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Wei W, Smrcka AV. Internalized β2-Adrenergic Receptors Inhibit Subcellular Phospholipase C-Dependent Cardiac Hypertrophic Signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544153. [PMID: 37333278 PMCID: PMC10274790 DOI: 10.1101/2023.06.07.544153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Chronically elevated neurohumoral drive, and particularly elevated adrenergic tone leading to β-adrenergic receptor (β-AR) overstimulation in cardiac myocytes, is a key mechanism involved in the progression of heart failure. β1-AR and β2-ARs are the two major subtypes of β-ARs present in the human heart, however, they elicit different or even opposite effects on cardiac function and hypertrophy. For example, chronic activation of β1ARs drives detrimental cardiac remodeling while β2AR signaling is protective. The underlying molecular mechanisms for cardiac protection through β2ARs remain unclear. Here we show that β2-AR protects against hypertrophy through inhibition of PLCε signaling at the Golgi apparatus. The mechanism for β2AR-mediated PLC inhibition requires internalization of β2AR, activation of Gi and Gβγ subunit signaling at endosomes and ERK activation. This pathway inhibits both angiotensin II and Golgi-β1-AR-mediated stimulation of phosphoinositide hydrolysis at the Golgi apparatus ultimately resulting in decreased PKD and HDAC5 phosphorylation and protection against cardiac hypertrophy. This reveals a mechanism for β2-AR antagonism of the PLCε pathway that may contribute to the known protective effects of β2-AR signaling on the development of heart failure.
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Affiliation(s)
- Wenhui Wei
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, United States
| | - Alan V. Smrcka
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, United States
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2
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Kanemaru K, Nakamura Y. Activation Mechanisms and Diverse Functions of Mammalian Phospholipase C. Biomolecules 2023; 13:915. [PMID: 37371495 DOI: 10.3390/biom13060915] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/28/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Phospholipase C (PLC) plays pivotal roles in regulating various cellular functions by metabolizing phosphatidylinositol 4,5-bisphosphate in the plasma membrane. This process generates two second messengers, inositol 1,4,5-trisphosphate and diacylglycerol, which respectively regulate the intracellular Ca2+ levels and protein kinase C activation. In mammals, six classes of typical PLC have been identified and classified based on their structure and activation mechanisms. They all share X and Y domains, which are responsible for enzymatic activity, as well as subtype-specific domains. Furthermore, in addition to typical PLC, atypical PLC with unique structures solely harboring an X domain has been recently discovered. Collectively, seven classes and 16 isozymes of mammalian PLC are known to date. Dysregulation of PLC activity has been implicated in several pathophysiological conditions, including cancer, cardiovascular diseases, and neurological disorders. Therefore, identification of new drug targets that can selectively modulate PLC activity is important. The present review focuses on the structures, activation mechanisms, and physiological functions of mammalian PLC.
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Affiliation(s)
- Kaori Kanemaru
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba 278-8510, Japan
| | - Yoshikazu Nakamura
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba 278-8510, Japan
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3
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Fan Y, Hao Y, Zhu C, Hu B, Ma R, Liu Y, Li G. PLCε promotes the Warburg effect and tumorigenesis through AKT/GSK3β/Cdc25a in bladder cancer. Biotechnol Genet Eng Rev 2023:1-15. [PMID: 37018449 DOI: 10.1080/02648725.2023.2199188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Phospholipase C epsilon (PLCε) is a oncogene in various malignancies and regulates diverse cellular functions. But understanding of the relation between PLCε and glycolytic pathways has not been clearly identified. In the present study, we explored the effect of PLCε on the Warburg effect and tumorigenesis in bladder cancer (BCa). In our study, we showed that PLCε expression was elevated in BCa samples compared with matched adjacent nonmalignant bladder tissues. PLCε depletion using Lentivirus-shPLCε (LV-shPLCε) dramatically decreased cell growth, glucose consumption and lactate production, arresting T24 and BIU cells in the S phase of the cell cycle. We also observed that PLCε was correlated with the activation of protein kinase B (AKT) and cell division cycle 25 homolog A (Cdc25a) overexpression. In addition, we demonstrated that AKT/glycogen synthase kinase 3 beta (GSK3β)/Cdc25a signaling pathways are involved in the PLCε-mediated Warburg effect in BCa. Moreover, we showed that PLCε had an effect on tumorigenesis in in vivo experiments. In summary, our findings demonstrate that AKT/GSK3β/Cdc25a is critical for the effect PLCε on Warburg effect and tumorigenesis.
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Affiliation(s)
- Yanru Fan
- Clinical Lab department, Henan Provincial People's Hospital, Zhengzhou, China
| | - Yanni Hao
- Clinical Lab department, Jiaocheng County maternal and Child Health and Family Planning Service Centre, Taiyuan, China
| | - Chunkai Zhu
- Clinical Lab department, Henan Provincial People's Hospital, Zhengzhou, China
| | - Biao Hu
- Clinical Lab department, Henan Provincial People's Hospital, Zhengzhou, China
| | - Rufei Ma
- Clinical Lab department, Henan Provincial People's Hospital, Zhengzhou, China
| | - Yanhong Liu
- Clinical Lab department, Henan Provincial People's Hospital, Zhengzhou, China
| | - Gang Li
- Clinical Lab department, Henan Provincial People's Hospital, Zhengzhou, China
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4
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Sinnett-Smith J, Torres-Marquez ME, Chang JK, Shimizu Y, Hao F, Martin MG, Rozengurt E. Statins inhibit protein kinase D (PKD) activation in intestinal cells and prevent PKD1-induced growth of murine enteroids. Am J Physiol Cell Physiol 2023; 324:C807-C820. [PMID: 36779664 PMCID: PMC10042602 DOI: 10.1152/ajpcell.00286.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 02/14/2023]
Abstract
We examined the impact of statins on protein kinase D (PKD) activation by G protein-coupled receptor (GPCR) agonists. Treatment of intestinal IEC-18 cells with cerivastatin inhibited PKD autophosphorylation at Ser916 induced by angiotensin II (ANG II) or vasopressin in a dose-dependent manner with half-maximal inhibition at 0.2 µM. Cerivastatin treatment inhibited PKD activation stimulated by these agonists for different times (5-60 min) and blunted HDAC5 phosphorylation, a substrate of PKD. Other lipophilic statins, including simvastatin, atorvastatin, and fluvastatin also prevented PKD activation in a dose-dependent manner. Using IEC-18 cell lines expressing PKD1 tagged with EGFP (enhanced green fluorescent protein), cerivastatin or simvastatin blocked GPCR-mediated PKD1-EGFP translocation to the plasma membrane and its subsequent nuclear accumulation. Similar results were obtained in IEC-18 cells expressing PKD3-EGFP. Mechanistically, statins inhibited agonist-dependent PKD activation rather than acting directly on PKD catalytic activity since exposure to cerivastatin or simvastatin did not impair PKD autophosphorylation or PKD1-EGFP membrane translocation in response to phorbol dibutyrate, which bypasses GPCRs and directly stimulates PKC and PKD. Furthermore, cerivastatin did not inhibit recombinant PKD activity determined via an in vitro kinase assay. Using enteroids generated from intestinal crypt-derived epithelial cells from PKD1 transgenic mice as a model of intestinal regeneration, we show that statins oppose PKD1-mediated increase in enteroid area, complexity (number of crypt-like buds), and DNA synthesis. Our results revealed a previously unappreciated inhibitory effect of statins on receptor-mediated PKD activation and in opposing the growth-promoting effects of PKD1 on intestinal epithelial cells.
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Affiliation(s)
- James Sinnett-Smith
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
- VA Greater Los Angeles Health Care System, Los Angeles, California, United States
| | - M Eugenia Torres-Marquez
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Jen-Kuan Chang
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Yuki Shimizu
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Fang Hao
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Martin G Martin
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Enrique Rozengurt
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
- VA Greater Los Angeles Health Care System, Los Angeles, California, United States
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5
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Dhakal P, Chaudhry SI, Signorelli R, Collins KM. Serotonin signals through postsynaptic Gαq, Trio RhoGEF, and diacylglycerol to promote Caenorhabditis elegans egg-laying circuit activity and behavior. Genetics 2022; 221:iyac084. [PMID: 35579369 PMCID: PMC9252285 DOI: 10.1093/genetics/iyac084] [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] [Received: 03/09/2022] [Accepted: 04/26/2022] [Indexed: 11/12/2022] Open
Abstract
Activated Gαq signals through phospholipase-Cβ and Trio, a Rho GTPase exchange factor (RhoGEF), but how these distinct effector pathways promote cellular responses to neurotransmitters like serotonin remains poorly understood. We used the egg-laying behavior circuit of Caenorhabditis elegans to determine whether phospholipase-Cβ and Trio mediate serotonin and Gαq signaling through independent or related biochemical pathways. Our genetic rescue experiments suggest that phospholipase-Cβ functions in neurons while Trio Rho GTPase exchange factor functions in both neurons and the postsynaptic vulval muscles. While Gαq, phospholipase-Cβ, and Trio Rho GTPase exchange factor mutants fail to lay eggs in response to serotonin, optogenetic stimulation of the serotonin-releasing HSN neurons restores egg laying only in phospholipase-Cβ mutants. Phospholipase-Cβ mutants showed vulval muscle Ca2+ transients while strong Gαq and Trio Rho GTPase exchange factor mutants had little or no vulval muscle Ca2+ activity. Treatment with phorbol 12-myristate 13-acetate that mimics 1,2-diacylglycerol, a product of PIP2 hydrolysis, rescued egg-laying circuit activity and behavior defects of Gαq signaling mutants, suggesting both phospholipase-C and Rho signaling promote synaptic transmission and egg laying via modulation of 1,2-diacylglycerol levels. 1,2-Diacylglycerol activates effectors including UNC-13; however, we find that phorbol esters, but not serotonin, stimulate egg laying in unc-13 and phospholipase-Cβ mutants. These results support a model where serotonin signaling through Gαq, phospholipase-Cβ, and UNC-13 promotes neurotransmitter release, and that serotonin also signals through Gαq, Trio Rho GTPase exchange factor, and an unidentified, phorbol 12-myristate 13-acetate-responsive effector to promote postsynaptic muscle excitability. Thus, the same neuromodulator serotonin can signal in distinct cells and effector pathways to coordinate activation of a motor behavior circuit.
