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Rodriguez-Contreras D, García-Nafría J, Chan AE, Shinde U, Neve KA. Comparison of the function of two novel human dopamine D2 receptor variants identifies a likely mechanism for their pathogenicity. Biochem Pharmacol 2024:116228. [PMID: 38643909 DOI: 10.1016/j.bcp.2024.116228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/29/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024]
Abstract
Two recently discovered DRD2 mutations, c.634A > T, p.Ile212Phe and c.1121T > G, p.Met374Arg, cause hyperkinetic movement disorders that have overlapping features but apparently differ in severity. The two known carriers of the Met374Arg variant had early childhood disease onset and more severe motor, cognitive, and neuropsychiatric deficits than any known carriers of the Ile212Phe variant, whose symptoms were first apparent in adolescence. Here, we evaluated if differences in the function of the two variants in cultured cells could explain differing pathogenicity. Both variants were expressed less abundantly than the wild type receptor and exhibited loss of agonist-induced arrestin binding, but differences in expression and arrestin binding between the variants were minor. Basal and agonist-induced activation of heterotrimeric Gi/o/z proteins, however, showed clear differences; agonists were generally more potent at Met374Arg than at the Ile212Phe or wild type variants. Furthermore, all Gα subtypes tested were constitutively activated more by Met374Arg than by Ile212Phe. Met374Arg produced greater constitutive inhibition of cyclic AMP accumulation than Ile212Phe or the wild type D2 receptor. Met374Arg and Ile212Phe were more sensitive to thermal inactivation than the wild type D2 receptor, as reported for other constitutively active receptors, but Ile212Phe was affected more than Met374Arg. Additional pharmacological characterization suggested that the mutations differentially affect the shape of the agonist binding pocket and the potency of dopamine, norepinephrine, and tyramine. Molecular dynamics simulations provided a structural rationale for enhanced constitutive activation and agonist potency. Enhanced constitutive and agonist-induced G protein-mediated signaling likely contributes to the pathogenicity of these novel variants.
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Affiliation(s)
- Dayana Rodriguez-Contreras
- Research Service, Veterans Affairs Portland Health Care System, and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA
| | - Javier García-Nafría
- Institute for Biocomputation and Physics of Complex Systems (BIFI) and Laboratory of Advanced Microscopy (LMA), University of Zaragoza, 50018, Zaragoza, Spain
| | - Amy E Chan
- Research Service, Veterans Affairs Portland Health Care System, and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ujwal Shinde
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kim A Neve
- Research Service, Veterans Affairs Portland Health Care System, and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA.
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2
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Lefevre TJ, Wei W, Mukhaleva E, Meda Venkata SP, Chandan NR, Abraham S, Li Y, Dessauer CW, Vaidehi N, Smrcka AV. Stabilization of interdomain interactions in G protein α subunits as a determinant of Gα i subtype signaling specificity. J Biol Chem 2024; 300:107211. [PMID: 38522511 DOI: 10.1016/j.jbc.2024.107211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 03/26/2024] Open
Abstract
Highly homologous members of the Gαi family, Gαi1-3, have distinct tissue distributions and physiological functions, yet their biochemical and functional properties are very similar. We recently identified PDZ-RhoGEF (PRG) as a novel Gαi1 effector that is poorly activated by Gαi2. In a proteomic proximity labeling screen we observed a strong preference for Gαi1 relative to Gαi2 with respect to engagement of a broad range of potential targets. We investigated the mechanistic basis for this selectivity using PRG as a representative target. Substitution of either the helical domain (HD) from Gαi1 into Gαi2 or substitution of a single amino acid, A230 in Gαi2 with the corresponding D in Gαi1, largely rescues PRG activation and interactions with other potential Gαi targets. Molecular dynamics simulations combined with Bayesian network models revealed that in the GTP bound state, separation at the HD-Ras-like domain (RLD) interface is more pronounced in Gαi2 than Gαi1. Mutation of A230 to D in Gαi2 stabilizes HD-RLD interactions via ionic interactions with R145 in the HD which in turn modify the conformation of Switch III. These data support a model where D229 in Gαi1 interacts with R144 and stabilizes a network of interactions between HD and RLD to promote protein target recognition. The corresponding A230 in Gαi2 is unable to stabilize this network leading to an overall lower efficacy with respect to target interactions. This study reveals distinct mechanistic properties that could underly differential biological and physiological consequences of activation of Gαi1 or Gαi2 by G protein-coupled receptors.
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Affiliation(s)
- Tyler J Lefevre
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA; Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Wenyuan Wei
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA
| | - Elizaveta Mukhaleva
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA
| | | | - Naincy R Chandan
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA; Genentech, South San Francisco, California, USA
| | - Saji Abraham
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Yong Li
- Department of Integrative Biology and Pharmacology McGovern Medical School, UTHealth, Houston, Texas, USA
| | - Carmen W Dessauer
- Department of Integrative Biology and Pharmacology McGovern Medical School, UTHealth, Houston, Texas, USA
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA
| | - Alan V Smrcka
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
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3
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Schuster D, Khanppnavar B, Kantarci I, Mehta V, Korkhov VM. Structural insights into membrane adenylyl cyclases, initiators of cAMP signaling. Trends Biochem Sci 2024; 49:156-168. [PMID: 38158273 DOI: 10.1016/j.tibs.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024]
Abstract
Membrane adenylyl cyclases (ACs) catalyze the conversion of ATP to the ubiquitous second messenger cAMP. As effector proteins of G protein-coupled receptors and other signaling pathways, ACs receive and amplify signals from the cell surface, translating them into biochemical reactions in the intracellular space and integrating different signaling pathways. Despite their importance in signal transduction and physiology, our knowledge about the structure, function, regulation, and molecular interactions of ACs remains relatively scarce. In this review, we summarize recent advances in our understanding of these membrane enzymes.
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Affiliation(s)
- Dina Schuster
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen, Switzerland; Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Switzerland; Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Switzerland
| | - Basavraj Khanppnavar
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen, Switzerland; Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Switzerland
| | - Ilayda Kantarci
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen, Switzerland
| | - Ved Mehta
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen, Switzerland
| | - Volodymyr M Korkhov
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen, Switzerland; Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Switzerland.
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4
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Ferrero-Serrano Á, Chakravorty D, Kirven KJ, Assmann SM. Oryza CLIMtools: A Genome-Environment Association Resource Reveals Adaptive Roles for Heterotrimeric G Proteins in the Regulation of Rice Agronomic Traits. bioRxiv 2023:2023.05.10.540241. [PMID: 37214799 PMCID: PMC10197702 DOI: 10.1101/2023.05.10.540241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Modern crop varieties display a degree of mismatch between their current distributions and the suitability of the local climate for their productivity. To this end, we present Oryza CLIMtools (https://gramene.org/CLIMtools/oryza_v1.0/), the first resource for pan-genome prediction of climate-associated genetic variants in a crop species. Oryza CLIMtools consists of interactive web-based databases that allow the user to: i) explore the local environments of traditional rice varieties (landraces) in South-Eastern Asia, and; ii) investigate the environment by genome associations for 658 Indica and 283 Japonica rice landrace accessions collected from georeferenced local environments and included in the 3K Rice Genomes Project. We exemplify the value of these resources, identifying an interplay between flowering time and temperature in the local environment that is facilitated by adaptive natural variation in OsHD2 and disrupted by a natural variant in OsSOC1. Prior QTL analysis has suggested the importance of heterotrimeric G proteins in the control of agronomic traits. Accordingly, we analyzed the climate associations of natural variants in the different heterotrimeric G protein subunits. We identified a coordinated role of G proteins in adaptation to the prevailing Potential Evapotranspiration gradient and their regulation of key agronomic traits including plant height and seed and panicle length. We conclude by highlighting the prospect of targeting heterotrimeric G proteins to produce crops that are climate resilient.
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Affiliation(s)
- Ángel Ferrero-Serrano
- Biology Department, Pennsylvania State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
| | - David Chakravorty
- Biology Department, Pennsylvania State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
| | - Kobie J. Kirven
- Intercollege Graduate Degree Program in Bioinformatics and Genomics, Pennsylvania State University
| | - Sarah M. Assmann
- Biology Department, Pennsylvania State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
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5
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Cantos CF, dePamphilis CW, Assmann SM. Extra-large G proteins have extra-large effects on agronomic traits and stress tolerance in maize and rice. Trends Plant Sci 2023; 28:1033-1044. [PMID: 37156701 PMCID: PMC10524845 DOI: 10.1016/j.tplants.2023.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 04/01/2023] [Accepted: 04/04/2023] [Indexed: 05/10/2023]
Abstract
Heterotrimeric G proteins - comprising Gα, Gβ, and Gγ subunits - are ubiquitous elements in eukaryotic cell signaling. Plant genomes contain both canonical Gα subunit genes and a family of plant-specific extra-large G protein genes (XLGs) that encode proteins consisting of a domain with Gα-like features downstream of a long N-terminal domain. In this review we summarize phenotypes modulated by the canonical Gα and XLG proteins of arabidopsis and highlight recent studies in maize and rice that reveal dramatic phenotypic consequences of XLG clustered regularly interspaced short palindromic repeats (CRISPR) mutagenesis in these important crop species. XLGs have both redundant and specific roles in the control of agronomically relevant plant architecture and resistance to both abiotic and biotic stresses. We also point out areas of current controversy, suggest future research directions, and propose a revised, phylogenetically-based nomenclature for XLG protein genes.
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Affiliation(s)
- Christian F Cantos
- Biology Department, Penn State University, University Park, State College, PA, USA; Intercollege Graduate Degree Program in Plant Biology, Penn State University, University Park, State College, PA, USA
| | - Claude W dePamphilis
- Biology Department, Penn State University, University Park, State College, PA, USA; Intercollege Graduate Degree Program in Plant Biology, Penn State University, University Park, State College, PA, USA
| | - Sarah M Assmann
- Biology Department, Penn State University, University Park, State College, PA, USA; Intercollege Graduate Degree Program in Plant Biology, Penn State University, University Park, State College, PA, USA.
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6
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Su X, Pang YT, Li W, Gumbart JC, Kelley J, Torres M. N-terminal intrinsic disorder is an ancestral feature of Gγ subunits that influences the balance between different Gβγ signaling axes in yeast. J Biol Chem 2023; 299:104947. [PMID: 37354971 PMCID: PMC10393545 DOI: 10.1016/j.jbc.2023.104947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/02/2023] [Accepted: 06/16/2023] [Indexed: 06/26/2023] Open
Abstract
Activated G protein-coupled receptors promote the dissociation of heterotrimeric G proteins into Gα and Gβγ subunits that bind to effector proteins to drive intracellular signaling responses. In yeast, Gβγ subunits coordinate the simultaneous activation of multiple signaling axes in response to mating pheromones, including MAP kinase (MAPK)-dependent transcription, cell polarization, and cell cycle arrest responses. The Gγ subunit in this complex contains an N-terminal intrinsically disordered region that governs Gβγ-dependent signal transduction in yeast and mammals. Here, we demonstrate that N-terminal intrinsic disorder is likely an ancestral feature that has been conserved across different Gγ subtypes and organisms. To understand the functional contribution of structural disorder in this region, we introduced precise point mutations that produce a stepwise disorder-to-order transition in the N-terminal tail of the canonical yeast Gγ subunit, Ste18. Mutant tail structures were confirmed using circular dichroism and molecular dynamics and then substituted for the wildtype gene in yeast. We find that increasing the number of helix-stabilizing mutations, but not isometric mutation controls, has a negative and proteasome-independent effect on Ste18 protein levels as well as a differential effect on pheromone-induced levels of active MAPK/Fus3, but not MAPK/Kss1. When expressed at wildtype levels, we further show that mutants with an alpha-helical N terminus exhibit a counterintuitive shift in Gβγ signaling that reduces active MAPK/Fus3 levels whilst increasing cell polarization and cell cycle arrest. These data reveal a role for Gγ subunit intrinsically disordered regions in governing the balance between multiple Gβγ signaling axes.
