1
|
Hammill AM, Boscolo E. Capillary malformations. J Clin Invest 2024; 134:e172842. [PMID: 38618955 PMCID: PMC11014659 DOI: 10.1172/jci172842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024] Open
Abstract
Capillary malformation (CM), or port wine birthmark, is a cutaneous congenital vascular anomaly that occurs in 0.1%-2% of newborns. Patients with a CM localized on the forehead have an increased risk of developing a neurocutaneous disorder called encephalotrigeminal angiomatosis or Sturge-Weber syndrome (SWS), with complications including seizure, developmental delay, glaucoma, and vision loss. In 2013, a groundbreaking study revealed causative activating somatic mutations in the gene (GNAQ) encoding guanine nucleotide-binding protein Q subunit α (Gαq) in CM and SWS patient tissues. In this Review, we discuss the disease phenotype, the causative GNAQ mutations, and their cellular origin. We also present the endothelial Gαq-related signaling pathways, the current animal models to study CM and its complications, and future options for therapeutic treatment. Further work remains to fully elucidate the cellular and molecular mechanisms underlying the formation and maintenance of the abnormal vessels.
Collapse
Affiliation(s)
- Adrienne M. Hammill
- Division of Hematology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Elisa Boscolo
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| |
Collapse
|
2
|
Miller WE, O'Connor CM. CMV-encoded GPCRs in infection, disease, and pathogenesis. Adv Virus Res 2024; 118:1-75. [PMID: 38461029 DOI: 10.1016/bs.aivir.2024.01.001] [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] [Indexed: 03/11/2024]
Abstract
G protein coupled receptors (GPCRs) are seven-transmembrane domain proteins that modulate cellular processes in response to external stimuli. These receptors represent the largest family of membrane proteins, and in mammals, their signaling regulates important physiological functions, such as vision, taste, and olfaction. Many organisms, including yeast, slime molds, and viruses encode GPCRs. Cytomegaloviruses (CMVs) are large, betaherpesviruses, that encode viral GPCRs (vGPCRs). Human CMV (HCMV) encodes four vGPCRs, including UL33, UL78, US27, and US28. Each of these vGPCRs, as well as their rodent and primate orthologues, have been investigated for their contributions to viral infection and disease. Herein, we discuss how the CMV vGPCRs function during lytic and latent infection, as well as our understanding of how they impact viral pathogenesis.
Collapse
Affiliation(s)
- William E Miller
- Department of Molecular and Cellular Bioscience, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christine M O'Connor
- Infection Biology, Sheikha Fatima bint Mubarak Global Center for Pathogen and Human Health Research, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States; Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, OH, United States; Case Comprehensive Cancer Center, Cleveland, OH, United States.
| |
Collapse
|
3
|
Pan D, Ladds G, Rahman KM, Pitchford SC. Exploring bias in platelet P2Y 1 signalling: Host defence versus haemostasis. Br J Pharmacol 2024; 181:580-592. [PMID: 37442808 PMCID: PMC10952580 DOI: 10.1111/bph.16191] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/21/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
Platelets are necessary for maintaining haemostasis. Separately, platelets are important for the propagation of inflammation during the host immune response against infection. The activation of platelets also causes inappropriate inflammation in various disease pathologies, often in the absence of changes to haemostasis. The separate functions of platelets during inflammation compared with haemostasis are therefore varied and this will be reflected in distinct pathways of activation. The activation of platelets by the nucleotide adenosine diphosphate (ADP) acting on P2Y1 and P2Y12 receptors is important for the development of platelet thrombi during haemostasis. However, P2Y1 stimulation of platelets is also important during the inflammatory response and paradoxically in scenarios where no changes to haemostasis and platelet aggregation occur. In these events, Rho-GTPase signalling, rather than the canonical phospholipase Cβ (PLCβ) signalling pathway, is necessary. We describe our current understanding of these differences, reflecting on recent advances in knowledge of P2Y1 structure, and the possibility of biased agonism occurring from activation via other endogenous nucleotides compared with ADP. Knowledge arising from these different pathways of P2Y1 stimulation of platelets during inflammation compared with haemostasis may help therapeutic control of platelet function during inflammation or infection, while preserving essential haemostasis. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.
Collapse
Affiliation(s)
- Dingxin Pan
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical ScienceKing's College LondonLondonUK
| | - Graham Ladds
- Department of PharmacologyUniversity of CambridgeCambridgeUK
| | - Khondaker Miraz Rahman
- Chemical Biology Group, Institute of Pharmaceutical ScienceKing's College LondonLondonUK
| | - Simon C. Pitchford
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical ScienceKing's College LondonLondonUK
| |
Collapse
|
4
|
Cevheroğlu O, Demir N, Kesici MS, Özçubukçu S, Son ÇD. Downstream signalling of the disease-associated mutations on GPR56/ADGRG1. Basic Clin Pharmacol Toxicol 2023; 133:331-341. [PMID: 37056198 DOI: 10.1111/bcpt.13873] [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: 01/10/2023] [Revised: 03/02/2023] [Accepted: 04/01/2023] [Indexed: 04/15/2023]
Abstract
GPR56/ADGRG1 is an adhesion G protein-coupled receptor (GPCR) and mutations on this receptor cause cortical malformation due to the over-migration of neural progenitor cells on brain surface. At pial surface, GPR56 interacts with collagen III, induces Rho-dependent activation through Gα12/13 and inhibits the neuronal migration. In human glioma cells, GPR56 inhibits cell migration through Gαq/11 -dependent Rho pathway. GPR56-tetraspanin complex is known to couple Gαq/11 . GPR56 is an aGPCR that couples with various G proteins and signals through different downstream pathways. In this study, bilateral frontoparietal polymicrogyria (BFPP) mutants disrupting GPR56 function but remaining to be expressed on plasma membrane were used to study receptor signalling through Gα12 , Gα13 and Gα11 with BRET biosensors. GPR56 showed coupling with all three G proteins and activated heterotrimeric G protein signalling upon stimulation with Stachel peptide. However, BFPP mutants showed different signalling defects for each G protein indicative of distinct activation and signalling properties of GPR56 for Gα12 , Gα13 or Gα11 . β-arrestin recruitment was also investigated following the activation of GPR56 with Stachel peptide using BRET biosensors. N-terminally truncated GPR56 showed enhanced β-arrestin recruitment; however, neither wild-type receptor nor BFPP mutants gave any measurable recruitment upon Stachel stimulation, pointing different activation mechanisms for β-arrestin involvement.
Collapse
Affiliation(s)
| | - Nil Demir
- Department of Biological Sciences, Middle East Technical University, Ankara, Türkiye
| | | | - Salih Özçubukçu
- Department of Chemistry, Middle East Technical University, Ankara, Türkiye
| | - Çağdaş D Son
- Department of Biological Sciences, Middle East Technical University, Ankara, Türkiye
| |
Collapse
|
5
|
Olson AC, Butt AM, Christie NTM, Shelar A, Koelle MR. Multiple Subthreshold GPCR Signals Combined by the G-Proteins Gα q and Gα s Activate the Caenorhabditis elegans Egg-Laying Muscles. J Neurosci 2023; 43:3789-3806. [PMID: 37055179 PMCID: PMC10219013 DOI: 10.1523/jneurosci.2301-22.2023] [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: 12/14/2022] [Revised: 03/21/2023] [Accepted: 04/07/2023] [Indexed: 04/15/2023] Open
Abstract
Individual neurons or muscle cells express many G-protein-coupled receptors (GPCRs) for neurotransmitters and neuropeptides, yet it remains unclear how cells integrate multiple GPCR signals that all must activate the same few G-proteins. We analyzed this issue in the Caenorhabditis elegans egg-laying system, where multiple GPCRs on muscle cells promote contraction and egg laying. We genetically manipulated individual GPCRs and G-proteins specifically in these muscle cells within intact animals and then measured egg laying and muscle calcium activity. Two serotonin GPCRs on the muscle cells, Gαq-coupled SER-1 and Gαs-coupled SER-7, together promote egg laying in response to serotonin. We found that signals produced by either SER-1/Gαq or SER-7/Gαs alone have little effect, but these two subthreshold signals combine to activate egg laying. We then transgenically expressed natural or designer GPCRs in the muscle cells and found that their subthreshold signals can also combine to induce muscle activity. However, artificially inducing strong signaling through just one of these GPCRs can be sufficient to induce egg laying. Knocking down Gαq and Gαs in the egg-laying muscle cells induced egg-laying defects that were stronger than those of a SER-1/SER-7 double knockout, indicating that additional endogenous GPCRs also activate the muscle cells. These results show that in the egg-laying muscles multiple GPCRs for serotonin and other signals each produce weak effects that individually do not result in strong behavioral outcomes. However, they combine to produce sufficient levels of Gαq and Gαs signaling to promote muscle activity and egg laying.SIGNIFICANCE STATEMENT How can neurons and other cells gather multiple independent pieces of information from the soup of chemical signals in their environment and compute an appropriate response? Most cells express >20 GPCRs that each receive one signal and transmit that information through three main types of G-proteins. We analyzed how this machinery generates responses by studying the egg-laying system of C. elegans, where serotonin and multiple other signals act through GPCRs on the egg-laying muscles to promote muscle activity and egg laying. We found that individual GPCRs within an intact animal each generate effects too weak to activate egg laying. However, combined signaling from multiple GPCR types reaches a threshold capable of activating the muscle cells.
Collapse
Affiliation(s)
- Andrew C Olson
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Allison M Butt
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Nakeirah T M Christie
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Ashish Shelar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Michael R Koelle
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| |
Collapse
|
6
|
Sudi S, Thomas FM, Daud SK, Ag Daud DM, Sunggip C. The Pleiotropic Role of Extracellular ATP in Myocardial Remodelling. Molecules 2023; 28:molecules28052102. [PMID: 36903347 PMCID: PMC10004151 DOI: 10.3390/molecules28052102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/17/2023] [Accepted: 02/18/2023] [Indexed: 03/12/2023] Open
Abstract
Myocardial remodelling is a molecular, cellular, and interstitial adaptation of the heart in response to altered environmental demands. The heart undergoes reversible physiological remodelling in response to changes in mechanical loading or irreversible pathological remodelling induced by neurohumoral factors and chronic stress, leading to heart failure. Adenosine triphosphate (ATP) is one of the potent mediators in cardiovascular signalling that act on the ligand-gated (P2X) and G-protein-coupled (P2Y) purinoceptors via the autocrine or paracrine manners. These activations mediate numerous intracellular communications by modulating the production of other messengers, including calcium, growth factors, cytokines, and nitric oxide. ATP is known to play a pleiotropic role in cardiovascular pathophysiology, making it a reliable biomarker for cardiac protection. This review outlines the sources of ATP released under physiological and pathological stress and its cell-specific mechanism of action. We further highlight a series of cardiovascular cell-to-cell communications of extracellular ATP signalling cascades in cardiac remodelling, which can be seen in hypertension, ischemia/reperfusion injury, fibrosis, hypertrophy, and atrophy. Finally, we summarize current pharmacological intervention using the ATP network as a target for cardiac protection. A better understanding of ATP communication in myocardial remodelling could be worthwhile for future drug development and repurposing and the management of cardiovascular diseases.
