, University of California San Diego, La Jolla, California, USA.,The Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, USA
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.,Netherlands Proteomics Centre, Utrecht, The Netherlands
| | - Arjen Scholten
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.,Netherlands Proteomics Centre, Utrecht, The Netherlands
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32
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Ding CL, Xu G, Tang HL, Zhu SY, Zhao LJ, Ren H, Zhao P, Qi ZT, Wang W. Anchoring of both PKA-RIIα and 14-3-3θ regulates retinoic acid induced 16 mediated phosphorylation of heat shock protein 70. Oncotarget 2016; 6:15540-50. [PMID: 25900241 PMCID: PMC4558169 DOI: 10.18632/oncotarget.3702] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/05/2015] [Indexed: 12/20/2022] Open
Abstract
Our previous study reported that retinoic acid induced 16 (RAI16) could enhance tumorigenesis in hepatocellular carcinoma (HCC). However, the cellular functions of RAI16 are still unclear. In this study, by immunoprecipitation and tandem (MS/MS) mass spectrometry analysis, we identified that RAI16 interacted with the type II regulatory subunit of PKA (PKA-RIIα), acting as a novel protein kinase A anchoring protein (AKAP). In addition, RAI16 also interacted with heat shock protein 70 (HSP70) and 14-3-3θ. Further studies indicated that RAI16 mediated PKA phosphorylation of HSP70 at serine 486, resulting in anti-apoptosis events. RAI16 was also phosphorylated by the anchored PKA at serine 325, which promoted the recruitment of 14-3-3θ, which, in turn, inhibited RAI16 mediated PKA phosphorylation of HSP70. These findings offer mechanism insight into RAI16 mediated anti-apoptosis signaling in HCC.
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Affiliation(s)
- Cui-Ling Ding
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Gang Xu
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Hai-Lin Tang
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Shi-Ying Zhu
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Lan-Juan Zhao
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Hao Ren
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Ping Zhao
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Zhong-Tian Qi
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
| | - Wen Wang
- Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China
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33
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AKAP18:PKA-RIIα structure reveals crucial anchor points for recognition of regulatory subunits of PKA. Biochem J 2016; 473:1881-94. [PMID: 27102985 DOI: 10.1042/bcj20160242] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 04/20/2016] [Indexed: 12/25/2022]
Abstract
A-kinase anchoring proteins (AKAPs) interact with the dimerization/docking (D/D) domains of regulatory subunits of the ubiquitous protein kinase A (PKA). AKAPs tether PKA to defined cellular compartments establishing distinct pools to increase the specificity of PKA signalling. Here, we elucidated the structure of an extended PKA-binding domain of AKAP18β bound to the D/D domain of the regulatory RIIα subunits of PKA. We identified three hydrophilic anchor points in AKAP18β outside the core PKA-binding domain, which mediate contacts with the D/D domain. Such anchor points are conserved within AKAPs that bind regulatory RII subunits of PKA. We derived a different set of anchor points in AKAPs binding regulatory RI subunits of PKA. In vitro and cell-based experiments confirm the relevance of these sites for the interaction of RII subunits with AKAP18 and of RI subunits with the RI-specific smAKAP. Thus we report a novel mechanism governing interactions of AKAPs with PKA. The sequence specificity of each AKAP around the anchor points and the requirement of these points for the tight binding of PKA allow the development of selective inhibitors to unequivocally ascribe cellular functions to the AKAP18-PKA and other AKAP-PKA interactions.
