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Garcia-Marcos M. Heterotrimeric G protein signaling without GPCRs: The Gα-binding-and-activating (GBA) motif. J Biol Chem 2024; 300:105756. [PMID: 38364891 PMCID: PMC10943482 DOI: 10.1016/j.jbc.2024.105756] [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: 10/28/2023] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 02/18/2024] Open
Abstract
Heterotrimeric G proteins (Gαβγ) are molecular switches that relay signals from 7-transmembrane receptors located at the cell surface to the cytoplasm. The function of these receptors is so intimately linked to heterotrimeric G proteins that they are named G protein-coupled receptors (GPCRs), showcasing the interdependent nature of this archetypical receptor-transducer axis of transmembrane signaling in eukaryotes. It is generally assumed that activation of heterotrimeric G protein signaling occurs exclusively by the action of GPCRs, but this idea has been challenged by the discovery of alternative mechanisms by which G proteins can propagate signals in the cell. This review will focus on a general principle of G protein signaling that operates without the direct involvement of GPCRs. The mechanism of G protein signaling reviewed here is mediated by a class of G protein regulators defined by containing an evolutionarily conserved sequence named the Gα-binding-and-activating (GBA) motif. Using the best characterized proteins with a GBA motif as examples, Gα-interacting vesicle-associated protein (GIV)/Girdin and dishevelled-associating protein with a high frequency of leucine residues (DAPLE), this review will cover (i) the mechanisms by which extracellular cues not relayed by GPCRs promote the coupling of GBA motif-containing regulators with G proteins, (ii) the structural and molecular basis for how GBA motifs interact with Gα subunits to facilitate signaling, (iii) the relevance of this mechanism in different cellular and pathological processes, including cancer and birth defects, and (iv) strategies to manipulate GBA-G protein coupling for experimental therapeutics purposes, including the development of rationally engineered proteins and chemical probes.
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Affiliation(s)
- Mikel Garcia-Marcos
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, Massachusetts, USA; Department of Biology, College of Arts & Sciences, Boston University, Boston, Massachusetts, USA.
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Kenworthy AK, Han B, Ariotti N, Parton RG. The Role of Membrane Lipids in the Formation and Function of Caveolae. Cold Spring Harb Perspect Biol 2023; 15:a041413. [PMID: 37277189 PMCID: PMC10513159 DOI: 10.1101/cshperspect.a041413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Caveolae are plasma membrane invaginations with a distinct lipid composition. Membrane lipids cooperate with the structural components of caveolae to generate a metastable surface domain. Recent studies have provided insights into the structure of essential caveolar components and how lipids are crucial for the formation, dynamics, and disassembly of caveolae. They also suggest new models for how caveolins, major structural components of caveolae, insert into membranes and interact with lipids.
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Affiliation(s)
- Anne K Kenworthy
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia 22903, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22903, USA
| | - Bing Han
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia 22903, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22903, USA
| | - Nicholas Ariotti
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
- Centre for Microscopy and Microanalysis, The University of Queensland, 4072 Brisbane, Australia
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Structural Basis of the Interaction of the G Proteins, Gαi 1, Gβ 1γ 2 and Gαi 1β 1γ 2, with Membrane Microdomains and Their Relationship to Cell Localization and Activity. Biomedicines 2023; 11:biomedicines11020557. [PMID: 36831093 PMCID: PMC9953545 DOI: 10.3390/biomedicines11020557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/17/2023] Open
Abstract
GPCRs receive signals from diverse messengers and activate G proteins that regulate downstream signaling effectors. Efficient signaling is achieved through the organization of these proteins in membranes. Thus, protein-lipid interactions play a critical role in bringing G proteins together in specific membrane microdomains with signaling partners. Significantly, the molecular basis underlying the membrane distribution of each G protein isoform, fundamental to fully understanding subsequent cell signaling, remains largely unclear. We used model membranes with lipid composition resembling different membrane microdomains, and monomeric, dimeric and trimeric Gi proteins with or without single and multiple mutations to investigate the structural bases of G protein-membrane interactions. We demonstrated that cationic amino acids in the N-terminal region of the Gαi1 and C-terminal region of the Gγ2 subunit, as well as their myristoyl, palmitoyl and geranylgeranyl moieties, define the differential G protein form interactions with membranes containing different lipid classes (PC, PS, PE, SM, Cho) and the various microdomains they may form (Lo, Ld, PC bilayer, charged, etc.). These new findings in part explain the molecular basis underlying amphitropic protein translocation to membranes and localization to different membrane microdomains and the role of these interactions in cell signal propagation, pathophysiology and therapies targeted to lipid membranes.
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Bondar A, Lazar J. Optical sensors of heterotrimeric G protein signaling. FEBS J 2020; 288:2570-2584. [DOI: 10.1111/febs.15655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/26/2020] [Accepted: 12/03/2020] [Indexed: 01/14/2023]
Affiliation(s)
- Alexey Bondar
- Center for Nanobiology and Structural Biology Institute of Microbiology of the Czech Academy of Sciences Nove Hrady Czech Republic
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic
- Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - Josef Lazar
- Center for Nanobiology and Structural Biology Institute of Microbiology of the Czech Academy of Sciences Nove Hrady Czech Republic
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic
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Role of Caveolin-1 in Diabetes and Its Complications. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:9761539. [PMID: 32082483 PMCID: PMC7007939 DOI: 10.1155/2020/9761539] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/10/2019] [Accepted: 12/26/2019] [Indexed: 12/25/2022]
Abstract
It is estimated that in 2017 there were 451 million people with diabetes worldwide. These figures are expected to increase to 693 million by 2045; thus, innovative preventative programs and treatments are a necessity to fight this escalating pandemic disorder. Caveolin-1 (CAV1), an integral membrane protein, is the principal component of caveolae in membranes and is involved in multiple cellular functions such as endocytosis, cholesterol homeostasis, signal transduction, and mechanoprotection. Previous studies demonstrated that CAV1 is critical for insulin receptor-mediated signaling, insulin secretion, and potentially the development of insulin resistance. Here, we summarize the recent progress on the role of CAV1 in diabetes and diabetic complications.
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Heuninck J, Perpiñá Viciano C, Işbilir A, Caspar B, Capoferri D, Briddon SJ, Durroux T, Hill SJ, Lohse MJ, Milligan G, Pin JP, Hoffmann C. Context-Dependent Signaling of CXC Chemokine Receptor 4 and Atypical Chemokine Receptor 3. Mol Pharmacol 2019; 96:778-793. [PMID: 31092552 DOI: 10.1124/mol.118.115477] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 03/21/2019] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are regulated by complex molecular mechanisms, both in physiologic and pathologic conditions, and their signaling can be intricate. Many factors influence their signaling behavior, including the type of ligand that activates the GPCR, the presence of interacting partners, the kinetics involved, or their location. The two CXC-type chemokine receptors, CXC chemokine receptor 4 (CXCR4) and atypical chemokine receptor 3 (ACKR3), both members of the GPCR superfamily, are important and established therapeutic targets in relation to cancer, human immunodeficiency virus infection, and inflammatory diseases. Therefore, it is crucial to understand how the signaling of these receptors works to be able to specifically target them. In this review, we discuss how the signaling pathways activated by CXCR4 and ACKR3 can vary in different situations. G protein signaling of CXCR4 depends on the cellular context, and discrepancies exist depending on the cell lines used. ACKR3, as an atypical chemokine receptor, is generally reported to not activate G proteins but can broaden its signaling spectrum upon heteromerization with other receptors, such as CXCR4, endothelial growth factor receptor, or the α 1-adrenergic receptor (α 1-AR). Also, CXCR4 forms heteromers with CC chemokine receptor (CCR) 2, CCR5, the Na+/H+ exchanger regulatory factor 1, CXCR3, α 1-AR, and the opioid receptors, which results in differential signaling from that of the monomeric subunits. In addition, CXCR4 is present on membrane rafts but can go into the nucleus during cancer progression, probably acquiring different signaling properties. In this review, we also provide an overview of the currently known critical amino acids involved in CXCR4 and ACKR3 signaling.
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Affiliation(s)
- Joyce Heuninck
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Cristina Perpiñá Viciano
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Ali Işbilir
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Birgit Caspar
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Davide Capoferri
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Stephen J Briddon
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Thierry Durroux
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Stephen J Hill
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Martin J Lohse
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Graeme Milligan
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Jean-Philippe Pin
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
| | - Carsten Hoffmann
- IGF, CNRS, Inserm, Université de Montpellier, Montpellier, France (J.H., T.D., J.-P.P.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.V., A.I., M.J.L., C.H.); Institute for Molecular Cell Biology, Centre for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany (C.P.V., C.H.); Max Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Centre for Translational Pharmacology, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.C., G.M.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom (B.C., S.J.B., S.J.H.); and Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., S.J.B., S.J.H.)
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Tanphaichitr N, Kongmanas K, Faull KF, Whitelegge J, Compostella F, Goto-Inoue N, Linton JJ, Doyle B, Oko R, Xu H, Panza L, Saewu A. Properties, metabolism and roles of sulfogalactosylglycerolipid in male reproduction. Prog Lipid Res 2018; 72:18-41. [PMID: 30149090 PMCID: PMC6239905 DOI: 10.1016/j.plipres.2018.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 08/20/2018] [Accepted: 08/21/2018] [Indexed: 12/16/2022]
Abstract
Sulfogalactosylglycerolipid (SGG, aka seminolipid) is selectively synthesized in high amounts in mammalian testicular germ cells (TGCs). SGG is an ordered lipid and directly involved in cell adhesion. SGG is indispensable for spermatogenesis, a process that greatly depends on interaction between Sertoli cells and TGCs. Spermatogenesis is disrupted in mice null for Cgt and Cst, encoding two enzymes essential for SGG biosynthesis. Sperm surface SGG also plays roles in fertilization. All of these results indicate the significance of SGG in male reproduction. SGG homeostasis is also important in male fertility. Approximately 50% of TGCs become apoptotic and phagocytosed by Sertoli cells. SGG in apoptotic remnants needs to be degraded by Sertoli lysosomal enzymes to the lipid backbone. Failure in this event leads to a lysosomal storage disorder and sub-functionality of Sertoli cells, including their support for TGC development, and consequently subfertility. Significantly, both biosynthesis and degradation pathways of the galactosylsulfate head group of SGG are the same as those of sulfogalactosylceramide (SGC), a structurally related sulfoglycolipid important for brain functions. If subfertility in males with gene mutations in SGG/SGC metabolism pathways manifests prior to neurological disorder, sperm SGG levels might be used as a reporting/predicting index of the neurological status.