Collapse
Affiliation(s)
- Suhaini Sudi
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Fiona Macniesia Thomas
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Siti Kadzirah Daud
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Dayang Maryama Ag Daud
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
- Health through Exercise and Active Living (HEAL) Research Unit, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Caroline Sunggip
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
- Correspondence:
| |
Collapse
|
7
|
A current overview of RhoA, RhoB, and RhoC functions in vascular biology and pathology. Biochem Pharmacol 2022; 206:115321. [DOI: 10.1016/j.bcp.2022.115321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/24/2022]
|
8
|
Kurose H. [Biased Signaling through G Protein-coupled Receptors]. YAKUGAKU ZASSHI 2022; 142:1091-1101. [PMID: 36184444 DOI: 10.1248/yakushi.22-00087] [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: 11/22/2022]
Abstract
It is well-established that G protein-coupled receptors (GPCRs) transduce signals into cells using G proteins as intermediary molecules. β-Arrestins are molecules involved in regulating GPCRs; however, it has recently been reported that β-arrestins can also mediate signaling through GPCRs. Signaling through G proteins or β-arrestins can be activated selectively using specific agonists; of the latter, those that can selectively activate either G proteins or β-arrestins are called biased agonists. The clinical use of biased agonists could potentially induce fewer side effects. However, partial agonists can also explain the mechanism of G protein-biased agonists; thus, appropriate assay systems must be considered. Endogenous agonists are known to bind to orthosteric and allosteric sites in the agonist binding site, and the allosteric site is associated with the activity of biased agonists. This current review presents a detailed discussion of biased agonists.
Collapse
Affiliation(s)
- Hitoshi Kurose
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University
| |
Collapse
|
9
|
Doan TNA, Bianco-Miotto T, Parry L, Winter M. The role of angiotensin II and relaxin in vascular adaptation to pregnancy. Reproduction 2022; 164:R87-R99. [PMID: 36018774 DOI: 10.1530/rep-21-0428] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/26/2022] [Indexed: 11/08/2022]
Abstract
In brief There is a pregnancy-induced vasodilation of blood vessels, which is known to have a protective effect on cardiovascular function and can be maintained postpartum. This review outlines the cardiovascular changes that occur in a healthy human and rodent pregnancy, as well as different pathways that are activated by angiotensin II and relaxin that result in blood vessel dilation. Abstract During pregnancy, systemic and uteroplacental blood flow increase to ensure an adequate blood supply that carries oxygen and nutrients from the mother to the fetus. This results in changes to the function of the maternal cardiovascular system. There is also a pregnancy-induced vasodilation of blood vessels, which is known to have a protective effect on cardiovascular health/function. Additionally, there is evidence that the effects of maternal vascular vasodilation are maintained post-partum, which may reduce the risk of developing high blood pressure in the next pregnancy and reduce cardiovascular risk later in life. At both non-pregnant and pregnant stages, vascular endothelial cells produce a number of vasodilators and vasoconstrictors, which transduce signals to the contractile vascular smooth muscle cells to control the dilation and constriction of blood vessels. These vascular cells are also targets of other vasoactive factors, including angiotensin II (Ang II) and relaxin. The binding of Ang II to its receptors activates different pathways to regulate the blood vessel vasoconstriction/vasodilation, and relaxin can interact with some of these pathways to induce vasodilation. Based on the available literature, this review outlines the cardiovascular changes that occur in a healthy human pregnancy, supplemented by studies in rodents. A specific focus is placed on vasodilation of blood vessels during pregnancy; the role of endothelial cells and endothelium-derived vasodilators will also be discussed. Additionally, different pathways that are activated by Ang II and relaxin that result in blood vessel dilation will also be reviewed.
Collapse
Affiliation(s)
- Thu Ngoc Anh Doan
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Tina Bianco-Miotto
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Laura Parry
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Marnie Winter
- Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
| |
Collapse
|
10
|
Navarro-Lérida I, Aragay AM, Asensio A, Ribas C. Gq Signaling in Autophagy Control: Between Chemical and Mechanical Cues. Antioxidants (Basel) 2022; 11:1599. [PMID: 36009317 PMCID: PMC9405508 DOI: 10.3390/antiox11081599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/14/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
All processes in human physiology relies on homeostatic mechanisms which require the activation of specific control circuits to adapt the changes imposed by external stimuli. One of the critical modulators of homeostatic balance is autophagy, a catabolic process that is responsible of the destruction of long-lived proteins and organelles through a lysosome degradative pathway. Identification of the mechanism underlying autophagic flux is considered of great importance as both protective and detrimental functions are linked with deregulated autophagy. At the mechanistic and regulatory levels, autophagy is activated in response to diverse stress conditions (food deprivation, hyperthermia and hypoxia), even a novel perspective highlight the potential role of physical forces in autophagy modulation. To understand the crosstalk between all these controlling mechanisms could give us new clues about the specific contribution of autophagy in a wide range of diseases including vascular disorders, inflammation and cancer. Of note, any homeostatic control critically depends in at least two additional and poorly studied interdependent components: a receptor and its downstream effectors. Addressing the selective receptors involved in autophagy regulation is an open question and represents a new area of research in this field. G-protein coupled receptors (GPCRs) represent one of the largest and druggable targets membrane receptor protein superfamily. By exerting their action through G proteins, GPCRs play fundamental roles in the control of cellular homeostasis. Novel studies have shown Gαq, a subunit of heterotrimeric G proteins, as a core modulator of mTORC1 and autophagy, suggesting a fundamental contribution of Gαq-coupled GPCRs mechanisms in the control of this homeostatic feedback loop. To address how GPCR-G proteins machinery integrates the response to different stresses including oxidative conditions and mechanical stimuli, could provide deeper insight into new signaling pathways and open potential and novel therapeutic strategies in the modulation of different pathological conditions.
Collapse
Affiliation(s)
- Inmaculada Navarro-Lérida
- Molecular Biology Department and Center of Molecular Biology “Severo Ochoa”, CSIC-UAM, 28049 Madrid, Spain
- Health Research Institute “La Princesa”, 28006 Madrid, Spain
- Center for Biomedical Research in Cardiovascular Diseases Network (CIBERCV), ISCIII, 28029 Madrid, Spain
- Connexion Cancer-CSIC, 28006 Madrid, Spain
| | - Anna M. Aragay
- Department of Biology, Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), 08028 Barcelona, Spain
| | - Alejandro Asensio
- Molecular Biology Department and Center of Molecular Biology “Severo Ochoa”, CSIC-UAM, 28049 Madrid, Spain
- Health Research Institute “La Princesa”, 28006 Madrid, Spain
- Center for Biomedical Research in Cardiovascular Diseases Network (CIBERCV), ISCIII, 28029 Madrid, Spain
- Connexion Cancer-CSIC, 28006 Madrid, Spain
| | - Catalina Ribas
- Molecular Biology Department and Center of Molecular Biology “Severo Ochoa”, CSIC-UAM, 28049 Madrid, Spain
- Health Research Institute “La Princesa”, 28006 Madrid, Spain
- Center for Biomedical Research in Cardiovascular Diseases Network (CIBERCV), ISCIII, 28029 Madrid, Spain
- Connexion Cancer-CSIC, 28006 Madrid, Spain
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Abstract
Agonists are defined as the ligands that activate intracellular signaling and evoke cellular responses. Synthetic and endogenous agonists should bind specific amino acids to activate G protein-coupled receptor (GPCR). Agonists that induce maximal responses are full agonists. Partial agonists cannot induce full responses unlike full agonists. In definition, antagonists inhibit agonist-stimulated responses by binding to orthosteric or allosteric sites. Antagonists modulate agonist-induced responses and are often related with inverse agonist activity. However, the relationship between antagonists and partial agonists is complex. An antagonist behaves as a partial agonist when the constitutive activity of the GPCR is high. In contrast, a partial agonist with very weak intrinsic activity may be classified as an antagonist. Thus, antagonisms of the compounds are influenced by constitutive activity of GPCRs, intrinsic activity and differences in the binding sites of GPCRs. Since "antagonism" has been revealed to have multiple aspects and more complex than previously thought, it may be difficult to classify each compound as simply "agonist" or "antagonist" as before. In this review, we discuss the recent findings and perspectives on the pharmacology of GPCR-binding antagonists, inverse agonists, and signaling.
Collapse
Affiliation(s)
- Hitoshi Kurose
- Department of Physiology, Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Sang Geon Kim
- Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University-Seoul
| |
Collapse
|
13
|
RGS3L allows for an M 2 muscarinic receptor-mediated RhoA-dependent inotropy in cardiomyocytes. Basic Res Cardiol 2022; 117:8. [PMID: 35230541 PMCID: PMC8888479 DOI: 10.1007/s00395-022-00915-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 01/31/2023]
Abstract
The role and outcome of the muscarinic M2 acetylcholine receptor (M2R) signaling in healthy and diseased cardiomyocytes is still a matter of debate. Here, we report that the long isoform of the regulator of G protein signaling 3 (RGS3L) functions as a switch in the muscarinic signaling, most likely of the M2R, in primary cardiomyocytes. High levels of RGS3L, as found in heart failure, redirect the Gi-mediated Rac1 activation into a Gi-mediated RhoA/ROCK activation. Functionally, this switch resulted in a reduced production of reactive oxygen species (- 50%) in cardiomyocytes and an inotropic response (+ 18%) in transduced engineered heart tissues. Importantly, we could show that an adeno-associated virus 9-mediated overexpression of RGS3L in rats in vivo, increased the contractility of ventricular strips by maximally about twofold. Mechanistically, we demonstrate that this switch is mediated by a complex formation of RGS3L with the GTPase-activating protein p190RhoGAP, which balances the activity of RhoA and Rac1 by altering its substrate preference in cardiomyocytes. Enhancement of this complex formation could open new possibilities in the regulation of the contractility of the diseased heart.
Collapse
|
14
|
Abstract
Cell migration, a crucial step in numerous biological processes, is tightly regulated in space and time. Cells employ Rho GTPases, primarily Rho, Rac, and Cdc42, to regulate their motility. Like other small G proteins, Rho GTPases function as biomolecular switches in regulating cell migration by operating between GDP bound 'OFF' and GTP bound 'ON' states. Guanine nucleotide exchange factors (GEFs) catalyse the shuttling of GTPases from OFF to ON state. G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors that are involved in many signalling phenomena including cell survival and cell migration events. In this review, we summarize signalling mechanisms, involving GPCRs, leading to the activation of RhoGEFs. GPCRs exhibit diverse GEF activation modes that include the interaction of heterotrimeric G protein subunits with different domains of GEFs, phosphorylation, protein-protein interaction, protein-lipid interaction, and/or a combination of these processes.
Collapse
Affiliation(s)
- Aishwarya Omble
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Kiran Kulkarni
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India,CONTACT Kiran Kulkarni Academy of Scientific and Innovative Research (Acsir), Ghaziabad 201002, India
| |
Collapse
|
15
|
Jelinek V, Mösslein N, Bünemann M. Structures in G proteins important for subtype selective receptor binding and subsequent activation. Commun Biol 2021; 4:635. [PMID: 34045638 PMCID: PMC8160216 DOI: 10.1038/s42003-021-02143-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 04/26/2021] [Indexed: 11/09/2022] Open
Abstract
G protein-coupled receptors (GPCRs) selectively couple to specific heterotrimeric G proteins comprised of four subfamilies in order to induce appropriate physiological responses. However, structural determinants in Gα subunits responsible for selective recognition by approximately 800 human GPCRs have remained elusive. Here, we directly compare the influence of subtype-specific Gα structures on the stability of GPCR-G protein complexes and the activation by two Gq-coupled receptors. We used FRET-assays designed to distinguish multiple Go and Gq-based Gα chimeras in their ability to be selectively bound and activated by muscarinic M3 and histaminic H1 receptors. We identify the N-terminus including the αN/β1-hinge, the β2/β3-loop and the α5 helix of Gα to be key selectivity determinants which differ in their impact on selective binding to GPCRs and subsequent activation depending on the specific receptor. Altogether, these findings provide new insights into the molecular basis of G protein-coupling selectivity even beyond the Gα C-terminus.