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Affiliation(s)
- Pravat Dhakal
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| | - Sana I Chaudhry
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| | | | - Kevin M Collins
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
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A Naturally Occurring Membrane-Anchored Gα s Variant, XLαs, Activates Phospholipase Cβ4. J Biol Chem 2022; 298:102134. [PMID: 35709985 PMCID: PMC9294334 DOI: 10.1016/j.jbc.2022.102134] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 12/02/2022] Open
Abstract
Extra-large stimulatory Gα (XLαs) is a large variant of G protein αs subunit (Gαs) that uses an alternative promoter and thus differs from Gαs at the first exon. XLαs activation by G protein–coupled receptors mediates cAMP generation, similarly to Gαs; however, Gαs and XLαs have been shown to have distinct cellular and physiological functions. For example, previous work suggests that XLαs can stimulate inositol phosphate production in renal proximal tubules and thereby regulate serum phosphate levels. In this study, we show that XLαs directly and specifically stimulates a specific isoform of phospholipase Cβ (PLCβ), PLCβ4, both in transfected cells and with purified protein components. We demonstrate that neither the ability of XLαs to activate cAMP generation nor the canonical G protein switch II regions are required for PLCβ stimulation. Furthermore, this activation is nucleotide independent but is inhibited by Gβγ, suggesting a mechanism of activation that relies on Gβγ subunit dissociation. Surprisingly, our results indicate that enhanced membrane targeting of XLαs relative to Gαs confers the ability to activate PLCβ4. We also show that PLCβ4 is required for isoproterenol-induced inositol phosphate accumulation in osteocyte-like Ocy454 cells. Taken together, we demonstrate a novel mechanism for activation of phosphoinositide turnover downstream of Gs-coupled receptors that may have a critical role in endocrine physiology.
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Phan HTN, Kim NH, Wei W, Tall GG, Smrcka AV. Uveal melanoma-associated mutations in PLCβ4 are constitutively activating and promote melanocyte proliferation and tumorigenesis. Sci Signal 2021; 14:eabj4243. [PMID: 34905385 DOI: 10.1126/scisignal.abj4243] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Hoa T N Phan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nam Hoon Kim
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Wenhui Wei
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alan V Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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8
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Inaba H, Miao Q, Nakata T. Optogenetic control of small GTPases reveals RhoA mediates intracellular calcium signaling. J Biol Chem 2021; 296:100290. [PMID: 33453281 PMCID: PMC7949103 DOI: 10.1016/j.jbc.2021.100290] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/06/2021] [Accepted: 01/11/2021] [Indexed: 01/05/2023] Open
Abstract
Rho/Ras family small GTPases are known to regulate numerous cellular processes, including cytoskeletal reorganization, cell proliferation, and cell differentiation. These processes are also controlled by Ca2+, and consequently, cross talk between these signals is considered likely. However, systematic quantitative evaluation has not yet been reported. To fill this gap, we constructed optogenetic tools to control the activity of small GTPases (RhoA, Rac1, Cdc42, Ras, Rap, and Ral) using an improved light-inducible dimer system (iLID). We characterized these optogenetic tools with genetically encoded red fluorescence intensity-based small GTPase biosensors and confirmed these optogenetic tools’ specificities. Using these optogenetic tools, we investigated calcium mobilization immediately after small GTPase activation. Unexpectedly, we found that a transient intracellular calcium elevation was specifically induced by RhoA activation in RPE1 and HeLa cells. RhoA activation also induced transient intracellular calcium elevation in MDCK and HEK293T cells, suggesting that generally RhoA induces calcium signaling. Interestingly, the molecular mechanisms linking RhoA activation to calcium increases were shown to be different among the different cell types: In RPE1 and HeLa cells, RhoA activated phospholipase C epsilon (PLCε) at the plasma membrane, which in turn induced Ca2+ release from the endoplasmic reticulum (ER). The RhoA–PLCε axis induced calcium-dependent nuclear factor of activated T cells nuclear translocation, suggesting that it does activate intracellular calcium signaling. Conversely, in MDCK and HEK293T cells, RhoA–ROCK–myosin II axis induced the calcium transients. These data suggest universal coordination of RhoA and calcium signaling in cellular processes, such as cellular contraction and gene expression.
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Affiliation(s)
- Hironori Inaba
- Department of Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan; The Center for Brain Integration Research (CBIR), Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Qianqian Miao
- Department of Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan; The Center for Brain Integration Research (CBIR), Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takao Nakata
- Department of Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan; The Center for Brain Integration Research (CBIR), Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
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9
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Katan M, Cockcroft S. Phospholipase C families: Common themes and versatility in physiology and pathology. Prog Lipid Res 2020; 80:101065. [PMID: 32966869 DOI: 10.1016/j.plipres.2020.101065] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/14/2020] [Accepted: 09/17/2020] [Indexed: 12/20/2022]
Abstract
Phosphoinositide-specific phospholipase Cs (PLCs) are expressed in all mammalian cells and play critical roles in signal transduction. To obtain a comprehensive understanding of these enzymes in physiology and pathology, a detailed structural, biochemical, cell biological and genetic information is required. In this review, we cover all these aspects to summarize current knowledge of the entire superfamily. The families of PLCs have expanded from 13 enzymes to 16 with the identification of the atypical PLCs in the human genome. Recent structural insights highlight the common themes that cover not only the substrate catalysis but also the mechanisms of activation. This involves the release of autoinhibitory interactions that, in the absence of stimulation, maintain classical PLC enzymes in their inactive forms. Studies of individual PLCs provide a rich repertoire of PLC function in different physiologies. Furthermore, the genetic studies discovered numerous mutated and rare variants of PLC enzymes and their link to human disease development, greatly expanding our understanding of their roles in diverse pathologies. Notably, substantial evidence now supports involvement of different PLC isoforms in the development of specific cancer types, immune disorders and neurodegeneration. These advances will stimulate the generation of new drugs that target PLC enzymes, and will therefore open new possibilities for treatment of a number of diseases where current therapies remain ineffective.
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Affiliation(s)
- Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Shamshad Cockcroft
- Department of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, 21 University Street, London WC1E 6JJ, UK.
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Owusu Obeng E, Rusciano I, Marvi MV, Fazio A, Ratti S, Follo MY, Xian J, Manzoli L, Billi AM, Mongiorgi S, Ramazzotti G, Cocco L. Phosphoinositide-Dependent Signaling in Cancer: A Focus on Phospholipase C Isozymes. Int J Mol Sci 2020; 21:ijms21072581. [PMID: 32276377 PMCID: PMC7177890 DOI: 10.3390/ijms21072581] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/03/2020] [Accepted: 04/06/2020] [Indexed: 12/12/2022] Open
Abstract
Phosphoinositides (PI) form just a minor portion of the total phospholipid content in cells but are significantly involved in cancer development and progression. In several cancer types, phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] play significant roles in regulating survival, proliferation, invasion, and growth of cancer cells. Phosphoinositide-specific phospholipase C (PLC) catalyze the generation of the essential second messengers diacylglycerol (DAG) and inositol 1,4,5 trisphosphate (InsP3) by hydrolyzing PtdIns(4,5)P2. DAG and InsP3 regulate Protein Kinase C (PKC) activation and the release of calcium ions (Ca2+) into the cytosol, respectively. This event leads to the control of several important biological processes implicated in cancer. PLCs have been extensively studied in cancer but their regulatory roles in the oncogenic process are not fully understood. This review aims to provide up-to-date knowledge on the involvement of PLCs in cancer. We focus specifically on PLCβ, PLCγ, PLCδ, and PLCε isoforms due to the numerous evidence of their involvement in various cancer types.
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Yu S, Choi WI, Choi YJ, Kim HY, Hildebrandt F, Gee HY. PLCE1 regulates the migration, proliferation, and differentiation of podocytes. Exp Mol Med 2020; 52:594-603. [PMID: 32238860 PMCID: PMC7210307 DOI: 10.1038/s12276-020-0410-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 02/07/2020] [Accepted: 02/12/2020] [Indexed: 12/31/2022] Open
Abstract
PLCE1 encodes phospholipase C epsilon, and its mutations cause recessive nephrotic syndrome. However, the mechanisms by which PLCE1 mutations result in defects associated with glomerular function are not clear. To address this, we investigated the function of PLCE1 in podocytes called glomerular epithelial cells, where the pathogenesis of nephrotic syndrome converges. PLCE1 colocalized with Rho GTPases in glomeruli. Further, it interacted with Rho GTPases through the pleckstrin homology domain and Ras GTP-binding domains 1/2. Knockdown or knockout of PLCE1 in podocytes resulted in decreased levels of GTP-bound Rac1 and Cdc42, but not those of RhoA, and caused a reduction in cell migration. PLCE1 interacted with NCK2 but not with NCK1. Similar to the PLCE1 knockout, NCK2 knockout resulted in decreased podocyte migration. Knockout of PLCE1 reduced the EGF-induced activation of ERK and cell proliferation in podocytes, whereas knockout of NCK2 did not affect proliferation. Further, the knockout of PLCE1 also resulted in decreased expression of podocyte markers, including NEPH1, NPHS1, WT1, and SYNPO, upon differentiation, but the knockout of NCK2 did not affect the expression of these markers. Therefore, our findings demonstrate that PLCE1 regulates Rho GTPase activity and cell migration through interacting with NCK2 and that PLCE1 also plays a role in the proliferation and differentiation of podocytes, regardless of the presence of NCK2. A genetic mutation associated with kidney disease impairs the maturation and migration of cells that filter waste products out of the blood. Tiny tendrils from kidney cells called podocytes establish a tight meshwork that keeps blood proteins in circulation while allowing unwanted contaminants to pass through. Mutations in the PLCE1 gene disrupt this filter, leading to a disorder called nephrotic syndrome Researchers led by Heon Yung Gee at Yonsei University College of Medicine, Seoul, South Korea, have uncovered mechanisms underlying this malfunction. Working with cultured podocytes, they showed that loss of PLCE1 impairs cell migration, potentially undermining their ability to form a meshwork. The researchers also found that the protein encoded by PLCE1 interacts with other molecules that promote cell division and maturation, revealing another mechanism by which mutations could contribute to loss of podocyte function.