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Affiliation(s)
- Xinya Su
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Yui Tik Pang
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Wei Li
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA; Southeast Center for Mathematics and Biology, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - J C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Joshua Kelley
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine, USA
| | - Matthew Torres
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA; Southeast Center for Mathematics and Biology, Georgia Institute of Technology, Atlanta, Georgia, USA.
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7
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Shpakov AO. Allosteric Regulation of G-Protein-Coupled Receptors: From Diversity of Molecular Mechanisms to Multiple Allosteric Sites and Their Ligands. Int J Mol Sci 2023; 24:6187. [PMID: 37047169 PMCID: PMC10094638 DOI: 10.3390/ijms24076187] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Allosteric regulation is critical for the functioning of G protein-coupled receptors (GPCRs) and their signaling pathways. Endogenous allosteric regulators of GPCRs are simple ions, various biomolecules, and protein components of GPCR signaling (G proteins and β-arrestins). The stability and functional activity of GPCR complexes is also due to multicenter allosteric interactions between protomers. The complexity of allosteric effects caused by numerous regulators differing in structure, availability, and mechanisms of action predetermines the multiplicity and different topology of allosteric sites in GPCRs. These sites can be localized in extracellular loops; inside the transmembrane tunnel and in its upper and lower vestibules; in cytoplasmic loops; and on the outer, membrane-contacting surface of the transmembrane domain. They are involved in the regulation of basal and orthosteric agonist-stimulated receptor activity, biased agonism, GPCR-complex formation, and endocytosis. They are targets for a large number of synthetic allosteric regulators and modulators, including those constructed using molecular docking. The review is devoted to the principles and mechanisms of GPCRs allosteric regulation, the multiplicity of allosteric sites and their topology, and the endogenous and synthetic allosteric regulators, including autoantibodies and pepducins. The allosteric regulation of chemokine receptors, proteinase-activated receptors, thyroid-stimulating and luteinizing hormone receptors, and beta-adrenergic receptors are described in more detail.
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Affiliation(s)
- Alexander O Shpakov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia
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8
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Wang Y, Zhang H, Wang P, Zhong H, Liu W, Zhang S, Xiong L, Wu Y, Xia Y. Arabidopsis EXTRA-LARGE G PROTEIN 1 (XLG1) functions together with XLG2 and XLG3 in PAMP-triggered MAPK activation and immunity. J Integr Plant Biol 2023; 65:825-837. [PMID: 36250681 DOI: 10.1111/jipb.13391] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Pattern-triggered immunity (PTI) is an essential strategy used by plants to deploy broad-spectrum resistance against pathogen attacks. Heterotrimeric G proteins have been reported to contribute to PTI. Of the three non-canonical EXTRA-LARGE G PROTEINs (XLGs) in Arabidopsis thaliana, XLG2 and XLG3 were shown to positively regulate immunity, but XLG1 was not considered to function in defense, based on the analysis of a weak xlg1 allele. In this study, we characterized the xlg1 xlg2 xlg3 triple knockout mutants generated from an xlg1 knockout allele. The strong xlg1 xlg2 xlg3 triple mutants compromised pathogen-associated molecular pattern (PAMP)-triggered activation of mitogen-activated protein kinases (MAPKs) and resistance to pathogen infection. The three XLGs interacted with MAPK cascade proteins involved in defense signaling, including the MAPK kinase kinases MAPKKK3 and MAPKKK5, the MAPK kinases MKK4 and MKK5, and the MAPKs MPK3 and MPK6. Expressing a constitutively active form of MKK4 restored MAPK activation and partially recovered the compromised disease resistance seen in the strong xlg1 xlg2 xlg3 triple mutant. Furthermore, mutations of all three XLGs largely restored the phenotype of the autoimmunity mutant bak1-interacting receptor-like kinase 1. Our study reveals that all three XLGs function redundantly in PAMP-triggered MAPK activation and plant immunity.
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Affiliation(s)
- Yiping Wang
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
- Institute for Research and Continuing Education, Hong Kong Baptist University, Shen Zhen, 518057, China
| | - Hailei Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
| | - Pengxi Wang
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
| | - Huan Zhong
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
| | - Wuzhen Liu
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
| | - Shoudong Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
| | - Liming Xiong
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
| | - Yingying Wu
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong, 999077, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, 999077, China
- State Key Laboratory of Biological and Environmental Analysis, Hong Kong Baptist University, Hong Kong, 999077, China
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9
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Jenkins JE, Roberts-Galbraith RH. Heterotrimeric G proteins regulate planarian regeneration and behavior. Genetics 2023; 223:7034221. [PMID: 36763503 PMCID: PMC10078920 DOI: 10.1093/genetics/iyad019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 01/23/2023] [Accepted: 01/30/2023] [Indexed: 02/11/2023] Open
Abstract
G protein-coupled receptors play broad roles in development and stem cell biology, but few roles for G protein-coupled receptor signaling in complex tissue regeneration have been uncovered. Planarian flatworms robustly regenerate all tissues and provide a model with which to explore potential functions for G protein-coupled receptor signaling in somatic regeneration and pluripotent stem cell biology. As a first step toward exploring G protein-coupled receptor function in planarians, we investigated downstream signal transducers that work with G protein-coupled receptors, called heterotrimeric G proteins. Here, we characterized the complete heterotrimeric G protein complement in Schmidtea mediterranea for the first time and found that seven heterotrimeric G protein subunits promote regeneration. We further characterized two subunits critical for regeneration, Gαq1 and Gβ1-4a, finding that they promote the late phase of anterior polarity re-establishment, likely through anterior pole-produced Follistatin. Incidentally, we also found that five G protein subunits modulate planarian behavior. We further identified a putative serotonin receptor, gcr052, that we propose works with Gαs2 and Gβx2 in planarian locomotion, demonstrating the utility of our strategy for identifying relevant G protein-coupled receptors. Our work provides foundational insight into roles of heterotrimeric G proteins in planarian biology and serves as a useful springboard towards broadening our understanding of G protein-coupled receptor signaling in adult tissue regeneration.
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Affiliation(s)
- Jennifer E Jenkins
- Department of Cellular Biology, University of Georgia, Athens, GA USA 30602
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10
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Wu TY, Krishnamoorthi S, Boonyaves K, Al-Darabsah I, Leong R, Jones AM, Ishizaki K, Liao KL, Urano D. G protein controls stress readiness by modulating transcriptional and metabolic homeostasis in Arabidopsis thaliana and Marchantia polymorpha. Mol Plant 2022; 15:1889-1907. [PMID: 36321200 DOI: 10.1016/j.molp.2022.10.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 10/03/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
The core G protein signaling module, which consists of Gα and extra-large Gα (XLG) subunits coupled with the Gβγ dimer, is a master regulator of various stress responses. In this study, we compared the basal and salt stress-induced transcriptomic, metabolomic and phenotypic profiles in Gα, Gβ, and XLG-null mutants of two plant species, Arabidopsis thaliana and Marchantia polymorpha, and showed that G protein mediates the shift of transcriptional and metabolic homeostasis to stress readiness status. We demonstrated that such stress readiness serves as an intrinsic protection mechanism against further stressors through enhancing the phenylpropanoid pathway and abscisic acid responses. Furthermore, WRKY transcription factors were identified as key intermediates of G protein-mediated homeostatic shifts. Statistical and mathematical model comparisons between A. thaliana and M. polymorpha revealed evolutionary conservation of transcriptional and metabolic networks over land plant evolution, whereas divergence has occurred in the function of plant-specific atypical XLG subunit. Taken together, our results indicate that the shifts in transcriptional and metabolic homeostasis at least partially act as the mechanisms of G protein-coupled stress responses that are conserved between two distantly related plants.
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Affiliation(s)
- Ting-Ying Wu
- Temasek Life Sciences Laboratory, Singapore, Singapore.
| | | | - Kulaporn Boonyaves
- Temasek Life Sciences Laboratory, Singapore, Singapore; Singapore-MIT Alliance for Research and Technology, Singapore, Singapore
| | - Isam Al-Darabsah
- Department of Mathematics, University of Manitoba, Winnipeg, MB, Canada
| | - Richalynn Leong
- Temasek Life Sciences Laboratory, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Alan M Jones
- Departments of Biology and Pharmacology, University of North Carolina, Chapel Hill, NC, USA
| | - Kimitsune Ishizaki
- Graduate School of Science, Kobe University, Kobe, Hyogo 657-8501, Japan
| | - Kang-Ling Liao
- Department of Mathematics, University of Manitoba, Winnipeg, MB, Canada.
| | - Daisuke Urano
- Temasek Life Sciences Laboratory, Singapore, Singapore; Singapore-MIT Alliance for Research and Technology, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore.
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Goolam MA, Brown AP, Edwards KT, Gregory KJ, Leach K, Conigrave AD. Cell Surface Calcium-Sensing Receptor Heterodimers: Mutant Gene Dosage Affects Ca 2+ Sensing but Not G Protein Interaction. J Bone Miner Res 2022; 37:1787-1807. [PMID: 35848051 PMCID: PMC9545990 DOI: 10.1002/jbmr.4651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 06/20/2022] [Accepted: 07/14/2022] [Indexed: 11/20/2022]
Abstract
The calcium-sensing receptor is a homodimeric class C G protein-coupled receptor (GPCR) that senses extracellular Ca2+ (Ca2+ o ) via a dimeric extracellular Venus flytrap (VFT) unit that activates G protein-dependent signaling via twin Cysteine-rich domains linked to transmembrane heptahelical (HH) bundles. It plays a key role in the regulation of human calcium and thus mineral metabolism. However, the nature of interactions between VFT units and HH bundles, and the impacts of heterozygous or homozygous inactivating mutations, which have implications for disorders of calcium metabolism are not yet clearly defined. Herein we generated CaSR-GABAB1 and CaSR-GABAB2 chimeras subject to GABAB -dependent endoplasmic reticulum sorting to traffic mutant heterodimers to the cell surface. Transfected HEK-293 cells were assessed for Ca2+ o -stimulated Ca2+ i mobilization using mutations in either the VFT domains and/or HH bundle intraloop-2 or intraloop-3. When the same mutation was present in both VFT domains of receptor dimers, analogous to homozygous neonatal severe hyperparathyroidism (NSHPT), receptor function was markedly impaired. Mutant heterodimers containing one wild-type (WT) and one mutant VFT domain, however, corresponding to heterozygous familial hypocalciuric hypercalcemia type-1 (FHH-1), supported maximal signaling with reduced Ca2+ o potency. Thus two WT VFT domains were required for normal Ca2+ o potency and there was a pronounced gene-dosage effect. In contrast, a single WT HH bundle was insufficient for maximal signaling and there was no functional difference between heterodimers in which the mutation was present in one or both intraloops; ie, no gene-dosage effect. Finally, we observed that the Ca2+ o -stimulated CaSR operated exclusively via signaling in-trans and not via combined in-trans and in-cis signaling. We consider how receptor asymmetry may support the underlying mechanisms. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Mahvash A Goolam
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
| | - Alice P Brown
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
| | - Kimberly T Edwards
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
| | - Karen J Gregory
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
| | - Katie Leach
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
| | - Arthur D Conigrave
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
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12
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Moo EV, Harpsøe K, Hauser AS, Masuho I, Bräuner-Osborne H, Gloriam DE, Martemyanov KA. Ligand-directed bias of G protein signaling at the dopamine D 2 receptor. Cell Chem Biol 2022; 29:226-238.e4. [PMID: 34302750 PMCID: PMC8770702 DOI: 10.1016/j.chembiol.2021.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/21/2021] [Accepted: 07/02/2021] [Indexed: 01/11/2023]
Abstract
G-protein-coupled receptors (GPCRs) represent the largest family of drug targets. Upon activation, GPCRs signal primarily via a diverse set of heterotrimeric G proteins. Most GPCRs can couple to several different G protein subtypes. However, how drugs act at GPCRs contributing to the selectivity of G protein recognition is poorly understood. Here, we examined the G protein selectivity profile of the dopamine D2 receptor (D2), a GPCR targeted by antipsychotic drugs. We show that D2 discriminates between six individual members of the Gi/o family, and its profile of functional selectivity is remarkably different across its ligands, which all engaged D2 with a distinct G protein coupling pattern. Using structural modeling, receptor mutagenesis, and pharmacological evaluation, we identified residues in the D2 binding pocket that shape these ligand-directed biases. We further provide pharmacogenomic evidence that natural variants in D2 differentially affect its G protein biases in response to different ligands.
