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Mechanisms of cyclic AMP/protein kinase A- and glucocorticoid-mediated apoptosis using S49 lymphoma cells as a model system. Proc Natl Acad Sci U S A 2015; 112:12681-6. [PMID: 26417071 DOI: 10.1073/pnas.1516057112] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Cyclic AMP/protein kinase A (cAMP/PKA) and glucocorticoids promote the death of many cell types, including cells of hematopoietic origin. In wild-type (WT) S49 T-lymphoma cells, signaling by cAMP and glucocorticoids converges on the induction of the proapoptotic B-cell lymphoma-family protein Bim to produce mitochondria-dependent apoptosis. Kin(-), a clonal variant of WT S49 cells, lacks PKA catalytic (PKA-Cα) activity and is resistant to cAMP-mediated apoptosis. Using sorbitol density gradient fractionation, we show here that in kin(-) S49 cells PKA-Cα is not only depleted but the residual PKA-Cα mislocalizes to heavier cell fractions and is not phosphorylated at two conserved residues (Ser(338) or Thr(197)). In WT S49 cells, PKA-regulatory subunit I (RI) and Bim coimmunoprecipitate upon treatment with cAMP analogs and forskolin (which increases endogenous cAMP concentrations). By contrast, in kin(-) cells, expression of PKA-RIα and Bim is prominently decreased, and increases in cAMP do not increase Bim expression. Even so, kin(-) cells undergo apoptosis in response to treatment with the glucocorticoid dexamethasone (Dex). In WT cells, glucorticoid-mediated apoptosis involves an increase in Bim, but in kin(-) cells, Dex-promoted cell death appears to occur by a caspase 3-independent apoptosis-inducing factor pathway. Thus, although cAMP/PKA-Cα and PKA-R1α/Bim mediate apoptotic cell death in WT S49 cells, kin(-) cells resist this response because of lower levels of PKA-Cα and PKA-RIα subunits as well as Bim. The findings for Dex-promoted apoptosis imply that these lymphoma cells have adapted to selective pressure that promotes cell death by altering canonical signaling pathways.
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53
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Seeger-Nukpezah T, Geynisman DM, Nikonova AS, Benzing T, Golemis EA. The hallmarks of cancer: relevance to the pathogenesis of polycystic kidney disease. Nat Rev Nephrol 2015; 11:515-34. [PMID: 25870008 PMCID: PMC5902186 DOI: 10.1038/nrneph.2015.46] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is a progressive inherited disorder in which renal tissue is gradually replaced with fluid-filled cysts, giving rise to chronic kidney disease (CKD) and progressive loss of renal function. ADPKD is also associated with liver ductal cysts, hypertension, chronic pain and extra-renal problems such as cerebral aneurysms. Intriguingly, improved understanding of the signalling and pathological derangements characteristic of ADPKD has revealed marked similarities to those of solid tumours, even though the gross presentation of tumours and the greater morbidity and mortality associated with tumour invasion and metastasis would initially suggest entirely different disease processes. The commonalities between ADPKD and cancer are provocative, particularly in the context of recent preclinical and clinical studies of ADPKD that have shown promise with drugs that were originally developed for cancer. The potential therapeutic benefit of such repurposing has led us to review in detail the pathological features of ADPKD through the lens of the defined, classic hallmarks of cancer. In addition, we have evaluated features typical of ADPKD, and determined whether evidence supports the presence of such features in cancer cells. This analysis, which places pathological processes in the context of defined signalling pathways and approved signalling inhibitors, highlights potential avenues for further research and therapeutic exploitation in both diseases.