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Affiliation(s)
- Seyoung Yu
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Won-Il Choi
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Yo Jun Choi
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Hye-Youn Kim
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Friedhelm Hildebrandt
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Heon Yung Gee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea.
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12
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Abstract
Phospholipase C (PLC) family members constitute a family of diverse enzymes. Thirteen different family members have been cloned. These family members have unique structures that mediate various functions. Although PLC family members all appear to signal through the bi-products of cleaving phospholipids, it is clear that each family member, and at times each isoform, contributes to unique cellular functions. This chapter provides a review of the current literature on PLC. In addition, references have been provided for more in-depth information regarding areas that are not discussed including tyrosine kinase activation of PLC. Understanding the roles of the individual PLC enzymes, and their distinct cellular functions, will lead to a better understanding of the physiological roles of these enzymes in the development of diseases and the maintenance of homeostasis.
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13
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Olayioye MA, Noll B, Hausser A. Spatiotemporal Control of Intracellular Membrane Trafficking by Rho GTPases. Cells 2019; 8:cells8121478. [PMID: 31766364 PMCID: PMC6952795 DOI: 10.3390/cells8121478] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/15/2019] [Accepted: 11/18/2019] [Indexed: 12/17/2022] Open
Abstract
As membrane-associated master regulators of cytoskeletal remodeling, Rho GTPases coordinate a wide range of biological processes such as cell adhesion, motility, and polarity. In the last years, Rho GTPases have also been recognized to control intracellular membrane sorting and trafficking steps directly; however, how Rho GTPase signaling is regulated at endomembranes is still poorly understood. In this review, we will specifically address the local Rho GTPase pools coordinating intracellular membrane trafficking with a focus on the endo- and exocytic pathways. We will further highlight the spatiotemporal molecular regulation of Rho signaling at endomembrane sites through Rho regulatory proteins, the GEFs and GAPs. Finally, we will discuss the contribution of dysregulated Rho signaling emanating from endomembranes to the development and progression of cancer.
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14
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Li L, Du Z, Gao Y, Tang Y, Fan Y, Sun W, Li T, Liu N, Yuan M, Fan J, Niu L, Yan J, Duan L, Wu X, Luo C. PLCε knockdown overcomes drug resistance to androgen receptor antagonist in castration-resistant prostate cancer by suppressing the wnt3a/β-catenin pathway. J Cell Physiol 2019; 234:15472-15486. [PMID: 30684266 DOI: 10.1002/jcp.28195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 01/10/2019] [Indexed: 01/24/2023]
Abstract
Most prostate cancers (Pcas) develop into castration-resistant prostate cancer (CRPC) after receiving androgen deprivation therapy (ADT). The expression levels of PLCε and wnt3a are increased in Pca and regulate androgen receptor (AR) activity. However, the biological function and mechanisms of PLCε and wnt3a in CRPC remain unknown. In this study, we found that the expression levels of PLCε, wnt3a, and AR were significantly increased in CRPC tissues as well as bicalutamide-resistant-LNCaP and enzalutamide-resistant-LNCaP cells. In addition, PLCε knockdown partly restored the sensitivity of drug-resistant cells to bicalutamide and enzalutamide by inhibiting the activity of the wnt3a/β-catenin/AR signaling axis. Interestingly, the resistance of LNCaP cells docetaxel is related to PLCε but not the wnt3a/β-catenin pathway. We also found that the combination of PLCε knockdown and enzalutamide treatment synergistically suppressed cell proliferation, tumor growth, and bone metastasis using in vitro and in vivo experiments. Our study revealed that PLCε is involved in the progression of drug-resistance in CRPC and could be a new target for the treatment of CRPC.
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Affiliation(s)
- Luo Li
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Zhongbo Du
- Department of Clinical Medicine, North Sichuan Medical College, Nanchong, China.,Department of Urology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Yingying Gao
- Department of Clinical Laboratory, Jiamusi University Clinical Medical College, Jiamusi, China
| | - Yu Tang
- State key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Biomedical Engineering College, Chongqing Medical University, Chongqing, China
| | - Yanru Fan
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Wei Sun
- Department of Urology, Fuling Center Hospital of Chongqing, Chongqing, China
| | - Ting Li
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Nanjing Liu
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Mengjuan Yuan
- Department of Urology, Fuling Center Hospital of Chongqing, Chongqing, China
| | - Jiaxin Fan
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Lingfang Niu
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Jinxiao Yan
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Limei Duan
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Xiaohou Wu
- Department of Urology, First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Chunli Luo
- Key Laboratory of Diagnostics Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China
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15
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Cheng H, Hao Y, Gao Y, He Y, Luo C, Sun W, Yuan M, Wu X. PLCε promotes urinary bladder cancer cells proliferation through STAT3/LDHA pathway‑mediated glycolysis. Oncol Rep 2019; 41:2844-2854. [PMID: 30864733 PMCID: PMC6448096 DOI: 10.3892/or.2019.7056] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 03/04/2019] [Indexed: 02/06/2023] Open
Abstract
Phospholipase Cε (PLCε) and anaerobic glycolysis were determined to be involved in the development of human urinary bladder cancer (UBC), but the mechanisms remain unclear. In the present study, 64 bladder cancer specimens and 42 adjacent tissue specimens were obtained from 64 patients, and immunochemistry indicated that PLCε and lactate dehydrogenase (LDHA) are overexpressed in UBC. PLCε and LDHA were demonstrated to be positively correlated at transcription levels, indicating that one of these two genes may be regulated by another. To elucidate the mechanisms, PLCε was knocked down in T24 cells by short hairpin RNA, and then signal transducer and activator of transcription 3 (STAT3) phosphorylation and LDHA were determined to be downregulated, which indicated that PLCε may serve roles upstream of LDHA through STAT3 to regulate glycolysis in UBC. Furthermore, chromatin immunoprecipitation and luciferase reporter assays were performed to confirm that STAT3 could bind to the promoter of the LDHA gene to enhance its expression. A xenograft tumor mouse model also demonstrated similar results as the in vitro experiments, further confirming the role of PLCε in regulating bladder cell growth in vivo. Collectively, the present study demonstrated that PLCε may regulate glycolysis through the STAT3/LDHA pathway to take part in the development of human UBC.
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Affiliation(s)
- Honglin Cheng
- Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Yanni Hao
- Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400010, P.R. China
| | - Yingying Gao
- Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400010, P.R. China
| | - Yunfeng He
- Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Chunli Luo
- Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400010, P.R. China
| | - Wei Sun
- Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Mengjuan Yuan
- Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Xiaohou Wu
- Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
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16
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Sun W, Li L, Du Z, Quan Z, Yuan M, Cheng H, Gao Y, Luo C, Wu X. Combination of phospholipase Cε knockdown with GANT61 sensitizes castration‑resistant prostate cancer cells to enzalutamide by suppressing the androgen receptor signaling pathway. Oncol Rep 2019; 41:2689-2702. [PMID: 30864728 PMCID: PMC6448124 DOI: 10.3892/or.2019.7054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 03/04/2019] [Indexed: 02/06/2023] Open
Abstract
Castration‑resistant prostate cancer (CRPC) is a major challenge in the treatment of prostate cancer (PCa). Phospholipase Cε (PLCε), an oncogene, has been found to be involved in the carcinogenesis, tumor proliferation and migration of several types of cancer. The effects, however, of PLCε on CRPC remains unclear. In the present study, the expression of PLCε and glioma‑associated homolog (Gli)‑1/Gli‑2 in benign prostatic hyperplasia (BPH), PCa and CRPC tissues and cells was investigated, and the correlations between PLCε and Gli‑1/Gli‑2 in CRPC tissues and cell lines were further explored. In addition, the effect of PLCε on cell proliferation and invasion was assessed in CRPC cell lines, and the sensitivity of EN‑R and 22RV1 cells to enzalutamide following the downregulation of PLCε expression was determined using lentivirus‑mediated shPLCε and/or treatment with specific Gli inhibitor GANT61. It was found that the PLCε expression was excessively upregulated in the majority of CRPC tissues, and PLCε positivity was linked to poor progression‑free survival (PFS) and overall survival (OS) in patients with PCa. Furthermore, PLCε knockdown significantly suppressed CRPC cell proliferation and invasion. Of note, it was found that PLCε knockdown increased the sensitivity of CRPC cells to enzalutamide in vitro by suppressing androgen receptor (AR) activities via the non‑canonical Hedgehog/Gli‑2 and p‑STAT3 signaling pathways. PLCε knockdown was shown to increase the sensitivity of CRPC cell xenografts to enzalutamide in vivo. Finally, the combination of PLCε knockdown with GANT61 significantly sensitized CRPC cells to enzalutamide. Collectively, the results of the present study suggest that PLCε is a potential therapeutic target for CRPC.
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Affiliation(s)
- Wei Sun
- Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Luo Li
- Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Zhongbo Du
- Department of Urology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, P.R. China
| | - Zhen Quan
- Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Mengjuan Yuan
- Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Honglin Cheng
- Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Yingying Gao
- Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Chunli Luo
- Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Xiaohou Wu
- Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, P.R. China
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17
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Eisler SA, Curado F, Link G, Schulz S, Noack M, Steinke M, Olayioye MA, Hausser A. A Rho signaling network links microtubules to PKD controlled carrier transport to focal adhesions. eLife 2018; 7:35907. [PMID: 30028295 PMCID: PMC6070338 DOI: 10.7554/elife.35907] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 07/19/2018] [Indexed: 12/22/2022] Open
Abstract
Protein kinase D (PKD) is a family of serine/threonine kinases that is required for the structural integrity and function of the Golgi complex. Despite its importance in the regulation of Golgi function, the molecular mechanisms regulating PKD activity are still incompletely understood. Using the genetically encoded PKD activity reporter G-PKDrep we now uncover a Rho signaling network comprising GEF-H1, the RhoGAP DLC3, and the Rho effector PLCε that regulate the activation of PKD at trans-Golgi membranes. We further show that this molecular network coordinates the formation of TGN-derived Rab6-positive transport carriers delivering cargo for localized exocytosis at focal adhesions.