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Affiliation(s)
- Ee Von Moo
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA,Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Kasper Harpsøe
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Alexander S Hauser
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Ikuo Masuho
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - David E. Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Kirill A. Martemyanov
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
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13
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Wu L, Wang X, Yu Z, Cui X, Xu Q. Simultaneous Improvement of Grain Yield and Quality through Manipulating Two Type C G Protein Gamma Subunits in Rice. Int J Mol Sci 2022; 23:1463. [PMID: 35163383 DOI: 10.3390/ijms23031463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 02/01/2023] Open
Abstract
Heterotrimeric G protein signaling is an evolutionarily conserved mechanism in diverse organisms that mediates intracellular responses to external stimuli. In rice, the G proteins are involved in the regulation of multiple important agronomic traits. In this paper, we present our finding that two type C G protein gamma subunits, DEP1 and GS3, antagonistically regulated grain yield and grain quality. The DEP1 gene editing we conducted, significantly increased the grain number per panicle but had a negative impact on taste value, texture properties, and chalkiness-related traits. The GS3 gene editing decreased grain number per panicle but significantly increased grain length. In addition, the GS3 gene-edited plants showed improved taste value, appearance, texture properties, and Rapid Visco Analyser (RVA) profiles. To combine the advantages of both gs3 and dep1, we conducted a molecular design breeding at the GS3 locus of a “super rice” variety, SN265, which has a truncated dep1 allele with erect panicle architecture, high-yield performance, and which is of mediocre eating quality. The elongated grain size of the sn265/gs3 gene-edited plants further increased the grain yield. More importantly, the texture properties and RVA profiles were significantly improved, and the taste quality was enhanced. Beyond showcasing the combined function of dep1 and gs3, this paper presents a strategy for the simultaneous improvement of rice grain yield and quality through manipulating two type C G protein gamma subunits in rice.
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14
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Hussain M, Cummins MC, Endo-Streeter S, Sondek J, Kuhlman B. Designer proteins that competitively inhibit Gα q by targeting its effector site. J Biol Chem 2021; 297:101348. [PMID: 34715131 PMCID: PMC8633581 DOI: 10.1016/j.jbc.2021.101348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 10/12/2021] [Accepted: 10/22/2021] [Indexed: 11/30/2022] Open
Abstract
During signal transduction, the G protein, Gαq, binds and activates phospholipase C-β isozymes. Several diseases have been shown to manifest upon constitutively activating mutation of Gαq, such as uveal melanoma. Therefore, methods are needed to directly inhibit Gαq. Previously, we demonstrated that a peptide derived from a helix-turn-helix (HTH) region of PLC-β3 (residues 852-878) binds Gαq with low micromolar affinity and inhibits Gαq by competing with full-length PLC-β isozymes for binding. Since the HTH peptide is unstructured in the absence of Gαq, we hypothesized that embedding the HTH in a folded protein might stabilize the binding-competent conformation and further improve the potency of inhibition. Using the molecular modeling software Rosetta, we searched the Protein Data Bank for proteins with similar HTH structures near their surface. The candidate proteins were computationally docked against Gαq, and their surfaces were redesigned to stabilize this interaction. We then used yeast surface display to affinity mature the designs. The most potent design bound Gαq/i with high affinity in vitro (KD = 18 nM) and inhibited activation of PLC-β isozymes in HEK293 cells. We anticipate that our genetically encoded inhibitor will help interrogate the role of Gαq in healthy and disease model systems. Our work demonstrates that grafting interaction motifs into folded proteins is a powerful approach for generating inhibitors of protein-protein interactions.
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Affiliation(s)
- Mahmud Hussain
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Matthew C Cummins
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Stuart Endo-Streeter
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - John Sondek
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA; Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA.
| | - Brian Kuhlman
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA.
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15
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Zait Y, Ferrero‐Serrano Á, Assmann SM. The α subunit of the heterotrimeric G protein regulates mesophyll CO 2 conductance and drought tolerance in rice. New Phytol 2021; 232:2324-2338. [PMID: 34515342 PMCID: PMC9293471 DOI: 10.1111/nph.17730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 09/01/2021] [Indexed: 05/03/2023]
Abstract
Mesophyll conductance gm determines CO2 diffusion rates from mesophyll intercellular air spaces to the chloroplasts and is an important factor limiting photosynthesis. Increasing gm in cultivated plants is a potential strategy to increase photosynthesis and intrinsic water use efficiency (WUEi ). The anatomy of the leaf and metabolic factors such as aquaporins and carbonic anhydrases have been identified as important determinants of gm . However, genes involved in the regulation and modulation of gm remain largely unknown. In this work, we investigated the role of heterotrimeric G proteins in gm and drought tolerance in rice d1 mutants, which harbor a null mutation in the Gα subunit gene, RGA1. d1 mutants in both cv Nipponbare and cv Taichung 65 exhibited increased gm , fostering improvement in photosynthesis, WUEi , and drought tolerance compared with wild-type. The increased surface area of mesophyll cells and chloroplasts exposed to intercellular airspaces and the reduced cell wall and chloroplast thickness in the d1 mutant are evident contributors to the increase in gm . Our results indicate that manipulation of heterotrimeric G protein signaling has the potential to improve crop WUEi and productivity under drought.
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Affiliation(s)
- Yotam Zait
- Biology DepartmentPenn State University208 Mueller LaboratoryUniversity ParkPA16802USA
| | - Ángel Ferrero‐Serrano
- Biology DepartmentPenn State University208 Mueller LaboratoryUniversity ParkPA16802USA
| | - Sarah M. Assmann
- Biology DepartmentPenn State University208 Mueller LaboratoryUniversity ParkPA16802USA
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16
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García-Jiménez I, Cervantes-Villagrana RD, Del-Río-Robles JE, Castillo-Kauil A, Beltrán-Navarro YM, García-Román J, Reyes-Cruz G, Vázquez-Prado J. Gβγ mediates activation of Rho guanine nucleotide exchange factor ARHGEF17 that promotes metastatic lung cancer progression. J Biol Chem 2021; 298:101440. [PMID: 34808208 PMCID: PMC8703085 DOI: 10.1016/j.jbc.2021.101440] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 11/10/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022] Open
Abstract
Metastatic lung cancer is a major cause of death worldwide. Dissemination of cancer cells can be facilitated by various agonists within the tumor microenvironment, including by lysophosphatidic acid (LPA). We postulate that Rho guanine nucleotide exchange factors (RhoGEFs), which integrate signaling cues driving cell migration, are critical effectors in metastatic cancer. Specifically, we addressed the hypothetical role of ARHGEF17, a RhoGEF, as a potential effector of Gβγ in metastatic lung cancer cells responding to LPA. Here, we show that ARHGEF17, originally identified as a tumor endothelial marker, is involved in tumor growth and metastatic dissemination of lung cancer cells in an immunocompetent murine model. Gene expression–based analysis of lung cancer datasets showed that increased levels of ARHGEF17 correlated with reduced survival of patients with advanced-stage tumors. Cellular assays also revealed that this RhoGEF participates in the invasive and migratory responses elicited by Gi protein–coupled LPA receptors via the Gβγ subunit complex. We demonstrate that this signaling heterodimer promoted ARHGEF17 recruitment to the cell periphery and actin fibers. Moreover, Gβγ allosterically activates ARHGEF17 by the removal of inhibitory intramolecular restrictions. Taken together, our results indicate that ARHGEF17 may be a valid potential target in the treatment of metastatic lung cancer.
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17
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Kamimura Y, Ueda M. Different Heterotrimeric G Protein Dynamics for Wide-Range Chemotaxis in Eukaryotic Cells. Front Cell Dev Biol 2021; 9:724797. [PMID: 34414196 PMCID: PMC8369479 DOI: 10.3389/fcell.2021.724797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 07/13/2021] [Indexed: 01/14/2023] Open
Abstract
Chemotaxis describes directional motility along ambient chemical gradients and has important roles in human physiology and pathology. Typical chemotactic cells, such as neutrophils and Dictyostelium cells, can detect spatial differences in chemical gradients over a background concentration of a 105 scale. Studies of Dictyostelium cells have elucidated the molecular mechanisms of gradient sensing involving G protein coupled receptor (GPCR) signaling. GPCR transduces spatial information through its cognate heterotrimeric G protein as a guanine nucleotide change factor (GEF). More recently, studies have revealed unconventional regulation of heterotrimeric G protein in the gradient sensing. In this review, we explain how multiple mechanisms of GPCR signaling ensure the broad range sensing of chemical gradients in Dictyostelium cells as a model for eukaryotic chemotaxis.
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Affiliation(s)
- Yoichiro Kamimura
- Laboratory for Cell Signaling Dynamics, RIKEN, Center for Biosystems Dynamics Research (BDR), Suita, Japan.,Laboratory of Single Molecule Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Masahiro Ueda
- Laboratory for Cell Signaling Dynamics, RIKEN, Center for Biosystems Dynamics Research (BDR), Suita, Japan.,Laboratory of Single Molecule Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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18
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Kumar S, Olson AC, Koelle MR. The neural G protein Gαo tagged with GFP at an internal loop is functional in C. elegans. G3 (Bethesda) 2021; 11:6277897. [PMID: 34003969 PMCID: PMC8496287 DOI: 10.1093/g3journal/jkab167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 05/01/2021] [Indexed: 11/23/2022]
Abstract
Gαo is the alpha subunit of the major heterotrimeric G protein in neurons and mediates signaling by every known neurotransmitter, yet the signaling mechanisms activated by Gαo remain to be fully elucidated. Genetic analysis in Caenorhabditis elegans has shown that Gαo signaling inhibits neuronal activity and neurotransmitter release, but studies of the molecular mechanisms underlying these effects have been limited by lack of tools to complement genetic studies with other experimental approaches. Here, we demonstrate that inserting the green fluorescent protein (GFP) into an internal loop of the Gαo protein results in a tagged protein that is functional in vivo and that facilitates cell biological and biochemical studies of Gαo. Transgenic expression of Gαo-GFP rescues the defects caused by loss of endogenous Gαo in assays of egg laying and locomotion behaviors. Defects in body morphology caused by loss of Gαo are also rescued by Gαo-GFP. The Gαo-GFP protein is localized to the plasma membrane of neurons, mimicking localization of endogenous Gαo. Using GFP as an epitope tag, Gαo-GFP can be immunoprecipitated from C. elegans lysates to purify Gαo protein complexes. The Gαo-GFP transgene reported in this study enables studies involving in vivo localization and biochemical purification of Gαo to compliment the already well-developed genetic analysis of Gαo signaling.