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Affiliation(s)
- Tamina Seeger-Nukpezah
- Department I of Internal Medicine and Centre for Integrated Oncology, University of Cologne, Kerpenerstrasse 62, D-50937 Cologne, Germany
| | - Daniel M Geynisman
- Department of Medical Oncology, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Anna S Nikonova
- Department of Developmental Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Thomas Benzing
- Department II of Internal Medicine and Centre for Molecular Medicine Cologne, University of Cologne, Kerpenerstrasse 62, D-50937 Cologne, Germany
| | - Erica A Golemis
- Department of Developmental Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
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Patel N, Gold MG. The genetically encoded tool set for investigating cAMP: more than the sum of its parts. Front Pharmacol 2015; 6:164. [PMID: 26300778 PMCID: PMC4526808 DOI: 10.3389/fphar.2015.00164] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/24/2015] [Indexed: 11/13/2022] Open
Abstract
Intracellular fluctuations of the second messenger cyclic AMP (cAMP) are regulated with spatial and temporal precision. This regulation is supported by the sophisticated arrangement of cyclases, phosphodiesterases, anchoring proteins, and receptors for cAMP. Discovery of these nuances to cAMP signaling has been facilitated by the development of genetically encodable tools for monitoring and manipulating cAMP and the proteins that support cAMP signaling. In this review, we discuss the state-of-the-art in development of different genetically encoded tools for sensing cAMP and the activity of its primary intracellular receptor protein kinase A (PKA). We introduce sequences for encoding adenylyl cyclases that enable cAMP levels to be artificially elevated within cells. We chart the evolution of sequences for selectively modifying protein-protein interactions that support cAMP signaling, and for driving cAMP sensors and manipulators to different subcellular locations. Importantly, these different genetically encoded tools can be applied synergistically, and we highlight notable instances that take advantage of this property. Finally, we consider prospects for extending the utility of the tool set to support further insights into the role of cAMP in health and disease.
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Affiliation(s)
- Neha Patel
- Department of Neuroscience, Physiology and Pharmacology, University College London London, UK
| | - Matthew G Gold
- Department of Neuroscience, Physiology and Pharmacology, University College London London, UK
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55
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Ahn BY, Saldanha-Gama RFG, Rahn JJ, Hao X, Zhang J, Dang NH, Alshehri M, Robbins SM, Senger DL. Glioma invasion mediated by the p75 neurotrophin receptor (p75(NTR)/CD271) requires regulated interaction with PDLIM1. Oncogene 2015; 35:1411-22. [PMID: 26119933 PMCID: PMC4800290 DOI: 10.1038/onc.2015.199] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 04/23/2015] [Accepted: 05/10/2015] [Indexed: 01/05/2023]
Abstract
The invasive nature of glioblastoma renders them incurable by current therapeutic interventions. Using a novel invasive human glioma model, we previously identified the neurotrophin receptor p75NTR (aka CD271) as a mediator of glioma invasion. Herein, we provide evidence that preventing phosphorylation of p75NTR on S303 by pharmacological inhibition of PKA, or by a mutational strategy (S303G), cripples p75NTR-mediated glioma invasion resulting in serine phosphorylation within the C-terminal PDZ-binding motif (SPV) of p75NTR. Consistent with this, deletion (ΔSPV) or mutation (SPM) of the PDZ motif results in abrogation of p75NTR-mediated invasion. Using a peptide-based strategy, we identified PDLIM1 as a novel signaling adaptor for p75NTR and provide the first evidence for a regulated interaction via S425 phosphorylation. Importantly, PDLIM1 was shown to interact with p75NTR in highly invasive patient-derived glioma stem cells/tumor-initiating cells and shRNA knockdown of PDLIM1 in vitro and in vivo results in complete ablation of p75NTR-mediated invasion. Collectively, these data demonstrate a requirement for a regulated interaction of p75NTR with PDLIM1 and suggest that targeting either the PDZ domain interactions and/or the phosphorylation of p75NTR by PKA could provide therapeutic strategies for patients with glioblastoma.