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Affiliation(s)
- Stephan A Eisler
- Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany
| | - Filipa Curado
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Gisela Link
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Sarah Schulz
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Melanie Noack
- Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany
| | - Maren Steinke
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Monilola A Olayioye
- Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany.,Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Angelika Hausser
- Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany.,Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
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18
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Madukwe JC, Garland-Kuntz EE, Lyon AM, Smrcka AV. G protein βγ subunits directly interact with and activate phospholipase Cϵ. J Biol Chem 2018. [PMID: 29535186 DOI: 10.1074/jbc.ra118.002354] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipase C (PLC) enzymes hydrolyze membrane phosphatidylinositol 4,5 bisphosphate (PIP2) and regulate Ca2+ and protein kinase signaling in virtually all mammalian cell types. Chronic activation of the PLCϵ isoform downstream of G protein-coupled receptors (GPCRs) contributes to the development of cardiac hypertrophy. We have previously shown that PLCϵ-catalyzed hydrolysis of Golgi-associated phosphatidylinositol 4-phosphate (PI4P) in cardiac myocytes depends on G protein βγ subunits released upon stimulation with endothelin-1. PLCϵ binds and is directly activated by Ras family small GTPases, but whether they directly interact with Gβγ has not been demonstrated. To identify PLCϵ domains that interact with Gβγ, here we designed various single substitutions and truncations of WT PLCϵ and tested them for activation by Gβγ in transfected COS-7 cells. Deletion of only a single domain in PLCϵ was not sufficient to completely block its activation by Gβγ, but blocked activation by Ras. Simultaneous deletion of the C-terminal RA2 domain and the N-terminal CDC25 and cysteine-rich domains completely abrogated PLCϵ activation by Gβγ, but activation by the GTPase Rho was retained. In vitro reconstitution experiments further revealed that purified Gβγ directly interacts with a purified fragment of PLCϵ (PLCϵ-PH-RA2) and increases PIP2 hydrolysis. Deletion of the RA2 domain decreased Gβγ binding and eliminated Gβγ stimulation of PIP2 hydrolysis. These results provide first evidence that Gβγ directly interacts with PLCϵ and yield insights into the mechanism by which βγ subunits activate PLCϵ.
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Affiliation(s)
- Jerry C Madukwe
- From the Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14267.,Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | | | - Angeline M Lyon
- Department of Chemistry Purdue University, West Lafayette, Indiana 47907, and
| | - Alan V Smrcka
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan 48109
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19
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Tyutyunnykova A, Telegeev G, Dubrovska A. The controversial role of phospholipase C epsilon (PLCε) in cancer development and progression. J Cancer 2017; 8:716-729. [PMID: 28382133 PMCID: PMC5381159 DOI: 10.7150/jca.17779] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/23/2016] [Indexed: 01/21/2023] Open
Abstract
The phospholipase C (PLC) enzymes are important regulators of membrane phospholipid metabolism. PLC proteins can be activated by the receptor tyrosine kinases (RTK) or G-protein coupled receptors (GPCR) in response to the different extracellular stimuli including hormones and growth factors. Activated PLC enzymes hydrolyze phosphoinositides to increase the intracellular level of Ca2+ and produce diacylglycerol, which are important mediators of the intracellular signaling transduction. PLC family includes 13 isozymes belonging to 6 subfamilies according to their domain structures and functions. Although importance of PLC enzymes for key cellular functions is well established, the PLC proteins belonging to the ε, ζ and η subfamilies were identified and characterized only during the last decade. As a largest known PLC protein, PLCε is involved in a variety of signaling pathways and controls different cellular properties. Nevertheless, its role in carcinogenesis remains elusive. The aim of this review is to provide a comprehensive and up-to-date overview of the experimental and clinical data about the role of PLCε in the development and progression of the different types of human and experimental tumors.
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Affiliation(s)
- Anna Tyutyunnykova
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Fetscherstrasse 74, 01307 Dresden, Germany
| | - Gennady Telegeev
- The Institute of Molecular Biology and Genetics of NASU, Kyiv, Ukraine
| | - Anna Dubrovska
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Fetscherstrasse 74, 01307 Dresden, Germany.; German Cancer Consortium (DKTK), Dresden, Germany.; Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
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20
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Wood BM, Bossuyt J. Emergency Spatiotemporal Shift: The Response of Protein Kinase D to Stress Signals in the Cardiovascular System. Front Pharmacol 2017; 8:9. [PMID: 28174535 PMCID: PMC5258689 DOI: 10.3389/fphar.2017.00009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/04/2017] [Indexed: 12/12/2022] Open
Abstract
Protein Kinase D isoforms (PKD 1-3) are key mediators of neurohormonal, oxidative, and metabolic stress signals. PKDs impact a wide variety of signaling pathways and cellular functions including actin dynamics, vesicle trafficking, cell motility, survival, contractility, energy substrate utilization, and gene transcription. PKD activity is also increasingly linked to cancer, immune regulation, pain modulation, memory, angiogenesis, and cardiovascular disease. This increasing complexity and diversity of PKD function, highlights the importance of tight spatiotemporal control of the kinase via protein–protein interactions, post-translational modifications or targeting via scaffolding proteins. In this review, we focus on the spatiotemporal regulation and effects of PKD signaling in response to neurohormonal, oxidant and metabolic signals that have implications for myocardial disease. Precise targeting of these mechanisms will be crucial in the design of PKD-based therapeutic strategies.
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Affiliation(s)
- Brent M Wood
- Department of Pharmacology, University of California, Davis, Davis CA, USA
| | - Julie Bossuyt
- Department of Pharmacology, University of California, Davis, Davis CA, USA
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21
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Smrcka AV. Regulation of phosphatidylinositol-specific phospholipase C at the nuclear envelope in cardiac myocytes. J Cardiovasc Pharmacol 2016; 65:203-10. [PMID: 25658460 DOI: 10.1097/fjc.0000000000000195] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Phosphatidylinositol 4,5-bisphosphate hydrolysis at the plasma membrane by phospholipase C is one of the major hormone regulated intracellular signaling systems. The system generates the diffusible second messenger IP3 and the membrane bound messenger diacylglycerol. Spatial regulation of this system has been thought to be through specific subcellular distributions of the IP3 receptor or PKC. As is becoming increasingly apparent, receptor-stimulated signaling systems are also found at intracellular membranes. As discussed in this issue, G protein-coupled receptors have been identified at the nuclear envelope implying intracellular localization of the signaling systems that respond to G protein-coupled receptors. Here, we discuss the evidence for the existence of PLC signals that regulate nuclear processes, as well as the evidence for nuclear and nuclear envelope localization of PLC signaling components, and their implications for cardiac physiology and disease.
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Affiliation(s)
- Alan V Smrcka
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY
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22
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Qu D, Huang H, DI J, Gao K, Lu Z, Zheng J. Structure, functional regulation and signaling properties of Rap2B. Oncol Lett 2016; 11:2339-2346. [PMID: 27073477 DOI: 10.3892/ol.2016.4261] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 12/17/2015] [Indexed: 12/16/2022] Open
Abstract
The Ras family small guanosine 5'-triphosphate (GTP)-binding protein Rap2B is is a member of the Ras oncogene family and a novel target of p53 that regulates the p53-mediated pro-survival function of cells. The Rap2B protein shares ~90% homology with Rap2A, and its sequence is 70% identical to other members of the Rap family such as RaplA and RaplB. As a result, Rap2B has been theorized to have similar signaling effectors to the GTPase-binding protein Rap, which mediates various biological functions, including the regulation of sterile 20/mitogen-activated proteins. Since its identification in the early 1990s, Rap2B has elicited a considerable interest. Numerous studies indicate that Rap2B exerts specific biological functions, including binding and stimulating phospholipase C-ε and interferon-γ. In addition, downregulation of Rap2B affects the growth of melanoma cells. The present review summarizes the possible effectors and biological functions of Rap2B. Increasing evidence clearly supports the association between Rap2B function and tumor development. Therefore, it is conceivable that anticancer drugs targeting Rap2B may be generated as novel therapies against cancer.
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Affiliation(s)
- Debao Qu
- Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China; Department of Radiotherapy, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Hui Huang
- Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Jiehui DI
- Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China; Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Keyu Gao
- Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Zheng Lu
- Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Junnian Zheng
- Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China; Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China; Center of Clinical Oncology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
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23
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Lu S, Jang H, Muratcioglu S, Gursoy A, Keskin O, Nussinov R, Zhang J. Ras Conformational Ensembles, Allostery, and Signaling. Chem Rev 2016; 116:6607-65. [PMID: 26815308 DOI: 10.1021/acs.chemrev.5b00542] [Citation(s) in RCA: 262] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ras proteins are classical members of small GTPases that function as molecular switches by alternating between inactive GDP-bound and active GTP-bound states. Ras activation is regulated by guanine nucleotide exchange factors that catalyze the exchange of GDP by GTP, and inactivation is terminated by GTPase-activating proteins that accelerate the intrinsic GTP hydrolysis rate by orders of magnitude. In this review, we focus on data that have accumulated over the past few years pertaining to the conformational ensembles and the allosteric regulation of Ras proteins and their interpretation from our conformational landscape standpoint. The Ras ensemble embodies all states, including the ligand-bound conformations, the activated (or inactivated) allosteric modulated states, post-translationally modified states, mutational states, transition states, and nonfunctional states serving as a reservoir for emerging functions. The ensemble is shifted by distinct mutational events, cofactors, post-translational modifications, and different membrane compositions. A better understanding of Ras biology can contribute to therapeutic strategies.
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Affiliation(s)
- Shaoyong Lu
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine , Shanghai, 200025, China.,Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | | | | | | | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States.,Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University , Tel Aviv 69978, Israel
| | - Jian Zhang
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine , Shanghai, 200025, China
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24
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Abstract
A new study reports that the RhoGAP SPV-1 senses membrane curvature and cell stretch in the Caenorhabditis elegans spermatheca. Without SPV-1, the cells of the spermatheca are hypercontractile, leading to deformation and rapid ejection of the fertilized eggs. The spermatheca may provide a paradigm for understanding how cells detect mechanical stimuli in vivo.