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34
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Chávez-Vargas L, Adame-García SR, Cervantes-Villagrana RD, Castillo-Kauil A, Bruystens JGH, Fukuhara S, Taylor SS, Mochizuki N, Reyes-Cruz G, Vázquez-Prado J. Protein Kinase A (PKA) Type I Interacts with P-Rex1, a Rac Guanine Nucleotide Exchange Factor: EFFECT ON PKA LOCALIZATION AND P-Rex1 SIGNALING. J Biol Chem 2016; 291:6182-99. [PMID: 26797121 DOI: 10.1074/jbc.m115.712216] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Indexed: 12/15/2022] Open
Abstract
Morphology of migrating cells is regulated by Rho GTPases and fine-tuned by protein interactions and phosphorylation. PKA affects cell migration potentially through spatiotemporal interactions with regulators of Rho GTPases. Here we show that the endogenous regulatory (R) subunit of type I PKA interacts with P-Rex1, a Rac guanine nucleotide exchange factor that integrates chemotactic signals. Type I PKA holoenzyme interacts with P-Rex1 PDZ domains via the CNB B domain of RIα, which when expressed by itself facilitates endothelial cell migration. P-Rex1 activation localizes PKA to the cell periphery, whereas stimulation of PKA phosphorylates P-Rex1 and prevents its activation in cells responding to SDF-1 (stromal cell-derived factor 1). The P-Rex1 DEP1 domain is phosphorylated at Ser-436, which inhibits the DH-PH catalytic cassette by direct interaction. In addition, the P-Rex1 C terminus is indirectly targeted by PKA, promoting inhibitory interactions independently of the DEP1-PDZ2 region. A P-Rex1 S436A mutant construct shows increased RacGEF activity and prevents the inhibitory effect of forskolin on sphingosine 1-phosphate-dependent endothelial cell migration. Altogether, these results support the idea that P-Rex1 contributes to the spatiotemporal localization of type I PKA, which tightly regulates this guanine exchange factor by a multistep mechanism, initiated by interaction with the PDZ domains of P-Rex1 followed by direct phosphorylation at the first DEP domain and putatively indirect regulation of the C terminus, thus promoting inhibitory intramolecular interactions. This reciprocal regulation between PKA and P-Rex1 might represent a key node of integration by which chemotactic signaling is fine-tuned by PKA.
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Affiliation(s)
| | - Sendi Rafael Adame-García
- Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, 07360 Mexico
| | | | - Alejandro Castillo-Kauil
- Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, 07360 Mexico
| | | | - Shigetomo Fukuhara
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute (NCVC), Osaka, 565-8565 Japan, and
| | - Susan S Taylor
- Departments of Chemistry and Biochemistry and Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Naoki Mochizuki
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute (NCVC), Osaka, 565-8565 Japan, and
| | - Guadalupe Reyes-Cruz
- Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, 07360 Mexico
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35
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Araujo CM, Hermidorff MM, Amancio GDCS, Lemos DDS, Silva ME, de Assis LVM, Isoldi MC. Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor? J Recept Signal Transduct Res 2015; 36:435-44. [PMID: 27305962 DOI: 10.3109/10799893.2015.1122042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the levels of ANP, which was confirmed by the analysis of the superficial area of cardiomyocytes. Aldosterone increased the levels of ANP and the cellular area of the cardiomyocytes; spironolactone reduced the aldosterone-increased ANP level and cellular area of cardiomyocytes. Aldosterone or spironolactone alone did not increase the level of cyclic 3',5'-adenosine monophosphate (cAMP), but aldosterone plus spironolactone led to increased cAMP level; the treatment with aldosterone + spironolactone + BAPTA-AM reduced the levels of cAMP. These data suggest that aldosterone-induced cAMP increase is independent of mineralocorticoid receptor (MR) and dependent on Ca(2+). Next, we have evaluated the role of A-kinase anchor proteins (AKAP) in the aldosterone-induced hypertrophic response. We have found that St-Ht31 (AKAP inhibitor) reduced the increased level of ANP which was induced by aldosterone; in addition, we have found an increase on protein kinase C (PKC) and extracellular signal-regulated kinase 5 (ERK5) activity when cells were treated with aldosterone alone, spironolactone alone and with a combination of both. Our data suggest that PKC could be responsible for ERK5 aldosterone-induced phosphorylation. Our study suggests that the aldosterone through its rapid effects promotes a hypertrophic response in cardiomyocytes that is controlled by an AKAP, being dependent on ERK5 and PKC, but not on cAMP/cAMP-dependent protein kinase signaling pathways. Lastly, we provide evidence that the targeting of AKAPs could be relevant in patients with aldosterone-induced cardiac hypertrophy and heart failure.