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Affiliation(s)
- Nongnuj Tanphaichitr
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Department of Obstetrics/Gynecology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Department of Biochemistry, Microbiology, Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
| | - Kessiri Kongmanas
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Department of Biochemistry, Microbiology, Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Division of Dengue Hemorrhagic Fever Research, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Kym F Faull
- Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, California, USA
| | - Julian Whitelegge
- Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, California, USA
| | - Federica Compostella
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Via Saldini 50, 20133 Milano, Italy
| | - Naoko Goto-Inoue
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University, Kanagawa 252-0880, Japan
| | - James-Jules Linton
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Brendon Doyle
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Department of Biochemistry, Microbiology, Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Richard Oko
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Hongbin Xu
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Department of Biochemistry, Microbiology, Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Luigi Panza
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Arpornrad Saewu
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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8
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Pálvölgyi A, Simpson J, Bodnár I, Bíró J, Palkovits M, Radovits T, Skehel P, Antoni FA. Auto-inhibition of adenylyl cyclase 9 (AC9) by an isoform-specific motif in the carboxyl-terminal region. Cell Signal 2018; 51:266-275. [PMID: 30121334 DOI: 10.1016/j.cellsig.2018.08.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/13/2018] [Accepted: 08/13/2018] [Indexed: 01/30/2023]
Abstract
Trans-membrane adenylyl cyclase (tmAC) isoforms show markedly distinct regulatory properties that have not been fully explored. AC9 is highly expressed in vital organs such as the heart and the brain. Here, we report that the isoform-specific carboxyl-terminal domain (C2b) of AC9 inhibits the activation of the enzyme by Gs-coupled receptors (GsCR). In human embryonic kidney cells (HEK293) stably overexpressing AC9, cAMP production by AC9 induced upon the activation of endogenous β-adrenergic and prostanoid GsCRs was barely discernible. Cells expressing AC9 lacking the C2b domain showed a markedly enhanced cAMP response to GsCR. Subsequent studies of the response of AC9 mutants to the activation of GsCR revealed that residues 1268-1276 in the C2b domain were critical for auto-inhibition. Two main species of AC9 of 130 K and ≥ 170 K apparent molecular weight were observed on immunoblots of rodent and human myocardial membranes with NH2-terminally directed anti-AC9 antibodies. The lower molecular weight AC9 band did not react with antibodies directed against the C2b domain. It was the predominant species of AC9 in rodent heart tissue and some of the human samples. There is a single gene for AC9 in vertebrates, moreover, amino acids 957-1353 of the COOH-terminus are encoded by a single exon with no apparent signs of mRNA splicing or editing making it highly unlikely that COOH-terminally truncated AC9 could arise through the processing or editing of mRNA. Thus, deductive reasoning leads to the suggestion that proteolytic cleavage of the C2b auto-inhibitory domain may govern the activation of AC9 by GsCR.
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Affiliation(s)
- Adrienn Pálvölgyi
- Division of Preclinical Research, Egis Pharmaceuticals PLC, Budapest, Hungary
| | - James Simpson
- Centre for Discovery Brain Sciences, Deanery of Biomedical Sciences University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Ibolya Bodnár
- Division of Preclinical Research, Egis Pharmaceuticals PLC, Budapest, Hungary
| | - Judit Bíró
- Division of Preclinical Research, Egis Pharmaceuticals PLC, Budapest, Hungary
| | - Miklós Palkovits
- Human Brain Tissue Bank and Laboratory, Semmelweis University, Budapest, Hungary
| | - Tamás Radovits
- Semmelweis University Heart and Vascular Center, Budapest, Hungary
| | - Paul Skehel
- Centre for Discovery Brain Sciences, Deanery of Biomedical Sciences University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Ferenc A Antoni
- Division of Preclinical Research, Egis Pharmaceuticals PLC, Budapest, Hungary; Centre for Discovery Brain Sciences, Deanery of Biomedical Sciences University of Edinburgh, Edinburgh, Scotland, United Kingdom.
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Anwar MA, Samaha AA, Baydoun S, Iratni R, Eid AH. Rhus coriaria L. (Sumac) Evokes Endothelium-Dependent Vasorelaxation of Rat Aorta: Involvement of the cAMP and cGMP Pathways. Front Pharmacol 2018; 9:688. [PMID: 30002626 PMCID: PMC6031713 DOI: 10.3389/fphar.2018.00688] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 06/07/2018] [Indexed: 12/13/2022] Open
Abstract
Rhus coriaria L. (sumac) is widely used in traditional remedies and cuisine of countries of the Mediterranean as well as Central and South-West Asia. Administration of sumac to experimental models and patients with diverse pathological conditions generates multi-faceted propitious effects, including the quality as a vasodilator. Together, the effects are concertedly channeled toward cardiovasobolic protection. However, there is paucity of data on the mechanism of action for sumac’s vasodilatory effect, an attribute which is considered to be advantageous for unhealthy circulatory system. Accordingly, we sought to determine the mechanisms by which sumac elicits its vasorelaxatory effects. We deciphered the signaling networks by application of a range of pharmacological inhibitors, biochemical assays and including the quantification of cyclic nucleotide monophosphates. Herein, we provide evidence that an ethanolic extract of sumac fruit, dose-dependently, relaxes rat isolated aorta. The mechanistic effect is achieved via stimulation of multiple transducers namely PI3-K/Akt, eNOS, NO, guanylyl cyclase, cGMP, and PKG. Interestingly, the arachidonic acid pathway (cyclooxygenases), adenylyl cyclase/cAMP and ATP-dependent potassium channels appear to partake in this sumac-orchestrated attenuation of vascular tone. Clearly, our data support the favorable potential cardio-vasculoprotective action of sumac.
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Affiliation(s)
- Mohammad A Anwar
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Ali A Samaha
- Department of Biomedical Sciences, Lebanese International University, Beirut, Lebanon.,Faculty of Public Health IV, Lebanese University, Beirut, Lebanon
| | - Safaa Baydoun
- Research Center for Environment and Development, Beirut Arab University, Beirut, Lebanon
| | - Rabah Iratni
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Ali H Eid
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar.,Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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10
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Casas J, Ibarguren M, Álvarez R, Terés S, Lladó V, Piotto SP, Concilio S, Busquets X, López DJ, Escribá PV. G protein-membrane interactions II: Effect of G protein-linked lipids on membrane structure and G protein-membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1526-1535. [PMID: 28411171 DOI: 10.1016/j.bbamem.2017.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/21/2017] [Accepted: 04/09/2017] [Indexed: 10/19/2022]
Abstract
G proteins often bear myristoyl, palmitoyl and isoprenyl moieties, which favor their association with the membrane and their accumulation in G Protein Coupled Receptor-rich microdomains. These lipids influence the biophysical properties of membranes and thereby modulate G protein binding to bilayers. In this context, we showed here that geranylgeraniol, but neither myristate nor palmitate, increased the inverted hexagonal (HII) phase propensity of phosphatidylethanolamine-containing membranes. While myristate and palmitate preferentially associated with phosphatidylcholine membranes, geranylgeraniol favored nonlamellar-prone membranes. In addition, Gαi1 monomers had a higher affinity for lamellar phases, while Gβγ and Gαβγ showed a marked preference for nonlamellar prone membranes. Moreover, geranylgeraniol enhanced the binding of G protein dimers and trimers to phosphatidylethanolamine-containing membranes, yet it decreased that of monomers. By contrast, both myristate and palmitate increased the Gαi1 preference for lamellar membranes. Palmitoylation reinforced the binding of the monomer to PC membranes and myristoylation decreased its binding to PE-enriched bilayer. Finally, binding of dimers and trimers to lamellar-prone membranes was decreased by palmitate and myristate, but it was increased in nonlamellar-prone bilayers. These results demonstrate that co/post-translational G protein lipid modifications regulate the membrane lipid structure and that they influence the physico-chemical properties of membranes, which in part explains why G protein subunits sort to different plasma membrane domains. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
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Affiliation(s)
- Jesús Casas
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain
| | - Maitane Ibarguren
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain; Lipopharma Therapeutics, S.L., ParcBit, 07121 Palma de Mallorca, Spain
| | - Rafael Álvarez
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain
| | - Silvia Terés
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain; Lipopharma Therapeutics, S.L., ParcBit, 07121 Palma de Mallorca, Spain
| | - Victoria Lladó
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain
| | - Stefano P Piotto
- Department of Pharmacy, University of Salerno, Via Ponte don Melillo, 84084 Fisciano, SA, Italy
| | - Simona Concilio
- Department of Industrial Engineering, University of Salerno, Via Ponte don Melillo, 84084 Fisciano, SA, Italy
| | - Xavier Busquets
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain
| | - David J López
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain; Lipopharma Therapeutics, S.L., ParcBit, 07121 Palma de Mallorca, Spain.
| | - Pablo V Escribá
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, E-07122 Palma de Mallorca, Spain
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11
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Shihata WA, Michell DL, Andrews KL, Chin-Dusting JPF. Caveolae: A Role in Endothelial Inflammation and Mechanotransduction? Front Physiol 2016; 7:628. [PMID: 28066261 PMCID: PMC5168557 DOI: 10.3389/fphys.2016.00628] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 12/02/2016] [Indexed: 12/15/2022] Open
Abstract
Vascular inflammation and disease progression, such as atherosclerosis, are in part a consequence of haemodynamic forces generated by changes in blood flow. The haemodynamic forces, such as shear stress or stretch, interact with vascular endothelial cells, which transduce the mechanical stimuli into biochemical signals via mechanosensors, which can induce an upregulation in pathways involved in inflammatory signaling. However, it is unclear how these mechanosensors respond to shear stress and most significantly what cellular mechanisms are involved in sensing the haemodynamic stimuli. This review explores the transition from shear forces, stretch and pressure to endothelial inflammation and the process of mechanotransduction, specifically highlighting evidence to suggest that caveolae play as a role as mechanosensors.