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Affiliation(s)
- B Y Ahn
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hughes Childhood Cancer Program, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada
| | - R F G Saldanha-Gama
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada.,Clark H. Smith Brain Tumour Centre, University of Calgary, Calgary, Alberta, Canada
| | - J J Rahn
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hughes Childhood Cancer Program, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada
| | - X Hao
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hughes Childhood Cancer Program, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada
| | - J Zhang
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Clark H. Smith Brain Tumour Centre, University of Calgary, Calgary, Alberta, Canada
| | - N-H Dang
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada.,Clark H. Smith Brain Tumour Centre, University of Calgary, Calgary, Alberta, Canada
| | - M Alshehri
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada.,Clark H. Smith Brain Tumour Centre, University of Calgary, Calgary, Alberta, Canada
| | - S M Robbins
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hughes Childhood Cancer Program, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada.,Clark H. Smith Brain Tumour Centre, University of Calgary, Calgary, Alberta, Canada
| | - D L Senger
- Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hughes Childhood Cancer Program, University of Calgary, Calgary, Alberta, Canada.,Department of Oncology, University of Calgary, Calgary, Alberta, Canada.,Clark H. Smith Brain Tumour Centre, University of Calgary, Calgary, Alberta, Canada
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Mohanty S, Kennedy EJ, Herberg FW, Hui R, Taylor SS, Langsley G, Kannan N. Structural and evolutionary divergence of cyclic nucleotide binding domains in eukaryotic pathogens: Implications for drug design. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1575-85. [PMID: 25847873 DOI: 10.1016/j.bbapap.2015.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 03/25/2015] [Indexed: 12/24/2022]
Abstract
Many cellular functions in eukaryotic pathogens are mediated by the cyclic nucleotide binding (CNB) domain, which senses second messengers such as cyclic AMP and cyclic GMP. Although CNB domain-containing proteins have been identified in many pathogenic organisms, an incomplete understanding of how CNB domains in pathogens differ from other eukaryotic hosts has hindered the development of selective inhibitors for CNB domains associated with infectious diseases. Here, we identify and classify CNB domain-containing proteins in eukaryotic genomes to understand the evolutionary basis for CNB domain functional divergence in pathogens. We identify 359 CNB domain-containing proteins in 31 pathogenic organisms and classify them into distinct subfamilies based on sequence similarity within the CNB domain as well as functional domains associated with the CNB domain. Our study reveals novel subfamilies with pathogen-specific variations in the phosphate-binding cassette. Analyzing these variations in light of existing structural and functional data provides new insights into ligand specificity and promiscuity and clues for drug design. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases.
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Affiliation(s)
- Smita Mohanty
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia College of Pharmacy, Athens, GA 30602, USA
| | | | - Raymond Hui
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Susan S Taylor
- Department of Chemistry & Biochemistry and Pharmacology, University of CA, San Diego, USA
| | - Gordon Langsley
- INSERM U1016, CNRS UMR8104, Cochin Institute, Paris, 75014 France; Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, France
| | - Natarajan Kannan
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA; Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA.
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Phosphoproteomic analysis of the highly-metastatic hepatocellular carcinoma cell line, MHCC97-H. Int J Mol Sci 2015; 16:4209-25. [PMID: 25690035 PMCID: PMC4346953 DOI: 10.3390/ijms16024209] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/03/2015] [Accepted: 02/03/2015] [Indexed: 11/29/2022] Open
Abstract
Invasion and metastasis of hepatocellular carcinoma (HCC) is a major cause for lethal liver cancer. Signaling pathways associated with cancer progression are frequently reconfigured by aberrant phosphorylation of key proteins. To capture the key phosphorylation events in HCC metastasis, we established a methodology by an off-line high-pH HPLC separation strategy combined with multi-step IMAC and LC–MS/MS to study the phosphoproteome of a metastatic HCC cell line, MHCC97-H (high metastasis). In total, 6593 phosphopeptides with 6420 phosphorylation sites (p-sites) of 2930 phosphoproteins were identified. Statistical analysis of gene ontology (GO) categories for the identified phosphoproteins showed that several of the biological processes, such as transcriptional regulation, mRNA processing and RNA splicing, were over-represented. Further analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations demonstrated that phosphoproteins in multiple pathways, such as spliceosome, the insulin signaling pathway and the cell cycle, were significantly enriched. In particular, we compared our dataset with a previously published phosphoproteome in a normal liver sample, and the results revealed that a number of proteins in the spliceosome pathway, such as U2 small nuclear RNA Auxiliary Factor 2 (U2AF2), Eukaryotic Initiation Factor 4A-III (EIF4A3), Cell Division Cycle 5-Like (CDC5L) and Survival Motor Neuron Domain Containing 1 (SMNDC1), were exclusively identified as phosphoproteins only in the MHCC97-H cell line. These results indicated that the phosphorylation of spliceosome proteins may participate in the metastasis of HCC by regulating mRNA processing and RNA splicing.