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Affiliation(s)
- Carolina Morais Araujo
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Milla Marques Hermidorff
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Gabriela de Cassia Sousa Amancio
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Denise da Silveira Lemos
- b Laboratory of Immunoparasitology , Center for Research in Biological Sciences, Institute of Biological and Exact Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Marcelo Estáquio Silva
- c Laboratory of Experimental Nutrition , School of Nutrition, Federal University of Ouro Preto , Ouro Preto , Brazil , and
| | | | - Mauro César Isoldi
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
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36
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Kennedy EJ, Scott JD. Selective disruption of the AKAP signaling complexes. Methods Mol Biol 2015; 1294:137-50. [PMID: 25783883 DOI: 10.1007/978-1-4939-2537-7_11] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Synthesis of the second messenger cAMP activates a variety of signaling pathways critical for all facets of intracellular regulation. Protein kinase A (PKA) is the major cAMP-responsive effector. Where and when this enzyme is activated has profound implications on the cellular role of PKA. A-Kinase Anchoring Proteins (AKAPs) play a critical role in this process by orchestrating spatial and temporal aspects of PKA action. A popular means of evaluating the impact of these anchored signaling events is to biochemically interfere with the PKA-AKAP interface. Hence, peptide disruptors of PKA anchoring are valuable tools in the investigation of local PKA action. This article outlines the development of PKA isoform-selective disruptor peptides, documents the optimization of cell-soluble peptide derivatives, and introduces alternative cell-based approaches that interrogate other aspects of the PKA-AKAP interface.
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Affiliation(s)
- Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia College of Pharmacy, Athens, GA, USA
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37
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Turnham RE, Scott JD. Protein kinase A catalytic subunit isoform PRKACA; History, function and physiology. Gene 2015; 577:101-8. [PMID: 26687711 DOI: 10.1016/j.gene.2015.11.052] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 01/01/2023]
Abstract
Our appreciation of the scope and influence of second messenger signaling has its origins in pioneering work on the cAMP-dependent protein kinase. Also called protein kinase A (PKA), this holoenzyme exists as a tetramer comprised of a regulatory (R) subunit dimer and two catalytic (C) subunits. Upon binding of two molecules of the second messenger cAMP to each R subunit, a conformational change in the PKA holoenzyme occurs to release the C subunits. These active kinases phosphorylate downstream targets to propagate cAMP responsive cell signaling events. This article focuses on the discovery, structure, cellular location and physiological effects of the catalytic subunit alpha of protein kinase A (encoded by the gene PRKACA). We also explore the potential role of this essential gene as a molecular mediator of certain disease states.
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Affiliation(s)
- Rigney E Turnham
- Howard Hughes Medical Institute, Department of Pharmacology, Box 357750, University of Washington School of Medicine, 1959 Pacific St. NE, Seattle, WA 98195, United States
| | - John D Scott
- Howard Hughes Medical Institute, Department of Pharmacology, Box 357750, University of Washington School of Medicine, 1959 Pacific St. NE, Seattle, WA 98195, United States.
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38
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Dema A, Perets E, Schulz MS, Deák VA, Klussmann E. Pharmacological targeting of AKAP-directed compartmentalized cAMP signalling. Cell Signal 2015; 27:2474-87. [PMID: 26386412 DOI: 10.1016/j.cellsig.2015.09.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/08/2015] [Accepted: 09/14/2015] [Indexed: 01/26/2023]
Abstract
The second messenger cyclic adenosine monophosphate (cAMP) can bind and activate protein kinase A (PKA). The cAMP/PKA system is ubiquitous and involved in a wide array of biological processes and therefore requires tight spatial and temporal regulation. Important components of the safeguard system are the A-kinase anchoring proteins (AKAPs), a heterogeneous family of scaffolding proteins defined by its ability to directly bind PKA. AKAPs tether PKA to specific subcellular compartments, and they bind further interaction partners to create local signalling hubs. The recent discovery of new AKAPs and advances in the field that shed light on the relevance of these hubs for human disease highlight unique opportunities for pharmacological modulation. This review exemplifies how interference with signalling, particularly cAMP signalling, at such hubs can reshape signalling responses and discusses how this could lead to novel pharmacological concepts for the treatment of disease with an unmet medical need such as cardiovascular disease and cancer.
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Affiliation(s)
- Alessandro Dema
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Ekaterina Perets
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Maike Svenja Schulz
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Veronika Anita Deák
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany; DZHK, German Centre for Cardiovascular Research, Oudenarder Straße 16, 13347 Berlin, Germany.