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Affiliation(s)
- Santosh Kumar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 USA
| | - Andrew C Olson
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 USA
| | - Michael R Koelle
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 USA
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19
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Sandhu HK, Neuman JC, Schaid MD, Davis SE, Connors KM, Challa R, Guthery E, Fenske RJ, Patibandla C, Breyer RM, Kimple ME. Rat prostaglandin EP3 receptor is highly promiscuous and is the sole prostanoid receptor family member that regulates INS-1 (832/3) cell glucose-stimulated insulin secretion. Pharmacol Res Perspect 2021; 9:e00736. [PMID: 33694300 PMCID: PMC7947324 DOI: 10.1002/prp2.736] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/27/2021] [Accepted: 01/27/2021] [Indexed: 12/19/2022] Open
Abstract
Chronic elevations in fatty acid metabolites termed prostaglandins can be found in circulation and in pancreatic islets from mice or humans with diabetes and have been suggested as contributing to the β‐cell dysfunction of the disease. Two‐series prostaglandins bind to a family of G‐protein‐coupled receptors, each with different biochemical and pharmacological properties. Prostaglandin E receptor (EP) subfamily agonists and antagonists have been shown to influence β‐cell insulin secretion, replication, and/or survival. Here, we define EP3 as the sole prostanoid receptor family member expressed in a rat β‐cell‐derived line that regulates glucose‐stimulated insulin secretion. Several other agonists classically understood as selective for other prostanoid receptor family members also reduce glucose‐stimulated insulin secretion, but these effects are only observed at relatively high concentrations, and, using a well‐characterized EP3‐specific antagonist, are mediated solely by cross‐reactivity with rat EP3. Our findings confirm the critical role of EP3 in regulating β‐cell function, but are also of general interest, as many agonists supposedly selective for other prostanoid receptor family members are also full and efficacious agonists of EP3. Therefore, care must be taken when interpreting experimental results from cells or cell lines that also express EP3.
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Affiliation(s)
- Harpreet K Sandhu
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Joshua C Neuman
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael D Schaid
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Sarah E Davis
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kelsey M Connors
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Romith Challa
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Erin Guthery
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Rachel J Fenske
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Chinmai Patibandla
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Richard M Breyer
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michelle E Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA.,Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, USA
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20
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Patt J, Alenfelder J, Pfeil EM, Voss JH, Merten N, Eryilmaz F, Heycke N, Rick U, Inoue A, Kehraus S, Deupi X, Müller CE, König GM, Crüsemann M, Kostenis E. An experimental strategy to probe Gq contribution to signal transduction in living cells. J Biol Chem 2021; 296:100472. [PMID: 33639168 PMCID: PMC8024710 DOI: 10.1016/j.jbc.2021.100472] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 12/14/2022] Open
Abstract
Heterotrimeric G protein subunits Gαq and Gα11 are inhibited by two cyclic depsipeptides, FR900359 (FR) and YM-254890 (YM), both of which are being used widely to implicate Gq/11 proteins in the regulation of diverse biological processes. An emerging major research question therefore is whether the cellular effects of both inhibitors are on-target, that is, mediated via specific inhibition of Gq/11 proteins, or off-target, that is, the result of nonspecific interactions with other proteins. Here we introduce a versatile experimental strategy to discriminate between these possibilities. We developed a Gαq variant with preserved catalytic activity, but refractory to FR/YM inhibition. A minimum of two amino acid changes were required and sufficient to achieve complete inhibitor resistance. We characterized the novel mutant in HEK293 cells depleted by CRISPR–Cas9 of endogenous Gαq and Gα11 to ensure precise control over the Gα-dependent cellular signaling route. Using a battery of cellular outcomes with known and concealed Gq contribution, we found that FR/YM specifically inhibited cellular signals after Gαq introduction via transient transfection. Conversely, both inhibitors were inert across all assays in cells expressing the drug-resistant variant. These findings eliminate the possibility that inhibition of non-Gq proteins contributes to the cellular effects of the two depsipeptides. We conclude that combined application of FR or YM along with the drug-resistant Gαq variant is a powerful in vitro strategy to discern on-target Gq against off-target non-Gq action. Consequently, it should be of high value for uncovering Gq input to complex biological processes with high accuracy and the requisite specificity.
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Affiliation(s)
- Julian Patt
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Judith Alenfelder
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Eva Marie Pfeil
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Jan Hendrik Voss
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical and Medicinal Chemistry, University of Bonn, Bonn, Germany
| | - Nicole Merten
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Funda Eryilmaz
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Nina Heycke
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Uli Rick
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Stefan Kehraus
- Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Xavier Deupi
- Laboratory of Biomolecular Research and Condensed Matter Theory Group, Paul Scherrer Institute, Villigen, Switzerland
| | - Christa E Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical and Medicinal Chemistry, University of Bonn, Bonn, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Max Crüsemann
- Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Evi Kostenis
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany.
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21
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Castillo-Kauil A, García-Jiménez I, Cervantes-Villagrana RD, Adame-García SR, Beltrán-Navarro YM, Gutkind JS, Reyes-Cruz G, Vázquez-Prado J. Gα s directly drives PDZ-RhoGEF signaling to Cdc42. J Biol Chem 2020; 295:16920-16928. [PMID: 33023908 PMCID: PMC7863908 DOI: 10.1074/jbc.ac120.015204] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/24/2020] [Indexed: 12/16/2022] Open
Abstract
Gα proteins promote dynamic adjustments of cell shape directed by actin-cytoskeleton reorganization via their respective RhoGEF effectors. For example, Gα13 binding to the RGS-homology (RH) domains of several RH-RhoGEFs allosterically activates these proteins, causing them to expose their catalytic Dbl-homology (DH)/pleckstrin-homology (PH) regions, which triggers downstream signals. However, whether additional Gα proteins might directly regulate the RH-RhoGEFs was not known. To explore this question, we first examined the morphological effects of expressing shortened RH-RhoGEF DH/PH constructs of p115RhoGEF/ARHGEF1, PDZ-RhoGEF (PRG)/ARHGEF11, and LARG/ARHGEF12. As expected, the three constructs promoted cell contraction and activated RhoA, known to be downstream of Gα13 Intriguingly, PRG DH/PH also induced filopodia-like cell protrusions and activated Cdc42. This pathway was stimulated by constitutively active Gαs (GαsQ227L), which enabled endogenous PRG to gain affinity for Cdc42. A chemogenetic approach revealed that signaling by Gs-coupled receptors, but not by those coupled to Gi or Gq, enabled PRG to bind Cdc42. This receptor-dependent effect, as well as CREB phosphorylation, was blocked by a construct derived from the PRG:Gαs-binding region, PRG-linker. Active Gαs interacted with isolated PRG DH and PH domains and their linker. In addition, this construct interfered with GαsQ227L's ability to guide PRG's interaction with Cdc42. Endogenous Gs-coupled prostaglandin receptors stimulated PRG binding to membrane fractions and activated signaling to PKA, and this canonical endogenous pathway was attenuated by PRG-linker. Altogether, our results demonstrate that active Gαs can recognize PRG as a novel effector directing its DH/PH catalytic module to gain affinity for Cdc42.
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Affiliation(s)
- Alejandro Castillo-Kauil
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Irving García-Jiménez
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | | | - Sendi Rafael Adame-García
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Yarely Mabell Beltrán-Navarro
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - J Silvio Gutkind
- Moores Cancer Center and Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Guadalupe Reyes-Cruz
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - José Vázquez-Prado
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico.
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22
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Pfeil EM, Brands J, Merten N, Vögtle T, Vescovo M, Rick U, Albrecht IM, Heycke N, Kawakami K, Ono Y, Ngako Kadji FM, Hiratsuka S, Aoki J, Häberlein F, Matthey M, Garg J, Hennen S, Jobin ML, Seier K, Calebiro D, Pfeifer A, Heinemann A, Wenzel D, König GM, Nieswandt B, Fleischmann BK, Inoue A, Simon K, Kostenis E. Heterotrimeric G Protein Subunit Gαq Is a Master Switch for Gβγ-Mediated Calcium Mobilization by Gi-Coupled GPCRs. Mol Cell 2020; 80:940-954.e6. [PMID: 33202251 DOI: 10.1016/j.molcel.2020.10.027] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 09/21/2020] [Accepted: 10/16/2020] [Indexed: 12/18/2022]
Abstract
Mechanisms that control mobilization of cytosolic calcium [Ca2+]i are key for regulation of numerous eukaryotic cell functions. One such paradigmatic mechanism involves activation of phospholipase Cβ (PLCβ) enzymes by G protein βγ subunits from activated Gαi-Gβγ heterotrimers. Here, we report identification of a master switch to enable this control for PLCβ enzymes in living cells. We find that the Gαi-Gβγ-PLCβ-Ca2+ signaling module is entirely dependent on the presence of active Gαq. If Gαq is pharmacologically inhibited or genetically ablated, Gβγ can bind to PLCβ but does not elicit Ca2+ signals. Removal of an auto-inhibitory linker that occludes the active site of the enzyme is required and sufficient to empower "stand-alone control" of PLCβ by Gβγ. This dependence of Gi-Gβγ-Ca2+ on Gαq places an entire signaling branch of G-protein-coupled receptors (GPCRs) under hierarchical control of Gq and changes our understanding of how Gi-GPCRs trigger [Ca2+]i via PLCβ enzymes.
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Affiliation(s)
- Eva Marie Pfeil
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany; Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Julian Brands
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany; Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Nicole Merten
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Timo Vögtle
- Institute of Experimental Biomedicine I, University Hospital Würzburg and Rudolf Virchow Center, University of Würzburg, 97080 Würzburg, Germany
| | - Maddalena Vescovo
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Ulrike Rick
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Ina-Maria Albrecht
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Nina Heycke
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Kouki Kawakami
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Yuki Ono
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | | | - Suzune Hiratsuka
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Junken Aoki
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Felix Häberlein
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany; Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Michaela Matthey
- Department of Systems Physiology, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany; Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Jaspal Garg
- Institute of Pharmacology and Toxicology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Stephanie Hennen
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Marie-Lise Jobin
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, 97078 Würzburg, Germany
| | - Kerstin Seier
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, 97078 Würzburg, Germany
| | - Davide Calebiro
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, 97078 Würzburg, Germany; Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors, University of Birmingham, B15 2TT Birmingham, UK
| | - Alexander Pfeifer
- Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Akos Heinemann
- Division of Pharmacology, Otto-Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, 8010 Graz, Austria
| | - Daniela Wenzel
- Department of Systems Physiology, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany; Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Bernhard Nieswandt
- Institute of Experimental Biomedicine I, University Hospital Würzburg and Rudolf Virchow Center, University of Würzburg, 97080 Würzburg, Germany
| | - Bernd K Fleischmann
- Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Asuka Inoue
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Katharina Simon
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany.
| | - Evi Kostenis
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany.