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Affiliation(s)
- Waled A Shihata
- Cardiovascular Disease Program and Department of Pharmacology, Biomedical Discovery Institute, Monash UniversityClayton, VIC, Australia; Vascular Pharmacology, Baker IDI Heart and Diabetes InstituteMelbourne, VIC, Australia
| | - Danielle L Michell
- Vascular Pharmacology, Baker IDI Heart and Diabetes Institute Melbourne, VIC, Australia
| | - Karen L Andrews
- Cardiovascular Disease Program and Department of Pharmacology, Biomedical Discovery Institute, Monash UniversityClayton, VIC, Australia; Vascular Pharmacology, Baker IDI Heart and Diabetes InstituteMelbourne, VIC, Australia
| | - Jaye P F Chin-Dusting
- Cardiovascular Disease Program and Department of Pharmacology, Biomedical Discovery Institute, Monash UniversityClayton, VIC, Australia; Vascular Pharmacology, Baker IDI Heart and Diabetes InstituteMelbourne, VIC, Australia
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12
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Parag-Sharma K, Leyme A, DiGiacomo V, Marivin A, Broselid S, Garcia-Marcos M. Membrane Recruitment of the Non-receptor Protein GIV/Girdin (Gα-interacting, Vesicle-associated Protein/Girdin) Is Sufficient for Activating Heterotrimeric G Protein Signaling. J Biol Chem 2016; 291:27098-27111. [PMID: 27864364 DOI: 10.1074/jbc.m116.764431] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 11/17/2016] [Indexed: 11/06/2022] Open
Abstract
GIV (aka Girdin) is a guanine nucleotide exchange factor that activates heterotrimeric G protein signaling downstream of RTKs and integrins, thereby serving as a platform for signaling cascade cross-talk. GIV is recruited to the cytoplasmic tail of receptors upon stimulation, but the mechanism of activation of its G protein regulatory function is not well understood. Here we used assays in humanized yeast models and G protein activity biosensors in mammalian cells to investigate the role of GIV subcellular compartmentalization in regulating its ability to promote G protein signaling. We found that in unstimulated cells GIV does not co-fractionate with its substrate G protein Gαi3 on cell membranes and that constitutive membrane anchoring of GIV in yeast cells or rapid membrane translocation in mammalian cells via chemically induced dimerization leads to robust G protein activation. We show that membrane recruitment of the GIV "Gα binding and activating" motif alone is sufficient for G protein activation and that it does not require phosphomodification. Furthermore, we engineered a synthetic protein to show that recruitment of the GIV "Gα binding and activating" motif to membranes via association with active RTKs, instead of via chemically induced dimerization, is also sufficient for G protein activation. These results reveal that recruitment of GIV to membranes in close proximity to its substrate G protein is a major mechanism responsible for the activation of its G protein regulatory function.
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Affiliation(s)
- Kshitij Parag-Sharma
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Anthony Leyme
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Vincent DiGiacomo
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Arthur Marivin
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Stefan Broselid
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Mikel Garcia-Marcos
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
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13
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Mystek P, Dutka P, Tworzydło M, Dziedzicka-Wasylewska M, Polit A. The role of cholesterol and sphingolipids in the dopamine D 1 receptor and G protein distribution in the plasma membrane. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1775-1786. [PMID: 27570114 DOI: 10.1016/j.bbalip.2016.08.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 07/29/2016] [Accepted: 08/24/2016] [Indexed: 12/26/2022]
Abstract
G proteins are peripheral membrane proteins which interact with the inner side of the plasma membrane and form part of the signalling cascade activated by G protein-coupled receptors (GPCRs). Since many signalling proteins do not appear to be homogeneously distributed on the cell surface, they associate in particular membrane regions containing specific lipids. Therefore, protein-lipid interactions play a pivotal role in cell signalling. Our previous results showed that although Gαs and Gαi3 prefer different types of membrane domains they are both co-localized with the D1 receptor. In the present report we characterize the role of cholesterol and sphingolipids in the membrane localization of Gαs, Gαi3 and their heterotrimers, as well as the D1 receptor. We measured the lateral diffusion and membrane localization of investigated proteins using fluorescence recovery after photobleaching (FRAP) microscopy and fluorescence resonance energy transfer (FRET) detected by lifetime imaging microscopy (FLIM). The treatment with either methyl-β-cyclodextrin or Fumonisin B1 led to the disruption of cholesterol-sphingolipids containing domains and changed the diffusion of Gαi3 and the D1 receptor but not of Gαs. Our results imply a sequestration of Gαs into cholesterol-independent solid-like membrane domains. Gαi3 prefers cholesterol-dependent lipid rafts so it does not bind to those domains and its diffusion is reduced. In turn, the D1 receptor exists in several different membrane localizations, depending on the receptor's conformation. We conclude that the inactive G protein heterotrimers are localized in the low-density membrane phase, from where they displace upon dissociation into the membrane-anchor- and subclass-specific lipid domain.
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Affiliation(s)
- Paweł Mystek
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Przemysław Dutka
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Magdalena Tworzydło
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Marta Dziedzicka-Wasylewska
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Agnieszka Polit
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
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14
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Tanphaichitr N, Kongmanas K, Kruevaisayawan H, Saewu A, Sugeng C, Fernandes J, Souda P, Angel JB, Faull KF, Aitken RJ, Whitelegge J, Hardy D, Berger T, Baker M. Remodeling of the plasma membrane in preparation for sperm-egg recognition: roles of acrosomal proteins. Asian J Androl 2016; 17:574-82. [PMID: 25994642 PMCID: PMC4492047 DOI: 10.4103/1008-682x.152817] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The interaction of sperm with the egg's extracellular matrix, the zona pellucida (ZP) is the first step of the union between male and female gametes. The molecular mechanisms of this process have been studied for the past six decades with the results obtained being both interesting and confusing. In this article, we describe our recent work, which attempts to address two lines of questions from previous studies. First, because there are numerous ZP binding proteins reported by various researchers, how do these proteins act together in sperm–ZP interaction? Second, why do a number of acrosomal proteins have ZP affinity? Are they involved mainly in the initial sperm–ZP binding or rather in anchoring acrosome reacting/reacted spermatozoa to the ZP? Our studies reveal that a number of ZP binding proteins and chaperones, extracted from the anterior sperm head plasma membrane, coexist as high molecular weight (HMW) complexes, and that these complexes in capacitated spermatozoa have preferential ability to bind to the ZP. Zonadhesin (ZAN), known as an acrosomal protein with ZP affinity, is one of these proteins in the HMW complexes. Immunoprecipitation indicates that ZAN interacts with other acrosomal proteins, proacrosin/acrosin and sp32 (ACRBP), also present in the HMW complexes. Immunodetection of ZAN and proacrosin/acrosin on spermatozoa further indicates that both proteins traffic to the sperm head surface during capacitation where the sperm acrosomal matrix is still intact, and therefore they are likely involved in the initial sperm–ZP binding step.
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Affiliation(s)
- Nongnuj Tanphaichitr
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa; Department of Obstetrics and Gynaecology, University of Ottawa; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada,
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15
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Dijkman PM, Watts A. Lipid modulation of early G protein-coupled receptor signalling events. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2889-97. [DOI: 10.1016/j.bbamem.2015.08.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/20/2015] [Accepted: 08/10/2015] [Indexed: 11/29/2022]
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16
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Mystek P, Tworzydło M, Dziedzicka-Wasylewska M, Polit A. New insights into the model of dopamine D1 receptor and G-proteins interactions. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:594-603. [DOI: 10.1016/j.bbamcr.2014.12.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/03/2014] [Accepted: 12/10/2014] [Indexed: 01/11/2023]
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17
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Israeli-Rosenberg S, Chen C, Li R, Deussen DN, Niesman IR, Okada H, Patel HH, Roth DM, Ross RS. Caveolin modulates integrin function and mechanical activation in the cardiomyocyte. FASEB J 2014; 29:374-84. [PMID: 25366344 DOI: 10.1096/fj.13-243139] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
β1 integrins (β1) transduce mechanical signals in many cells, including cardiac myocytes (CM). Given their close localization, as well as their role in mechanotransduction and signaling, we hypothesized that caveolin (Cav) proteins might regulate integrins in the CM. β1 localization, complex formation, activation state, and signaling were analyzed using wild-type, Cav3 knockout, and Cav3 CM-specific transgenic heart and myocyte samples. Studies were performed under basal and mechanically loaded conditions. We found that: (1) β1 and Cav3 colocalize in CM and coimmunoprecipitate from CM protein lysates; (2) β1 is detected in a subset of caveolae; (3) loss of Cav3 caused reduction of β1D integrin isoform and active β1 integrin from the buoyant domains in the heart; (4) increased expression of myocyte Cav3 correlates with increased active β1 integrin in adult CM; (5) in vivo pressure overload of the wild-type heart results in increased activated integrin in buoyant membrane domains along with increased association between active integrin and Cav3; and (6) Cav3-deficient myocytes have perturbed basal and stretch mediated signaling responses. Thus, Cav3 protein can modify integrin function and mechanotransduction in the CM and intact heart.
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Affiliation(s)
- Sharon Israeli-Rosenberg
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - Chao Chen
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - Ruixia Li
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - Daniel N Deussen
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - Ingrid R Niesman
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - Hideshi Okada
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - Hemal H Patel
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - David M Roth
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
| | - Robert S Ross
- *Department of Medicine and Department of Anesthesiology, University of California at San Diego, School of Medicine, San Diego, California, USA; U.S. Veterans Administration, San Diego Healthcare System, San Diego, California, USA; and Maastricht University, Maastricht, The Netherlands
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18
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Yu P, Sun M, Villar VAM, Zhang Y, Weinman EJ, Felder RA, Jose PA. Differential dopamine receptor subtype regulation of adenylyl cyclases in lipid rafts in human embryonic kidney and renal proximal tubule cells. Cell Signal 2014; 26:2521-9. [PMID: 25049074 DOI: 10.1016/j.cellsig.2014.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/09/2014] [Indexed: 01/11/2023]
Abstract
Dopamine D1-like receptors (D1R and D5R) stimulate adenylyl cyclase (AC) activity, whereas the D2-like receptors (D2, D3 and D4) inhibit AC activity. D1R, but not the D5R, has been reported to regulate AC activity in lipid rafts (LRs). We tested the hypothesis that D1R and D5R differentially regulate AC activity in LRs using human embryonic kidney (HEK) 293 cells heterologously expressing human D1 or D5 receptor (HEK-hD1R or HEK-hD5R) and human renal proximal tubule (hRPT) cells that endogenously express D1R and D5R. Of the AC isoforms expressed in HEK and hRPT cells (AC3, AC5, AC6, AC7, and AC9), AC5/6 was distributed to a greater extent in LRs than non-LRs in HEK-hD1R (84.5±2.3% of total), HEK-hD5R (68.9±3.1% of total), and hRPT cells (66.6 ± 2.2% of total) (P<0.05, n=4/group). In HEK-hD1R cells, the D1-like receptor agonist fenoldopam (1 μM/15 min) increased AC5/6 protein (+17.2 ± 3.9% of control) in LRs but decreased it in non-LRs (-47.3±5.3% of control) (P<0.05, vs. control, n=4/group). By contrast, in HEK-hD5R cells, fenoldopam increased AC5/6 protein in non-LRs (+67.1 ± 5.3% of control, P<0.006, vs. control, n=4) but had no effect in LRs. In hRPT cells, fenoldopam increased AC5/6 in LRs but had little effect in non-LRs. Disruption of LRs with methyl-β-cyclodextrin decreased basal AC activity in HEK-D1R (-94.5 ± 2.0% of control) and HEK-D5R cells (-87.1 ± 4.6% of control) but increased it in hRPT cells (6.8±0.5-fold). AC6 activity was stimulated to a greater extent by D1R than D5R, in agreement with the greater colocalization of AC5/6 with D1R than D5R in LRs. We conclude that LRs are essential not only for the proper membrane distribution and maintenance of AC5/6 activity but also for the regulation of D1R- and D5R-mediated AC signaling.