Collapse
Affiliation(s)
- Volker Jelinek
- Institute of Pharmacology and Clinical Pharmacy, Philipps-University Marburg, Marburg, Germany
| | - Nadja Mösslein
- Institute of Pharmacology and Clinical Pharmacy, Philipps-University Marburg, Marburg, Germany
| | - Moritz Bünemann
- Institute of Pharmacology and Clinical Pharmacy, Philipps-University Marburg, Marburg, Germany.
| |
Collapse
|
16
|
Kilian LS, Voran J, Frank D, Rangrez AY. RhoA: a dubious molecule in cardiac pathophysiology. J Biomed Sci 2021; 28:33. [PMID: 33906663 PMCID: PMC8080415 DOI: 10.1186/s12929-021-00730-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/23/2021] [Indexed: 02/08/2023] Open
Abstract
The Ras homolog gene family member A (RhoA) is the founding member of Rho GTPase superfamily originally studied in cancer cells where it was found to stimulate cell cycle progression and migration. RhoA acts as a master switch control of actin dynamics essential for maintaining cytoarchitecture of a cell. In the last two decades, however, RhoA has been coined and increasingly investigated as an essential molecule involved in signal transduction and regulation of gene transcription thereby affecting physiological functions such as cell division, survival, proliferation and migration. RhoA has been shown to play an important role in cardiac remodeling and cardiomyopathies; underlying mechanisms are however still poorly understood since the results derived from in vitro and in vivo experiments are still inconclusive. Interestingly its role in the development of cardiomyopathies or heart failure remains largely unclear due to anomalies in the current data available that indicate both cardioprotective and deleterious effects. In this review, we aimed to outline the molecular mechanisms of RhoA activation, to give an overview of its regulators, and the probable mechanisms of signal transduction leading to RhoA activation and induction of downstream effector pathways and corresponding cellular responses in cardiac (patho)physiology. Furthermore, we discuss the existing studies assessing the presented results and shedding light on the often-ambiguous data. Overall, we provide an update of the molecular, physiological and pathological functions of RhoA in the heart and its potential in cardiac therapeutics.
Collapse
Affiliation(s)
- Lucia Sophie Kilian
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, Rosalind-Franklin Str. 12, 24105, Kiel, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105, Kiel, Germany
| | - Jakob Voran
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, Rosalind-Franklin Str. 12, 24105, Kiel, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105, Kiel, Germany
| | - Derk Frank
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, Rosalind-Franklin Str. 12, 24105, Kiel, Germany. .,DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105, Kiel, Germany.
| | - Ashraf Yusuf Rangrez
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, Rosalind-Franklin Str. 12, 24105, Kiel, Germany. .,DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105, Kiel, Germany. .,Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
| |
Collapse
|
17
|
Yang C, Wang Y, Hardy P. Emerging roles of microRNAs and their implications in uveal melanoma. Cell Mol Life Sci 2021; 78:545-559. [PMID: 32783068 PMCID: PMC11072399 DOI: 10.1007/s00018-020-03612-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/14/2020] [Accepted: 07/30/2020] [Indexed: 12/19/2022]
Abstract
Uveal melanoma (UM) is the most common intraocular malignant tumor in adults with an extremely high mortality rate. Genetic and epigenetic dysregulation contribute to the development of UM. Recent discoveries have revealed dysregulation of the expression levels of microRNAs (miRNAs) as one of the epigenetic mechanisms underlying UM tumorigenesis. Based on their roles, miRNAs are characterized as either oncogenic or tumor suppressive. This review focuses on the roles of miRNAs in UM tumorigenesis, diagnosis, and prognosis, as well as their therapeutic potentials. Particularly, the actions of collective miRNAs are summarized with respect to their involvement in major, aberrant signaling pathways that are implicated in the development and progression of UM. Elucidation of the underlying functional mechanisms and biological aspects of miRNA dysregulation in UM is invaluable in the development of miRNA-based therapeutics, which may be used in combination with conventional treatments to improve therapeutic outcomes. In addition, the expression levels of some miRNAs are correlated with UM initiation and progression and, therefore, may be used as biomarkers for diagnosis and prognosis.
Collapse
Affiliation(s)
- Chun Yang
- Departments of Pediatrics, Pharmacology, and Physiology, University of Montréal, Montréal, Québec, H3T 1C5, Canada
| | - Yuejiao Wang
- Department of Gynecological Endocrinology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Pierre Hardy
- Departments of Pediatrics, Pharmacology, and Physiology, University of Montréal, Montréal, Québec, H3T 1C5, Canada.
- Research Center of CHU Sainte-Justine, 3175 Côte-Sainte-Catherine, Room 2.17.004, Montréal, Québec, H3T 1C5, Canada.
| |
Collapse
|
18
|
Li Y, Shi J, Yang J, Ge S, Zhang J, Jia R, Fan X. Uveal melanoma: progress in molecular biology and therapeutics. Ther Adv Med Oncol 2020; 12:1758835920965852. [PMID: 33149769 PMCID: PMC7586035 DOI: 10.1177/1758835920965852] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 09/16/2020] [Indexed: 12/15/2022] Open
Abstract
Uveal melanoma (UM) is the most common intraocular malignancy in adults. So far, no systemic therapy or standard treatment exists to reduce the risk of metastasis and improve overall survival of patients. With the increased knowledge regarding the molecular pathways that underlie the oncogenesis of UM, it is expected that novel therapeutic approaches will be available to conquer this disease. This review provides a summary of the current knowledge of, and progress made in understanding, the pathogenesis, genetic mutations, epigenetics, and immunology of UM. With the advent of the omics era, multi-dimensional big data are publicly available, providing an innovation platform to develop effective targeted and personalized therapeutics for UM patients. Indeed, recently, a great number of therapies have been reported specifically for UM caused by oncogenic mutations, as well as other etiologies. In this review, special attention is directed to advancements in targeted therapies. In particular, we discuss the possibilities of targeting: GNAQ/GNA11, PLCβ, and CYSLTR2 mutants; regulators of G-protein signaling; the secondary messenger adenosine diphosphate (ADP)-ribosylation factor 6 (ARF6); downstream pathways, such as those involving mitogen-activated protein kinase/MEK/extracellular signal-related kinase, protein kinase C (PKC), phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (mTOR), Trio/Rho/Rac/Yes-associated protein, and inactivated BAP1; and immune-checkpoint proteins cytotoxic T-lymphocyte antigen 4 and programmed cell-death protein 1/programmed cell-death ligand 1. Furthermore, we conducted a survey of completed and ongoing clinical trials applying targeted and immune therapies for UM. Although drug combination therapy based on the signaling pathways involved in UM has made great progress, targeted therapy is still an unmet medical need.
Collapse
Affiliation(s)
- Yongyun Li
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Jiahao Shi
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Jie Yang
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Shengfang Ge
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Jianming Zhang
- National Research Center for Translational Medicine, Shanghai State Key Laboratory of Medical Genomics, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Renbing Jia
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Huangpu District, Shanghai 200001, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, 200001, China
| | - Xianqun Fan
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Huangpu District, Shanghai 200001, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, 833 Zhizaoju Road, Huangpu District, Shanghai 200001, China
| |
Collapse
|
19
|
Blankenbach KV, Claas RF, Aster NJ, Spohner AK, Trautmann S, Ferreirós N, Black JL, Tesmer JJG, Offermanns S, Wieland T, Meyer zu Heringdorf D. Dissecting G q/11-Mediated Plasma Membrane Translocation of Sphingosine Kinase-1. Cells 2020; 9:cells9102201. [PMID: 33003441 PMCID: PMC7599897 DOI: 10.3390/cells9102201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/25/2020] [Accepted: 09/27/2020] [Indexed: 12/24/2022] Open
Abstract
Diverse extracellular signals induce plasma membrane translocation of sphingosine kinase-1 (SphK1), thereby enabling inside-out signaling of sphingosine-1-phosphate. We have shown before that Gq-coupled receptors and constitutively active Gαq/11 specifically induced a rapid and long-lasting SphK1 translocation, independently of canonical Gq/phospholipase C (PLC) signaling. Here, we further characterized Gq/11 regulation of SphK1. SphK1 translocation by the M3 receptor in HEK-293 cells was delayed by expression of catalytically inactive G-protein-coupled receptor kinase-2, p63Rho guanine nucleotide exchange factor (p63RhoGEF), and catalytically inactive PLCβ3, but accelerated by wild-type PLCβ3 and the PLCδ PH domain. Both wild-type SphK1 and catalytically inactive SphK1-G82D reduced M3 receptor-stimulated inositol phosphate production, suggesting competition at Gαq. Embryonic fibroblasts from Gαq/11 double-deficient mice were used to show that amino acids W263 and T257 of Gαq, which interact directly with PLCβ3 and p63RhoGEF, were important for bradykinin B2 receptor-induced SphK1 translocation. Finally, an AIXXPL motif was identified in vertebrate SphK1 (positions 100–105 in human SphK1a), which resembles the Gαq binding motif, ALXXPI, in PLCβ and p63RhoGEF. After M3 receptor stimulation, SphK1-A100E-I101E and SphK1-P104A-L105A translocated in only 25% and 56% of cells, respectively, and translocation efficiency was significantly reduced. The data suggest that both the AIXXPL motif and currently unknown consequences of PLCβ/PLCδ(PH) expression are important for regulation of SphK1 by Gq/11.
Collapse
Affiliation(s)
- Kira Vanessa Blankenbach
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Ralf Frederik Claas
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Natalie Judith Aster
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Anna Katharina Spohner
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Sandra Trautmann
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (N.F.)
| | - Nerea Ferreirós
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (N.F.)
| | - Justin L. Black
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA;
| | - John J. G. Tesmer
- Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University West Lafayette, West Lafayette, IN 47907-2054, USA;
| | - Stefan Offermanns
- Abteilung für Pharmakologie, Max-Planck-Institut für Herz- und Lungenforschung, 61231 Bad Nauheim, Germany;
| | - Thomas Wieland
- Experimentelle Pharmakologie Mannheim, European Center for Angioscience, Universität Heidelberg, 68167 Mannheim, Germany;
| | - Dagmar Meyer zu Heringdorf
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
- Correspondence: ; Tel.: +49-69-6301-3906
| |
Collapse
|
20
|
Nunes KP, Webb RC. New insights into RhoA/Rho-kinase signaling: a key regulator of vascular contraction. Small GTPases 2020; 12:458-469. [PMID: 32970516 DOI: 10.1080/21541248.2020.1822721] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
While Rho-signalling controlling vascular contraction is a canonical mechanism, with the modern approaches used in research, we are advancing our understanding and details into this pathway are often uncovered. RhoA-mediated Rho-kinase is the major regulator of vascular smooth muscle cells and a key player manoeuvring other functions in these cells. The discovery of new interactions, such as oxidative stress and hydrogen sulphide with Rho signalling are emerging addition not only in the physiology of the smooth muscle, but especially in the pathophysiology of vascular diseases. Likewise, the interplay between ageing and Rho-kinase in the vasculature has been recently considered. Importantly, in smooth muscle contraction, this pathway may also be affected by sex hormones, and consequently, sex-differences. This review provides an overview of Rho signalling mediating vascular contraction and focuses on recent topics discussed in the literature affecting this pathway such as ageing, sex differences and oxidative stress.
Collapse
Affiliation(s)
- Kenia Pedrosa Nunes
- Laboratory of Vascular Physiology, Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL, USA
| | - R Clinton Webb
- Department of Cell Biology and Anatomy, University of South Carolina, Columbia, SC, USA
| |
Collapse
|
21
|
The constitutive activity of the viral-encoded G protein-coupled receptor US28 supports a complex signalling network contributing to cancer development. Biochem Soc Trans 2020; 48:1493-1504. [PMID: 32779712 PMCID: PMC7458396 DOI: 10.1042/bst20190988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/05/2020] [Accepted: 07/14/2020] [Indexed: 12/23/2022]
Abstract
US28 is a viral G protein-coupled receptor (GPCR) encoded by the human cytomegalovirus (HCMV). This receptor, expressed both during lytic replication and viral latency, is required for latency. US28 is binding to a wide variety of chemokines but also exhibits a particularly high constitutive activity robustly modulating a wide network of cellular pathways altering the host cell environment to benefit HCMV infection. Several studies suggest that US28-mediated signalling may contribute to cancer progression. In this review, we discuss the unique structural characteristics that US28 acquired through evolution that confer a robust constitutive activity to this viral receptor. We also describe the wide downstream signalling network activated by this constitutive activation of US28 and discuss how these signalling pathways may promote and support important cellular aspects of cancer.