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39
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Scott J, Harris GJ, Pinder EM, Macfarlane JG, Hellyer TP, Rostron AJ, Conway Morris A, Thickett DR, Perkins GD, McAuley DF, Widdrington JD, Wiscombe S, Baudouin SV, Roy AI, Linnett VC, Wright SE, Ruchaud-Sparagano MH, Simpson AJ. Exchange protein directly activated by cyclic AMP (EPAC) activation reverses neutrophil dysfunction induced by β2-agonists, corticosteroids, and critical illness. J Allergy Clin Immunol 2015; 137:535-44. [PMID: 26388312 DOI: 10.1016/j.jaci.2015.07.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 06/20/2015] [Accepted: 07/14/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND Neutrophils play a role in the pathogenesis of asthma, chronic obstructive pulmonary disease, and pulmonary infection. Impaired neutrophil phagocytosis predicts hospital-acquired infection. Despite this, remarkably few neutrophil-specific treatments exist. OBJECTIVES We sought to identify novel pathways for the restoration of effective neutrophil phagocytosis and to activate such pathways effectively in neutrophils from patients with impaired neutrophil phagocytosis. METHODS Blood neutrophils were isolated from healthy volunteers and patients with impaired neutrophil function. In healthy neutrophils phagocytic impairment was induced experimentally by using β2-agonists. Inhibitors and activators of cyclic AMP (cAMP)-dependent pathways were used to assess the influence on neutrophil phagocytosis in vitro. RESULTS β2-Agonists and corticosteroids inhibited neutrophil phagocytosis. Impairment of neutrophil phagocytosis by β2-agonists was associated with significantly reduced RhoA activity. Inhibition of protein kinase A (PKA) restored phagocytosis and RhoA activity, suggesting that cAMP signals through PKA to drive phagocytic impairment. However, cAMP can signal through effectors other than PKA, such as exchange protein directly activated by cyclic AMP (EPAC). An EPAC-activating analog of cAMP (8CPT-2Me-cAMP) reversed neutrophil dysfunction induced by β2-agonists or corticosteroids but did not increase RhoA activity. 8CPT-2Me-cAMP reversed phagocytic impairment induced by Rho kinase inhibition but was ineffective in the presence of Rap-1 GTPase inhibitors. 8CPT-2Me-cAMP restored function to neutrophils from patients with known acquired impairment of neutrophil phagocytosis. CONCLUSIONS EPAC activation consistently reverses clinical and experimental impairment of neutrophil phagocytosis. EPAC signals through Rap-1 and bypasses RhoA. EPAC activation represents a novel potential means by which to reverse impaired neutrophil phagocytosis.
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Affiliation(s)
- Jonathan Scott
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Graham J Harris
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Emma M Pinder
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - James G Macfarlane
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Thomas P Hellyer
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Anthony J Rostron
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew Conway Morris
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - David R Thickett
- Centre for Translational Inflammation Research, University of Birmingham, Queen Elizabeth Hospital, Birmingham, United Kingdom
| | - Gavin D Perkins
- Warwick Medical School Clinical Trials Unit and Heart of England Foundation Trust, University of Warwick, Coventry, United Kingdom
| | - Daniel F McAuley
- Centre for Infection and Immunity, Health Sciences Building, Queen's University Belfast, Belfast, United Kingdom; Regional Intensive Care Unit, Royal Victoria Hospital, Belfast, United Kingdom
| | - John D Widdrington
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Sarah Wiscombe
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Simon V Baudouin
- Department of Anaesthetics, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Alistair I Roy
- Integrated Critical Care Unit, Sunderland Royal Hospital, Sunderland, United Kingdom
| | - Vanessa C Linnett
- Intensive Care Unit, Queen Elizabeth Hospital, Gateshead, United Kingdom
| | - Stephen E Wright
- Intensive Care Unit, Freeman Hospital, Newcastle upon Tyne, United Kingdom
| | | | - A John Simpson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.
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40
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Gerbaud P, Taskén K, Pidoux G. Spatiotemporal regulation of cAMP signaling controls the human trophoblast fusion. Front Pharmacol 2015; 6:202. [PMID: 26441659 PMCID: PMC4569887 DOI: 10.3389/fphar.2015.00202] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 09/02/2015] [Indexed: 01/01/2023] Open
Abstract
During human placentation, mononuclear cytotrophoblasts fuse to form multinucleated syncytia ensuring hormonal production and nutrient exchanges between the maternal and fetal circulation. Syncytial formation is essential for the maintenance of pregnancy and for fetal growth. The cAMP signaling pathway is the major route to trigger trophoblast fusion and its activation results in phosphorylation of specific intracellular target proteins, in transcription of fusogenic genes and assembly of macromolecular protein complexes constituting the fusogenic machinery at the plasma membrane. Specificity in cAMP signaling is ensured by generation of localized pools of cAMP controlled by cAMP phosphodiesterases (PDEs) and by discrete spatial and temporal activation of protein kinase A (PKA) in supramolecular signaling clusters inside the cell organized by A-kinase-anchoring proteins (AKAPs) and by organization of signal termination by protein phosphatases (PPs). Here we present original observations on the available components of the cAMP signaling pathway in the human placenta including PKA, PDE, and PP isoforms as well as AKAPs. We continue to discuss the current knowledge of the spatiotemporal regulation of cAMP signaling triggering trophoblast fusion.