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Affiliation(s)
- Peiying Yu
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Min Sun
- Department of Biological Sciences, School of Life Science, Anhui University, Anhui, China
| | - Van Anthony M Villar
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Yanrong Zhang
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Edward J Weinman
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Robin A Felder
- Department of Pathology, University of Virginia Health Sciences Center, Charlottesville, VA 22903, United States
| | - Pedro A Jose
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States
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19
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Yu XF, Ni QC, Chen JP, Xu JF, Jiang Y, Yang SY, Ma J, Gu XL, Wang H, Wang YY. Knocking down the expression of adenylate cyclase-associated protein 1 inhibits the proliferation and migration of breast cancer cells. Exp Mol Pathol 2014; 96:188-94. [PMID: 24509166 DOI: 10.1016/j.yexmp.2014.02.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/03/2014] [Indexed: 01/05/2023]
Abstract
Adenylate cyclase-associated protein 1 (CAP1) is a conserved protein that was found to be up-regulated in breast cancer and related to the migration of breast cancer. We verified its roles in breast cancer specimens and cell lines. In our results, 71 of 100 specimens of breast cancer showed high levels of CAP1 by immunohistochemistry. Associated with statistical analysis, we saw that CAP1 was related to the grade of breast cancer. In MDA-MB-231, the expression of CAP1 was the highest and by knocking down the expression of CAP1 in MDA-MB-231, its ability for proliferating and migrating apparently decreased and induced changes in morphology, which were related to the arrangement of F-actin. Therefore, CAP1 might be a potential molecular targeted therapy for surgery and immune treatment.
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Affiliation(s)
- Xia-Fei Yu
- Department of General Surgery, The Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu, China
| | - Qi-Chao Ni
- Department of General Surgery, The Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu, China
| | - Jin-Peng Chen
- Department of General Surgery, The Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu, China
| | - Jun-Fei Xu
- Department of General Surgery, The Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu, China
| | - Ying Jiang
- Department of Pathogen Biology, Medical College, Nantong University, Nantong 226001, Jiangsu, China
| | - Shu-Yun Yang
- Department of Pathology, Nantong University Cancer Hospital, Nantong 226363, Jiangsu, China
| | - Jing Ma
- Department of General Surgery, The Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu, China
| | - Xiao-Ling Gu
- Department of Pathogen Biology, Medical College, Nantong University, Nantong 226001, Jiangsu, China
| | - Hua Wang
- Department of General Surgery, The Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu, China.
| | - Ying-Ying Wang
- Department of Pathogen Biology, Medical College, Nantong University, Nantong 226001, Jiangsu, China.
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20
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Yang H, Liu Y, Lu XL, Li XH, Zhang HG. Transmembrane transport of the Gαq protein carboxyl terminus imitation polypeptide GCIP-27. Eur J Pharm Sci 2013; 49:791-9. [PMID: 23748000 DOI: 10.1016/j.ejps.2013.05.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/22/2013] [Accepted: 05/28/2013] [Indexed: 12/22/2022]
Abstract
The Gαq protein carboxyl terminus imitation polypeptide (GCIP)-27 has been shown to affect cardiac hypertrophy and vascular remodeling in various models both in vitro and in vivo. Transport across the plasma membrane is a critical step in regulating the action of this peptide drug. This study was designed to explore the mechanisms underlying the transmembrane transport of GCIP-27. The peptide drug was labeled with fluorescein isothiocyanate (FITC), and measured in a time- and concentration-dependent manner using laser confocal microscopy. Various transport inhibitors, including energy and endocytosis inhibitors, were used to identify the factors that regulate its transmembrane transport. GCIP-27 transport was examined in cardiomyocytes, cardiac fibroblasts, vascular endothelial cells, vascular smooth muscle cells (VSMCs) and hepatocytes. Atomic force microscopy and scanning electron microscopy were used to determine the ultrastructure of the cardiomyocyte membranes. The results showed that GCIP-27 was transported through the plasmalemma in a time- and concentration-dependent manner. The rate of uptake and the level of GCIP-27 in the cells decreased significantly after treatment with energy inhibitors, methyl-ß-cyclodextrin chlorpromazine or heparin. GCIP-27 levels in VSMCs and cardiomyocytes were significantly greater than the levels observed in hepatocytes, cardiac fibroblasts and vascular endothelial cells. Treatment with GCIP-27 led to a marked increase in the surface roughness of the cellular membrane. In conclusion, the transmembrane transport of GCIP-27 is mediated by endocytosis, which requires energy, and GCIP-27 preferentially enters myocardial cells and VSMCs.
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Affiliation(s)
- Hua Yang
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 40038, China
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Arora K, Sinha C, Zhang W, Ren A, Moon CS, Yarlagadda S, Naren AP. Compartmentalization of cyclic nucleotide signaling: a question of when, where, and why? Pflugers Arch 2013; 465:1397-407. [PMID: 23604972 DOI: 10.1007/s00424-013-1280-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 04/04/2013] [Accepted: 04/05/2013] [Indexed: 01/21/2023]
Abstract
Preciseness of cellular behavior depends upon how an extracellular cue mobilizes a correct orchestra of cellular messengers and effector proteins spatially and temporally. This concept, termed compartmentalization of cellular signaling, is now known to form the molecular basis of many aspects of cellular behavior in health and disease. The cyclic nucleotides cyclic adenosine monophosphate and cyclic guanosine monophosphate are ubiquitous cellular messengers that can be compartmentalized in three ways: first, by their physical containment; second, by formation of multiple protein signaling complexes; and third, by their selective depletion. Compartmentalized cyclic nucleotide signaling is a very prevalent response among all cell types. In order to understand how it becomes relevant to cellular behavior, it is important to know how it is executed in cells to regulate physiological responses and, also, how its execution or dysregulation can lead to a pathophysiological condition, which forms the scope of the presented review.
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Affiliation(s)
- Kavisha Arora
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
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22
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Zhou X, Zhang H, Li G, Shaw B, Xu JR. The Cyclase-associated protein Cap1 is important for proper regulation of infection-related morphogenesis in Magnaporthe oryzae. PLoS Pathog 2012; 8:e1002911. [PMID: 22969430 PMCID: PMC3435248 DOI: 10.1371/journal.ppat.1002911] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 08/02/2012] [Indexed: 12/03/2022] Open
Abstract
Surface recognition and penetration are critical steps in the infection cycle of many plant pathogenic fungi. In Magnaporthe oryzae, cAMP signaling is involved in surface recognition and pathogenesis. Deletion of the MAC1 adenylate cyclase gene affected appressorium formation and plant infection. In this study, we used the affinity purification approach to identify proteins that are associated with Mac1 in vivo. One of the Mac1-interacting proteins is the adenylate cyclase-associated protein named Cap1. CAP genes are well-conserved in phytopathogenic fungi but none of them have been functionally characterized. Deletion of CAP1 blocked the effects of a dominant RAS2 allele and resulted in defects in invasive growth and a reduced intracellular cAMP level. The Δcap1 mutant was defective in germ tube growth, appressorium formation, and formation of typical blast lesions. Cap1-GFP had an actin-like localization pattern, localizing to the apical regions in vegetative hyphae, at the periphery of developing appressoria, and in circular structures at the base of mature appressoria. Interestingly, Cap1, similar to LifeAct, did not localize to the apical regions in invasive hyphae, suggesting that the apical actin cytoskeleton differs between vegetative and invasive hyphae. Domain deletion analysis indicated that the proline-rich region P2 but not the actin-binding domain (AB) of Cap1 was responsible for its subcellular localization. Nevertheless, the AB domain of Cap1 must be important for its function because CAP1ΔAB only partially rescued the Δcap1 mutant. Furthermore, exogenous cAMP induced the formation of appressorium-like structures in non-germinated conidia in CAP1ΔAB transformants. This novel observation suggested that AB domain deletion may result in overstimulation of appressorium formation by cAMP treatment. Overall, our results indicated that CAP1 is important for the activation of adenylate cyclase, appressorium morphogenesis, and plant infection in M. oryzae. CAP1 may also play a role in feedback inhibition of Ras2 signaling when Pmk1 is activated. In Magnaporthe oryzae, cAMP signaling is known to play an important role in surface recognition and plant penetration. The Mac1 adenylate cyclase is essential for plant infection. To better understand Mac1 activation mechanisms, in this study we used the affinity purification approach to identify proteins that are associated with Mac1 in vivo. One of the Mac1-interacting protein is the adenylate cyclase associated protein (CAP) encoded by the CAP1 gene. Results from our study indicated that Cap1 is important for Mac1 activation and plant infection in M. oryzae. The Δcap1 mutant was defective in germ tube growth and appressorium formation and failed to cause typical blast lesions. Like LifeAct, Cap1 localized to apical patches in vegetative hyphae but not in invasive hyphae. The P2 proline-rich region was important for Cap1 localization but the actin-binding domain played a role in feedback inhibition of Ras signaling. To our knowledge, functional characterization of CAP genes has not been reported in filamentous fungi. Our results indicate that CAP1 is important for regulating adenylate cyclase activities, appressorium morphogenesis, and plant infection. Further characterization of CAP1 will be important to better understand the interaction between cAMP signaling and the PMK1 pathway in M. oryzae.