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23
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Shackley M, Ma Y, Tate EW, Brown AJH, Frost G, Hanyaloglu AC. Short Chain Fatty Acids Enhance Expression and Activity of the Umami Taste Receptor in Enteroendocrine Cells via a Gα i/o Pathway. Front Nutr 2020; 7:568991. [PMID: 33195366 PMCID: PMC7658341 DOI: 10.3389/fnut.2020.568991] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/29/2020] [Indexed: 12/20/2022] Open
Abstract
The short chain fatty acids (SCFAs) acetate, butyrate and propionate, are produced by fermentation of non-digestible carbohydrates by the gut microbiota and regulate appetite, adiposity, metabolism, glycemic control, and immunity. SCFAs act at two distinct G protein coupled receptors (GPCRs), FFAR2 and FFAR3 and are expressed in intestinal enteroendocrine cells (EECs), where they mediate anorectic gut hormone release. EECs also express other GPCRs that act as nutrient sensors, thus SCFAs may elicit some of their health-promoting effects by altering GPCR expression in EECs and enhance gut sensitivity to dietary molecules. Here, we identify that exposure of the murine EEC STC-1 cell line or intestinal organoids to physiological concentrations of SCFAs enhances mRNA levels of the umami taste receptors TASR1 and TASR3, without altering levels of the SCFA GPCRs, FFAR2 and FFAR3. Treatment of EECs with propionate or butyrate, but not acetate, increased levels of umami receptor transcripts, while propionate also reduced CCK expression. This was reversed by inhibiting Gαi/o signaling with pertussis toxin, suggesting that SCFAs act through FFAR2/3 to alter gene expression. Surprisingly, neither a FFAR3 nor a FFAR2 selective ligand could increase TASR1/TASR3 mRNA levels. We assessed the functional impact of increased TASR1/TASR3 expression using unique pharmacological properties of the umami taste receptor; namely, the potentiation of signaling by inosine monophosphate. Activation of umami taste receptor induced inositol-1-phosphate and calcium signaling, and butyrate pretreatment significantly enhanced such signaling. Our study reveals that SCFAs may contribute to EEC adaptation and alter EEC sensitivity to bioactive nutrients.
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Affiliation(s)
- Matilda Shackley
- Section of Nutrition Research, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, United Kingdom.,Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, United Kingdom
| | - Yue Ma
- Section of Nutrition Research, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, United Kingdom
| | - Edward W Tate
- Department of Chemistry, Imperial College London, London, United Kingdom
| | | | - Gary Frost
- Section of Nutrition Research, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, United Kingdom
| | - Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, United Kingdom
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24
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Iwasaki Y, Itoh T, Hagi Y, Matsuta S, Nishiyama A, Chaya G, Kobayashi Y, Miura K, Komatsu S. Proteomics Analysis of Plasma Membrane Fractions of the Root, Leaf, and Flower of Rice. Int J Mol Sci 2020; 21:ijms21196988. [PMID: 32977500 PMCID: PMC7583858 DOI: 10.3390/ijms21196988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/19/2020] [Accepted: 09/21/2020] [Indexed: 12/03/2022] Open
Abstract
The plasma membrane regulates biological processes such as ion transport, signal transduction, endocytosis, and cell differentiation/proliferation. To understand the functional characteristics and organ specificity of plasma membranes, plasma membrane protein fractions from rice root, etiolated leaf, green leaf, developing leaf sheath, and flower were analyzed by proteomics. Among the proteins identified, 511 were commonly accumulated in the five organs, whereas 270, 132, 359, 146, and 149 proteins were specifically accumulated in the root, etiolated leaf, green leaf, developing leaf sheath, and developing flower, respectively. The principle component analysis revealed that the functions of the plasma membrane in the root was different from those of green and etiolated leaves and that the plasma membrane protein composition of the leaf sheath was similar to that of the flower, but not that of the green leaf. Functional classification revealed that the root plasma membrane has more transport-related proteins than the leaf plasma membrane. Furthermore, the leaf sheath and flower plasma membranes were found to be richer in proteins involved in signaling and cell function than the green leaf plasma membrane. To validate the proteomics data, immunoblot analysis was carried out, focusing on four heterotrimeric G protein subunits, Gα, Gβ, Gγ1, and Gγ2. All subunits could be detected by both methods and, in particular, Gγ1 and Gγ2 required concentration by immunoprecipitation for mass spectrometry detection.
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Affiliation(s)
- Yukimoto Iwasaki
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
- Correspondence: (Y.I.); (S.K.); Tel.: +81-776-61-6000 (ext. 3514) (Y.I.); +81-776-29-2466 (S.K.)
| | - Takafumi Itoh
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
| | - Yusuke Hagi
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
| | - Sakura Matsuta
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
| | - Aki Nishiyama
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
| | - Genki Chaya
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
| | - Yuki Kobayashi
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
| | - Kotaro Miura
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui 910-1195, Japan; (T.I.); (Y.H.); (S.M.); (A.N.); (G.C.); (Y.K.); (K.M.)
| | - Setsuko Komatsu
- Department of Environmental and Food Sciences, Fukui University of Technology, Fukui 910-8505, Japan
- Correspondence: (Y.I.); (S.K.); Tel.: +81-776-61-6000 (ext. 3514) (Y.I.); +81-776-29-2466 (S.K.)
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25
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Abstract
Agonist-activated G protein-coupled receptors (GPCRs) must correctly select from hundreds of potential downstream signaling cascades and effectors. To accomplish this, GPCRs first bind to an intermediary signaling protein, such as G protein or arrestin. These intermediaries initiate signaling cascades that promote the activity of different effectors, including several protein kinases. The relative roles of G proteins versus arrestins in initiating and directing signaling is hotly debated, and it remains unclear how the correct final signaling pathway is chosen given the ready availability of protein partners. Here, we begin to deconvolute the process of signal bias from the dopamine D1 receptor (D1R) by exploring factors that promote the activation of ERK1/2 or Src, the kinases that lead to cell growth and proliferation. We found that ERK1/2 activation involves both arrestin and Gαs, while Src activation depends solely on arrestin. Interestingly, we found that the phosphorylation pattern influences both arrestin and Gαs coupling, suggesting an additional way the cells regulate G protein signaling. The phosphorylation sites in the D1R intracellular loop 3 are particularly important for directing the binding of G protein versus arrestin and for selecting between the activation of ERK1/2 and Src. Collectively, these studies correlate functional outcomes with a physical basis for signaling bias and provide fundamental information on how GPCR signaling is directed.
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Affiliation(s)
- Ali I Kaya
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | - Nicole A Perry
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | | | - T M Iverson
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232;
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232
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26
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Stoveken HM, Zucca S, Masuho I, Grill B, Martemyanov KA. The orphan receptor GPR139 signals via G q/11 to oppose opioid effects. J Biol Chem 2020; 295:10822-10830. [PMID: 32576659 DOI: 10.1074/jbc.ac120.014770] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/22/2020] [Indexed: 12/13/2022] Open
Abstract
The interplay between G protein-coupled receptors (GPCRs) is critical for controlling neuronal activity that shapes neuromodulatory outcomes. Recent evidence indicates that the orphan receptor GPR139 influences opioid modulation of key brain circuits by opposing the actions of the µ-opioid receptor (MOR). However, the function of GPR139 and its signaling mechanisms are poorly understood. In this study, we report that GPR139 activates multiple heterotrimeric G proteins, including members of the Gq/11 and Gi/o families. Using a panel of reporter assays in reconstituted HEK293T/17 cells, we found that GPR139 functions via the Gq/11 pathway and thereby distinctly regulates cellular effector systems, including stimulation of cAMP production and inhibition of G protein inward rectifying potassium (GIRK) channels. Electrophysiological recordings from medial habenular neurons revealed that GPR139 signaling via Gq/11 is necessary and sufficient for counteracting MOR-mediated inhibition of neuronal firing. These results uncover a mechanistic interplay between GPCRs involved in controlling opioidergic neuromodulation in the brain.
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Affiliation(s)
- Hannah M Stoveken
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, USA
| | - Stefano Zucca
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, USA
| | - Ikuo Masuho
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, USA
| | - Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, USA
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27
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Abstract
Heterotrimeric G proteins are the core upstream elements that transduce and amplify the cellular signals from G protein-coupled receptors (GPCRs) to intracellular effectors. GPCRs are the largest family of membrane proteins encoded in the human genome and are the targets of about one-third of prescription medicines. However, to date, no single therapeutic agent exerts its effects via perturbing heterotrimeric G protein function, despite a plethora of evidence linking G protein malfunction to human disease. Several recent studies have brought to light that the Gq family-specific inhibitor FR900359 (FR) is unexpectedly efficacious in silencing the signaling of Gq oncoproteins, mutant Gq variants that mostly exist in the active state. These data not only raise the hope that researchers working in drug discovery may be able to potentially strike Gq oncoproteins from the list of undruggable targets, but also raise questions as to how FR achieves its therapeutic effect. Here, we place emphasis on these recent studies and explain why they expand our pharmacological armamentarium for targeting Gq protein oncogenes as well as broaden our mechanistic understanding of Gq protein oncogene function. We also highlight how this novel insight impacts the significance and utility of using G(q) proteins as targets in drug discovery efforts.
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Affiliation(s)
- Evi Kostenis
- Section of Molecular, Cellular and Pharmacobiology, Institute of Pharmaceutical Biology, Nussallee 6, 53115 Bonn, Germany.
| | - Eva Marie Pfeil
- Section of Molecular, Cellular and Pharmacobiology, Institute of Pharmaceutical Biology, Nussallee 6, 53115 Bonn, Germany
| | - Suvi Annala
- Section of Molecular, Cellular and Pharmacobiology, Institute of Pharmaceutical Biology, Nussallee 6, 53115 Bonn, Germany
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28
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Matthias J, Cui Q, Shumate LT, Plagge A, He Q, Bastepe M. Extra-Large Gα Protein (XLαs) Deficiency Causes Severe Adenine-Induced Renal Injury with Massive FGF23 Elevation. Endocrinology 2020; 161:5638044. [PMID: 31758181 PMCID: PMC6986553 DOI: 10.1210/endocr/bqz025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/22/2019] [Indexed: 11/19/2022]
Abstract
Fibroblast growth factor-23 (FGF23) is critical for phosphate and vitamin D homeostasis. Cellular and molecular mechanisms underlying FGF23 production remain poorly defined. The extra-large Gα subunit (XLαs) is a variant of the stimulatory G protein alpha-subunit (Gsα), which mediates the stimulatory action of parathyroid hormone in skeletal FGF23 production. XLαs ablation causes diminished FGF23 levels in early postnatal mice. Herein we found that plasma FGF23 levels were comparable in adult XLαs knockout (XLKO) and wild-type littermates. Upon adenine-rich diet-induced renal injury, a model of chronic kidney disease, both mice showed increased levels of plasma FGF23. Unexpectedly, XLKO mice had markedly higher FGF23 levels than WT mice, with higher blood urea nitrogen and more severe tubulopathy. FGF23 mRNA levels increased substantially in bone and bone marrow in both genotypes; however, the levels in bone were markedly higher than in bone marrow. In XLKO mice, a positive linear correlation was observed between plasma FGF23 and bone, but not bone marrow, FGF23 mRNA levels, suggesting that bone, rather than bone marrow, is an important contributor to severely elevated FGF23 levels in this model. Upon folic acid injection, a model of acute kidney injury, XLKO and WT mice exhibited similar degrees of tubulopathy; however, plasma phosphate and FGF23 elevations were modestly blunted in XLKO males, but not in females, compared to WT counterparts. Our findings suggest that XLαs ablation does not substantially alter FGF23 production in adult mice but increases susceptibility to adenine-induced kidney injury, causing severe FGF23 elevations in plasma and bone.