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Affiliation(s)
- Pascale Gerbaud
- INSERM, UMR-S-1139, Group Cell Fusion, Université Paris Descartes Paris, France ; Université Paris Descartes Paris, France
| | - Kjetil Taskén
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital Oslo, Norway ; Biotechnology Centre, University of Oslo Oslo, Norway ; K.G. Jebsen Inflammation Research Centre, University of Oslo Oslo, Norway ; K.G. Jebsen Centre for Cancer Immunotherapy, University of Oslo Oslo, Norway ; Department of Infectious Diseases, Oslo University Hospital Oslo, Norway
| | - Guillaume Pidoux
- INSERM, UMR-S-1139, Group Cell Fusion, Université Paris Descartes Paris, France ; Université Paris Descartes Paris, France ; INSERM, U1180 Châtenay-Malabry, France ; Faculté de Pharmacie, Université Paris-Sud Châtenay-Malabry, France
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41
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Calejo AI, Taskén K. Targeting protein-protein interactions in complexes organized by A kinase anchoring proteins. Front Pharmacol 2015; 6:192. [PMID: 26441649 PMCID: PMC4562273 DOI: 10.3389/fphar.2015.00192] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/24/2015] [Indexed: 01/06/2023] Open
Abstract
Cyclic AMP is a ubiquitous intracellular second messenger involved in the regulation of a wide variety of cellular processes, a majority of which act through the cAMP – protein kinase A (PKA) signaling pathway and involve PKA phosphorylation of specific substrates. PKA phosphorylation events are typically spatially restricted and temporally well controlled. A-kinase anchoring proteins (AKAPs) directly bind PKA and recruit it to specific subcellular loci targeting the kinase activity toward particular substrates, and thereby provide discrete spatiotemporal control of downstream phosphorylation events. AKAPs also scaffold other signaling molecules into multi-protein complexes that function as crossroads between different signaling pathways. Targeting AKAP coordinated protein complexes with high-affinity peptidomimetics or small molecules to tease apart distinct protein–protein interactions (PPIs) therefore offers important means to disrupt binding of specific components of the complex to better understand the molecular mechanisms involved in the function of individual signalosomes and their pathophysiological role. Furthermore, development of novel classes of small molecules involved in displacement of AKAP-bound signal molecules is now emerging. Here, we will focus on mechanisms for targeting PPI, disruptors that modulate downstream cAMP signaling and their role, especially in the heart.
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Affiliation(s)
- Ana I Calejo
- Biotechnology Centre, University of Oslo Oslo, Norway ; Centre for Molecular Medicine Norway, Nordic European Molecular Biology Laboratory Partnership, University of Oslo and Oslo University Hospital Oslo, Norway
| | - Kjetil Taskén
- Biotechnology Centre, University of Oslo Oslo, Norway ; Centre for Molecular Medicine Norway, Nordic European Molecular Biology Laboratory Partnership, University of Oslo and Oslo University Hospital Oslo, Norway
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42
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Rinaldi L, Sepe M, Donne RD, Feliciello A. A dynamic interface between ubiquitylation and cAMP signaling. Front Pharmacol 2015; 6:177. [PMID: 26388770 PMCID: PMC4559665 DOI: 10.3389/fphar.2015.00177] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/06/2015] [Indexed: 01/01/2023] Open
Abstract
Phosphorylation waves drive the propagation of signals generated in response to hormones and growth factors in target cells. cAMP is an ancient second messenger implicated in key biological functions. In mammals, most of the effects elicited by cAMP are mediated by protein kinase A (PKA). Activation of the kinase by cAMP results in the phosphorylation of a variety of cellular substrates, leading to differentiation, proliferation, survival, metabolism. The identification of scaffold proteins, namely A-Kinase Anchor proteins (AKAPs), that localize PKA in specific cellular districts, provided critical cues for our understanding of the role played by cAMP in cell biology. Multivalent complexes are assembled by AKAPs and include signaling enzymes, mRNAs, adapter molecules, receptors and ion channels. A novel development derived from the molecular analysis of these complexes nucleated by AKAPs is represented by the presence of components of the ubiquitin-proteasome system (UPS). More to it, the AKAP complex can be regulated by the UPS, eliciting relevant effects on downstream cAMP signals. This represents a novel, yet previously unpredicted interface between compartmentalized signaling and the UPS. We anticipate that impairment of these regulatory mechanisms could promote cell dysfunction and disease. Here, we will focus on the reciprocal regulation between cAMP signaling and UPS, and its relevance to human degenerative and proliferative disorders.