Collapse
|
22
|
Girard M, Dagenais Bellefeuille S, Eiselt É, Brouillette R, Placet M, Arguin G, Longpré JM, Sarret P, Gendron FP. The P2Y 6 receptor signals through Gα q /Ca 2+ /PKCα and Gα 13 /ROCK pathways to drive the formation of membrane protrusions and dictate cell migration. J Cell Physiol 2020; 235:9676-9690. [PMID: 32420639 DOI: 10.1002/jcp.29779] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/09/2020] [Accepted: 05/01/2020] [Indexed: 12/14/2022]
Abstract
Cell migration is a ubiquitous process necessary to maintain and restore tissue functions. However, in cancer, cell migration leads to metastasis development and thus worsens the prognosis. Although the mechanism of cell migration is well understood, the identification of new targets modulating cell migration and deciphering their signaling events could lead to new therapies to restore tissue functions in diseases, such as inflammatory bowel disease, or to block metastatic development in different forms of cancer. Previous research has identified the G-protein-coupled P2Y6 receptor as an innovative target that could dictate cell migration under normal and pathological conditions. Surprisingly, there is little information on the cellular events triggered by activated P2Y6 during cell migration. Here, we demonstrated that P2Y6 activation stimulated A549 human lung cancer cells and Caco-2 colorectal cancer cell migration. Activated P2Y6 increased the number of filopodia and focal adhesions; two migratory structures required for cell migration. The generation of these structures involved Gαq /calcium/protein kinases C (PKC) and Gα13 /RHO-associated protein kinase-dependent pathways that dictate the formation of the migratory structures. These pathways led to the stabilization of the actin cytoskeleton through a PKC-dependent phosphorylation of cofilin. These results support the idea that the P2Y6 receptor represents a target of interest to modulate cell migration and revealed an intricate dialogue between two Gα-protein signaling pathways.
Collapse
Affiliation(s)
- Mélissa Girard
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Steve Dagenais Bellefeuille
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Émilie Eiselt
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Rebecca Brouillette
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Morgane Placet
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Guillaume Arguin
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jean-Michel Longpré
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Philippe Sarret
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Fernand-Pierre Gendron
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| |
Collapse
|
23
|
Liu CL, Cheng SP, Chen MJ, Lin CH, Chen SN, Kuo YH, Chang YC. Quinolinate Phosphoribosyltransferase Promotes Invasiveness of Breast Cancer Through Myosin Light Chain Phosphorylation. Front Endocrinol (Lausanne) 2020; 11:621944. [PMID: 33613454 PMCID: PMC7890081 DOI: 10.3389/fendo.2020.621944] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/16/2020] [Indexed: 12/14/2022] Open
Abstract
Perturbed Nicotinamide adenine dinucleotide (NAD+) homeostasis is involved in cancer progression and metastasis. Quinolinate phosphoribosyltransferase (QPRT) is the rate-limiting enzyme in the kynurenine pathway participating in NAD+ generation. In this study, we demonstrated that QPRT expression was upregulated in invasive breast cancer and spontaneous mammary tumors from MMTV-PyVT transgenic mice. Knockdown of QPRT expression inhibited breast cancer cell migration and invasion. Consistently, ectopic expression of QPRT promoted cell migration and invasion in breast cancer cells. Treatment with QPRT inhibitor (phthalic acid) or P2Y11 antagonist (NF340) could reverse the QPRT-induced invasiveness and phosphorylation of myosin light chain. Similar reversibility could be observed following treatment with Rho inhibitor (Y16), ROCK inhibitor (Y27632), PLC inhibitor (U73122), or MLCK inhibitor (ML7). Altogether, these results indicate that QPRT enhanced breast cancer invasiveness probably through purinergic signaling and might be a potential prognostic indicator and therapeutic target in breast cancer.
Collapse
Affiliation(s)
- Chien-Liang Liu
- Department of Surgery, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Surgery, School of Medicine, Mackay Medical College, New Taipei City, Taiwan
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Shih-Ping Cheng
- Department of Surgery, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Surgery, School of Medicine, Mackay Medical College, New Taipei City, Taiwan
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Ming-Jen Chen
- Department of Surgery, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Surgery, School of Medicine, Mackay Medical College, New Taipei City, Taiwan
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Chi-Hsin Lin
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan City, Taiwan
| | - Shan-Na Chen
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Yi-Hue Kuo
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Yuan-Ching Chang
- Department of Surgery, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Surgery, School of Medicine, Mackay Medical College, New Taipei City, Taiwan
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
- *Correspondence: Yuan-Ching Chang,
| |
Collapse
|
24
|
Klepac K, Yang J, Hildebrand S, Pfeifer A. RGS2: A multifunctional signaling hub that balances brown adipose tissue function and differentiation. Mol Metab 2019; 30:173-183. [PMID: 31767169 PMCID: PMC6807268 DOI: 10.1016/j.molmet.2019.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/12/2019] [Accepted: 09/28/2019] [Indexed: 12/28/2022] Open
Abstract
Objective Recruitment of brown adipose tissue (BAT) is a potential new strategy for increasing energy expenditure (EE) to treat obesity. G protein–coupled receptors (GPCRs) represent promising targets to activate BAT, as they are the major regulators of BAT biological function. To identify new regulators of GPCR signaling in BAT, we studied the role of Regulator of G protein Signaling 2 (RGS2) in brown adipocytes and BAT. Methods We combined pharmacological and genetic tools to investigate the role of RGS2 in BAT in vitro and in vivo. Adipocyte progenitors were isolated from wild-type (WT) and RGS2 knockout (RGS2−/−) BAT and differentiated to brown adipocytes. This approach was complemented with knockdown of RGS2 using lentiviral shRNAs (shRGS2). Adipogenesis was analyzed by Oil Red O staining and by determining the expression of adipogenic and thermogenic markers. Pharmacological modulators and fluorescence staining of F-acting stress fibers were employed to identify the underlying signaling pathways. In vivo, the activity of BAT was assessed by ex vivo lipolysis and by measuring whole-body EE by indirect calorimetry in metabolic cages. Results RGS2 is highly expressed in BAT, and treatment with cGMP—an important enhancer of brown adipocyte differentiation—further increased RGS2 expression. Loss of RGS2 strongly suppressed adipogenesis and the expression of thermogenic genes in brown adipocytes. Mechanistically, we found increased Gq/Rho/Rho kinase (ROCK) signaling in the absence of RGS2. Surprisingly, in vivo analysis revealed elevated BAT activity in RGS2-deficient mice that was caused by enhanced Gs/cAMP signaling. Conclusion Overall, RGS2 regulates two major signaling pathways in BAT: Gq and Gs. On the one hand, RGS2 promotes brown adipogenesis by counteracting the inhibitory action of Gq/Rho/ROCK signaling. On the other hand, RGS2 decreases the activity of BAT through the inhibition of Gs signaling and cAMP production. Thus, RGS2 might represent a stress modulator that protects BAT from overstimulation. RGS2 regulates brown adipose tissue (BAT) by inhibiting two major G protein-coupled receptor (GPCR) pathways – Gq and Gs. Deletion of RGS2 impairs the differentiation of murine brown adipocytes due to elevated Gq/Rho/ROCK signaling. In vivo, RGS2 knock-out mice show an increase in BAT lipolysis and whole-body energy expenditure.
Collapse
Affiliation(s)
- Katarina Klepac
- Institute of Pharmacology and Toxicology, University of Bonn, 53127 Bonn, Germany; Research Training Group 1873, University of Bonn, 53127 Bonn, Germany.
| | - JuHee Yang
- Institute of Pharmacology and Toxicology, University of Bonn, 53127 Bonn, Germany; Research Training Group 1873, University of Bonn, 53127 Bonn, Germany
| | - Staffan Hildebrand
- Institute of Pharmacology and Toxicology, University of Bonn, 53127 Bonn, Germany
| | - Alexander Pfeifer
- Institute of Pharmacology and Toxicology, University of Bonn, 53127 Bonn, Germany; Research Training Group 1873, University of Bonn, 53127 Bonn, Germany; PharmaCenter, University of Bonn, 53127 Bonn, Germany.
| |
Collapse
|
25
|
Aktories K, Gierschik P, Heringdorf DMZ, Schmidt M, Schultz G, Wieland T. cAMP guided his way: a life for G protein-mediated signal transduction and molecular pharmacology-tribute to Karl H. Jakobs. Naunyn Schmiedebergs Arch Pharmacol 2019; 392:887-911. [PMID: 31101932 DOI: 10.1007/s00210-019-01650-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 04/02/2019] [Indexed: 12/14/2022]
Abstract
Karl H. Jakobs, former editor-in-chief of Naunyn-Schmiedeberg's Archives of Pharmacology and renowned molecular pharmacologist, passed away in April 2018. In this article, his scientific achievements regarding G protein-mediated signal transduction and regulation of canonical pathways are summarized. Particularly, the discovery of inhibitory G proteins for adenylyl cyclase, methods for the analysis of receptor-G protein interactions, GTP supply by nucleoside diphosphate kinases, mechanisms in phospholipase C and phospholipase D activity regulation, as well as the development of the concept of sphingosine-1-phosphate as extra- and intracellular messenger will presented. His seminal scientific and methodological contributions are put in a general and timely perspective to display and honor his outstanding input to the current knowledge in molecular pharmacology.
Collapse
Affiliation(s)
- Klaus Aktories
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert Ludwigs University, 79104, Freiburg, Germany
| | - Peter Gierschik
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, 89070, Ulm, Germany
| | - Dagmar Meyer Zu Heringdorf
- Institute of General Pharmacology and Toxicology, University Hospital Frankfurt am Main, Goethe University, 60590, Frankfurt am Main, Germany
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, 9713AV, Groningen, The Netherlands
| | - Günter Schultz
- Department of Pharmacology, Charité University Medical Center Berlin, Campus Benjamin Franklin, 14195, Berlin, Germany
| | - Thomas Wieland
- Experimental Pharmacology Mannheim (EPM), European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13 - 17, 68167, Mannheim, Germany.
| |
Collapse
|
26
|
Abstract
PURPOSE OF REVIEW Currently, there are no U.S. Food and Drug Administration-approved or effective treatment options for advanced-stage uveal melanoma. In this article, we focus on therapeutic targets in pathways/mechanisms associated with common mutations in uveal melanoma. We review the challenges associated with targeting of these pathways and novel treatment strategies. RECENT FINDINGS Common mutations that promote uveal melanoma initiation and progression include alterations in G protein subunit alpha q/11 (GNAQ/GNA11) and breast cancer gene 1-associated protein 1 (BAP1). Mutant GNAQ/GNA11 induces constitutive activation of tumorigenic pathways such as extracellular signal-regulated kinase (ERK)1/2 and yes-associated protein. Inhibition of mitogen-activated protein kinase kinase (MEK) downstream of ERK1/2, however, was shown in trials to have limited clinical benefit. Recent reports suggested that combination therapies of MEK inhibition and modulators of mechanisms of drug resistance may improve tumor responses to MEK inhibitors. BAP1 has been shown to be involved in modulating chromatin dynamics and deubiquitination of proteins. Hence, epigenetic inhibitors are being investigated in BAP1 mutant uveal melanoma. However, other functions of BAP1, such as in DNA damage repair and cell cycle regulation, indicate additional targets for treatment of BAP1 mutant uveal melanoma. In addition, the frequent delayed development of uveal melanoma macrometastases is likely due to cellular dormancy mechanisms. Nuclear receptor subfamily 2, group F, member 1 and transforming growth factor beta 2 were among factors that have been shown in other cancers to induce dormant phenotypes. SUMMARY Findings from studies in uveal melanoma and in other cancers provide evidence for potential strategies that may be tested preclinically and clinically in advanced-stage uveal melanoma to improve treatment outcome and overall survival of patients.