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Affiliation(s)
- Julia Matthias
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Qiuxia Cui
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Lauren T Shumate
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Antonius Plagge
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Qing He
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
- Correspondence: Murat Bastepe, MD, PhD, 50 Blossom St. Thier 10 Boston, MA 02114, USA. E-mail: and Qing He, PhD 50 Blossom St. Thier 10 Boston, Massachusetts 02114, USA. E-mail:
| | - Murat Bastepe
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
- Correspondence: Murat Bastepe, MD, PhD, 50 Blossom St. Thier 10 Boston, MA 02114, USA. E-mail: and Qing He, PhD 50 Blossom St. Thier 10 Boston, Massachusetts 02114, USA. E-mail:
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29
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Wu Q, Xu F, Liu L, Char SN, Ding Y, Je BI, Schmelz E, Yang B, Jackson D. The maize heterotrimeric G protein β subunit controls shoot meristem development and immune responses. Proc Natl Acad Sci U S A 2020; 117:1799-805. [PMID: 31852823 DOI: 10.1073/pnas.1917577116] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heterotrimeric G proteins are important transducers of receptor signaling, functioning in plants with CLAVATA receptors in controlling shoot meristem size and with pathogen-associated molecular pattern receptors in basal immunity. However, whether specific members of the heterotrimeric complex potentiate cross-talk between development and defense, and the extent to which these functions are conserved across species, have not yet been addressed. Here we used CRISPR/Cas9 to knock out the maize G protein β subunit gene (Gβ) and found that the mutants are lethal, differing from those in Arabidopsis, in which homologous mutants have normal growth and fertility. We show that lethality is caused not by a specific developmental arrest, but by autoimmunity. We used a genetic diversity screen to suppress the lethal Gβ phenotype and also identified a maize Gβ allele with weak autoimmune responses but strong development phenotypes. Using these tools, we show that Gβ controls meristem size in maize, acting epistatically with G protein α subunit gene (Gα), suggesting that Gβ and Gα function in a common signaling complex. Furthermore, we used an association study to show that natural variation in Gβ influences maize kernel row number, an important agronomic trait. Our results demonstrate the dual role of Gβ in immunity and development in a cereal crop and suggest that it functions in cross-talk between these competing signaling networks. Therefore, modification of Gβ has the potential to optimize the trade-off between growth and defense signaling to improve agronomic production.
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30
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Jia H, Song G, Werth EG, Walley JW, Hicks LM, Jones AM. Receptor-Like Kinase Phosphorylation of Arabidopsis Heterotrimeric G-Protein Gα -Subunit AtGPA1. Proteomics 2019; 19:e1900265. [PMID: 31693794 PMCID: PMC7014827 DOI: 10.1002/pmic.201900265] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/04/2019] [Indexed: 01/07/2023]
Abstract
As molecular on-off switches, heterotrimeric G protein complexes, comprised of a Gα subunit and an obligate Gβγ dimer, transmit extracellular signals received by G protein-coupled receptors (GPCRs) to cytoplasmic targets that respond to biotic and abiotic stimuli. Signal transduction is modulated by phosphorylation of GPCRs and G protein complexes. In Arabidopsis thaliana, the Gα subunit AtGPA1 is phosphorylated by the receptor-like kinase (RLK) BRI1-associated Kinase 1 (BAK1), but the extent that other RLKs phosphorylates AtGPA1 is unknown. Twenty-two trans-phosphorylation sites on AtGPA1 are mapped by 12 RLKs hypothesized to act in the Arabidopsis G protein signaling pathway. Cis-phosphorylation sites are also identified on these RLKs, some newly shown to be dual specific kinases. Multiple sites are present in the core AtGPA1 functional units, including pSer52 and/or pThr53 of the conserved P-loop that directly binds nucleotide/phosphate, pThr164, and pSer175 from αE helix in the intramolecular domain interface for nucleotide exchange and GTP hydrolysis, and pThr193 and/or pThr194 in Switch I (SwI) that coordinates nucleotide exchange and protein partner binding. Several AtGPA1 S/T phosphorylation sites are potentially nucleotide-dependent phosphorylation patterns, such as Ser52/Thr53 in the P-loop and Thr193 and/or Thr194 in SwI.
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Affiliation(s)
- Haiyan Jia
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Gaoyuan Song
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Emily G Werth
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Justin W Walley
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Alan M Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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31
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Song C, Orlandi C, Sutton LP, Martemyanov KA. The signaling proteins GPR158 and RGS7 modulate excitability of L2/3 pyramidal neurons and control A-type potassium channel in the prelimbic cortex. J Biol Chem 2019; 294:13145-13157. [PMID: 31311860 DOI: 10.1074/jbc.ra119.007533] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 07/11/2019] [Indexed: 12/18/2022] Open
Abstract
Stress profoundly affects physiological properties of neurons across brain circuits and thereby increases the risk for depression. However, the molecular and cellular mechanisms mediating these effects are poorly understood. In this study, we report that chronic physical restraint stress in mice decreases excitability specifically in layer 2/3 of pyramidal neurons within the prelimbic subarea of the prefrontal cortex (PFC) accompanied by the induction of depressive-like behavioral states. We found that a complex between G protein-coupled receptor (GPCR) 158 (GPR158) and regulator of G protein signaling 7 (RGS7), a regulatory GPCR signaling node recently discovered to be a key modulator of affective behaviors, plays a key role in controlling stress-induced changes in excitability in this neuronal population. Deletion of GPR158 or RGS7 enhanced excitability of layer 2/3 PFC neurons and prevented the impact of stress. Investigation of the underlying molecular mechanisms revealed that the A-type potassium channel Kv4.2 subunit is a molecular target of the GPR158-RGS7 complex. We further report that GPR158 physically associates with Kv4.2 channel and promotes its function by suppressing inhibitory modulation by cAMP-protein kinase A (PKA)-mediated phosphorylation. Taken together, our observations reveal a critical mechanism that adjusts neuronal excitability in L2/3 pyramidal neurons of the PFC and may thereby modulate the effects of stress on depression.
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Affiliation(s)
- Chenghui Song
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458
| | - Laurie P Sutton
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458.
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32
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Zeng B, Mou TC, Doukov TI, Steiner A, Yu W, Papasergi-Scott M, Tall GG, Hagn F, Sprang SR. Structure, Function, and Dynamics of the Gα Binding Domain of Ric-8A. Structure 2019; 27:1137-1147.e5. [PMID: 31155309 DOI: 10.1016/j.str.2019.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/01/2019] [Accepted: 04/23/2019] [Indexed: 10/26/2022]
Abstract
Ric-8A is a 530-amino acid cytoplasmic molecular chaperone and guanine nucleotide exchange factor (GEF) for i, q, and 12/13 classes of heterortrimeric G protein alpha subunits (Gα). We report the 2.2-Å crystal structure of the Ric-8A Gα-binding domain with GEF activity, residues 1-452, and is phosphorylated at Ser435 and Thr440. Residues 1-429 adopt a superhelical fold comprised of Armadillo (ARM) and HEAT repeats, and the C terminus is disordered. One of the phosphorylated residues potentially binds to a basic cluster in an ARM motif. Amino acid sequence conservation and published hydrogen-deuterium exchange data indicate repeats 3 through 6 to be a putative Gα-binding surface. Normal mode modeling of small-angle X-ray scattering data indicates that phosphorylation induces relative rotation between repeats 1-4, 5-6, and 7-9. 2D 1H-15N-TROSY spectra of [2H,15N]-labeled Gαi1 in the presence of R452 reveals chemical shift perturbations of the C terminus and Gαi1 residues involved in nucleotide binding.
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Affiliation(s)
- Baisen Zeng
- Graduate Program in Biochemistry and Biophysics, University of Montana, Missoula, MT 59812, USA
| | - Tung-Chung Mou
- Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA; Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Tzanko I Doukov
- Macromolecular Crystallography Group, Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94309, USA
| | - Andrea Steiner
- Bavarian NMR Center at the Department of Chemistry and Institute for Advanced Study, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany; Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Wenxi Yu
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Makaia Papasergi-Scott
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Franz Hagn
- Bavarian NMR Center at the Department of Chemistry and Institute for Advanced Study, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany; Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Stephen R Sprang
- Graduate Program in Biochemistry and Biophysics, University of Montana, Missoula, MT 59812, USA; Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA; Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
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33
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Abstract
Heterotrimeric GTP-binding proteins are key regulators of a multitude of signaling pathways in all eukaryotes. Although the core G-protein components and their basic biochemistries are broadly conserved throughout evolution, the regulatory mechanisms of G proteins seem to have been rewired in plants to meet specific needs. These proteins are currently the focus of intense research in plants due to their involvement in many agronomically important traits, such as seed yield, organ size regulation, biotic and abiotic stress responses, symbiosis, and nitrogen use efficiency. The availability of massive sequence information from a variety of plant species, extensive biochemical data generated over decades, and impressive genetic resources for plant G proteins have made it possible to examine their role, unique properties, and novel regulation. This review focuses on some recent advances in our understanding of the mechanistic details of this critical signaling pathway to enable the precise manipulation and generation of plants to meet future needs.
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Affiliation(s)
- Sona Pandey
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA;
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34
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Biswal AK, McConnell EW, Werth EG, Lo SF, Yu SM, Hicks LM, Jones AM. The Nucleotide-Dependent Interactome of Rice Heterotrimeric G-Protein α -Subunit. Proteomics 2019; 19:e1800385. [PMID: 30866160 DOI: 10.1002/pmic.201800385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 02/12/2019] [Indexed: 11/09/2022]
Abstract
The rice heterotrimeric G-protein complex, a guanine-nucleotide-dependent on-off switch, mediates vital cellular processes and responses to biotic and abiotic stress. Exchange of bound GDP (resting state) for GTP (active state) is spontaneous in plants including rice and thus there is no need for promoting guanine nucleotide exchange in vivo as a mechanism for regulating the active state of signaling as it is well known for animal G signaling. As such, a master regulator controlling the G-protein activation state is unknown in plants. Therefore, an ab initio approach is taken to discover candidate regulators. The rice Gα subunit (RGA1) is used as bait to screen for nucleotide-dependent protein partners. A total of 264 proteins are identified by tandem mass spectrometry of which 32 were specific to the GDP-bound inactive state and 22 specific to the transition state. Approximately, 10% are validated as previously identified G-protein interactors.
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Affiliation(s)
- Akshaya Kumar Biswal
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Evan Wesley McConnell
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Emily Grace Werth
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Shuen-Fang Lo
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, China
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, China
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Alan M Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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35
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Sieng M, Hayes MP, O'Brien JB, Andrew Fowler C, Houtman JC, Roman DL, Lyon AM. High-resolution structure of RGS17 suggests a role for Ca 2+ in promoting the GTPase-activating protein activity by RZ subfamily members. J Biol Chem 2019; 294:8148-8160. [PMID: 30940727 DOI: 10.1074/jbc.ra118.006059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 03/27/2019] [Indexed: 11/06/2022] Open
Abstract
Regulator of G protein signaling (RGS) proteins are negative regulators of G protein-coupled receptor (GPCR) signaling through their ability to act as GTPase-activating proteins (GAPs) for activated Gα subunits. Members of the RZ subfamily of RGS proteins bind to activated Gαo, Gαz, and Gαi1-3 proteins in the nervous system and thereby inhibit downstream pathways, including those involved in Ca2+-dependent signaling. In contrast to other RGS proteins, little is known about RZ subfamily structure and regulation. Herein, we present the 1.5-Å crystal structure of RGS17, the most complete and highest-resolution structure of an RZ subfamily member to date. RGS17 cocrystallized with Ca2+ bound to conserved positions on the predicted Gα-binding surface of the protein. Using NMR chemical shift perturbations, we confirmed that Ca2+ binds in solution to the same site. Furthermore, RGS17 had greater than 55-fold higher affinity for Ca2+ than for Mg2+ Finally, we found that Ca2+ promotes interactions between RGS17 and activated Gα and decreases the Km for GTP hydrolysis, potentially by altering the binding mechanism between these proteins. Taken together, these findings suggest that Ca2+ positively regulates RGS17, which may represent a general mechanism by which increased Ca2+ concentration promotes the GAP activity of the RZ subfamily, leading to RZ-mediated inhibition of Ca2+ signaling.
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Affiliation(s)
- Monita Sieng
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Michael P Hayes
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242
| | - Joseph B O'Brien
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242
| | - C Andrew Fowler
- NMR Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jon C Houtman
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa 52242
| | - David L Roman
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242
| | - Angeline M Lyon
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907; Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907.