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Affiliation(s)
- Erin J Cram
- 134Mugar Life Sciences, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
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25
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Dusaban SS, Kunkel MT, Smrcka AV, Brown JH. Thrombin promotes sustained signaling and inflammatory gene expression through the CDC25 and Ras-associating domains of phospholipase Cϵ. J Biol Chem 2015; 290:26776-83. [PMID: 26350460 DOI: 10.1074/jbc.m115.676098] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Indexed: 01/24/2023] Open
Abstract
Phospholipase C-epsilon (PLCϵ) plays a critical role in G-protein-coupled receptor-mediated inflammation. In addition to its ability to generate the second messengers inositol 1,4,5-trisphosphate and diacylglycerol, PLCϵ, unlike the other phospholipase C family members, is activated in a sustained manner. We hypothesized that the ability of PLCϵ to function as a guanine nucleotide exchange factor (GEF) for Rap1 supports sustained downstream signaling via feedback of Rap1 to the enzyme Ras-associating (RA2) domain. Using gene deletion and adenoviral rescue, we demonstrate that both the GEF (CDC25 homology domain) and RA2 domains of PLCϵ are required for long term protein kinase D (PKD) activation and subsequent induction of inflammatory genes. PLCϵ localization is largely intracellular and its compartmentalization could contribute to its sustained activation. Here we show that localization of PLCϵ to the Golgi is required for activation of PKD in this compartment as well as for subsequent induction of inflammatory genes. These data provide a molecular mechanism by which PLCϵ mediates sustained signaling and by which astrocytes mediate pathophysiological inflammatory responses.
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Affiliation(s)
- Stephanie S Dusaban
- From the Department of Pharmacology, School of Medicine and Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093 and
| | - Maya T Kunkel
- From the Department of Pharmacology, School of Medicine and
| | - Alan V Smrcka
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
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26
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Knockdown of PLCε inhibits inflammatory cytokine release via STAT3 phosphorylation in human bladder cancer cells. Tumour Biol 2015; 36:9723-32. [PMID: 26156799 DOI: 10.1007/s13277-015-3712-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 06/23/2015] [Indexed: 01/05/2023] Open
Abstract
Phospholipase Cε (PLCε) is a multifunctional enzyme implicated in inflammatory functions. There are limited data, however, on how PLCε can alter inflammatory cytokine by affecting downstream pathways. Recent studies suggest that inflammation is likely to have an important role in transitional cell carcinoma of bladder (TCCB) and cancer disease progression. Here, we showed that PLCε and p-STAT3 expression were both elevated in TCCB tissues compared to adjacent tissues, and the increase of PLCε level was associated with the increase of p-STAT3 level. Then, knockdown of PLCε using adenovirus-shPLCε significantly decreased inflammatory cytokine (IL-6, TNF-α, IL-1β) expression and inflammation-associated gene (TLR4, MyD88, p-STAT3) expression. Furthermore, we demonstrated that PLCε knockdown blocked LPS-induced inflammatory cytokine and p-STAT3 expression. Additionally, we found that combined treatment of STAT3 inhibitor S3I-201 with adenovirus-shPLCε exhibited synergistic inhibitory effects on expression of p-STAT3. Our results suggested that STAT3 phosphorylation is involved in PLCε-mediated inflammatory cytokine release. Our research is of potential importance in drug development programs using PLCε as a therapeutic target for TCCB.
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27
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Zhang RY, Du WQ, Zhang YC, Zheng JN, Pei DS. PLCε signaling in cancer. J Cancer Res Clin Oncol 2015; 142:715-22. [PMID: 26109147 DOI: 10.1007/s00432-015-1999-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 06/09/2015] [Indexed: 12/14/2022]
Abstract
PURPOSE As one of the members of the PLC family, the phosphoinositide-specific phospholipase Cε (PLCε) has been shown to play pivotal roles in multiple signal pathways and control a variety of cellular functions. A number of studies have shown that aberrant regulation of PLCε was involved in various types of animal and human cancer. However, the role of PLCε in cancer remains elusive. In this review, we provide an overview of the PLCε, especially its roles in multiple signal pathways, and summarize the recent findings that highlight the roles of PLCε in carcinogenesis and cancer progression, making an avenue to provide a novel therapeutic strategy for the treatment of cancer. METHODS A literature search mainly paying attention to the network of PLCε involved in tumorigenesis and development was performed in electronic databases. RESULTS PLCε plays a key role in medicating the development and progression of human cancers with highest potency to be a target of cancer prevention and treatment.
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Affiliation(s)
- Rui-Yan Zhang
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, 221002, Jiangsu, People's Republic of China
| | - Wen-Qi Du
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, 221002, Jiangsu, People's Republic of China
| | - Ying-Chun Zhang
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, 221002, Jiangsu, People's Republic of China
| | - Jun-Nian Zheng
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, 221002, Jiangsu, People's Republic of China. .,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, People's Republic of China. .,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Xuzhou Medical College, Xuzhou, 221002, Jiangsu, People's Republic of China.
| | - Dong-Sheng Pei
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, 221002, Jiangsu, People's Republic of China.
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AlSuleimani YM, Hiley CR. The GPR55 agonist lysophosphatidylinositol relaxes rat mesenteric resistance artery and induces Ca(2+) release in rat mesenteric artery endothelial cells. Br J Pharmacol 2015; 172:3043-57. [PMID: 25652040 DOI: 10.1111/bph.13107] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 01/11/2015] [Accepted: 02/02/2015] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Lysophosphatidylinositol (LPI), a lipid signalling molecule, activates GPR55 and elevates intracellular Ca(2+). Here, we examine the actions of LPI in the rat resistance mesenteric artery and Ca(2+) responses in endothelial cells isolated from the artery. EXPERIMENTAL APPROACH Vascular responses were studied using wire myographs. Single-cell fluorescence imaging was performed using a MetaFluor system. Hypotensive effects of LPI were assessed using a Biopac system. KEY RESULTS In isolated arteries, LPI-induced vasorelaxation was concentration- and endothelium-dependent and inhibited by CID 16020046, a GPR55 antagonist. The CB1 receptor antagonist AM 251 had no effect, whereas rimonabant and O-1918 significantly potentiated LPI responses. Vasorelaxation was reduced by charybdotoxin and iberiotoxin, alone or combined. LPI decreased systemic arterial pressure. GPR55 is expressed in rat mesenteric artery. LPI caused biphasic elevations of endothelial cell intracellular Ca(2+). Pretreatment with thapsigargin or 2-aminoethoxydiphenyl borate abolished both phases. The PLC inhibitor U73122 attenuated the initial phase and enhanced the second phase, whereas the Rho-associated kinase inhibitor Y-27632 abolished the late phase but not the early phase. CONCLUSIONS AND IMPLICATIONS LPI is an endothelium-dependent vasodilator in the rat small mesenteric artery and a hypotensive agent. The vascular response involves activation of Ca(2+)-sensitive K(+) channels and is not mediated by CB1 receptors, but unexpectedly enhanced by antagonists of the 'endothelial anandamide' receptor. In endothelial cells, LPI utilizes PLC-IP3 and perhaps ROCK-RhoA pathways to elevate intracellular Ca(2+). Overall, these findings support an endothelial site of action for LPI and suggest a possible role for GPR55 in vasculature.
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Affiliation(s)
- Y M AlSuleimani
- Department of Pharmacology, University of Cambridge, Cambridge, UK.,Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health Sciences, Sultan Qaboos University, Alkoudh, Sultanate of Oman
| | - C R Hiley
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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Yu OM, Brown JH. G Protein-Coupled Receptor and RhoA-Stimulated Transcriptional Responses: Links to Inflammation, Differentiation, and Cell Proliferation. Mol Pharmacol 2015; 88:171-80. [PMID: 25904553 DOI: 10.1124/mol.115.097857] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/22/2015] [Indexed: 01/06/2023] Open
Abstract
The low molecular weight G protein RhoA (rat sarcoma virus homolog family member A) serves as a node for transducing signals through G protein-coupled receptors (GPCRs). Activation of RhoA occurs through coupling of G proteins, most prominently, G12/13, to Rho guanine nucleotide exchange factors. The GPCR ligands that are most efficacious for RhoA activation include thrombin, lysophosphatidic acid, sphingosine-1-phosphate, and thromboxane A2. These ligands also stimulate proliferation, differentiation, and inflammation in a variety of cell and tissues types. The molecular events underlying these responses are the activation of transcription factors, transcriptional coactivators, and downstream gene programs. This review describes the pathways leading from GPCRs and RhoA to the regulation of activator protein-1, NFκB (nuclear factor κ-light-chain-enhancer of activated B cells), myocardin-related transcription factor A, and Yes-associated protein. We also focus on the importance of two prominent downstream transcriptional gene targets, the inflammatory mediator cyclooxygenase 2, and the matricellular protein cysteine-rich angiogenic inducer 61 (CCN1). Finally, we describe the importance of GPCR-induced activation of these pathways in the pathophysiology of cancer, fibrosis, and cardiovascular disease.
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Affiliation(s)
- Olivia M Yu
- Department of Pharmacology (O.Y., J.H.B.) and Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, California (O.Y.)
| | - Joan Heller Brown
- Department of Pharmacology (O.Y., J.H.B.) and Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, California (O.Y.)