Collapse
|
27
|
Masuho I, Skamangas NK, Martemyanov KA. Live cell optical assay for precise characterization of receptors coupling to Gα12. Basic Clin Pharmacol Toxicol 2019; 126 Suppl 6:88-95. [PMID: 30916867 DOI: 10.1111/bcpt.13228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 02/14/2019] [Indexed: 12/25/2022]
Abstract
Heterotrimeric G proteins are essential mediators of G protein-coupled receptors (GPCRs) signalling to intracellular effectors. There is a considerable diversity of G protein subunits that channel signals initiated by GPCRs into specific outcome. In particular, mammalian genomes contain 16 conserved genes encoding G protein α subunits with unique properties. Of four Gα subfamilies (Gi/o, Gq, Gs and G12/13), members of the G12/13 group have received considerable attention for their roles in carcinogenesis. However, our ability to study activation of G12/13 by GPCRs with the power to distinguish between the two subunits is limited. Here, we present an adaptation of the bioluminescence resonance energy transfer (BRET)-based assay to specifically monitor activity of Gα12 in living cells. In this kinetic assay, agonist-induced release of Venus-tagged Gβγ subunits from Gα12 is followed in real time using nano-luciferase (Nluc)-tagged BRET donor. Using this assay, we characterized bradykinin B2 receptor (BDKRB2) and found that the receptor couples to Gα12 in addition to Gαo, and Gαq, but not to Gαs. We demonstrated the utility of this assay to quantify rates of G protein activation and inactivation as well as performing dose-response studies while rank ordering signalling via individual Gα subunits. We further showed the utility of this assay to other GPCRs by demonstrating Gα12 coupling of cholecystokinin A receptor (CCKAR). Introduction of the Gα12-coupling BRET assay is expected to accelerate characterization of GPCR actions on this understudied G protein.
Collapse
Affiliation(s)
- Ikuo Masuho
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, Florida
| | - Nickolas K Skamangas
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, Florida
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, Florida
| |
Collapse
|
28
|
Cervantes-Villagrana RD, Adame-García SR, García-Jiménez I, Color-Aparicio VM, Beltrán-Navarro YM, König GM, Kostenis E, Reyes-Cruz G, Gutkind JS, Vázquez-Prado J. Gβγ signaling to the chemotactic effector P-REX1 and mammalian cell migration is directly regulated by Gα q and Gα 13 proteins. J Biol Chem 2018; 294:531-546. [PMID: 30446620 DOI: 10.1074/jbc.ra118.006254] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/12/2018] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptors stimulate Rho guanine nucleotide exchange factors that promote mammalian cell migration. Rac and Rho GTPases exert opposing effects on cell morphology and are stimulated downstream of Gβγ and Gα12/13 or Gαq, respectively. These Gα subunits might in turn favor Rho pathways by preventing Gβγ signaling to Rac. Here, we investigated whether Gβγ signaling to phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchange factor 1 (P-REX1), a key Gβγ chemotactic effector, is directly controlled by Rho-activating Gα subunits. We show that pharmacological inhibition of Gαq makes P-REX1 activation by Gq/Gi-coupled lysophosphatidic acid receptors more effective. Moreover, chemogenetic control of Gi and Gq by designer receptors exclusively activated by designer drugs (DREADDs) confirmed that Gi differentially activates P-REX1. GTPase-deficient GαqQL and Gα13QL variants formed stable complexes with Gβγ, impairing its interaction with P-REX1. The N-terminal regions of these variants were essential for stable interaction with Gβγ. Pulldown assays revealed that chimeric Gα13-i2QL interacts with Gβγ unlike to Gαi2-13QL, the reciprocal chimera, which similarly to Gαi2QL could not interact with Gβγ. Moreover, Gβγ was part of tetrameric Gβγ-GαqQL-RGS2 and Gβγ-Gα13-i2QL-RGS4 complexes, whereas Gα13QL dissociated from Gβγ to interact with the PDZ-RhoGEF-RGS domain. Consistent with an integrated response, Gβγ and AKT kinase were associated with active SDF-1/CXCL12-stimulated P-REX1. This pathway was inhibited by GαqQL and Gα13QL, which also prevented CXCR4-dependent cell migration. We conclude that a coordinated mechanism prioritizes Gαq- and Gα13-mediated signaling to Rho over a Gβγ-dependent Rac pathway, attributed to heterotrimeric Gi proteins.
Collapse
Affiliation(s)
| | - Sendi Rafael Adame-García
- Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), 07360 Mexico City, Mexico
| | - Irving García-Jiménez
- Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), 07360 Mexico City, Mexico
| | | | | | - Gabriele M König
- the University of Bonn, Institute of Pharmaceutical Biology, 53115 Bonn, Germany, and
| | - Evi Kostenis
- the University of Bonn, Institute of Pharmaceutical Biology, 53115 Bonn, Germany, and
| | - Guadalupe Reyes-Cruz
- Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), 07360 Mexico City, Mexico
| | - J Silvio Gutkind
- the Moores Cancer Center and Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
| | | |
Collapse
|
29
|
Herman JA, Willits AB, Bellemer A. Gαq and Phospholipase Cβ signaling regulate nociceptor sensitivity in Drosophila melanogaster larvae. PeerJ 2018; 6:e5632. [PMID: 30258723 PMCID: PMC6151255 DOI: 10.7717/peerj.5632] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 08/24/2018] [Indexed: 12/29/2022] Open
Abstract
Drosophila melanogaster larvae detect noxious thermal and mechanical stimuli in their environment using polymodal nociceptor neurons whose dendrites tile the larval body wall. Activation of these nociceptors by potentially tissue-damaging stimuli elicits a stereotyped escape locomotion response. The cellular and molecular mechanisms that regulate nociceptor function are increasingly well understood, but gaps remain in our knowledge of the broad mechanisms that control nociceptor sensitivity. In this study, we use cell-specific knockdown and overexpression to show that nociceptor sensitivity to noxious thermal and mechanical stimuli is correlated with levels of Gαq and phospholipase Cβ signaling. Genetic manipulation of these signaling mechanisms does not result in changes in nociceptor morphology, suggesting that changes in nociceptor function do not arise from changes in nociceptor development, but instead from changes in nociceptor activity. These results demonstrate roles for Gαq and phospholipase Cβ signaling in facilitating the basal sensitivity of the larval nociceptors to noxious thermal and mechanical stimuli and suggest future studies to investigate how these signaling mechanisms may participate in neuromodulation of sensory function.
Collapse
Affiliation(s)
- Joshua A Herman
- Department of Biology, Appalachian State University, Boone, NC, United States of America
| | - Adam B Willits
- Department of Biology, Appalachian State University, Boone, NC, United States of America
| | - Andrew Bellemer
- Department of Biology, Appalachian State University, Boone, NC, United States of America
| |
Collapse
|
30
|
Björling K, Joseph PD, Egebjerg K, Salomonsson M, Hansen JL, Ludvigsen TP, Jensen LJ. Role of age, Rho-kinase 2 expression, and G protein-mediated signaling in the myogenic response in mouse small mesenteric arteries. Physiol Rep 2018; 6:e13863. [PMID: 30198176 PMCID: PMC6129776 DOI: 10.14814/phy2.13863] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 08/21/2018] [Indexed: 12/16/2022] Open
Abstract
The myogenic response (MR) and myogenic tone (MT) in resistance vessels is crucial for maintaining peripheral vascular resistance and blood flow autoregulation. Development of MT involves G protein-coupled receptors, and may be affected by aging. AIMS (1) to estimate the mesenteric blood flow in myogenically active small mesenteric arteries; (2) to investigate the signaling from Gαq/11 and/or Gα12 activation to MT development; (3) to investigate the role of Rho-kinase 2 and aging on MT in mesenteric resistance arteries. METHODS we used pressure myography, quantitative real-time PCR, and immunolocalization to study small (<200 μm) mesenteric arteries (SMA) from young, mature adult, and middle aged mice. RESULTS Poiseuille flow calculations indicated autoregulation of blood flow at 60-120 mm Hg arterial pressure. Gαq/11 and Gα12 were abundantly expressed at the mRNA and protein levels in SMA. The Gαq/11 inhibitor YM-254890 suppressed MT development, and the Phosholipase C inhibitors U73122 and ET-18-OCH3 robustly inhibited it. We found an age-dependent increase in ROCK2 mRNA expression, and in basal MT. The specific ROCK2 inhibitor KD025 robustly inhibited MT in SMAs in all mice with an age-dependent variation in KD025 sensitivity. The inhibitory effect of KD025 was not prevented by the L-type Ca2+ channel activator BayK 8644. KD025 reversibly inhibited MT and endothelin-1 vasoconstriction in small pial arteries from Göttingen minipigs. CONCLUSIONS MT development in SMAs occurs through a Gαq/11 /PLC/Ca2+ -dependent pathway, and is maintained via ROCK2-mediated Ca2+ sensitization. Increased MT at mature adulthood can be explained by increased ROCK2 expression/activity.
Collapse
Affiliation(s)
- Karl Björling
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
| | - Philomeena D. Joseph
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
| | - Kristian Egebjerg
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
| | - Max Salomonsson
- Department of Biomedical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagen NDenmark
- Department of Internal MedicineTrelleborg HospitalTrelleborgSweden
| | | | | | - Lars J. Jensen
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
| |
Collapse
|
31
|
Kapfhamer J, Waite C, Ascoli M. The Gα q/11-provoked induction of Akr1c18 in murine luteal cells is mediated by phospholipase C. Mol Cell Endocrinol 2018; 470:179-187. [PMID: 29107092 DOI: 10.1016/j.mce.2017.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/23/2017] [Accepted: 10/23/2017] [Indexed: 11/29/2022]
Abstract
Towards the end of gestation prostaglandin F2α (PGF2α) stimulates the expression of Akr1c18 in the murine corpus luteum. Akr1c18 codes for 20α-hydroxysteroid dehydrogenase, an enzyme that precipitates parturition by catabolizing progesterone. Previous results from our laboratory have shown that this effect of PGF2α is mediated by the activation of Gαq/11, but the downstream effector(s) of Gαq/11 that elicit the increase in Akr1c18 expression have not been identified. The physiological effects of Gαq/11 are mediated by its ability to interact with phospholipase Cβ, p63RhoGEF, and PKCζ. In the experiments described herein we used biochemical and pharmacological approaches, as well as adenoviral-mediated expression of a constitutively active form of Gαq and mutants thereof, to examine the role of each of these effectors as potential mediators of the increased expression of luteal Akr1c18. By measuring the effects of PGF2α on the activation of RhoA (activated by p63RhoGEF) and the effects of activators and inhibitors of RhoA on the PGF2α-induced expression of luteal Akr1c18, we determined that RhoA is neither activated by PGF2α or involved in the PGF2α-induced expression of luteal Akr1c18. The potential involvement of PKCζ was ruled out by the inability of a mutant of a constitutively active Gαq that prevents PKCζ binding to block the increased expression of Akr1c18. Furthermore, PGF2α does not increase the phosphorylation of ERK-5, the only known downstream target of PKCζ. On the other hand, three different mutants of a constitutively active Gαq that prevent phospholipase C activation blocked the induction of luteal Akr1c18. We conclude that the induction of luteal Akr1c18 by Gαq/11 is mediated by the activation of phospholipase C.