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Affiliation(s)
- Xiaoying Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Haifeng Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Guotian Li
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Brian Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
- * E-mail:
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Abstract
Caveolins (Cavs) are integrated plasma membrane proteins that are complex signaling regulators with numerous partners and whose activity is highly dependent on cellular context. Cavs are both positive and negative regulators of cell signaling in and/or out of caveolae, invaginated lipid raft domains whose formation is caveolin expression dependent. Caveolins and rafts have been implicated in membrane compartmentalization; proteins and lipids accumulate in these membrane microdomains where they transmit fast, amplified and specific signaling cascades. The concept of plasma membrane organization within functional rafts is still in exploration and sometimes questioned. In this chapter, we discuss the opposing functions of caveolin in cell signaling regulation focusing on the role of caveolin both as a promoter and inhibitor of different signaling pathways and on the impact of membrane domain localization on caveolin functionality in cell proliferation, survival, apoptosis and migration.
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Oddi S, Dainese E, Sandiford S, Fezza F, Lanuti M, Chiurchiù V, Totaro A, Catanzaro G, Barcaroli D, De Laurenzi V, Centonze D, Mukhopadhyay S, Selent J, Howlett AC, Maccarrone M. Effects of palmitoylation of Cys(415) in helix 8 of the CB(1) cannabinoid receptor on membrane localization and signalling. Br J Pharmacol 2012; 165:2635-51. [PMID: 21895628 PMCID: PMC3423250 DOI: 10.1111/j.1476-5381.2011.01658.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 07/15/2011] [Accepted: 08/05/2011] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The CB(1) cannabinoid receptor is regulated by its association with membrane microdomains such as lipid rafts. Here, we investigated the role of palmitoylation of the CB(1) receptor by analysing the functional consequences of site-specific mutation of Cys(415) , the likely site of palmitoylation at the end of helix 8, in terms of membrane association, raft targeting and signalling. EXPERIMENTAL APPROACH The palmitoylation state of CB(1) receptors in rat forebrain was assessed by depalmitoylation/repalmitoylation experiments. Cys(415) was replaced with alanine by site-directed mutagenesis. Green fluorescence protein chimeras of both wild-type and mutant receptors were transiently expressed and functionally characterized in SH-SY5Y cells and HEK-293 cells by means of confocal microscopy, cytofluorimetry and competitive binding assays. Confocal fluorescence recovery after photobleaching was used to assess receptor membrane dynamics, whereas signalling activity was assessed by [(35) S]GTPγS, cAMP and co-immunoprecipitation assays. KEY RESULTS Endogenous CB(1) receptors in rat brain were palmitoylated. Mutation of Cys(415) prevented the palmitoylation of the receptor in transfected cells and reduced its recruitment to plasma membrane and lipid rafts; it also increased protein diffusional mobility. The same mutation markedly reduced the functional coupling of CB(1) receptors with G-proteins and adenylyl cyclase, whereas depalmitoylation abolished receptor association with a specific subset of G-proteins. CONCLUSIONS AND IMPLICATIONS CB(1) receptors were post-translationally modified by palmitoylation. Mutation of Cys(415) provides a receptor that is functionally impaired in terms of membrane targeting and signalling. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.
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Affiliation(s)
- Sergio Oddi
- Department of Biomedical Sciences, University of TeramoTeramo, Italy
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
| | - Enrico Dainese
- Department of Biomedical Sciences, University of TeramoTeramo, Italy
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
| | - Simone Sandiford
- Neuroscience/Drug Abuse Research Program, Biomedical Biotechnology Research Institute, North Carolina Central UniversityDurham, NC, USA
| | - Filomena Fezza
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
- Department of Experimental Medicine and Biochemical Sciences, University of Rome ‘Tor Vergata’Rome, Italy
| | - Mirko Lanuti
- Department of Biomedical Sciences, University of TeramoTeramo, Italy
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
| | - Valerio Chiurchiù
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
| | - Antonio Totaro
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
| | - Giuseppina Catanzaro
- Department of Biomedical Sciences, University of TeramoTeramo, Italy
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
| | - Daniela Barcaroli
- Department of Biomedical Sciences, University of Chieti-Pescara ‘G. d'Annunzio’Chieti, Italy
| | - Vincenzo De Laurenzi
- Department of Biomedical Sciences, University of Chieti-Pescara ‘G. d'Annunzio’Chieti, Italy
| | - Diego Centonze
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
- Department of Neurosciences, University of Rome ‘Tor Vergata’Rome, Italy
| | - Somnath Mukhopadhyay
- Neuroscience/Drug Abuse Research Program, Biomedical Biotechnology Research Institute, North Carolina Central UniversityDurham, NC, USA
| | - Jana Selent
- Research Group of biomedical Informatics (GRIB-IMIM), University of Pompeu Fabra, Barcelona Biomedical Research Park (PRBB)Barcelona, Spain
| | - Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest University Health SciencesWinston-Salem, NC, USA
| | - Mauro Maccarrone
- Department of Biomedical Sciences, University of TeramoTeramo, Italy
- European Center for Brain Research (CERC)/Santa Lucia Foundation I.R.C.C.S.Rome, Italy
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Sutor S, Heilmann J, Seifert R. Impact of fusion to Gα(i2) and co-expression with RGS proteins on pharmacological properties of human cannabinoid receptors CB₁R and CB₂R. ACTA ACUST UNITED AC 2011; 63:1043-55. [PMID: 21718288 DOI: 10.1111/j.2042-7158.2011.01307.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES G protein coupled receptor (GPCR)-Gα fusion proteins are often employed to investigate receptor/G protein interaction. In this study, the impact of Gα fusion proteins on pharmacology of CBRs, both mediating signals through Gα(i) proteins, were investigated. Gα(i2) was fused to the C-terminus of the CBRs or co-expressed with non-fused Gα(i2) in Sf9 cells, always together with Gβ₁γ₂. Furthermore, the impact of RGS proteins on CBR signaling in combination with the CBR fusion approach was examined, using RGS4 and RGS19 as paradigms. METHODS CBR ligands were characterized in the steady-state GTPase assay and pharmacological properties of ligands in the different test systems were correlated. KEY FINDINGS Fusion of CBRs to Gα(i2) enhanced the maximal stimulatory effects of ligands compared to the co-expression system, especially for CB₂R. RGS4, but not RGS19, behaved as a GTPase-activating protein at CBRs in the Gα(i2) co-expression and fusion system. Fusion of GPCR, most prominently CB₂R, to Gα(i2) , and co-expression with RGS4 altered the pharmacological properties of ligands. CONCLUSIONS Our data suggest that fusion of CB₂R to Gα(i2) and co-expression with RGS4 impedes with conformational changes. Moreover, our results support the concept of ligand-specific receptor conformations. Finally, this paper describes the most sensitive CBR test system currently available.
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Affiliation(s)
- Sarah Sutor
- Department of Pharmaceutical Biology, Institute of Pharmacy, University of Regensburg, Regensburg Institute of Pharmacology, Medical School of Hannover, Hannover, Germany
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26
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Cyclic AMP-mediated immune regulation--overview of mechanisms of action in T cells. Cell Signal 2010; 23:1009-16. [PMID: 21130867 DOI: 10.1016/j.cellsig.2010.11.018] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 11/23/2010] [Accepted: 11/25/2010] [Indexed: 01/21/2023]
Abstract
The canonical second messenger cAMP is well established as a potent negative regulator of T cell immune function. Through protein kinase A (PKA) it regulates T cell function at the level of transcription factors, members of the mitogen-activated protein kinase pathway, phospholipases (PLs), Ras homolog (Rho)A and proteins involved in the control of cell cycle progression. Type I PKA is the predominant PKA isoform in T cells. Furthermore, whereas type II PKA is located at the centrosome, type I PKA is anchored close to the T cell receptor (TCR) in lipid rafts by the Ezrin-ERM-binding phosphoprotein of 50 kDa (EBP50)-phosphoprotein associated with glycosphingolipid-enriched microdomains (PAG) scaffold complex. The most TCR-proximal target for type I PKA is C-terminal Src kinase (Csk), which upon activation by raft recruitment and phosphorylation inhibits the Src family tyrosine kinases Lck and Fyn and thus functions to maintain T cell homeostasis. Recently, induction of cAMP levels in responder T cells has emerged as one of the mechanisms by which regulatory T (T(R)) cells execute their suppressive action. Thus, the cAMP-type I PKA-Csk pathway emerges as a putative target for therapeutic intervention in autoimmune disorders as well as in cancer, where T(R) cell-mediated suppression contributes to suboptimal local immune responses.
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Goncalves JA, Ahuja S, Erfani S, Eilers M, Smith SO. Structure and function of G protein-coupled receptors using NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 57:159-80. [PMID: 20633362 PMCID: PMC2907352 DOI: 10.1016/j.pnmrs.2010.04.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 04/08/2010] [Indexed: 05/15/2023]
Affiliation(s)
- Joseph A Goncalves
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA
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28
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Mitchell KAP, Szabo G, Otero ADS. Methods for the isolation of sensory and primary cilia--an overview. Methods Cell Biol 2009; 94:87-101. [PMID: 20362086 DOI: 10.1016/s0091-679x(08)94004-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Detailed proteomic analyses of mammalian olfactory and rod photoreceptor sensory cilia are now available, providing an inventory of resident ciliary proteins and laying the foundation for future studies of developmental and spatiotemporal changes in the composition of sensory cilia. Cilia purification methods that were elaborated and perfected over several decades were essential for these advances. In contrast, the proteome of primary cilia is yet to be established, because purification procedures for this organelle have been developed only recently. In this chapter, we review current techniques for the purification of olfactory and photoreceptor cilia, and evaluate methods designed for the selective isolation of primary cilia.