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Affiliation(s)
- Laura Rinaldi
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Maria Sepe
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Rossella Delle Donne
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Antonio Feliciello
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
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43
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Nygren PJ, Scott JD. Therapeutic strategies for anchored kinases and phosphatases: exploiting short linear motifs and intrinsic disorder. Front Pharmacol 2015; 6:158. [PMID: 26283967 PMCID: PMC4516873 DOI: 10.3389/fphar.2015.00158] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/16/2015] [Indexed: 12/17/2022] Open
Abstract
Phosphorylation events that occur in response to the second messenger cAMP are controlled spatially and temporally by protein kinase A (PKA) interacting with A-kinase anchoring proteins (AKAPs). Recent advances in understanding the structural basis for this interaction have reinforced the hypothesis that AKAPs create spatially constrained signaling microdomains. This has led to the realization that the PKA/AKAP interface is a potential drug target for modulating a plethora of cell-signaling events. Pharmacological disruption of kinase–AKAP interactions has previously been explored for disease treatment and remains an interesting area of research. However, disrupting or enhancing the association of phosphatases with AKAPs is a therapeutic concept of equal promise, particularly since they oppose the actions of many anchored kinases. Accordingly, numerous AKAPs bind phosphatases such as protein phosphatase 1 (PP1), calcineurin (PP2B), and PP2A. These multimodal signaling hubs are equally able to control the addition of phosphate groups onto target substrates, as well as the removal of these phosphate groups. In this review, we describe recent advances in structural analysis of kinase and phosphatase interactions with AKAPs, and suggest future possibilities for targeting these interactions for therapeutic benefit.
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Affiliation(s)
- Patrick J Nygren
- Department of Pharmacology, University of Washington Seattle, WA, USA ; Howard Hughes Medical Institute Chevy Chase, MD, USA
| | - John D Scott
- Department of Pharmacology, University of Washington Seattle, WA, USA ; Howard Hughes Medical Institute Chevy Chase, MD, USA
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44
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Wang Y, Ho TG, Franz E, Hermann JS, Smith FD, Hehnly H, Esseltine JL, Hanold LE, Murph MM, Bertinetti D, Scott JD, Herberg FW, Kennedy EJ. PKA-type I selective constrained peptide disruptors of AKAP complexes. ACS Chem Biol 2015; 10:1502-10. [PMID: 25765284 DOI: 10.1021/acschembio.5b00009] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A-Kinase Anchoring Proteins (AKAPs) coordinate complex signaling events by serving as spatiotemporal modulators of cAMP-dependent protein kinase activity in cells. Although AKAPs organize a plethora of diverse pathways, their cellular roles are often elusive due to the dynamic nature of these signaling complexes. AKAPs can interact with the type I or type II PKA holoenzymes by virtue of high-affinity interactions with the R-subunits. As a means to delineate AKAP-mediated PKA signaling in cells, we sought to develop isoform-selective disruptors of AKAP signaling. Here, we report the development of conformationally constrained peptides named RI-STapled Anchoring Disruptors (RI-STADs) that target the docking/dimerization domain of the type 1 regulatory subunit of PKA. These high-affinity peptides are isoform-selective for the RI isoforms, can outcompete binding by the classical AKAP disruptor Ht31, and can selectively displace RIα, but not RIIα, from binding the dual-specific AKAP149 complex. Importantly, these peptides are cell-permeable and disrupt Type I PKA-mediated phosphorylation events in the context of live cells. Hence, RI-STAD peptides are versatile cellular tools to selectively probe anchored type I PKA signaling events.