Collapse
Affiliation(s)
- Joshua Kapfhamer
- Department of Obstetrics and Gynecology, The University of Iowa College of Medicine, Iowa City, IA 52246, United States
| | - Courtney Waite
- Department of Obstetrics and Gynecology, The University of Iowa College of Medicine, Iowa City, IA 52246, United States; Department of Pharmacology, The University of Iowa College of Medicine, Iowa City, IA 52246, United States
| | - Mario Ascoli
- Department of Obstetrics and Gynecology, The University of Iowa College of Medicine, Iowa City, IA 52246, United States; Department of Pharmacology, The University of Iowa College of Medicine, Iowa City, IA 52246, United States.
| |
Collapse
|
32
|
P2Y 11 Receptors: Properties, Distribution and Functions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1051:107-122. [PMID: 29134605 DOI: 10.1007/5584_2017_89] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The P2Y11 receptor is a G protein-coupled receptor that is stimulated by endogenous purine nucleotides, particularly ATP. Amongst P2Y receptors it has several unique properties; (1) it is the only human P2Y receptor gene that contains an intron in the coding sequence; (2) the gene does not appear to be present in the rodent genome; (3) it couples to stimulation of both phospholipase C and adenylyl cyclase. Its absence in mice and rats, along with a limited range of selective pharmacological tools, has hampered the development of our knowledge and understanding of its properties and functions. Nonetheless, through a combination of careful use of the available tools, suppression of receptor expression using siRNA and genetic screening for SNPs, possible functions of native P2Y11 receptors have been identified in a variety of human cells and tissues. Many are in blood cells involved in inflammatory responses, consistent with extracellular ATP being a damage-associated signalling molecule in the immune system. Thus proposed potential therapeutic applications relate, in the main, to modulation of acute and chronic inflammatory responses.
Collapse
|
33
|
Coleman B, Topalidou I, Ailion M. Modulation of Gq-Rho Signaling by the ERK MAPK Pathway Controls Locomotion in Caenorhabditis elegans. Genetics 2018; 209:523-535. [PMID: 29615470 PMCID: PMC5972424 DOI: 10.1534/genetics.118.300977] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/29/2018] [Indexed: 12/17/2022] Open
Abstract
The heterotrimeric G protein Gq regulates neuronal activity through distinct downstream effector pathways. In addition to the canonical Gq effector phospholipase Cβ, the small GTPase Rho was recently identified as a conserved effector of Gq. To identify additional molecules important for Gq signaling in neurons, we performed a forward genetic screen in the nematode Caenorhabditis elegans for suppressors of the hyperactivity and exaggerated waveform of an activated Gq mutant. We isolated two mutations affecting the MAP kinase scaffold protein KSR-1 and found that KSR-1 modulates locomotion downstream of, or in parallel to, the Gq-Rho pathway. Through epistasis experiments, we found that the core ERK MAPK cascade is required for Gq-Rho regulation of locomotion, but that the canonical ERK activator LET-60/Ras may not be required. Through neuron-specific rescue experiments, we found that the ERK pathway functions in head acetylcholine neurons to control Gq-dependent locomotion. Additionally, expression of activated LIN-45/Raf in head acetylcholine neurons is sufficient to cause an exaggerated waveform phenotype and hypersensitivity to the acetylcholinesterase inhibitor aldicarb, similar to an activated Gq mutant. Taken together, our results suggest that the ERK MAPK pathway modulates the output of Gq-Rho signaling to control locomotion behavior in C. elegans.
Collapse
Affiliation(s)
- Brantley Coleman
- Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington 98195
| |
Collapse
|
34
|
Park JJ, Diefenbach RJ, Joshua AM, Kefford RF, Carlino MS, Rizos H. Oncogenic signaling in uveal melanoma. Pigment Cell Melanoma Res 2018; 31:661-672. [DOI: 10.1111/pcmr.12708] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 04/19/2018] [Accepted: 04/25/2018] [Indexed: 12/14/2022]
Affiliation(s)
- John J. Park
- Department of Biomedical Sciences; Faculty of Medicine and Health Sciences; Macquarie University; Sydney New South Wales Australia
- Melanoma Institute Australia; Sydney New South Wales Australia
| | - Russell J. Diefenbach
- Department of Biomedical Sciences; Faculty of Medicine and Health Sciences; Macquarie University; Sydney New South Wales Australia
- Melanoma Institute Australia; Sydney New South Wales Australia
| | - Anthony M. Joshua
- Melanoma Institute Australia; Sydney New South Wales Australia
- Kinghorn Cancer Centre; St Vincent’s Hospital; Sydney New South Wales Australia
| | - Richard F. Kefford
- Department of Biomedical Sciences; Faculty of Medicine and Health Sciences; Macquarie University; Sydney New South Wales Australia
- Melanoma Institute Australia; Sydney New South Wales Australia
- Department of Medical Oncology; Crown Princess Mary Cancer Centre; Westmead and Blacktown Hospitals; Sydney New South Wales Australia
| | - Matteo S. Carlino
- Department of Biomedical Sciences; Faculty of Medicine and Health Sciences; Macquarie University; Sydney New South Wales Australia
- Melanoma Institute Australia; Sydney New South Wales Australia
- Department of Medical Oncology; Crown Princess Mary Cancer Centre; Westmead and Blacktown Hospitals; Sydney New South Wales Australia
| | - Helen Rizos
- Department of Biomedical Sciences; Faculty of Medicine and Health Sciences; Macquarie University; Sydney New South Wales Australia
- Melanoma Institute Australia; Sydney New South Wales Australia
| |
Collapse
|
35
|
Pagnin E, Ravarotto V, Maiolino G, Naso E, Davis PA, Calò LA. Gαq/p63RhoGEF interaction in RhoA/Rho kinase signaling: investigation in Gitelman's syndrome and implications with hypertension. J Endocrinol Invest 2018; 41:351-356. [PMID: 28840514 DOI: 10.1007/s40618-017-0749-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 08/19/2017] [Indexed: 12/26/2022]
Abstract
PURPOSE Gitelman's syndrome (GS) presents normo-hypotension and absence of cardiovascular-renal remodeling despite high angiotensin II (Ang II), activation of renin-angiotensin-aldosterone system and is a human model of endogenous antagonism of Ang II signaling, opposite to hypertension. GS's clinical presentation leads to questions regarding what features might be responsible. One area of investigation involves Ang II signaling. In hypertensive patients, RhoA/Rho kinase (RhoA/ROCK) pathway activation by Ang II is involved in hypertension development/maintenance and induction of long-term consequences (cardiovascular-renal remodeling), while GS has reduced p63RhoGEF gene and protein levels and ROCK activity. Ang II signaling is mediated by Gαq, which interacts with p63RhoGEF via the α6-αN linker connecting p63RhoGEF's DH and PH domains acting as a conformational switch to activate RhoA/ROCK signaling. METHODS We have investigated in GS patients, the presence of mutations in either p63RhoGEF's α6-αN linker domain and in Gαq's Ala253, Trp263, and Tyr356 residues, crucial for p63RhoGEF-Gαq interplay. RESULTS No mutations have been found in specific aminoacids of p63RhoGEF α6-αN linker and Gαq, key for p63RhoGEF/Gαq interplay. CONCLUSIONS Gitelman's syndrome normo/hypotension and lack of cardiovascular-renal remodeling are not due to mutations of p63RhoGEF α6-αN linker and Gαq interactions. This opens the way for investigations on different coding and no-coding regions (p63RhoGEF and Gαq promoters) and on altered transcriptional/post-transcriptional regulation. Clarification of how these biochemical/molecular mechanisms work/interact would provide insights into mechanisms involved in the GS's Ang II signaling fine tuning, in human physiology/pathophysiology in general and could also identify significant targets for intervention in the treatments of hypertension.
Collapse
Affiliation(s)
- E Pagnin
- Department of Medicine (DIMED), Nephrology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - V Ravarotto
- Department of Medicine (DIMED), Nephrology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - G Maiolino
- Hypertension, University of Padova, Padua, Italy
| | - E Naso
- Department of Medicine (DIMED), Nephrology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - P A Davis
- Department of Nutrition, University of California, Davis, USA
| | - L A Calò
- Department of Medicine (DIMED), Nephrology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy.
| |
Collapse
|
36
|
Bird SD. Calcium mediates cell shape change in human peritoneal mesothelial cells. Cell Calcium 2018; 72:116-126. [PMID: 29730478 DOI: 10.1016/j.ceca.2018.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/15/2018] [Accepted: 02/15/2018] [Indexed: 12/13/2022]
Abstract
Mast cells in the peritoneal membrane (PM) may degranulate to release preformed inflammatory mediators including histamine which is capable of diffusing into the surrounding interstitium, modulating cells in their vicinity including, human peritoneal mesothelial cells (hPMC). The present study aimed to investigate the quorum intracellular calcium ([Ca2+i]) response to histamine compared to the membrane soluble ionophore, A23187, in adherent cultured hPMC. To examine [Ca2+i] handling, Fura - 2 loaded cells were exposed to histamine and A23187. Agonist induced transient [Ca2+i] event(s) (TCE) were defined and compared including, resting calcium, peak height, recovery and transient kinetics. Changes in cell shape were examined with immunocytochemistry of the cortical actin (CA) and microtubule (MT) cytoskeleton. To investigate whether histamine induced changes in cell shape were mediated by [Ca2+i], mobilization of [Ca2+i] was prevented with 20 μmol/l of the calcium chelator 1,2-bis-(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM). Histamine produced a dose dependent increase of [Ca2+i], maximal at 1.0 mmol/l which recovered to the pre-challenge resting value. Transient multiplicity with repeated challenge was evident below a histamine threshold of 10-2 mmol/l. Morphometric analysis of MTs and CA showed significant cell elongation plus histamine and A23187. The histamine induced cell elongation was eliminated with [Ca2+i] clamping. This data indicated that increased [Ca2+i] was essential for cell elongation and the formation of stress fibres and therefore has a pivotal role in the regulation of the PM barrier.
Collapse
Affiliation(s)
- Stephen D Bird
- Department of Obstetrics and Gynaecology, The University of Melbourne, Victoria, Australia; Department of Medicine, Dunedin School of Medicine, The University of Otago, Dunedin, New Zealand.
| |
Collapse
|
37
|
G-Protein Gα 13 Functions with Abl Kinase to Regulate Actin Cytoskeletal Reorganization. J Mol Biol 2017; 429:3836-3849. [PMID: 29079481 DOI: 10.1016/j.jmb.2017.10.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 11/23/2022]
Abstract
Heterotrimeric G-proteins are essential cellular signal transducers. One of the G-proteins, Gα13, is critical for actin cytoskeletal reorganization, cell migration, cell proliferation, and apoptosis. Previously, we have shown that Gα13 is essential for both G-protein-coupled receptor and receptor tyrosine kinase-induced actin cytoskeletal reorganization such as dynamic dorsal ruffle turnover and cell migration. However, the mechanism by which Gα13 signals to actin cytoskeletal reorganization is not completely understood. Here we show that Gα13 directly interacts with Abl tyrosine kinase, which is a critical regulator of actin cytoskeleton. This interaction is critical for Gα13-induced dorsal ruffle turnover, endothelial cell remodeling, and cell migration. Our data uncover a new molecular signaling pathway by which Gα13 controls actin cytoskeletal reorganization.