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Affiliation(s)
- Kimberly A P Mitchell
- Department of Biology and Chemistry, Liberty University, Lynchburg, Virginia 24502, USA
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29
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Hu CL, Chandra R, Ge H, Pain J, Yan L, Babu G, Depre C, Iwatsubo K, Ishikawa Y, Sadoshima J, Vatner SF, Vatner DE. Adenylyl cyclase type 5 protein expression during cardiac development and stress. Am J Physiol Heart Circ Physiol 2009; 297:H1776-82. [PMID: 19734365 DOI: 10.1152/ajpheart.00050.2009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adenylyl cyclase (AC) types 5 and 6 (AC5 and AC6) are the two major AC isoforms expressed in the mammalian heart that mediate signals from beta-adrenergic receptor stimulation. Because of the unavailability of isoform-specific antibodies, it is difficult to ascertain the expression levels of AC5 protein in the heart. Here we demonstrated the successful generation of an AC5 isoform-specific mouse monoclonal antibody and studied the expression of AC5 protein during cardiac development in different mammalian species. The specificity of the antibody was confirmed using heart and brain tissues from AC5 knockout mice and from transgenic mice overexpressing AC5. In mice, the AC5 protein was highest in the brain but was also detectable in all organs studied, including the heart, brain, lung, liver, stomach, kidney, skeletal muscle, and vascular tissues. Western blot analysis showed that AC5 was most abundant in the neonatal heart and declined to basal levels in the adult heart. AC5 protein increased in the heart with pressure-overload left ventricular hypertrophy. Thus this new AC5 antibody demonstrated that this AC isoform behaves similarly to fetal type genes, such as atrial natriuretic peptide; i.e., it declines with development and increases with pressure-overload hypertrophy.
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Affiliation(s)
- Che-Lin Hu
- Department of Cell Biology and Molecular Medicine and the Cardiovascular Research Institute at the University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ, USA
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Lipid raft-mediated regulation of G-protein coupled receptor signaling by ligands which influence receptor dimerization: a computational study. PLoS One 2009; 4:e6604. [PMID: 19668374 PMCID: PMC2719103 DOI: 10.1371/journal.pone.0006604] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 07/22/2009] [Indexed: 11/19/2022] Open
Abstract
G-protein coupled receptors (GPCRs) are the largest family of cell surface receptors; they activate heterotrimeric G-proteins in response to ligand stimulation. Although many GPCRs have been shown to form homo- and/or heterodimers on the cell membrane, the purpose of this dimerization is not known. Recent research has shown that receptor dimerization may have a role in organization of receptors on the cell surface. In addition, microdomains on the cell membrane termed lipid rafts have been shown to play a role in GPCR localization. Using a combination of stochastic (Monte Carlo) and deterministic modeling, we propose a novel mechanism for lipid raft partitioning of GPCRs based on reversible dimerization of receptors and then demonstrate that such localization can affect GPCR signaling. Modeling results are consistent with a variety of experimental data indicating that lipid rafts have a role in amplification or attenuation of G-protein signaling. Thus our work suggests a new mechanism by which dimerization-inducing or inhibiting characteristics of ligands can influence GPCR signaling by controlling receptor organization on the cell membrane.
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31
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Lents NH, Irintcheva V, Goel R, Wheeler LW, Baldassare JJ. The rapid activation of N-Ras by alpha-thrombin in fibroblasts is mediated by the specific G-protein Galphai2-Gbeta1-Ggamma5 and occurs in lipid rafts. Cell Signal 2009; 21:1007-14. [PMID: 19250965 DOI: 10.1016/j.cellsig.2009.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 02/18/2009] [Accepted: 02/18/2009] [Indexed: 11/20/2022]
Abstract
alpha-thrombin is a potent mitogen for fibroblasts and initiates a rapid signal transduction pathway leading to the activation of Ras and the stimulation of cell cycle progression. While the signaling events downstream of Ras have been studied in significant detail and appear well conserved across many species and cell types, the precise molecular events beginning with thrombin receptor activation and leading to the activation of Ras are not as well understood. In this study, we examined the immediate events in the rapid response to alpha-thrombin, in a single cell type, and found that an unexpected degree of specificity exists in the pathway linking alpha-thrombin to Ras activation. Specifically, although IIC9 cells express all three Ras isoforms, only N-Ras is rapidly activated by alpha-thrombin. Further, although several Galpha subunits associate with PAR1 and are released following stimulation, only Galpha(i2) couples to the rapid activation of Ras. Similarly, although IIC9 cells express many Gbeta and Ggamma subunits, only a subset associates with Galpha(i2), and of those, only a single Gbetagamma dimer, Gbeta(1)gamma(5), participates in the rapid activation of N-Ras. We then hypothesized that co-localization into membrane microdomains called lipid rafts, or caveolae, is at least partially responsible for this degree of specificity. Accordingly, we found that all components localize to lipid rafts and that disruption of caveolae abolishes the rapid activation of N-Ras by alpha-thrombin. We thus report the molecular elucidation of an extremely specific and rapid signal transduction pathway linking alpha-thrombin stimulation to the activation of Ras.
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Affiliation(s)
- Nathan H Lents
- Department of Sciences at John Jay College of Criminal Justice, City University of New York, New York, NY 10019, USA.
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Yamashita T. Biological function of glycosphingolipids—mouse early stage development and neuronal function—. TRENDS GLYCOSCI GLYC 2009. [DOI: 10.4052/tigg.21.290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Tadashi Yamashita
- Frontier Research Center for Post-genome Science and Technology, Hokkaido University
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Garcia-Marcos M, Dehaye JP, Marino A. Membrane compartments and purinergic signalling: the role of plasma membrane microdomains in the modulation of P2XR-mediated signalling. FEBS J 2008; 276:330-40. [DOI: 10.1111/j.1742-4658.2008.06794.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Vögler O, Barceló JM, Ribas C, Escribá PV. Membrane interactions of G proteins and other related proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2008; 1778:1640-52. [PMID: 18402765 DOI: 10.1016/j.bbamem.2008.03.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 03/01/2008] [Accepted: 03/12/2008] [Indexed: 01/25/2023]
Abstract
Guanine nucleotide-binding proteins, G proteins, propagate incoming messages from receptors to effector proteins. They switch from an inactive to active state by exchanging a GDP molecule for GTP, and they return to the inactive form by hydrolyzing GTP to GDP. Small monomeric G proteins, such as Ras, are involved in controlling cell proliferation, differentiation and apoptosis, and they interact with membranes through isoprenyl moieties, fatty acyl moieties, and electrostatic interactions. This protein-lipid binding facilitates productive encounters of Ras and Raf proteins in defined membrane regions, so that signals can subsequently proceed through MEK and ERK kinases, which constitute the canonical MAP kinase signaling cassette. On the other hand, heterotrimeric G proteins undergo co/post-translational modifications in the alpha (myristic and/or palmitic acid) and the gamma (farnesol or geranylgeraniol) subunits. These modifications not only assist the G protein to localize to the membrane but they also help distribute the heterotrimer (Galphabetagamma) and the subunits generated upon activation (Galpha and Gbetagamma) to appropriate membrane microdomains. These proteins transduce messages from ubiquitous serpentine receptors, which control important functions such as taste, vision, blood pressure, body weight, cell proliferation, mood, etc. Moreover, the exchange of GDP by GTP is triggered by nucleotide exchange factors. Membrane receptors that activate G proteins can be considered as such, but other cytosolic, membranal or amphitropic proteins can accelerate the rate of G protein exchange or even activate this process in the absence of receptor-mediated activation. These and other protein-protein interactions of G proteins with other signaling proteins are regulated by their lipid preferences. Thus, G protein-lipid interactions control the features of messages and cell physiology.
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Affiliation(s)
- Oliver Vögler
- Molecular Cell Biomedicine, Department of Biology-IUNICS, Universitat de les Illes Balears, Palma de Mallorca, Spain
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35
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Guruswamy S, Rao CV. Multi-Target Approaches in Colon Cancer Chemoprevention Based on Systems Biology of Tumor Cell-Signaling. GENE REGULATION AND SYSTEMS BIOLOGY 2008; 2:163-176. [PMID: 19763245 PMCID: PMC2745153 DOI: 10.4137/grsb.s486] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Colorectal cancer is the leading cause of cancer related deaths in the United States. Although it is preventable, thousands of lives are lost each year in the U.S. to colorectal cancer than to breast cancer and AIDS combined. In colon cancer, the formation and progression of precancerous lesions like aberrant crypt foci and polyps is associated with the up-regulation of cycloxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and hydroxy methyl glutaryl CoA reductase (HMG-CoA reductase). The current review will focus on the signaling pathway involving COX-2 and HMG-CoA reductase enzymes and their downstream effectors in signaling mechanism. Cancer cells need huge pools of both cholesterol and isoprenoids to sustain their unlimited growth potential. Cholesterol by modulating caveolae formation regulates several signaling molecules like AKT, IGFR, EGFR and Rho which are involved in cell growth and survival. Cholesterol is also essential for lipid body formation which serves as storage sites for COX-2, eicosanoids and caveolin-1. Experimental studies have identified important mechanisms showing that COX-2, caveolin-1, lipid bodies and prenylated proteins is involved in carcinogenesis. Therefore multi-target, multi-drug approach is the ideal choice for effective colon cancer chemoprevention. This review will give an overview of the two pathways, their signaling networks, and the interactions between the components of the two networks in the activation and regulation of cell signaling involving growth/survival and explain the rationale for colon cancer chemoprevention using COX-2 inhibitors and statins.
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Affiliation(s)
- Suresh Guruswamy
- Department of Medicine, Hematology-Oncology Section, University of Oklahoma Health Sciences Center, Oklahoma City, OK, U.S.A
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Actin cytoskeleton-dependent dynamics of the human serotonin1A receptor correlates with receptor signaling. Biophys J 2008; 95:451-63. [PMID: 18339759 DOI: 10.1529/biophysj.107.125732] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Analyzing the dynamics of membrane proteins in the context of cellular signaling represents a challenging problem in contemporary cell biology. Lateral diffusion of lipids and proteins in the cell membrane is known to be influenced by the cytoskeleton. In this work, we explored the role of the actin cytoskeleton on the mobility of the serotonin(1A) (5-HT(1A)) receptor, stably expressed in CHO cells, and its implications in signaling. FRAP analysis of 5-HT(1A)R-EYFP shows that destabilization of the actin cytoskeleton induced by either CD or elevation of cAMP levels mediated by forskolin results in an increase in the mobile fraction of the receptor. The increase in the mobile fraction is accompanied by a corresponding increase in the signaling efficiency of the receptor. Interestingly, with increasing concentrations of CD used, the increase in the mobile fraction exhibited a correlation of approximately 0.95 with the efficiency in ligand-mediated signaling of the receptor. Radioligand binding and G-protein coupling of the receptor were found to be unaffected upon treatment with CD. Our results suggest that signaling by the serotonin(1A) receptor is correlated with receptor mobility, implying thereby that the actin cytoskeleton could play a regulatory role in receptor signaling. These results may have potential significance in the context of signaling by GPCRs in general and in the understanding of GPCR-cytoskeleton interactions with respect to receptor signaling in particular.