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Affiliation(s)
- Yuxiao Wang
- Department
of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602, United States
| | - Tienhuei G. Ho
- Department
of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602, United States
| | - Eugen Franz
- Department
of Biochemistry, University of Kassel, 34132 Kassel, Germany
| | | | - F. Donelson Smith
- Howard
Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195, United States
| | - Heidi Hehnly
- Howard
Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195, United States
| | - Jessica L. Esseltine
- Howard
Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195, United States
| | - Laura E. Hanold
- Department
of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602, United States
| | - Mandi M. Murph
- Department
of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602, United States
| | | | - John D. Scott
- Howard
Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195, United States
| | | | - Eileen J. Kennedy
- Department
of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602, United States
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45
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Walpoth BN, Erman B. Regulation of ryanodine receptor RyR2 by protein-protein interactions: prediction of a PKA binding site on the N-terminal domain of RyR2 and its relation to disease causing mutations. F1000Res 2015; 4:29. [PMID: 25901278 PMCID: PMC4392826 DOI: 10.12688/f1000research.5858.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/15/2015] [Indexed: 01/28/2023] Open
Abstract
Protein-protein interactions are the key processes responsible for signaling and function in complex networks. Determining the correct binding partners and predicting the ligand binding sites in the absence of experimental data require predictive models. Hybrid models that combine quantitative atomistic calculations with statistical thermodynamics formulations are valuable tools for bioinformatics predictions. We present a hybrid prediction and analysis model for determining putative binding partners and interpreting the resulting correlations in the yet functionally uncharacterized interactions of the ryanodine RyR2 N-terminal domain. Using extensive docking calculations and libraries of hexameric peptides generated from regulator proteins of the RyR2 channel, we show that the residues 318-323 of protein kinase A, PKA, have a very high affinity for the N-terminal of RyR2. Using a coarse grained Elastic Net Model, we show that the binding site lies at the end of a pathway of evolutionarily conserved residues in RyR2. The two disease causing mutations are also on this path. The program for the prediction of the energetically responsive residues by the Elastic Net Model is freely available on request from the corresponding author.
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Affiliation(s)
- Belinda Nazan Walpoth
- Swiss Cardiovascular Center, University of Bern, Inselspital, Cardiology, Bern, CH-3012, Switzerland
| | - Burak Erman
- Department of Chemical and Biological Engineering, Koc University, Instanbul, 34450 S, Turkey
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46
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Sarma GN, Moody IS, Ilouz R, Phan RH, Sankaran B, Hall RA, Taylor SS. D-AKAP2:PKA RII:PDZK1 ternary complex structure: insights from the nucleation of a polyvalent scaffold. Protein Sci 2014; 24:105-16. [PMID: 25348485 DOI: 10.1002/pro.2593] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 02/02/2023]
Abstract
A-kinase anchoring proteins (AKAPs) regulate cAMP-dependent protein kinase (PKA) signaling in space and time. Dual-specific AKAP2 (D-AKAP2/AKAP10) binds with high affinity to both RI and RII regulatory subunits of PKA and is anchored to transporters through PDZ domain proteins. Here, we describe a structure of D-AKAP2 in complex with two interacting partners and the exact mechanism by which a segment that on its own is disordered presents an α-helix to PKA and a β-strand to PDZK1. These two motifs nucleate a polyvalent scaffold and show how PKA signaling is linked to the regulation of transporters. Formation of the D-AKAP2: PKA binary complex is an important first step for high affinity interaction with PDZK1, and the structure reveals important clues toward understanding this phenomenon. In contrast to many other AKAPs, D-AKAP2 does not interact directly with the membrane protein. Instead, the interaction is facilitated by the C-terminus of D-AKAP2, which contains two binding motifs-the D-AKAP2AKB and the PDZ motif-that are joined by a short linker and only become ordered upon binding to their respective partner signaling proteins. The D-AKAP2AKB binds to the D/D domain of the R-subunit and the C-terminal PDZ motif binds to a PDZ domain (from PDZK1) that serves as a bridging protein to the transporter. This structure also provides insights into the fundamental question of why D-AKAP2 would exhibit a differential mode of binding to the two PKA isoforms.
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Affiliation(s)
- Ganapathy N Sarma
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California, 92093-0654; Department of Pharmacology, University of California, San Diego, La Jolla, California, 92093-0654
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47
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Soni S, Scholten A, Vos MA, van Veen TAB. Anchored protein kinase A signalling in cardiac cellular electrophysiology. J Cell Mol Med 2014; 18:2135-46. [PMID: 25216213 PMCID: PMC4224547 DOI: 10.1111/jcmm.12365] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 06/10/2014] [Indexed: 01/13/2023] Open
Abstract
The cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) is an elementary molecule involved in both acute and chronic modulation of cardiac function. Substantial research in recent years has highlighted the importance of A-kinase anchoring proteins (AKAP) therein as they act as the backbones of major macromolecular signalling complexes of the β-adrenergic/cAMP/PKA pathway. This review discusses the role of AKAP-associated protein complexes in acute and chronic cardiac modulation by dissecting their role in altering the activity of different ion channels, which underlie cardiac action potential (AP) generation. In addition, we review the involvement of different AKAP complexes in mechanisms of cardiac remodelling and arrhythmias.