Collapse
|
38
|
Katrancha SM, Wu Y, Zhu M, Eipper BA, Koleske AJ, Mains RE. Neurodevelopmental disease-associated de novo mutations and rare sequence variants affect TRIO GDP/GTP exchange factor activity. Hum Mol Genet 2017; 26:4728-4740. [PMID: 28973398 PMCID: PMC5886096 DOI: 10.1093/hmg/ddx355] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 08/07/2017] [Accepted: 08/22/2017] [Indexed: 12/19/2022] Open
Abstract
Bipolar disorder, schizophrenia, autism and intellectual disability are complex neurodevelopmental disorders, debilitating millions of people. Therapeutic progress is limited by poor understanding of underlying molecular pathways. Using a targeted search, we identified an enrichment of de novo mutations in the gene encoding the 330-kDa triple functional domain (TRIO) protein associated with neurodevelopmental disorders. By generating multiple TRIO antibodies, we show that the smaller TRIO9 isoform is the major brain protein product, and its levels decrease after birth. TRIO9 contains two guanine nucleotide exchange factor (GEF) domains with distinct specificities: GEF1 activates both Rac1 and RhoG; GEF2 activates RhoA. To understand the impact of disease-associated de novo mutations and other rare sequence variants on TRIO function, we utilized two FRET-based biosensors: a Rac1 biosensor to study mutations in TRIO (T)GEF1, and a RhoA biosensor to study mutations in TGEF2. We discovered that one autism-associated de novo mutation in TGEF1 (K1431M), at the TGEF1/Rac1 interface, markedly decreased its overall activity toward Rac1. A schizophrenia-associated rare sequence variant in TGEF1 (F1538Intron) was substantially less active, normalized to protein level and expressed poorly. Overall, mutations in TGEF1 decreased GEF1 activity toward Rac1. One bipolar disorder-associated rare variant (M2145T) in TGEF2 impaired inhibition by the TGEF2 pleckstrin-homology domain, resulting in dramatically increased TGEF2 activity. Overall, genetic damage to both TGEF domains altered TRIO catalytic activity, decreasing TGEF1 activity and increasing TGEF2 activity. Importantly, both GEF changes are expected to decrease neurite outgrowth, perhaps consistent with their association with neurodevelopmental disorders.
Collapse
Affiliation(s)
- Sara M Katrancha
- Interdepartmental Neuroscience Program
- Department of Neuroscience
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Yi Wu
- Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, USA
| | - Minsheng Zhu
- Model Animal Research Center, Nanjing University, Nanjing 210061, China
| | - Betty A Eipper
- Department of Neuroscience
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA
| | - Anthony J Koleske
- Interdepartmental Neuroscience Program
- Department of Neuroscience
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | | |
Collapse
|
39
|
Kanai SM, Edwards AJ, Rurik JG, Osei-Owusu P, Blumer KJ. Proteolytic degradation of regulator of G protein signaling 2 facilitates temporal regulation of G q/11 signaling and vascular contraction. J Biol Chem 2017; 292:19266-19278. [PMID: 28974581 DOI: 10.1074/jbc.m117.797134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/18/2017] [Indexed: 12/18/2022] Open
Abstract
Regulator of G protein signaling 2 (RGS2) controls signaling by receptors coupled to the Gq/11 class heterotrimeric G proteins. RGS2 deficiency causes several phenotypes in mice and occurs in several diseases, including hypertension in which a proteolytically unstable RGS2 mutant has been reported. However, the mechanisms and functions of RGS2 proteolysis remain poorly understood. Here we addressed these questions by identifying degradation signals in RGS2, and studying dynamic regulation of Gq/11-evoked Ca2+ signaling and vascular contraction. We identified a novel bipartite degradation signal in the N-terminal domain of RGS2. Mutations disrupting this signal blunted proteolytic degradation downstream of E3 ubiquitin ligase binding to RGS2. Analysis of RGS2 mutants proteolyzed at various rates and the effects of proteasome inhibition indicated that proteolytic degradation controls agonist efficacy by setting RGS2 protein expression levels, and affecting the rate at which cells regain agonist responsiveness as synthesis of RGS2 stops. Analyzing contraction of mesenteric resistance arteries supported the biological relevance of this mechanism. Because RGS2 mRNA expression often is strikingly and transiently up-regulated and then down-regulated upon cell stimulation, our findings indicate that proteolytic degradation tightly couples RGS2 transcription, protein levels, and function. Together these mechanisms provide tight temporal control of Gq/11-coupled receptor signaling in the cardiovascular, immune, and nervous systems.
Collapse
Affiliation(s)
- Stanley M Kanai
- From the Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Alethia J Edwards
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Joel G Rurik
- From the Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Patrick Osei-Owusu
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Kendall J Blumer
- From the Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| |
Collapse
|
40
|
Topalidou I, Cooper K, Pereira L, Ailion M. Dopamine negatively modulates the NCA ion channels in C. elegans. PLoS Genet 2017; 13:e1007032. [PMID: 28968387 PMCID: PMC5638609 DOI: 10.1371/journal.pgen.1007032] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 10/12/2017] [Accepted: 09/18/2017] [Indexed: 02/07/2023] Open
Abstract
The NALCN/NCA ion channel is a cation channel related to voltage-gated sodium and calcium channels. NALCN has been reported to be a sodium leak channel with a conserved role in establishing neuronal resting membrane potential, but its precise cellular role and regulation are unclear. The Caenorhabditis elegans orthologs of NALCN, NCA-1 and NCA-2, act in premotor interneurons to regulate motor circuit activity that sustains locomotion. Recently we found that NCA-1 and NCA-2 are activated by a signal transduction pathway acting downstream of the heterotrimeric G protein Gq and the small GTPase Rho. Through a forward genetic screen, here we identify the GPCR kinase GRK-2 as a new player affecting signaling through the Gq-Rho-NCA pathway. Using structure-function analysis, we find that the GPCR phosphorylation and membrane association domains of GRK-2 are required for its function. Genetic epistasis experiments suggest that GRK-2 acts on the D2-like dopamine receptor DOP-3 to inhibit Go signaling and positively modulate NCA-1 and NCA-2 activity. Through cell-specific rescuing experiments, we find that GRK-2 and DOP-3 act in premotor interneurons to modulate NCA channel function. Finally, we demonstrate that dopamine, through DOP-3, negatively regulates NCA activity. Thus, this study identifies a pathway by which dopamine modulates the activity of the NCA channels.
Collapse
Affiliation(s)
- Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail: (IT); (MA)
| | - Kirsten Cooper
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Laura Pereira
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, New York, United States of America
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail: (IT); (MA)
| |
Collapse
|
41
|
Smith CA, Miner AS, Barbee RW, Ratz PH. Metabolic Stress-Induced Activation of AMPK and Inhibition of Constitutive Phosphoproteins Controlling Smooth Muscle Contraction: Evidence for Smooth Muscle Fatigue? Front Physiol 2017; 8:681. [PMID: 28943852 PMCID: PMC5596101 DOI: 10.3389/fphys.2017.00681] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/24/2017] [Indexed: 11/23/2022] Open
Abstract
Metabolic stress diminishes smooth muscle contractile strength by a poorly defined mechanism. To test the hypothesis that metabolic stress activates a compensatory cell signaling program to reversibly downregulate contraction, arterial rings and bladder muscle strips in vitro were deprived of O2 and glucose for 30 and 60 min (“starvation”) to induce metabolic stress, and the phosphorylation status of proteins involved in regulation of contraction and metabolic stress were assessed in tissues under basal and stimulated conditions. A 15–30 min recovery period (O2 and glucose repletion) tested whether changes induced by starvation were reversible. Starvation decreased basal phosphorylation of myosin regulatory light chain (MLC-pS19) and of the rho kinase (ROCK) downstream substrates cofilin (cofilin-pS3) and myosin phosphatase targeting subunit MYPT1 (MYPT1-pT696 and MYPT1-pT853), and abolished the ability of contractile stimuli to cause a strong, sustained contraction. Starvation increased basal phosphorylation of AMPK (AMPK-pT172) and 3 downstream AMPK substrates, acetyl-CoA carboxylase (ACC-pS79), rhoA (rhoA-pS188), and phospholamban (PLB-pS16). Increases in rhoA-pS188 and PLB-pS16 would be expected to inhibit contraction. Recovery restored basal AMPK-pT172 and MLC-pS19 to control levels, and restored contraction. In AMPKα2 deficient mice (AMPKα2-/-), the basal level of AMPK-pT172 was reduced by 50%, and MLC-pS19 was elevated by 50%, but AMPKα2-/- did not prevent starvation-induced contraction inhibition nor enhance recovery from starvation. These results indicate that constitutive AMPK activity participates in constitutive regulation of contractile proteins, and suggest that AMPK activation is necessary, but may not be sufficient, to cause smooth muscle contraction inhibition during metabolic stress.
Collapse
Affiliation(s)
- Corey A Smith
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Amy S Miner
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Robert W Barbee
- Departments of Emergency Medicine and Physiology, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Paul H Ratz
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth UniversityRichmond, VA, United States
| |
Collapse
|
42
|
He Z, Yang Y, Wen Z, Chen C, Xu X, Zhu Y, Wang Y, Wang DW. CYP2J2 metabolites, epoxyeicosatrienoic acids, attenuate Ang II-induced cardiac fibrotic response by targeting Gα 12/13. J Lipid Res 2017; 58:1338-1353. [PMID: 28554983 DOI: 10.1194/jlr.m074229] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/23/2017] [Indexed: 12/23/2022] Open
Abstract
The arachidonic acid-cytochrome P450 2J2-epoxyeicosatrienoic acid (AA-CYP2J2-EET) metabolic pathway has been identified to be protective in the cardiovascular system. This study explored the effects of the AA-CYP2J2-EET metabolic pathway on cardiac fibrosis from the perspective of cardiac fibroblasts and underlying mechanisms. In in vivo studies, 8-week-old male CYP2J2 transgenic mice (aMHC-CYP2J2-Tr) and littermates were infused with angiotensin II (Ang II) or saline for 2 weeks. Results showed that CYP2J2 overexpression increased EET production. Meanwhile, impairment of cardiac function and fibrotic response were attenuated by CYP2J2 overexpression. The effects of CYP2J2 were associated with reduced activation of the α subunits of G12 family G proteins (Gα12/13)/RhoA/Rho kinase (ROCK) cascade and elevation of the NO/cyclic guanosine monophosphate (cGMP) level in cardiac tissue. In in vitro studies, cardiac fibroblast activation, proliferation, migration, and collagen production induced by Ang II were associated with activation of the Gα12/13/RhoA/ROCK pathway, which was inhibited by exogenous 11,12-EET. Moreover, silencing of Gα12/13 or RhoA exerted similar effects as 11,12-EET. Furthermore, inhibitory effects of 11,12-EET on Gα12/13 were blocked by NO/cGMP pathway inhibitors. Our findings indicate that enhancement of the AA-CYP2J2-EET metabolic pathway by CYP2J2 overexpression attenuates Ang II-induced cardiac dysfunction and fibrosis by reducing the fibrotic response of cardiac fibroblasts by targeting the Gα12/13/RhoA/ROCK pathway via NO/cGMP signaling.
Collapse
Affiliation(s)
- Zuowen He
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Yong Yang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Zheng Wen
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Chen Chen
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Xizhen Xu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Yanfang Zhu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Yan Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Dao Wen Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
| |
Collapse
|
43
|
The NCA-1 and NCA-2 Ion Channels Function Downstream of G q and Rho To Regulate Locomotion in Caenorhabditis elegans. Genetics 2017; 206:265-282. [PMID: 28325749 DOI: 10.1534/genetics.116.198820] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/15/2017] [Indexed: 02/07/2023] Open
Abstract
The heterotrimeric G protein Gq positively regulates neuronal activity and synaptic transmission. Previously, the Rho guanine nucleotide exchange factor Trio was identified as a direct effector of Gq that acts in parallel to the canonical Gq effector phospholipase C. Here, we examine how Trio and Rho act to stimulate neuronal activity downstream of Gq in the nematode Caenorhabditis elegans Through two forward genetic screens, we identify the cation channels NCA-1 and NCA-2, orthologs of mammalian NALCN, as downstream targets of the Gq-Rho pathway. By performing genetic epistasis analysis using dominant activating mutations and recessive loss-of-function mutations in the members of this pathway, we show that NCA-1 and NCA-2 act downstream of Gq in a linear pathway. Through cell-specific rescue experiments, we show that function of these channels in head acetylcholine neurons is sufficient for normal locomotion in C. elegans Our results suggest that NCA-1 and NCA-2 are physiologically relevant targets of neuronal Gq-Rho signaling in C. elegans.