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Tan P, Zaidel-Bar R. Transient Membrane Localization of SPV-1 Drives Cyclical Actomyosin Contractions in the C. elegans Spermatheca. Curr Biol 2015; 25:141-151. [DOI: 10.1016/j.cub.2014.11.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/27/2014] [Accepted: 11/13/2014] [Indexed: 12/25/2022]
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Dusaban SS, Brown JH. PLCε mediated sustained signaling pathways. Adv Biol Regul 2014; 57:17-23. [PMID: 25453218 DOI: 10.1016/j.jbior.2014.09.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 09/22/2014] [Accepted: 09/25/2014] [Indexed: 01/09/2023]
Abstract
Phospholipase C-ε (PLCε) integrates signaling from G-protein coupled receptors (GPCRs) to downstream kinases to regulate a broad range of biological and pathophysiological responses. Relative to other PLCs, PLCε is unique in that it not only serves a catalytic function in phosphoinositide hydrolysis but also functions as an exchange factor small the low molecular weight G-protein Rap1. PLCε is selectively stimulated by agonists for GPCRs that couple to RhoA, which bind directly to the enzyme to regulate its activity. Rap1 also regulates PLCε activity by binding to its RA2 domain and this generates a feedback mechanism allowing sustained signaling. As a result of its regulation by inflammatory ligands for GPCRs and its ability to promote chronic signals, PLCε has been implicated in diseases ranging from cancer to ischemia/reperfusion injury. This review will discuss the regulation of PLCε, molecular mechanisms that contribute to sustained signaling, and the role of the enzyme in various disease contexts.
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Affiliation(s)
- Stephanie S Dusaban
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joan Heller Brown
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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Xiang SY, Ouyang K, Yung BS, Miyamoto S, Smrcka AV, Chen J, Heller Brown J. PLCε, PKD1, and SSH1L transduce RhoA signaling to protect mitochondria from oxidative stress in the heart. Sci Signal 2013; 6:ra108. [PMID: 24345679 DOI: 10.1126/scisignal.2004405] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Activation of the small guanosine triphosphatase RhoA can promote cell survival in cultured cardiomyocytes and in the heart. We showed that the circulating lysophospholipid sphingosine 1-phosphate (S1P), a G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor (GPCR) agonist, signaled through RhoA and phospholipase Cε (PLCε) to increase the phosphorylation and activation of protein kinase D1 (PKD1). Genetic deletion of either PKD1 or its upstream regulator PLCε inhibited S1P-mediated cardioprotection against ischemia/reperfusion injury. Cardioprotection involved PKD1-mediated phosphorylation and inhibition of the cofilin phosphatase Slingshot 1L (SSH1L). Cofilin 2 translocates to mitochondria in response to oxidative stress or ischemia/reperfusion injury, and both S1P pretreatment and SSH1L knockdown attenuated translocation of cofilin 2 to mitochondria. Cofilin 2 associates with the proapoptotic protein Bax, and the mitochondrial translocation of Bax in response to oxidative stress was also attenuated by S1P treatment in isolated hearts or by knockdown of SSH1L or cofilin 2 in cardiomyocytes. Furthermore, SSH1L knockdown, like S1P treatment, increased cardiomyocyte survival and preserved mitochondrial integrity after oxidative stress. These findings reveal a pathway initiated by GPCR agonist-induced RhoA activation, in which PLCε signals to PKD1-mediated phosphorylation of cytoskeletal proteins to prevent the mitochondrial translocation and proapoptotic function of cofilin 2 and Bax and thereby promote cell survival.
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Affiliation(s)
- Sunny Y Xiang
- 1Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA
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Bement WM, von Dassow G. Single cell pattern formation and transient cytoskeletal arrays. Curr Opin Cell Biol 2013; 26:51-9. [PMID: 24529246 DOI: 10.1016/j.ceb.2013.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/25/2013] [Accepted: 09/26/2013] [Indexed: 12/28/2022]
Abstract
A major goal of developmental biology is to explain the emergence of pattern in cell layers, tissues and organs. Developmental biologists now accept that reaction diffusion-based mechanisms are broadly employed in developing organisms to direct pattern formation. Here we briefly consider these mechanisms and then apply some of the concepts derived from them to several processes that occur in single cells: wound repair, yeast budding, and cytokinesis. Two conclusions emerge from this analysis: first, there is considerable overlap at the level of general mechanisms between developmental and single cell pattern formation; second, dynamic structures based on the actin cytoskeleton may be far more ordered than is generally recognized.
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Affiliation(s)
- William M Bement
- Laboratory of Cell and Molecular Biology and Department of Zoology, University of Wisconsin-Madison, 1525 Linden Drive, Madison, Wisconsin 53706, USA; Oregon Institute of Marine Biology, University of Oregon, P.O. Box 5389, Charleston, OR 97420, USA.
| | - George von Dassow
- Laboratory of Cell and Molecular Biology and Department of Zoology, University of Wisconsin-Madison, 1525 Linden Drive, Madison, Wisconsin 53706, USA.
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Eishingdrelo H, Kongsamut S. Minireview: Targeting GPCR Activated ERK Pathways for Drug Discovery. Curr Chem Genom Transl Med 2013; 7:9-15. [PMID: 24396730 PMCID: PMC3854659 DOI: 10.2174/2213988501307010009] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 04/08/2013] [Accepted: 04/15/2013] [Indexed: 02/07/2023] Open
Abstract
It has become clear in recent years that multiple signal transduction pathways are employed upon GPCR
activation. One of the major cellular effectors activated by GPCRs is extracellular signal-regulated kinase (ERK). Both G-protein and β-arrestin mediated signaling pathways can lead to ERK activation. However, depending on activation
pathway, the subcellular destination of activated ERK1/2 may be different. G-protein -dependent ERK activation results in the translocation of active ERK to the nucleus, whereas ERK activated via an arrestin-dependent mechanism remains largely in the cytoplasm. The subcellular location of activated ERK1/2 determines the downstream signaling cascade. Many substrates of ERK1/2 are found in the nucleus: nuclear transcription factors that participate in gene transcription, cell proliferation and differentiation. ERK1/2 substrates are also found in cytosol and other cellular organelles: they may play roles in translation, mitosis, apoptosis and cross-talk with other signaling pathways. Therefore, determining specific subcellular locations of activated ERK1/2 mediated by GPCR ligands would be important in correlating signaling pathways with cellular physiological functions. While GPCR-stimulated selective ERK pathway activation has been studied in several receptor systems, exploitation of these different signaling cascades for therapeutics has not yet been seriously
pursued. Many old drug candidates were identified from screens based on G-protein signaling assays, and their activity on β-arrestin signaling pathways being mostly unknown, especially regarding their subcellular ERK pathways. With today’s knowledge of complicated GPCR signaling pathways, drug discovery can no longer rely on single-pathway approaches. Since ERK activation is an important signaling pathway and associated with many physiological functions, targeting the ERK pathway, especially specific subcellular activation pathways should provide new avenues for GPCR drug discovery.
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Affiliation(s)
- Haifeng Eishingdrelo
- BioInvenu Corporation, 50 Williams Parkway, East Hanover, New Jersey, 07936, USA
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Filamin and phospholipase C-ε are required for calcium signaling in the Caenorhabditis elegans spermatheca. PLoS Genet 2013; 9:e1003510. [PMID: 23671426 PMCID: PMC3650001 DOI: 10.1371/journal.pgen.1003510] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 03/30/2013] [Indexed: 12/05/2022] Open
Abstract
The Caenorhabditis elegans spermatheca is a myoepithelial tube that stores sperm and undergoes cycles of stretching and constriction as oocytes enter, are fertilized, and exit into the uterus. FLN-1/filamin, a stretch-sensitive structural and signaling scaffold, and PLC-1/phospholipase C-ε, an enzyme that generates the second messenger IP3, are required for embryos to exit normally after fertilization. Using GCaMP, a genetically encoded calcium indicator, we show that entry of an oocyte into the spermatheca initiates a distinctive series of IP3-dependent calcium oscillations that propagate across the tissue via gap junctions and lead to constriction of the spermatheca. PLC-1 is required for the calcium release mechanism triggered by oocyte entry, and FLN-1 is required for timely initiation of the calcium oscillations. INX-12, a gap junction subunit, coordinates propagation of the calcium transients across the spermatheca. Gain-of-function mutations in ITR-1/IP3R, an IP3-dependent calcium channel, and loss-of-function mutations in LFE-2, a negative regulator of IP3 signaling, increase calcium release and suppress the exit defect in filamin-deficient animals. We further demonstrate that a regulatory cassette consisting of MEL-11/myosin phosphatase and NMY-1/non-muscle myosin is required for coordinated contraction of the spermatheca. In summary, this study answers long-standing questions concerning calcium signaling dynamics in the C. elegans spermatheca and suggests FLN-1 is needed in response to oocyte entry to trigger calcium release and coordinated contraction of the spermathecal tissue. During organism development and normal physiological function cells sense, integrate, and respond to a variety of cues or signals including biochemical and mechanical stimuli. In this study we used Caenorhabditis elegans, a small transparent worm, to study filamin (FLN-1), a structural protein that may act as a molecular strain gauge. The C. elegans spermatheca is a contractile tube that is stretched during normal function, making it an ideal candidate for study of how cells respond to stretch. Oocytes are ovulated into the spermatheca, fertilized, and then pushed into the uterus by constriction of the spermatheca. The ability of the spermatheca to constrict depends on inositol 1,4,5-triphosphate (IP3), a signaling molecule produced by the enzyme phospholipase C (PLC-1) that triggers calcium release within cells. In animals with mutated FLN-1 or PLC-1 the spermathecal cells fail to constrict. Using genetic analysis and a calcium-sensitive fluorescent protein, we show that FLN-1 functions with PLC-1 to regulate IP3 production, calcium release, and contraction of the spermatheca. Filamin may function to sense stretch caused by entering oocytes and to trigger constriction. These findings establish a link between filamin and calcium signaling that may apply to similar signaling pathways in other systems.