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Means CK, Miyamoto S, Chun J, Brown JH. S1P1 receptor localization confers selectivity for Gi-mediated cAMP and contractile responses. J Biol Chem 2008; 283:11954-63. [PMID: 18296752 DOI: 10.1074/jbc.m707422200] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adult mouse ventricular myocytes express S1P(1), S1P(2), and S1P(3) receptors. S1P activates Akt and ERK in adult mouse ventricular myocytes through a pertussis toxin-sensitive (G(i/o)-mediated) pathway. Akt and ERK activation by S1P are reduced approximately 30% in S1P(3) and 60% in S1P(2) receptor knock-out myocytes. With combined S1P(2,3) receptor deletion, activation of Akt is abolished and ERK activation is reduced by nearly 90%. Thus the S1P(1) receptor, while present in S1P(2,3) receptor knock-out myocytes, is unable to mediate Akt or ERK activation. In contrast, S1P induces pertussis toxin-sensitive inhibition of isoproterenol-stimulated cAMP accumulation in both WT and S1P(2,3) receptor knock-out myocytes demonstrating that the S1P(1) receptor can functionally couple to G(i). An S1P(1) receptor selective agonist, SEW2871, also decreased cAMP accumulation but failed to activate ERK or Akt. To determine whether localization of the S1P(1) receptor mediates this signaling specificity, methyl-beta-cyclodextrin (MbetaCD) treatment was used to disrupt caveolae. The S1P(1) receptor was concentrated in caveolar fractions, and associated with caveolin-3 and this localization was disrupted by MbetaCD. S1P-mediated activation of ERK or Akt was not diminished but inhibition of cAMP accumulation by S1P and SEW2871 was abolished by MbetaCD treatment. S1P inhibits the positive inotropic response to isoproterenol and this response is also mediated through the S1P(1) receptor and lost following caveolar disruption. Thus localization of S1P(1) receptors to caveolae is required for the ability of this receptor to inhibit adenylyl cyclase and contractility but compromises receptor coupling to Akt and ERK.
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Affiliation(s)
- Christopher Kable Means
- Biomedical Sciences Graduate Program and Department of Pharmacology, University of California, San Diego, California 92093-0636, USA
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Kalipatnapu S, Chattopadhyay A. Membrane Organization and Function of the Serotonin1A Receptor. Cell Mol Neurobiol 2007; 27:1097-116. [PMID: 17710529 DOI: 10.1007/s10571-007-9189-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 07/27/2007] [Indexed: 01/02/2023]
Abstract
(1) The serotonin(1A) receptor is a G-protein coupled receptor involved in several cognitive, behavioral, and developmental functions. It binds the neurotransmitter serotonin and signals across the membrane through its interactions with heterotrimeric G-proteins. (2) Lipid-protein interactions in membranes play an important role in the assembly, stability, and function of membrane proteins. The role of membrane environment in serotonin(1A) receptor function is beginning to be addressed by exploring the consequences of lipid manipulations on the ligand binding and G-protein coupling of serotonin(1A) receptors, the ability to functionally solubilize the serotonin(1A) receptor, and the factors influencing the membrane organization of the serotonin(1A) receptor. (3) Recent developments involving the application of detergent-based and detergent-free approaches to understand the membrane organization of the serotonin(1A) receptor under conditions of ligand activation and modulation of membrane lipid content, with an emphasis on membrane cholesterol, are described.
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Affiliation(s)
- Shanti Kalipatnapu
- Divisionof Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0377, USA
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39
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Willoughby D, Cooper DMF. Organization and Ca2+Regulation of Adenylyl Cyclases in cAMP Microdomains. Physiol Rev 2007; 87:965-1010. [PMID: 17615394 DOI: 10.1152/physrev.00049.2006] [Citation(s) in RCA: 327] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The adenylyl cyclases are variously regulated by G protein subunits, a number of serine/threonine and tyrosine protein kinases, and Ca2+. In some physiological situations, this regulation can be readily incorporated into a hormonal cascade, controlling processes such as cardiac contractility or neurotransmitter release. However, the significance of some modes of regulation is obscure and is likely only to be apparent in explicit cellular contexts (or stages of the cell cycle). The regulation of many of the ACs by the ubiquitous second messenger Ca2+provides an overarching mechanism for integrating the activities of these two major signaling systems. Elaborate devices have been evolved to ensure that this interaction occurs, to guarantee the fidelity of the interaction, and to insulate the microenvironment in which it occurs. Subcellular targeting, as well as a variety of scaffolding devices, is used to promote interaction of the ACs with specific signaling proteins and regulatory factors to generate privileged domains for cAMP signaling. A direct consequence of this organization is that cAMP will exhibit distinct kinetics in discrete cellular domains. A variety of means are now available to study cAMP in these domains and to dissect their components in real time in live cells. These topics are explored within the present review.
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Affiliation(s)
- Debbie Willoughby
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
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Marrari Y, Crouthamel M, Irannejad R, Wedegaertner PB. Assembly and trafficking of heterotrimeric G proteins. Biochemistry 2007; 46:7665-77. [PMID: 17559193 PMCID: PMC2527407 DOI: 10.1021/bi700338m] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To be activated by cell surface G protein-coupled receptors, heterotrimeric G proteins must localize at the cytoplasmic surface of plasma membranes. Moreover, some G protein subunits are able to traffic reversibly from the plasma membrane to intracellular locations upon activation. This current topic will highlight new insights into how nascent G protein subunits are assembled and how they arrive at plasma membranes. In addition, recent reports have increased our knowledge of activation-induced trafficking of G proteins. Understanding G protein assembly and trafficking will lead to a greater understanding of novel ways that cells regulate G protein signaling.
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Affiliation(s)
| | | | | | - Philip B. Wedegaertner
- *address correspondence to: Philip B. Wedegaertner, Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 S. 10 St., 839 BLSB, Philadelphia, PA 19107, Tel: 215-503-3137, Fax: 215-923-2117, e-mail:
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Kalipatnapu S, Chattopadhyay A, Pucadyil T. Membrane Organization and Dynamics of the Serotonin 1A Receptor Monitored Using Fluorescence Microscopic Approaches. Front Neurosci 2007. [DOI: 10.1201/9781420005752.ch3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Awasthi V, Mandal SK, Papanna V, Rao LVM, Pendurthi UR. Modulation of tissue factor-factor VIIa signaling by lipid rafts and caveolae. Arterioscler Thromb Vasc Biol 2007; 27:1447-55. [PMID: 17413039 PMCID: PMC2647778 DOI: 10.1161/atvbaha.107.143438] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Coagulation factor VIIa (VIIa) binding to its cellular receptor, tissue factor (TF), not only initiates the coagulation cascade but also induces cell signaling by activating G-protein coupled protease-activated receptors. The objective of the present study is to investigate the role of lipid rafts and caveolae in modulating TF-VIIa signaling and coagulant functions. METHODS AND RESULTS TF-VIIa coagulant function was measured in factor X activation assay and the signaling function was evaluated in phosphoinositide hydrolysis and IL-8 gene induction. Buoyant density gradient centrifugation and immunofluorescence confocal microscopy were used to determine cellular localization of TF and protease-activated receptor 2. The data show that a substantial fraction of TF and protease-activated receptor 2 resides in lipid rafts/caveolae, and disruption of lipid rafts by cholesterol depletion or modification reduced TF-VIIa-induced cell signaling. Disruption of caveolae with caveolin-1 silencing had no effect on the TF-VIIa coagulant activity but inhibited the TF-VIIa-induced cell signaling. CONCLUSION Overall our data show that lipid raft/caveolae play a selective role in modulating the TF-VIIa signaling function without affecting the TF-VIIa coagulant activity.
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Affiliation(s)
- Vineet Awasthi
- Biomedical Research Division, The University of Texas Health Center at Tyler, 11937 US Highway 271, Tyler, TX 75708, USA
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43
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Escribá PV, Wedegaertner PB, Goñi FM, Vögler O. Lipid–protein interactions in GPCR-associated signaling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:836-52. [PMID: 17067547 DOI: 10.1016/j.bbamem.2006.09.001] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2006] [Revised: 09/05/2006] [Accepted: 09/06/2006] [Indexed: 10/24/2022]
Abstract
Signal transduction via G-protein-coupled receptors (GPCRs) is a fundamental pathway through which the functions of an individual cell can be integrated within the demands of a multicellular organism. Since this family of receptors first discovered, the proteins that constitute this signaling cascade and their interactions with one another have been studied intensely. In parallel, the pivotal role of lipids in the correct and efficient propagation of extracellular signals has attracted ever increasing attention. This is not surprising given that most of the signal transduction machinery is membrane-associated and therefore lipid-related. Hence, lipid-protein interactions exert a considerable influence on the activity of these proteins. This review focuses on the post-translational lipid modifications of GPCRs and G proteins (palmitoylation, myristoylation, and isoprenylation) and their significance for membrane binding, trafficking and signaling. Moreover, we address how the particular biophysical properties of different membrane structures may regulate the localization of these proteins and the potential functional consequences of this phenomenon in signal transduction. Finally, the interactions that occur between membrane lipids and GPCR effector enzymes such as PLC and PKC are also considered.
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Affiliation(s)
- Pablo V Escribá
- Laboratory of Molecular and Cellular Biomedicine, Institut Universitari d'Investigació en Ciències de la Salut, Department of Biology, University of the Balearic Islands, Palma de Mallorca, Spain.
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44
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Iancu RV, Jones SW, Harvey RD. Compartmentation of cAMP signaling in cardiac myocytes: a computational study. Biophys J 2007; 92:3317-31. [PMID: 17293406 PMCID: PMC1852367 DOI: 10.1529/biophysj.106.095356] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Receptor-mediated changes in cAMP production play an essential role in sympathetic and parasympathetic regulation of the electrical, mechanical, and metabolic activity of cardiac myocytes. However, responses to receptor activation cannot be easily ascribed to a uniform increase or decrease in cAMP activity throughout the entire cell. In this study, we used a computational approach to test the hypothesis that in cardiac ventricular myocytes the effects of beta(1)-adrenergic receptor (beta(1)AR) and M(2) muscarinic receptor (M(2)R) activation involve compartmentation of cAMP. A model consisting of two submembrane (caveolar and extracaveolar) microdomains and one bulk cytosolic domain was created using published information on the location of beta(1)ARs and M(2)Rs, as well as the location of stimulatory (G(s)) and inhibitory (G(i)) G-proteins, adenylyl cyclase isoforms inhibited (AC5/6) and stimulated (AC4/7) by G(i), and multiple phosphodiesterase isoforms (PDE2, PDE3, and PDE4). Results obtained with the model indicate that: 1), bulk basal cAMP can be high ( approximately 1 microM) and only modestly stimulated by beta(1)AR activation ( approximately 2 microM), but caveolar cAMP varies in a range more appropriate for regulation of protein kinase A ( approximately 100 nM to approximately 2 microM); 2), M(2)R activation strongly reduces the beta(1)AR-induced increases in caveolar cAMP, with less effect on bulk cAMP; and 3), during weak beta(1)AR stimulation, M(2)R activation not only reduces caveolar cAMP, but also produces a rebound increase in caveolar cAMP following termination of M(2)R activity. We conclude that compartmentation of cAMP can provide a quantitative explanation for several aspects of cardiac signaling.