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36
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Caballero A, Mahn SA, Ali MS, Rogers MR, Marchese A. Heterologous regulation of CXCR4 lysosomal trafficking. J Biol Chem 2019; 294:8023-8036. [PMID: 30936203 DOI: 10.1074/jbc.ra118.005991] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 03/26/2019] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptor (GPCR) signaling is regulated by members of the protein kinase C (PKC) and GPCR kinase (GRK) families, although the relative contribution of each to GPCR function varies among specific GPCRs. The CXC motif receptor 4 (CXCR4) is a member of the GPCR superfamily that binds the CXC motif chemokine ligand 12 (CXCL12), initiating signaling that is subsequently terminated in part by internalization and lysosomal degradation of CXCR4. The purpose of this study is to define the relative contribution of PKC and GRK to CXCR4 signaling attenuation by studying their effects on CXCR4 lysosomal trafficking and degradation. Our results demonstrate that direct activation of PKC via the phorbol ester phorbol 12-myristate 13-acetate (PMA) mimics CXCL12-mediated desensitization, internalization, ubiquitination, and lysosomal trafficking of CXCR4. In agreement, heterologous activation of PKC by stimulating the chemokine receptor CXCR5 with its ligand, CXCL13, also mimics CXCL12-mediated desensitization, internalization, ubiquitination, and lysosomal degradation of CXCR4. Similar to CXCL12, PMA promotes PKC-dependent phosphorylation of serine residues within CXCR4 C-tail that are required for binding and ubiquitination by the E3 ubiquitin ligase AIP4 (atrophin-interacting protein 4). However, inhibition of PKC activity does not alter CXCL12-mediated ubiquitination and degradation of CXCR4, suggesting that other kinases are also required. Accordingly, siRNA-mediated depletion of GRK6 results in decreased degradation and ubiquitination of CXCR4. Overall, these results suggest that PKC and GRK6 contribute to unique aspects of CXCR4 phosphorylation and lysosomal degradation to ensure proper signal propagation and termination.
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Affiliation(s)
- Adriana Caballero
- Department of Pharmacology, Loyola University Chicago, Maywood, Illinois 60153
| | - Sarah A Mahn
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Mudassir S Ali
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - M Rose Rogers
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Adriano Marchese
- Department of Pharmacology, Loyola University Chicago, Maywood, Illinois 60153; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226.
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Dong H, Yan S, Liu J, Liu P, Sun J. TaCOLD1 defines a new regulator of plant height in bread wheat. Plant Biotechnol J 2019; 17:687-699. [PMID: 30183124 PMCID: PMC6381784 DOI: 10.1111/pbi.13008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/14/2018] [Accepted: 08/23/2018] [Indexed: 05/21/2023]
Abstract
Plant height is among the most important agronomic traits that influence crop yield. However, in addition to the Rht-1 alleles, the molecular basis of plant height in bread wheat remains largely unclear. Based on wheat gene expression profiling analysis, we identify a light-regulated gene from bread wheat, designated as TaCOLD1, whose encoding protein is homologous to cold sensor COLD1 in rice. We show that TaCOLD1 protein is localized to the endoplasmic reticulum (ER) and plasma membrane. Phenotypic analyses show that overexpression of a mutated form of TaCOLD1 (M187K) in bread wheat cultivar Kenong199 (Rht-B1b) background resulted in an obvious reduction in plant height. Further, we demonstrate that the hydrophilic loop of TaCOLD1 (residues 178-296) can interact with TaGα-7A (the α subunit of heterotrimeric G protein) protein but not TaGα-1B, and the mutation (M187K) in TaCOLD1 remarkably enhances its interaction with TaGα-7A. Physical interaction analyses show that the C-terminal region of TaGα-7A, which is lacking in the TaGα-1B protein, is necessary for its interaction with TaCOLD1. Intriguingly, the C-terminal region of TaGα-7A is also physically associated with the TaDEP1 protein (an atypical Gγ subunit). Significantly, we discover that TaCOLD1 and mTaCOLD1 (M187K) can interfere with the physical association between TaGα-7A and TaDEP1. Together, this study reveals that TaCOLD1 acts as a novel regulator of plant height through interfering with the formation of heterotrimeric G protein complex in bread wheat and is a valuable target for the engineering of wheat plant architecture.
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Affiliation(s)
- Huixue Dong
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Suli Yan
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Jie Liu
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Pan Liu
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Jiaqiang Sun
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
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38
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Miao J, Yang Z, Zhang D, Wang Y, Xu M, Zhou L, Wang J, Wu S, Yao Y, Du X, Gu F, Gong Z, Gu M, Liang G, Zhou Y. Mutation of RGG2, which encodes a type B heterotrimeric G protein γ subunit, increases grain size and yield production in rice. Plant Biotechnol J 2019; 17:650-664. [PMID: 30160362 PMCID: PMC6381795 DOI: 10.1111/pbi.13005] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 08/20/2018] [Accepted: 08/23/2018] [Indexed: 05/22/2023]
Abstract
Heterotrimeric G proteins, which consist of Gα , Gβ and Gγ subunits, function as molecular switches that regulate a wide range of developmental processes in plants. In this study, we characterised the function of rice RGG2, which encodes a type B Gγ subunit, in regulating grain size and yield production. The expression levels of RGG2 were significantly higher than those of other rice Gγ -encoding genes in all tissues tested, suggesting that RGG2 plays essential roles in rice growth and development. By regulating cell expansion, overexpression of RGG2 in Nipponbare (NIP) led to reduced plant height and decreased grain size. By contrast, two mutants generated by the clustered, regularly interspaced, short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system in the Zhenshan 97 (ZS97) background, zrgg2-1 and zrgg2-2, exhibited enhanced growth, including elongated internodes, increased 1000-grain weight and plant biomass and enhanced grain yield per plant (+11.8% and 16.0%, respectively). These results demonstrate that RGG2 acts as a negative regulator of plant growth and organ size in rice. By measuring the length of the second leaf sheath after gibberellin (GA3 ) treatment and the GA-induced α-amylase activity of seeds, we found that RGG2 is also involved in GA signalling. In summary, we propose that RGG2 may regulate grain and organ size via the GA pathway and that manipulation of RGG2 may provide a novel strategy for rice grain yield enhancement.
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Affiliation(s)
- Jun Miao
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Zefeng Yang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Dongping Zhang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Yuzhu Wang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Mengbin Xu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Lihui Zhou
- Institute of Food CropsJiangsu Academy of Agricultural SciencesNanjingChina
| | - Jun Wang
- Institute of Food CropsJiangsu Academy of Agricultural SciencesNanjingChina
| | - Shujun Wu
- Shanghai Academy of Agricultural SciencesShanghaiChina
| | - Youli Yao
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Xi Du
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Fangfei Gu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Zhiyun Gong
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Minghong Gu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Guohua Liang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
| | - Yong Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co‐Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhouChina
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Adame-García SR, Cervantes-Villagrana RD, Orduña-Castillo LB, Del Rio JC, Gutkind JS, Reyes-Cruz G, Taylor SS, Vázquez-Prado J. cAMP-dependent activation of the Rac guanine exchange factor P-REX1 by type I protein kinase A (PKA) regulatory subunits. J Biol Chem 2019; 294:2232-2246. [PMID: 30530493 PMCID: PMC6378977 DOI: 10.1074/jbc.ra118.006691] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 11/29/2018] [Indexed: 12/22/2022] Open
Abstract
Regulatory subunits of protein kinase A (PKA) inhibit its kinase subunits. Intriguingly, their potential as cAMP-dependent signal transducers remains uncharacterized. We recently reported that type I PKA regulatory subunits (RIα) interact with phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchange factor 1 (P-REX1), a chemotactic Rac guanine exchange factor (RacGEF). Because P-REX1 is known to be phosphorylated and inhibited by PKA, its interaction with RIα suggests that PKA regulatory and catalytic subunits may fine-tune P-REX1 activity or those of its target pools. Here, we tested whether RIα acts as a cAMP-dependent factor promoting P-REX1-mediated Rac activation and cell migration. We observed that Gs-coupled EP2 receptors indeed promote endothelial cell migration via RIα-activated P-REX1. Expression of the P-REX1-PDZ1 domain prevented RIα/P-REX1 interaction, P-REX1 activation, and EP2-dependent cell migration, and P-REX1 silencing abrogated RIα-dependent Rac activation. RIα-specific cAMP analogs activated P-REX1, but lost this activity in RIα-knockdown cells, and cAMP pulldown assays revealed that P-REX1 preferentially interacts with free RIα. Moreover, purified RIα directly activated P-REX1 in vitro We also found that the RIα CNB-B domain is critical for the interaction with P-REX1, which was increased in RIα mutants, such as the acrodysostosis-associated mutant, that activate P-REX1 at basal cAMP levels. RIα and Cα PKA subunits targeted distinct P-REX1 molecules, indicated by an absence of phosphorylation in the active fraction of P-REX1. This was in contrast to the inactive fraction in which phosphorylated P-REX1 was present, suggesting co-existence of dual stimulatory and inhibitory effects. We conclude that PKA's regulatory subunits are cAMP-dependent signal transducers.
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Affiliation(s)
| | | | | | | | | | | | - Susan S Taylor
- the Departments of Pharmacology
- Chemistry and
- Biochemistry, University of California San Diego, La Jolla, California 92093
| | - José Vázquez-Prado
- Pharmacology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), 07360 Mexico City, Mexico and
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40
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Wingler LM, Elgeti M, Hilger D, Latorraca NR, Lerch MT, Staus DP, Dror RO, Kobilka BK, Hubbell WL, Lefkowitz RJ. Angiotensin Analogs with Divergent Bias Stabilize Distinct Receptor Conformations. Cell 2019; 176:468-478.e11. [PMID: 30639099 DOI: 10.1016/j.cell.2018.12.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/13/2018] [Accepted: 12/04/2018] [Indexed: 01/14/2023]
Abstract
"Biased" G protein-coupled receptor (GPCR) agonists preferentially activate pathways mediated by G proteins or β-arrestins. Here, we use double electron-electron resonance spectroscopy to probe the changes that ligands induce in the conformational distribution of the angiotensin II type I receptor. Monitoring distances between 10 pairs of nitroxide labels distributed across the intracellular regions enabled mapping of four underlying sets of conformations. Ligands from different functional classes have distinct, characteristic effects on the conformational heterogeneity of the receptor. Compared to angiotensin II, the endogenous agonist, agonists with enhanced Gq coupling more strongly stabilize an "open" conformation with an accessible transducer-binding site. β-arrestin-biased agonists deficient in Gq coupling do not stabilize this open conformation but instead favor two more occluded conformations. These data suggest a structural mechanism for biased ligand action at the angiotensin receptor that can be exploited to rationally design GPCR-targeting drugs with greater specificity of action.