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Lefkimmiatis K, Zaccolo M. cAMP signaling in subcellular compartments. Pharmacol Ther 2014; 143:295-304. [PMID: 24704321 PMCID: PMC4117810 DOI: 10.1016/j.pharmthera.2014.03.008] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 03/24/2014] [Indexed: 01/11/2023]
Abstract
In the complex microcosm of a cell, information security and its faithful transmission are critical for maintaining internal stability. To achieve a coordinated response of all its parts to any stimulus the cell must protect the information received from potentially confounding signals. Physical segregation of the information transmission chain ensures that only the entities able to perform the encoded task have access to the relevant information. The cAMP intracellular signaling pathway is an important system for signal transmission responsible for the ancestral 'flight or fight' response and involved in the control of critical functions including frequency and strength of heart contraction, energy metabolism and gene transcription. It is becoming increasingly apparent that the cAMP signaling pathway uses compartmentalization as a strategy for coordinating the large number of key cellular functions under its control. Spatial confinement allows the formation of cAMP signaling "hot spots" at discrete subcellular domains in response to specific stimuli, bringing the information in proximity to the relevant effectors and their recipients, thus achieving specificity of action. In this report we discuss how the different constituents of the cAMP pathway are targeted and participate in the formation of cAMP compartmentalized signaling events. We illustrate a few examples of localized cAMP signaling, with a particular focus on the nucleus, the sarcoplasmic reticulum and the mitochondria. Finally, we discuss the therapeutic potential of interventions designed to perturb specific cAMP cascades locally.
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Affiliation(s)
| | - Manuela Zaccolo
- Department Of Physiology, Anatomy & Genetics, University of Oxford, UK.
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60
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Hossain MI, Roulston CL, Stapleton DI. Molecular basis of impaired glycogen metabolism during ischemic stroke and hypoxia. PLoS One 2014; 9:e97570. [PMID: 24858129 PMCID: PMC4032261 DOI: 10.1371/journal.pone.0097570] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/21/2014] [Indexed: 02/02/2023] Open
Abstract
Background Ischemic stroke is the combinatorial effect of many pathological processes including the loss of energy supplies, excessive intracellular calcium accumulation, oxidative stress, and inflammatory responses. The brain's ability to maintain energy demand through this process involves metabolism of glycogen, which is critical for release of stored glucose. However, regulation of glycogen metabolism in ischemic stroke remains unknown. In the present study, we investigate the role and regulation of glycogen metabolizing enzymes and their effects on the fate of glycogen during ischemic stroke. Results Ischemic stroke was induced in rats by peri-vascular application of the vasoconstrictor endothelin-1 and forebrains were collected at 1, 3, 6 and 24 hours post-stroke. Glycogen levels and the expression and activity of enzymes involved in glycogen metabolism were analyzed. We found elevated glycogen levels in the ipsilateral hemispheres compared with contralateral hemispheres at 6 and 24 hours (25% and 39% increase respectively; P<0.05). Glycogen synthase activity and glycogen branching enzyme expression were found to be similar between the ipsilateral, contralateral, and sham control hemispheres. In contrast, the rate-limiting enzyme for glycogen breakdown, glycogen phosphorylase, had 58% lower activity (P<0.01) in the ipsilateral hemisphere (24 hours post-stroke), which corresponded with a 48% reduction in cAMP-dependent protein kinase A (PKA) activity (P<0.01). In addition, glycogen debranching enzyme expression 24 hours post-stroke was 77% (P<0.01) and 72% lower (P<0.01) at the protein and mRNA level, respectively. In cultured rat primary cerebellar astrocytes, hypoxia and inhibition of PKA activity significantly reduced glycogen phosphorylase activity and increased glycogen accumulation but did not alter glycogen synthase activity. Furthermore, elevated glycogen levels provided metabolic support to astrocytes during hypoxia. Conclusion Our study has identified that glycogen breakdown is impaired during ischemic stroke, the molecular basis of which includes reduced glycogen debranching enzyme expression level together with reduced glycogen phosphorylase and PKA activity.
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Affiliation(s)
- Mohammed Iqbal Hossain
- Department of Physiology, St. Vincent's Campus, The University of Melbourne, Melbourne, Victoria, Australia
- * E-mail:
| | - Carli Lorraine Roulston
- Department of Medicine, St. Vincent's Campus, The University of Melbourne, Melbourne, Victoria, Australia
| | - David Ian Stapleton
- Department of Physiology, St. Vincent's Campus, The University of Melbourne, Melbourne, Victoria, Australia
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