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Affiliation(s)
- Radu V Iancu
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, USA
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45
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Oddi S, Spagnuolo P, Bari M, D'Agostino A, Maccarrone M. Differential modulation of type 1 and type 2 cannabinoid receptors along the neuroimmune axis. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2007; 82:327-37. [PMID: 17678969 DOI: 10.1016/s0074-7742(07)82017-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Endocannabinoid-signaling chains have been implicated in a variety of pathophysiological functions, including memory, coordination, vasoregulation, reproduction, neurodegeneration, and inflammation. These activities were thought to be mediated by the activation of two G-protein-coupled receptors (GPCRs), type 1 and type 2 cannabinoid receptors (CB(1)R and CB(2)R). These two CBR subtypes share common agonists and trigger similar signaling pathways, yet they present several important differences in structure and cell distribution. In particular, recent research has shown that the CB(1)R and CB(2)R are differentially linked to lipid rafts, specialized microdomains of the plasma membrane involved in the signaling of many other GPCRs. We present an overview of the current literature on the effects that lipid raft perturbation have on CBRs activities, and provide a mechanistic model to interpret these data in terms of structural and functional aspects. These findings may also have important implications for the development of new therapeutic approaches, including lipid raft perturbing drugs, aimed to selectively modulate CB(1)R signaling in a variety of pathological conditions.
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Affiliation(s)
- Sergio Oddi
- Department of Biomedical Sciences, University of Teramo, Teramo 64100, Italy
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46
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Pucadyil TJ, Chattopadhyay A. The human serotonin1A receptor exhibits G-protein-dependent cell surface dynamics. Glycoconj J 2006; 24:25-31. [PMID: 17123166 DOI: 10.1007/s10719-006-9008-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Seven transmembrane domain G-protein-coupled receptors constitute the largest family of proteins in mammals. Signal transduction events mediated by such receptors are the primary means by which cells communicate with and respond to their external environment. The major paradigm in this signal transduction process is that stimulation of the receptor leads to the recruitment and activation of heterotrimeric GTP-binding proteins. These initial events, which are fundamental to all types of G-protein-coupled receptor signaling, occur at the plasma membrane via protein-protein interactions. As a result, the dynamics of the activated receptor on cell surfaces represents an important determinant in its encounter with G-proteins, and has significant impact on the overall efficiency of the signal transduction process. We have monitored the cell surface dynamics of the serotonin(1A) receptor, an important member of the G-protein-coupled receptor superfamily, in relation to its interaction with G-proteins. Fluorescence recovery after photobleaching experiments carried out with the receptor tagged to the enhanced yellow fluorescent protein indicate that G-protein activation alters the diffusion properties of the receptor in a manner suggesting the activation process leads to dissociation of G-proteins from the receptor. This result demonstrates that the cell surface dynamics of the serotonin(1A) receptor is modulated in a G-protein-dependent manner. Importantly, this result could provide the basis for a sensitive and powerful approach to assess receptor/G-protein interaction in an intact cellular environment.
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Affiliation(s)
- Thomas J Pucadyil
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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47
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Perez JB, Segura JM, Abankwa D, Piguet J, Martinez KL, Vogel H. Monitoring the diffusion of single heterotrimeric G proteins in supported cell-membrane sheets reveals their partitioning into microdomains. J Mol Biol 2006; 363:918-30. [PMID: 16996083 DOI: 10.1016/j.jmb.2006.08.036] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2006] [Revised: 07/07/2006] [Accepted: 08/14/2006] [Indexed: 11/23/2022]
Abstract
Supported cell-membrane sheets are promising in vitro systems to investigate the properties of membranes with native protein/lipid composition, in particular their sub-compartmentalization and the differential localization of proteins associated to them. While such studies are usually performed using static microscopy techniques, we demonstrate here the potential offered by dynamic diffusion measurements. Whereas the overall fluidity of the lipid bilayer was preserved, the preparation of the membrane sheets led to the selective immobilization of extracellular and transmembrane (TM) glycosylated proteins and the anchored proteins/lipids associated with them. Taking advantage of this, we investigated the association of the G protein Gq with TM proteins, in particular G-protein coupled receptors (GPCRs), by monitoring the changes in diffusion occurring after preparation of the supported membranes. Two fluorescently tagged Galphaq proteins were constructed, which remained either mostly monomeric in the plasma membrane or associated with Gbetagamma in heterotrimers. While both constructs diffused similarly in living cells, the preparation of the supported membranes led to the selective immobilization of the heterotrimers with minimal changes of the diffusion of the monomeric Galphaq. The diverse mobility of monomeric and heterotrimeric Galphaq was a result of their different lipid anchors as demonstrated by monitoring the diffusion of the corresponding anchors alone. We propose that the immobilization of the heterotrimer was caused by its partitioning inside membrane microdomains surrounding GPCRs.
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Affiliation(s)
- Jean-Baptiste Perez
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Sciences et Ingénierie Chimiques, CH-1015 Lausanne, Switzerland
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Galés C, Van Durm JJJ, Schaak S, Pontier S, Percherancier Y, Audet M, Paris H, Bouvier M. Probing the activation-promoted structural rearrangements in preassembled receptor-G protein complexes. Nat Struct Mol Biol 2006; 13:778-86. [PMID: 16906158 DOI: 10.1038/nsmb1134] [Citation(s) in RCA: 341] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Accepted: 07/21/2006] [Indexed: 12/12/2022]
Abstract
Activation of heterotrimeric G proteins by their cognate seven transmembrane domain receptors is believed to involve conformational changes propagated from the receptor to the G proteins. However, the nature of these changes remains unknown. We monitored the conformational rearrangements at the interfaces between receptors and G proteins and between G protein subunits by measuring bioluminescence resonance energy transfer between probes inserted at multiple sites in receptor-G protein complexes. Using the data obtained for the alpha(2A)AR-G alpha(i1) beta1gamma2 complex and the available crystal structures of G alpha(i1) beta1gamma2, we propose a model wherein agonist binding induces conformational reorganization of a preexisting receptor-G protein complex, leading the G alpha-G betagamma interface to open but not dissociate. This conformational change may represent the movement required to allow nucleotide exit from the G alpha subunit, thus reflecting the initial activation event.
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Affiliation(s)
- Céline Galés
- Department of Biochemistry and Groupe de Recherche Universitaire sur le Médicament, Institute for Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown station, Montreal, Quebec, Canada H3C 3J7
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Lissandron V, Zaccolo M. Compartmentalized cAMP/PKA signalling regulates cardiac excitation-contraction coupling. J Muscle Res Cell Motil 2006; 27:399-403. [PMID: 16902751 DOI: 10.1007/s10974-006-9077-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Accepted: 06/21/2006] [Indexed: 02/03/2023]
Abstract
The sympathetic control over excitation-contraction coupling (ECC) is mediated by the cAMP/PKA signalling pathway. However, in the myocyte, the same signalling pathway is responsible for triggering a plethora of diverse intracellular functions the control of which must be independent of the regulation of ECC. Here we discuss what are the molecular mechanisms leading to selective modulation of ECC in cardiac myocytes with a particular focus on the role of spatial confinement of PKA subsets and the compartmentalization of cAMP.
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Affiliation(s)
- Valentina Lissandron
- Dulbecco Telethon Institute, Venetian Institute of Molecular Medicine, Via Orus 2, 35100, Padova, Italy
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50
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Head BP, Patel HH, Roth DM, Murray F, Swaney JS, Niesman IR, Farquhar MG, Insel PA. Microtubules and actin microfilaments regulate lipid raft/caveolae localization of adenylyl cyclase signaling components. J Biol Chem 2006; 281:26391-9. [PMID: 16818493 DOI: 10.1074/jbc.m602577200] [Citation(s) in RCA: 221] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Microtubules and actin filaments regulate plasma membrane topography, but their role in compartmentation of caveolae-resident signaling components, in particular G protein-coupled receptors (GPCR) and their stimulation of cAMP production, has not been defined. We hypothesized that the microtubular and actin cytoskeletons influence the expression and function of lipid rafts/caveolae, thereby regulating the distribution of GPCR signaling components that promote cAMP formation. Depolymerization of microtubules with colchicine (Colch) or actin microfilaments with cytochalasin D (CD) dramatically reduced the amount of caveolin-3 in buoyant (sucrose density) fractions of adult rat cardiac myocytes. Colch or CD treatment led to the exclusion of caveolin-1, caveolin-2, beta1-adrenergic receptors (beta1-AR), beta2-AR, Galpha(s), and adenylyl cyclase (AC)5/6 from buoyant fractions, decreasing AC5/6 and tyrosine-phosphorylated caveolin-1 in caveolin-1 immunoprecipitates but in parallel increased isoproterenol (beta-AR agonist)-stimulated cAMP production. Incubation with Colch decreased co-localization (by immunofluorescence microscopy) of caveolin-3 and alpha-tubulin; both Colch and CD decreased co-localization of caveolin-3 and filamin (an F-actin cross-linking protein), decreased phosphorylation of caveolin-1, Src, and p38 MAPK, and reduced the number of caveolae/mum of sarcolemma (determined by electron microscopy). Treatment of S49 T-lymphoma cells (which possess lipid rafts but lack caveolae) with CD or Colch redistributed a lipid raft marker (linker for activation of T cells (LAT)) and Galpha(s) from lipid raft domains. We conclude that microtubules and actin filaments restrict cAMP formation by regulating the localization and interaction of GPCR-G(s)-AC in lipid rafts/caveolae.
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Affiliation(s)
- Brian P Head
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, USA
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