Collapse
|
44
|
Chua V, Lapadula D, Randolph C, Benovic JL, Wedegaertner PB, Aplin AE. Dysregulated GPCR Signaling and Therapeutic Options in Uveal Melanoma. Mol Cancer Res 2017; 15:501-506. [PMID: 28223438 DOI: 10.1158/1541-7786.mcr-17-0007] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 01/31/2017] [Accepted: 02/15/2017] [Indexed: 12/20/2022]
Abstract
Uveal melanoma is the most common primary intraocular malignant tumor in adults and arises from the transformation of melanocytes in the uveal tract. Even after treatment of the primary tumor, up to 50% of patients succumb to metastatic disease. The liver is the predominant organ of metastasis. There is an important need to provide effective treatment options for advanced stage uveal melanoma. To provide the preclinical basis for new treatments, it is important to understand the molecular underpinnings of the disease. Recent genomic studies have shown that mutations within components of G protein-coupled receptor (GPCR) signaling are early events associated with approximately 98% of uveal melanomas.Implications: This review discusses the alterations in GPCR signaling components (GNAQ and GNA11), dysregulated GPCR signaling cascades, and viable targeted therapies with the intent to provide insight into new therapeutic strategies in uveal melanoma. Mol Cancer Res; 15(5); 501-6. ©2017 AACR.
Collapse
Affiliation(s)
- Vivian Chua
- Department of Cancer Biology, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Dominic Lapadula
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Clinita Randolph
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jeffrey L Benovic
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania.,Cancer Cell Biology and Signaling Program, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Philip B Wedegaertner
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania.,Cancer Cell Biology and Signaling Program, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Andrew E Aplin
- Department of Cancer Biology, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania. .,Cancer Cell Biology and Signaling Program, Sidney Kimmel Cancer Center at Jefferson, Thomas Jefferson University, Philadelphia, Pennsylvania
| |
Collapse
|
45
|
Heterotrimeric G protein Gαs subunit attenuates PLEKHG2, a Rho family-specific guanine nucleotide exchange factor, by direct interaction. Cell Signal 2017; 32:115-123. [PMID: 28108261 DOI: 10.1016/j.cellsig.2017.01.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 01/15/2017] [Indexed: 11/21/2022]
Abstract
PLEKHG2 is a Gβγ-dependent guanine nucleotide exchange factor (GEF) for the small GTPases Rac and Cdc42, and has been shown to mediate signalling pathways such as actin cytoskeleton reorganization and serum response element (SRE)-dependent gene transcription. Here we show that the constitutively active mutant of the Gαs subunit significantly attenuated PLEKHG2-induced SRE-mediated gene transcription. Strikingly, we observed that the constitutive activation of endogenous Gαs by treatment with CTx caused a similar inhibitory effect on PLEKHG2-induced activation of SRE. However, both the enforced expression of the catalytic subunit β of protein kinase A and the treatment with dibutyl-cyclic AMP failed to mimic the inhibitory effect of Gαs on PLEKHG2. Furthermore, the dominant negative mutant of protein kinase A had no effect on PLEKHG2-mediated SRE activation. Performing immunoprecipitation and an in vitro pulldown assay, we found that PLEKHG2 directly interacted with the active form of the Gαs subunit in cells. The interaction between PLEKHG2 and Gαs required the N-terminal region of PLEKHG2, which includes the DH domain, a functional domain of GEF, suggesting that Gαs directly masks the DH domain of PLEKHG2. In a previous study, we reported that Gβγ accelerates PLEKHG2-mediated SRE-dependent gene transcription. Interestingly, Gαs also inhibited the hyperactivation of SRE induced by the co-expression of Gβγ and PLEKHG2; however, Gαs and Gβγ bind to different regions of PLEKHG2. This is the first report to show that PLEKHG2 is a novel effector of Gαs, and is negatively regulated by the Gαs subunit through direct interaction.
Collapse
|
46
|
Kinetics of recruitment and allosteric activation of ARHGEF25 isoforms by the heterotrimeric G-protein Gαq. Sci Rep 2016; 6:36825. [PMID: 27833100 PMCID: PMC5105084 DOI: 10.1038/srep36825] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/17/2016] [Indexed: 02/06/2023] Open
Abstract
Rho GTPases are master regulators of the eukaryotic cytoskeleton. The activation of Rho GTPases is governed by Rho guanine nucleotide exchange factors (GEFs). Three RhoGEF isoforms are produced by the gene ARHGEF25; p63RhoGEF580, GEFT and a recently discovered longer isoform of 619 amino acids (p63RhoGEF619). The subcellular distribution of p63RhoGEF580 and p63RhoGEF619 is strikingly different in unstimulated cells, p63RhoGEF580 is located at the plasma membrane and p63RhoGEF619 is confined to the cytoplasm. Interestingly, we find that both P63RhoGEF580 and p63RhoGEF619 activate RhoGTPases to a similar extent after stimulation of Gαq coupled GPCRs. Furthermore, we show that p63RhoGEF619 relocates to the plasma membrane upon activation of Gαq coupled GPCRs, resembling the well-known activation mechanism of RhoGEFs activated by Gα12/13. Synthetic recruitment of p63RhoGEF619 to the plasma membrane increases RhoGEF activity towards RhoA, but full activation requires allosteric activation via Gαq. Together, these findings reveal a dual role for Gαq in RhoGEF activation, as it both recruits and allosterically activates cytosolic ARHGEF25 isoforms.
Collapse
|
47
|
Vázquez-Prado J, Bracho-Valdés I, Cervantes-Villagrana RD, Reyes-Cruz G. Gβγ Pathways in Cell Polarity and Migration Linked to Oncogenic GPCR Signaling: Potential Relevance in Tumor Microenvironment. Mol Pharmacol 2016; 90:573-586. [DOI: 10.1124/mol.116.105338] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 09/14/2016] [Indexed: 12/16/2022] Open
|
48
|
Syrovatkina V, Alegre KO, Dey R, Huang XY. Regulation, Signaling, and Physiological Functions of G-Proteins. J Mol Biol 2016; 428:3850-68. [PMID: 27515397 DOI: 10.1016/j.jmb.2016.08.002] [Citation(s) in RCA: 265] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/31/2016] [Accepted: 08/03/2016] [Indexed: 12/31/2022]
Abstract
Heterotrimeric guanine-nucleotide-binding regulatory proteins (G-proteins) mainly relay the information from G-protein-coupled receptors (GPCRs) on the plasma membrane to the inside of cells to regulate various biochemical functions. Depending on the targeted cell types, tissues, and organs, these signals modulate diverse physiological functions. The basic schemes of heterotrimeric G-proteins have been outlined. In this review, we briefly summarize what is known about the regulation, signaling, and physiological functions of G-proteins. We then focus on a few less explored areas such as the regulation of G-proteins by non-GPCRs and the physiological functions of G-proteins that cannot be easily explained by the known G-protein signaling pathways. There are new signaling pathways and physiological functions for G-proteins to be discovered and further interrogated. With the advancements in structural and computational biological techniques, we are closer to having a better understanding of how G-proteins are regulated and of the specificity of G-protein interactions with their regulators.
Collapse
Affiliation(s)
- Viktoriya Syrovatkina
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Kamela O Alegre
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Raja Dey
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Xin-Yun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA.
| |
Collapse
|
49
|
Abstract
Gαq signals with phospholipase C-β (PLC-β) to modify behavior in response to an agonist-bound GPCR. While the fundamental steps which prime Gαq to interact with PLC-β have been identified, questions remain concerning signal strength with PLC-β and other effectors. Gαq is generally viewed to function as a simple ON and OFF switch for its effector, dependent on the binding of GTP or GDP. However, Gαq does not have a single effector, Gαq has many different effectors. Furthermore, select effectors also regulate Gαq activity. PLC-β is a lipase and a GTPase activating protein (GAP) selective for Gαq. The contribution of G protein regulating activity to signal amplitude remains unclear. The unique PLC-β coiled-coil domain is essential for maximum Gαq response, both lipase and GAP. Nonetheless, coiled-coil domain associations necessary to maximum response have not been revealed by the structural approach. This review discusses progress towards understanding the basis for signal strength with PLC-β and other effectors. Shared and effector-specific interactions have been identified. Finally, the evidence for allosteric regulation of lipase stimulation by protein kinase C, the membrane, phosphatidic acid, phosphatidylinositol-4, 5-bisphosphate and GPCR is explored. Endogenous allosteric regulators can suppress or enhance maximum lipase stimulation dependent on the PLC-β coiled-coil domain. A better understanding of allosteric modulation may therefore identify a wealth of new targets to regulate signal strength and behavior.
Collapse
Affiliation(s)
- Irene Litosch
- Department of Molecular and Cellular Pharmacology, Miller School of Medicine University of Miami, Miami, FL 33101-6189, USA.
| |
Collapse
|
50
|
Sánchez-Fernández G, Cabezudo S, Caballero Á, García-Hoz C, Tall GG, Klett J, Michnick SW, Mayor F, Ribas C. Protein Kinase C ζ Interacts with a Novel Binding Region of Gαq to Act as a Functional Effector. J Biol Chem 2016; 291:9513-25. [PMID: 26887939 DOI: 10.1074/jbc.m115.684308] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 12/13/2022] Open
Abstract
Heterotrimeric G proteins play an essential role in the initiation of G protein-coupled receptor (GPCR) signaling through specific interactions with a variety of cellular effectors. We have recently reported that GPCR activation promotes a direct interaction between Gαq and protein kinase C ζ (PKCζ), leading to the stimulation of the ERK5 pathway independent of the canonical effector PLCβ. We report herein that the activation-dependent Gαq/PKCζ complex involves the basic PB1-type II domain of PKCζ and a novel interaction module in Gαq different from the classical effector-binding site. Point mutations in this Gαq region completely abrogate ERK5 phosphorylation, indicating that Gαq/PKCζ association is required for the activation of the pathway. Indeed, PKCζ was demonstrated to directly bind ERK5 thus acting as a scaffold between Gαq and ERK5 upon GPCR activation. The inhibition of these protein complexes by G protein-coupled receptor kinase 2, a known Gαq modulator, led to a complete abrogation of ERK5 stimulation. Finally, we reveal that Gαq/PKCζ complexes link Gαq to apoptotic cell death pathways. Our data suggest that the interaction between this novel region in Gαq and the effector PKCζ is a key event in Gαq signaling.
Collapse
Affiliation(s)
- Guzmán Sánchez-Fernández
- From the Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Universidad Autónoma de Madrid, 28049-Madrid, Spain, Instituto de Investigación Sanitaria La Princesa, 29006-Madrid, Spain, Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Sofía Cabezudo
- From the Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Universidad Autónoma de Madrid, 28049-Madrid, Spain, Instituto de Investigación Sanitaria La Princesa, 29006-Madrid, Spain
| | - Álvaro Caballero
- From the Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Universidad Autónoma de Madrid, 28049-Madrid, Spain, Instituto de Investigación Sanitaria La Princesa, 29006-Madrid, Spain
| | - Carlota García-Hoz
- From the Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Universidad Autónoma de Madrid, 28049-Madrid, Spain, Instituto de Investigación Sanitaria La Princesa, 29006-Madrid, Spain
| | - Gregory G Tall
- Departments of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York 14642, and
| | - Javier Klett
- From the Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Universidad Autónoma de Madrid, 28049-Madrid, Spain
| | - Stephen W Michnick
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale centre-ville, Montréal, Québec, H3C 3J7 Canada
| | - Federico Mayor
- From the Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Universidad Autónoma de Madrid, 28049-Madrid, Spain, Instituto de Investigación Sanitaria La Princesa, 29006-Madrid, Spain,
| | - Catalina Ribas
- From the Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Universidad Autónoma de Madrid, 28049-Madrid, Spain, Instituto de Investigación Sanitaria La Princesa, 29006-Madrid, Spain,
| |
Collapse
|