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Affiliation(s)
- Siddarth Soni
- Division of Heart & Lungs, Dept of Medical Physiology, University Medical Centre Utrecht, Utrecht, The Netherlands; Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
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48
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Burgers PP, van der Heyden MAG, Kok B, Heck AJR, Scholten A. A Systematic Evaluation of Protein Kinase A–A-Kinase Anchoring Protein Interaction Motifs. Biochemistry 2014; 54:11-21. [DOI: 10.1021/bi500721a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Pepijn P. Burgers
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
| | - Marcel A. G. van der Heyden
- Department
of Medical Physiology, Division of Heart and Lungs, University Medical Centre Utrecht, Yalelaan 50, 3584 CM Utrecht, The Netherlands
| | - Bart Kok
- Department
of Medical Physiology, Division of Heart and Lungs, University Medical Centre Utrecht, Yalelaan 50, 3584 CM Utrecht, The Netherlands
| | - Albert J. R. Heck
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
| | - Arjen Scholten
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
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49
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Xu K, Qi H. Sperm-specific AKAP3 is a dual-specificity anchoring protein that interacts with both protein kinase a regulatory subunits via conserved N-terminal amphipathic peptides. Mol Reprod Dev 2014; 81:595-607. [PMID: 24687590 DOI: 10.1002/mrd.22329] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 03/22/2014] [Indexed: 11/06/2022]
Abstract
cAMP-dependent protein kinase A (PKA) plays important regulatory roles during mouse spermatogenesis. PKA-mediated signaling has been shown to regulate gene expression, chromatin condensation, capacitation, and motility during sperm development and behavior, although how PKA is regulated in spatiotemporal manners during spermatogenesis is not fully understood. In the present study, we found that PKA subunit isoforms are expressed and localized differently in meiotic and post-meiotic mouse spermatogenic cells. Regulatory subunit I alpha (RIα) is expressed in spermatocytes and round spermatids, where it is localized diffusely throughout the cytoplasm of cells. During late spermiogenesis, RIα abundance gradually decreases. On the other hand, RIIα is expressed constantly throughout meiotic and post-meiotic stages, and is associated with cytoskeletal structures. Among several A kinase anchoring proteins (AKAPs) expressed in the testis, sperm-specific AKAP3 can be found in the cytoplasm of elongating spermatids and interacts with RIα, as demonstrated by both in vivo and in vitro experiments. In mature sperm, AKAP3 is exclusively found in the principal piece of the flagellum, coincident with only RIIα. Mutagenesis experiments further showed that the preferential interactions of AKAP3 with PKA regulatory subunits are mediated by two highly conserved amphipathic peptides located in the N-terminal region of AKAP3. Thus, AKAP3 is a dual-specificity molecule that modulates PKA isotypes in a spatiotemporal manner during mouse spermatogenesis.
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Affiliation(s)
- Kaibiao Xu
- Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
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Valsecchi F, Konrad C, Manfredi G. Role of soluble adenylyl cyclase in mitochondria. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2555-60. [PMID: 24907564 DOI: 10.1016/j.bbadis.2014.05.035] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/19/2014] [Accepted: 05/28/2014] [Indexed: 11/25/2022]
Abstract
The soluble adenylyl cyclase (sAC) catalyzes the conversion of ATP into cyclic AMP (cAMP). Recent studies have shed new light on the role of sAC localized in mitochondria and its product cAMP, which drives mitochondrial protein phosphorylation and regulation of the oxidative phosphorylation system and other metabolic enzymes, presumably through the activation of intra-mitochondrial PKA. In this review article, we summarize recent findings on mitochondrial sAC activation by bicarbonate (HCO(3)(-)) and calcium (Ca²⁺) and the effects on mitochondrial metabolism. We also discuss putative mechanisms whereby sAC-mediated mitochondrial protein phosphorylation regulates mitochondrial metabolism. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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Affiliation(s)
- Federica Valsecchi
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Csaba Konrad
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Giovanni Manfredi
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, NY 10065, USA.
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