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Phospholipase C epsilon links G protein-coupled receptor activation to inflammatory astrocytic responses. Proc Natl Acad Sci U S A 2013; 110:3609-14. [PMID: 23401561 DOI: 10.1073/pnas.1217355110] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neuroinflammation plays a major role in the pathophysiology of diseases of the central nervous system, and the role of astroglial cells in this process is increasingly recognized. Thrombin and the lysophospholipids lysophosphatidic acid and sphingosine 1-phosphate (S1P) are generated during injury and can activate G protein-coupled receptors (GPCRs) on astrocytes. We postulated that GPCRs that couple to Ras homolog gene family, member A (RhoA) induce inflammatory gene expression in astrocytes through the small GTPase responsive phospholipase Cε (PLCε). Using primary astrocytes from wild-type and PLCε knockout mice, we demonstrate that 1-h treatment with thrombin or S1P increases cyclooxygenase 2 (COX-2) mRNA levels ∼10-fold and that this requires PLCε. Interleukin-6 and interleukin-1β mRNA levels are also increased in a PLCε-dependent manner. Thrombin, lysophosphatidic acid, and S1P increase COX-2 protein expression through a mechanism involving RhoA, catalytically active PLCε, sustained activation of protein kinase D (PKD), and nuclear translocation of NF-κB. Endogenous ligands that are released from astrocytes in an in vitro wounding assay also induce COX-2 expression through a PLCε- and NF-κB-dependent pathway. Additionally, in vivo stab wound injury activates PKD and induces COX-2 and other inflammatory genes in WT but not in PLCε knockout mouse brain. Thus, PLCε links GPCRs to sustained PKD activation, providing a means for GPCR ligands that couple to RhoA to induce NF-κB signaling and promote neuroinflammation.
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Wang LD, Bi X, Song X, Pohl NM, Cheng Y, Zhou Y, Shears S, Ansong E, Xing M, Wang S, Xu XC, Huang P, Xu L, Wang L, Fan Z, Zhao X, Dong H, Meltzer SJ, Ding I, Yang W. A sequence variant in the phospholipase C epsilon C2 domain is associated with esophageal carcinoma and esophagitis. Mol Carcinog 2013; 52 Suppl 1:E80-6. [PMID: 23390063 DOI: 10.1002/mc.22016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 01/13/2013] [Accepted: 01/18/2013] [Indexed: 12/14/2022]
Abstract
A single-nucleotide polymorphism (rs2274223: A5780G:His1927Arg) in the phospholipase C epsilon gene (PLCϵ) was recently identified as a susceptibility locus for esophageal cancer in Chinese subjects. To determine the underlying mechanisms of PLCϵ and this SNP in esophageal carcinogenesis, we analyzed PLCϵ genotypes, expression, and their correlation in esophageal cancer cell lines, non-transformed esophageal cells, 58 esophageal squamous cell carcinomas and 10,614 non-cancer subjects from China. We found that the G allele (AG or GG) was associated with increased PLCϵ mRNA and protein expression in esophageal cancer tissues and in esophageal cancer cell lines. G allele was also associated with higher enzyme activity, which might be associated with increased protein expression. Quantitative analysis of the C2 domain sequences revealed that A:G allelic imbalance was strongly linked to esophageal malignancy. Moreover, the analysis of 10,614 non-cancer subjects demonstrated that the G allele was strongly associated with moderate to severe esophagitis in the subjects from the high-incidence areas of China (OR 6.03, 95% CI 1.59-22.9 in high-incidence area vs. OR 0.74, 95% CI 0.33-1.64 in low-incidence area; P = 0.008). In conclusion, the PLCϵ gene, particularly the 5780G allele, might play a pivotal role in esophageal carcinogenesis via upregulating PLCϵ mRNA, protein, and enzyme activity, and augmenting inflammatory process in esophageal epithelium. Thus, 5780G allele may constitute a promising biomarker for esophageal squamous cell carcinoma risk stratification, early detection, and progression prediction.
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Affiliation(s)
- Li-Dong Wang
- Department of Pathology, Xinxiang Medical University, Xinxiang, China; Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Xiang SY, Dusaban SS, Brown JH. Lysophospholipid receptor activation of RhoA and lipid signaling pathways. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:213-22. [PMID: 22986288 DOI: 10.1016/j.bbalip.2012.09.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Revised: 09/08/2012] [Accepted: 09/08/2012] [Indexed: 01/08/2023]
Abstract
The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) signal through G-protein coupled receptors (GPCRs) which couple to multiple G-proteins and their effectors. These GPCRs are quite efficacious in coupling to the Gα(12/13) family of G-proteins, which stimulate guanine nucleotide exchange factors (GEFs) for RhoA. Activated RhoA subsequently regulates downstream enzymes that transduce signals which affect the actin cytoskeleton, gene expression, cell proliferation and cell survival. Remarkably many of the enzymes regulated downstream of RhoA either use phospholipids as substrates (e.g. phospholipase D, phospholipase C-epsilon, PTEN, PI3 kinase) or are regulated by phospholipid products (e.g. protein kinase D, Akt). Thus lysophospholipids signal from outside of the cell and control phospholipid signaling processes within the cell that they target. Here we review evidence suggesting an integrative role for RhoA in responding to lysophospholipids upregulated in the pathophysiological environment, and in transducing this signal to cellular responses through effects on phospholipid regulatory or phospholipid regulated enzymes. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.
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Affiliation(s)
- Sunny Yang Xiang
- Department of Pharmacology, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
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Montresor A, Toffali L, Constantin G, Laudanna C. Chemokines and the signaling modules regulating integrin affinity. Front Immunol 2012; 3:127. [PMID: 22654882 PMCID: PMC3360201 DOI: 10.3389/fimmu.2012.00127] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/03/2012] [Indexed: 01/05/2023] Open
Abstract
Integrin-mediated adhesion is a general concept referring to a series of adhesive phenomena including tethering–rolling, affinity, valency, and binding stabilization altogether controlling cell avidity (adhesiveness) for the substrate. Arrest chemokines modulate each aspect of integrin activation, although integrin affinity regulation has been recognized as the prominent event in rapid leukocyte arrest induced by chemokines. A variety of inside-out and outside-in signaling mechanisms have been related to the process of integrin-mediated adhesion in different cellular models, but only few of them have been clearly contextualized to rapid integrin affinity modulation by arrest chemokines in primary leukocytes. Complex signaling processes triggered by arrest chemokines and controlling leukocyte integrin activation have been described for ras-related rap and for rho-related small GTPases. We summarize the role of rap and rho small GTPases in the regulation of rapid integrin affinity in primary leukocytes and provide a modular view of these pro-adhesive signaling events. A potential, albeit still speculative, mechanism of rho-mediated regulation of cytoskeletal proteins controlling the last step of integrin activation is also discussed. We also discuss data suggesting a functional integration between the rho- and rap-modules of integrin activation. Finally we examine the universality of signaling mechanisms regulating integrin triggering by arrest chemokines.
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Affiliation(s)
- Alessio Montresor
- Division of General Pathology, Department of Pathology, University of Verona Verona, Italy
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Abstract
Phospholipase C (PLC) family members constitute a family of diverse enzymes. Thirteen different family members have been cloned. These family members have unique structures that mediate diverse functions. Although PLC family members all appear to signal through the bi-products of cleaving phospholipids, it is clear that each family member, and at times each isoform, contributes to unique cellular functions. This chapter provides a review of the current literature. In addition, references have been provided for more in depth information regarding areas that are discussed. Ultimately, understanding the roles of the individual PLC enzymes, and their distinct cellular functions, will lead to a better understanding of the development of diseases and the maintenance of homeostasis.
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Abstract
The physiological effects of many extracellular neurotransmitters, hormones, growth factors, and other stimuli are mediated by receptor-promoted activation of phospholipase C (PLC) and consequential activation of inositol lipid signaling pathways. These signaling responses include the classically described conversion of phosphatidylinositol(4,5)P(2) to the Ca(2+)-mobilizing second messenger inositol(1,4,5)P(3) and the protein kinase C-activating second messenger diacylglycerol as well as alterations in membrane association or activity of many proteins that harbor phosphoinositide binding domains. The 13 mammalian PLCs elaborate a minimal catalytic core typified by PLC-d to confer multiple modes of regulation of lipase activity. PLC-b isozymes are activated by Gaq- and Gbg-subunits of heterotrimeric G proteins, and activation of PLC-g isozymes occurs through phosphorylation promoted by receptor and non-receptor tyrosine kinases. PLC-e and certain members of the PLC-b and PLC-g subclasses of isozymes are activated by direct binding of small G proteins of the Ras, Rho, and Rac subfamilies of GTPases. Recent high resolution three dimensional structures together with biochemical studies have illustrated that the X/Y linker region of the catalytic core mediates autoinhibition of most if not all PLC isozymes. Activation occurs as a consequence of removal of this autoinhibition.
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Zhang L, Malik S, Kelley GG, Kapiloff MS, Smrcka AV. Phospholipase C epsilon scaffolds to muscle-specific A kinase anchoring protein (mAKAPbeta) and integrates multiple hypertrophic stimuli in cardiac myocytes. J Biol Chem 2011; 286:23012-21. [PMID: 21550986 DOI: 10.1074/jbc.m111.231993] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To define a role for phospholipase Cε (PLCε) signaling in cardiac myocyte hypertrophic growth, PLCε protein was depleted from neonatal rat ventricular myocytes (NRVMs) using siRNA. NRVMs with PLCε depletion were stimulated with endothelin (ET-1), norepinephrine, insulin-like growth factor-1 (IGF-1), or isoproterenol and assessed for development of hypertrophy. PLCε depletion dramatically reduced hypertrophic growth and gene expression induced by all agonists tested. PLCε catalytic activity was required for hypertrophy development, yet PLCε depletion did not reduce global agonist-stimulated inositol phosphate production, suggesting a requirement for localized PLC activity. PLCε was found to be scaffolded to a muscle-specific A kinase anchoring protein (mAKAPβ) in heart and NRVMs, and mAKAPβ localizes to the nuclear envelope in NRVMs. PLCε-mAKAP interaction domains were defined and overexpressed to disrupt endogenous mAKAPβ-PLCε complexes in NRVMs, resulting in significantly reduced ET-1-dependent NRVM hypertrophy. We propose that PLCε integrates multiple upstream signaling pathways to generate local signals at the nucleus that regulate hypertrophy.
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Affiliation(s)
- Lianghui Zhang
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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Epac2-dependent rap1 activation and the control of islet insulin secretion by glucagon-like peptide-1. VITAMINS AND HORMONES 2011; 84:279-302. [PMID: 21094904 DOI: 10.1016/b978-0-12-381517-0.00010-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) binds its Class II G protein-coupled receptor to stimulate cyclic adenosine monophosphate (cAMP) production and to potentiate the glucose metabolism-dependent secretion of insulin from pancreatic β cells located within the islets of Langerhans. Prior clinical studies demonstrate that this cAMP-mediated action of GLP-1 to potentiate glucose-stimulated insulin secretion (GSIS) is of major therapeutic importance when evaluating the abilities of GLP-1 receptor (GLP-1R) agonists to lower levels of blood glucose in type 2 diabetic subjects. Surprisingly, recent in vitro studies of human or rodent islets of Langerhans provide evidence for the existence of a noncanonical mechanism of β cell cAMP signal transduction, one that may explain how GLP-1R agonists potentiate GSIS. What these studies demonstrate is that a cAMP-regulated guanine nucleotide exchange factor designated as Epac2 couples β cell cAMP production to the protein kinase A-independent stimulation of insulin exocytosis. Provided here is an overview of the Epac2 signal transduction system in β cells, with special emphasis on Rap1, a Ras-related GTPase that is an established target of Epac2.
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Phospholipase C-η1 is activated by intracellular Ca(2+) mobilization and enhances GPCRs/PLC/Ca(2+) signaling. Cell Signal 2011; 23:1022-9. [PMID: 21262355 DOI: 10.1016/j.cellsig.2011.01.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 01/14/2011] [Indexed: 11/20/2022]
Abstract
Phospholipase C-η1 (PLC-η1) is the most recently identified PLC isotype and is primarily expressed in nerve tissue. However, its functional role is unclear. In the present study, we report for the first time that PLC-η1 acts as a signal amplifier in G protein-coupled receptor (GPCR)-mediated PLC and Ca(2+) signaling. Short-hairpin RNA (shRNA)-mediated knockdown of endogenous PLC-η1 reduced lysophosphatidic acid (LPA)-, bradykinin (BK)-, and PACAP-induced PLC activity in mouse neuroblastoma Neuro2A (N2A) cells, indicating that PLC-η1 participates in GPCR-mediated PLC activation. Interestingly, ionomycin-induced PLC activity was significantly decreased by PLC-η1, but not PLC-η2, knockdown. In addition, we found that intracellular Ca(2+) source is enough for PLC-η1 activation. Furthermore, the IP(3) receptor inhibitor, 2-APB, inhibited LPA-induced PLC activity in control N2A cells, whereas this effect was not observed in PLC-η1 knockdown N2A cells, suggesting a pivotal role of intracellular Ca(2+) mobilization in PLC-η1 activation. Finally, we found that LPA-induced ERK1/2 phosphorylation and expression of the downstream target gene, krox-24, were significantly decreased by PLC-η1 knockdown, and these knockdown effects were abolished by 2-APB. Taken together, our results strongly suggest that PLC-η1 is activated via intracellular Ca(2+) mobilization from the ER, and therefore amplifies GPCR-mediated signaling.
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Spatial regulation of cyclic AMP-Epac1 signaling in cell adhesion by ERM proteins. Mol Cell Biol 2010; 30:5421-31. [PMID: 20855527 DOI: 10.1128/mcb.00463-10] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Epac1 is a guanine nucleotide exchange factor for the small G protein Rap and is involved in membrane-localized processes such as integrin-mediated cell adhesion and cell-cell junction formation. Cyclic AMP (cAMP) directly activates Epac1 by release of autoinhibition and in addition induces its translocation to the plasma membrane. Here, we show an additional mechanism of Epac1 recruitment, mediated by activated ezrin-radixin-moesin (ERM) proteins. Epac1 directly binds with its N-terminal 49 amino acids to ERM proteins in their open conformation. Receptor-induced activation of ERM proteins results in increased binding of Epac1 and consequently the clustered localization of Epac1 at the plasma membrane. Deletion of the N terminus of Epac1, as well as disruption of the Epac1-ERM interaction by an interfering radixin mutant or small interfering RNA (siRNA)-mediated depletion of the ERM proteins, impairs Epac1-mediated cell adhesion. We conclude that ERM proteins are involved in the spatial regulation of Epac1 and cooperate with cAMP- and Rap-mediated signaling to regulate adhesion to the extracellular matrix.
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Miyamoto S, Del Re DP, Xiang SY, Zhao X, Florholmen G, Brown JH. Revisited and revised: is RhoA always a villain in cardiac pathophysiology? J Cardiovasc Transl Res 2010; 3:330-43. [PMID: 20559774 DOI: 10.1007/s12265-010-9192-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 04/22/2010] [Indexed: 01/10/2023]
Abstract
The neonatal rat ventricular myocyte model of hypertrophy has provided tremendous insight with regard to signaling pathways regulating cardiac growth and gene expression. Many mediators thus discovered have been successfully extrapolated to the in vivo setting, as assessed using genetically engineered mice and physiological interventions. Studies in neonatal rat ventricular myocytes demonstrated a role for the small G-protein RhoA and its downstream effector kinase, Rho-associated coiled-coil containing protein kinase (ROCK), in agonist-mediated hypertrophy. Transgenic expression of RhoA in the heart does not phenocopy this response, however, nor does genetic deletion of ROCK prevent hypertrophy. Pharmacologic inhibition of ROCK has effects most consistent with roles for RhoA signaling in the development of heart failure or responses to ischemic damage. Whether signals elicited downstream of RhoA promote cell death or survival and are deleterious or salutary is, however, context and cell-type dependent. The concepts discussed above are reviewed, and the hypothesis that RhoA might protect cardiomyocytes from ischemia and other insults is presented. Novel RhoA targets including phospholipid regulated and regulating enzymes (Akt, PI kinases, phospholipase C, protein kinases C and D) and serum response element-mediated transcriptional responses are considered as possible pathways through which RhoA could affect cardiomyocyte survival.
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Affiliation(s)
- Shigeki Miyamoto
- Department of Pharmacology, University of California, 9500 Gilman Dr., La Jolla, San Diego, CA 92093-0636, USA
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Rebres RA, Moon C, Decamp D, Lin KM, Fraser ID, Milne SB, Roach TIA, Brown HA, Seaman WE. Clostridium difficile toxin B differentially affects GPCR-stimulated Ca2+ responses in macrophages: independent roles for Rho and PLA2. J Leukoc Biol 2010; 87:1041-57. [PMID: 20200401 DOI: 10.1189/jlb.1108708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Clostridium difficile toxins cause acute colitis by disrupting the enterocyte barrier and promoting inflammation. ToxB from C. difficile inactivates Rho family GTPases and causes release of cytokines and eicosanoids by macrophages. We studied the effects of ToxB on GPCR signaling in murine RAW264.7 macrophages and found that ToxB elevated Ca(2+) responses to Galphai-linked receptors, including the C5aR, but reduced responses to Galphaq-linked receptors, including the UDP receptors. Other Rho inhibitors also reduced UDP Ca(2+) responses, but they did not affect C5a responses, suggesting that ToxB inhibited UDP responses by inhibiting Rho but enhanced C5a responses by other mechanisms. By using PLCbeta isoform-deficient BMDM, we found that ToxB inhibited Ca(2+) signaling through PLCbeta4 but enhanced signaling through PLCbeta3. Effects of ToxB on GPCR Ca(2+) responses correlated with GPCR use of PLCbeta3 versus PLCbeta4. ToxB inhibited UDP Ca(2+) signaling without reducing InsP3 production or the sensitivity of cellular Ca(2+) stores to exogenous InsP3, suggesting that ToxB impairs UDP signaling at the level of InsP3/Ca(2+)coupling. In contrast, ToxB elevated InsP3 production by C5a, and the enhancement of Ca(2+) signaling by C5a was prevented by inhibition of PLA(2) or 5-LOX but not COX, implicating LTs but not prostanoids in the mechanism. In sum, ToxB has opposing, independently regulated effects on Ca(2+) signaling by different GPCR-linked PLCbeta isoforms in macrophages.
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Affiliation(s)
- Robert A Rebres
- Alliance for Cellular Signaling at Northern California Institute for Research and Education, VA Medical Center, San Francisco, California, USA.
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Valenti G, Mira A, Mastrofrancesco L, Lasorsa DR, Ranieri M, Svelto M. Differential Modulation of Intracellular Ca 2+ Responses Associated with Calcium-Sensing Receptor Activation in Renal Collecting Duct Cells. Cell Physiol Biochem 2010; 26:901-12. [DOI: 10.1159/000323999] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2010] [Indexed: 12/26/2022] Open
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Sossin WS, Abrams TW. Evolutionary conservation of the signaling proteins upstream of cyclic AMP-dependent kinase and protein kinase C in gastropod mollusks. BRAIN, BEHAVIOR AND EVOLUTION 2009; 74:191-205. [PMID: 20029183 DOI: 10.1159/000258666] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The protein kinase C (PKC) and the cAMP-dependent kinase (protein kinase A; PKA) pathways are known to play important roles in behavioral plasticity and learning in the nervous systems of a wide variety of species across phyla. We briefly review the members of the PKC and PKA family and focus on the evolution of the immediate upstream activators of PKC and PKA i.e., phospholipase C (PLC) and adenylyl cyclase (AC), and their conservation in gastropod mollusks, taking advantage of the recent assembly of the Aplysiacalifornica and Lottia gigantea genomes. The diversity of PLC and AC family members present in mollusks suggests a multitude of possible mechanisms to activate PKA and PKC; we briefly discuss the relevance of these pathways to the known physiological activation of these kinases in Aplysia neurons during plasticity and learning. These multiple mechanisms of activation provide the gastropod nervous system with tremendous flexibility for implementing neuromodulatory responses to both neuronal activity and extracellular signals.
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Affiliation(s)
- Wayne S Sossin
- Department of Neurology and Neurosurgery, McGill University, Montreal Neurological Institute, Montreal, Que., Canada.
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Yun S, Byun HY, Oh YS, Yang YR, Ryu SH, Suh PG. Protein kinase C-alpha negatively regulates EGF-induced PLC-epsilon activity through direct phosphorylation. ACTA ACUST UNITED AC 2009; 50:178-89. [PMID: 19948183 DOI: 10.1016/j.advenzreg.2009.10.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Sanguk Yun
- Department of Life Science and Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
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