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41
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Cervantes-Villagrana RD, Adame-García SR, García-Jiménez I, Color-Aparicio VM, Beltrán-Navarro YM, König GM, Kostenis E, Reyes-Cruz G, Gutkind JS, Vázquez-Prado J. Gβγ signaling to the chemotactic effector P-REX1 and mammalian cell migration is directly regulated by Gα q and Gα 13 proteins. J Biol Chem 2018; 294:531-546. [PMID: 30446620 DOI: 10.1074/jbc.ra118.006254] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/12/2018] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptors stimulate Rho guanine nucleotide exchange factors that promote mammalian cell migration. Rac and Rho GTPases exert opposing effects on cell morphology and are stimulated downstream of Gβγ and Gα12/13 or Gαq, respectively. These Gα subunits might in turn favor Rho pathways by preventing Gβγ signaling to Rac. Here, we investigated whether Gβγ signaling to phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchange factor 1 (P-REX1), a key Gβγ chemotactic effector, is directly controlled by Rho-activating Gα subunits. We show that pharmacological inhibition of Gαq makes P-REX1 activation by Gq/Gi-coupled lysophosphatidic acid receptors more effective. Moreover, chemogenetic control of Gi and Gq by designer receptors exclusively activated by designer drugs (DREADDs) confirmed that Gi differentially activates P-REX1. GTPase-deficient GαqQL and Gα13QL variants formed stable complexes with Gβγ, impairing its interaction with P-REX1. The N-terminal regions of these variants were essential for stable interaction with Gβγ. Pulldown assays revealed that chimeric Gα13-i2QL interacts with Gβγ unlike to Gαi2-13QL, the reciprocal chimera, which similarly to Gαi2QL could not interact with Gβγ. Moreover, Gβγ was part of tetrameric Gβγ-GαqQL-RGS2 and Gβγ-Gα13-i2QL-RGS4 complexes, whereas Gα13QL dissociated from Gβγ to interact with the PDZ-RhoGEF-RGS domain. Consistent with an integrated response, Gβγ and AKT kinase were associated with active SDF-1/CXCL12-stimulated P-REX1. This pathway was inhibited by GαqQL and Gα13QL, which also prevented CXCR4-dependent cell migration. We conclude that a coordinated mechanism prioritizes Gαq- and Gα13-mediated signaling to Rho over a Gβγ-dependent Rac pathway, attributed to heterotrimeric Gi proteins.
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Affiliation(s)
| | - Sendi Rafael Adame-García
- Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), 07360 Mexico City, Mexico
| | - Irving García-Jiménez
- Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), 07360 Mexico City, Mexico
| | | | | | - Gabriele M König
- the University of Bonn, Institute of Pharmaceutical Biology, 53115 Bonn, Germany, and
| | - Evi Kostenis
- the University of Bonn, Institute of Pharmaceutical Biology, 53115 Bonn, Germany, and
| | - Guadalupe Reyes-Cruz
- Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), 07360 Mexico City, Mexico
| | - J Silvio Gutkind
- the Moores Cancer Center and Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
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Matsuta S, Nishiyama A, Chaya G, Itoh T, Miura K, Iwasaki Y. Characterization of Heterotrimeric G Protein γ4 Subunit in Rice. Int J Mol Sci 2018; 19:E3596. [PMID: 30441812 DOI: 10.3390/ijms19113596] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/05/2018] [Accepted: 11/09/2018] [Indexed: 11/25/2022] Open
Abstract
Heterotrimeric G proteins are the molecule switch that transmits information from external signals to intracellular target proteins in mammals and yeast cells. In higher plants, heterotrimeric G proteins regulate plant architecture. Rice harbors one canonical α subunit gene (RGA1), four extra-large GTP-binding protein genes (XLGs), one canonical β-subunit gene (RGB1), and five γ-subunit genes (tentatively designated RGG1, RGG2, RGG3/GS3/Mi/OsGGC1, RGG4/DEP1/DN1/qPE9-1/OsGGC3, and RGG5/OsGGC2) as components of the heterotrimeric G protein complex. Among the five γ-subunit genes, RGG1 encodes the canonical γ-subunit, RGG2 encodes a plant-specific type of γ-subunit with additional amino acid residues at the N-terminus, and the remaining three γ-subunit genes encode atypical γ-subunits with cysteine-rich C-termini. We characterized the RGG4/DEP1/DN1/qPE9-1/OsGGC3 gene product Gγ4 in the wild type (WT) and truncated protein Gγ4∆Cys in the RGG4/DEP1/DN1/qPE9-1/OsGGC3 mutant, Dn1-1, as littele information regarding the native Gγ4 and Gγ4∆Cys proteins is currently available. Based on liquid chromatography-tandem mass spectrometry analysis, immunoprecipitated Gγ4 candidates were confirmed as actual Gγ4. Similar to α-(Gα) and β-subunits (Gβ), Gγ4 was enriched in the plasma membrane fraction and accumulated in the developing leaf sheath. As RGG4/DEP1/DN1/qPE9-1/OsGGC3 mutants exhibited dwarfism, tissues that accumulated Gγ4 corresponded to the abnormal tissues observed in RGG4/DEP1/DN1/qPE9-1/OsGGC3 mutants.
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Nishiyama A, Matsuta S, Chaya G, Itoh T, Miura K, Iwasaki Y. Identification of Heterotrimeric G Protein γ3 Subunit in Rice Plasma Membrane. Int J Mol Sci 2018; 19:ijms19113591. [PMID: 30441767 PMCID: PMC6274724 DOI: 10.3390/ijms19113591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/07/2018] [Accepted: 11/07/2018] [Indexed: 12/02/2022] Open
Abstract
Heterotrimeric G proteins are important molecules for regulating plant architecture and transmitting external signals to intracellular target proteins in higher plants and mammals. The rice genome contains one canonical α subunit gene (RGA1), four extra-large GTP-binding protein genes (XLGs), one canonical β subunit gene (RGB1), and five γ subunit genes (tentatively named RGG1, RGG2, RGG3/GS3/Mi/OsGGC1, RGG4/DEP1/DN1/OsGGC3, and RGG5/OsGGC2). RGG1 encodes the canonical γ subunit; RGG2 encodes the plant-specific type of γ subunit with additional amino acid residues at the N-terminus; and the remaining three γ subunit genes encode the atypical γ subunits with cysteine abundance at the C-terminus. We aimed to identify the RGG3/GS3/Mi/OsGGC1 gene product, Gγ3, in rice tissues using the anti-Gγ3 domain antibody. We also analyzed the truncated protein, Gγ3∆Cys, in the RGG3/GS3/Mi/OsGGC1 mutant, Mi, using the anti-Gγ3 domain antibody. Based on nano-liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, the immunoprecipitated Gγ3 candidates were confirmed to be Gγ3. Similar to α (Gα) and β subunits (Gβ), Gγ3 was enriched in the plasma membrane fraction, and accumulated in the flower tissues. As RGG3/GS3/Mi/OsGGC1 mutants show the characteristic phenotype in flowers and consequently in seeds, the tissues that accumulated Gγ3 corresponded to the abnormal tissues observed in RGG3/GS3/Mi/OsGGC1 mutants.
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Affiliation(s)
- Aki Nishiyama
- Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
| | - Sakura Matsuta
- Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
| | - Genki Chaya
- Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
| | - Takafumi Itoh
- Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
| | - Kotaro Miura
- Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
| | - Yukimoto Iwasaki
- Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
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Maziarz M, Leyme A, Marivin A, Luebbers A, Patel PP, Chen Z, Sprang SR, Garcia-Marcos M. Atypical activation of the G protein Gα q by the oncogenic mutation Q209P. J Biol Chem 2018; 293:19586-19599. [PMID: 30352874 DOI: 10.1074/jbc.ra118.005291] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/15/2018] [Indexed: 12/22/2022] Open
Abstract
The causative role of G protein-coupled receptor (GPCR) pathway mutations in uveal melanoma (UM) has been well-established. Nearly all UMs bear an activating mutation in a GPCR pathway mediated by G proteins of the Gq/11 family, driving tumor initiation and possibly metastatic progression. Thus, targeting this pathway holds therapeutic promise for managing UM. However, direct targeting of oncogenic Gαq/11 mutants, present in ∼90% of UMs, is complicated by the belief that these mutants structurally resemble active Gαq/11 WT. This notion is solidly founded on previous studies characterizing Gα mutants in which a conserved catalytic glutamine (Gln-209 in Gαq) is replaced by leucine, which leads to GTPase function deficiency and constitutive activation. Whereas Q209L accounts for approximately half of GNAQ mutations in UM, Q209P is as frequent as Q209L and also promotes oncogenesis, but has not been characterized at the molecular level. Here, we characterized the biochemical and signaling properties of Gαq Q209P and found that it is also GTPase-deficient and activates downstream signaling as efficiently as Gαq Q209L. However, Gαq Q209P had distinct molecular and functional features, including in the switch II region of Gαq Q209P, which adopted a conformation different from that of Gαq Q209L or active WT Gαq, resulting in altered binding to effectors, Gβγ, and regulators of G-protein signaling (RGS) proteins. Our findings reveal that the molecular properties of Gαq Q209P are fundamentally different from those in other active Gαq proteins and could be leveraged as a specific vulnerability for the ∼20% of UMs bearing this mutation.
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Affiliation(s)
- Marcin Maziarz
- 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
| | - Arthur Marivin
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Alex Luebbers
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Prachi P Patel
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Zhe Chen
- the Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Stephen R Sprang
- the Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, Montana 59812
| | - Mikel Garcia-Marcos
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118,
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Yu Y, Assmann SM. Inter-relationships between the heterotrimeric Gβ subunit AGB1, the receptor-like kinase FERONIA, and RALF1 in salinity response. Plant Cell Environ 2018; 41:2475-2489. [PMID: 29907954 PMCID: PMC6150805 DOI: 10.1111/pce.13370] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 06/04/2018] [Accepted: 06/08/2018] [Indexed: 05/06/2023]
Abstract
Plant heterotrimeric G proteins modulate numerous developmental stress responses. Recently, receptor-like kinases (RLKs) have been implicated as functioning with G proteins and may serve as plant G-protein-coupled-receptors. The RLK FERONIA (FER), in the Catharantus roseus RLK1-like subfamily, is activated by a family of polypeptides called rapid alkalinization factors (RALFs). We previously showed that the Arabidopsis G protein β subunit, AGB1, physically interacts with FER, and that RALF1 regulation of stomatal movement through FER requires AGB1. Here, we investigated genetic interactions of AGB1 and FER in plant salinity response by comparing salt responses in the single and double mutants of agb1 and fer. We show that AGB1 and FER act additively or synergistically depending on the conditions of the NaCl treatments. We further show that the synergism likely occurs through salt-induced ROS production. In addition, we show that RALF1 enhances salt toxicity through increasing Na+ accumulation and decreasing K+ accumulation rather than by inducing ROS production, and that the RALF1 effect on salt response occurs in an AGB1-independent manner. Our results indicate that RLK epistatic relationships are not fixed, as AGB1 and FER display different genetic relationships to RALF1 in stomatal versus salinity responses.
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Affiliation(s)
| | - Sarah M. Assmann
- To whom correspondence should be addressed: , tel. 814-863-9579, fax. 814-865-9131
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Gerber KJ, Squires KE, Hepler JR. 14-3-3γ binds regulator of G protein signaling 14 (RGS14) at distinct sites to inhibit the RGS14:Gα i-AlF 4- signaling complex and RGS14 nuclear localization. J Biol Chem 2018; 293:14616-14631. [PMID: 30093406 DOI: 10.1074/jbc.ra118.002816] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 07/23/2018] [Indexed: 11/06/2022] Open
Abstract
Regulator of G protein signaling 14 (RGS14) is a multifunctional brain scaffolding protein that integrates G protein and Ras/ERK signaling pathways. It is also a nucleocytoplasmic shuttling protein. RGS14 binds active Gαi/o via its RGS domain, Raf and active H-Ras-GTP via its R1 Ras-binding domain (RBD), and inactive Gαi1/3 via its G protein regulatory (GPR) domain. RGS14 suppresses long-term potentiation (LTP) in the CA2 region of the hippocampus, thereby regulating hippocampally based learning and memory. The 14-3-3 family of proteins is necessary for hippocampal LTP and associative learning and memory. Here, we show direct interaction between RGS14 and 14-3-3γ at two distinct sties, one phosphorylation-independent and the other phosphorylation-dependent at Ser-218 that is markedly potentiated by signaling downstream of active H-Ras. Using bioluminescence resonance energy transfer (BRET), we show that the pSer-218-dependent RGS14/14-3-3γ interaction inhibits active Gαi1-AlF4- binding to the RGS domain of RGS14 but has no effect on active H-Ras and inactive Gαi1-GDP binding to RGS14. By contrast, the phosphorylation-independent binding of 14-3-3 has no effect on RGS14/Gαi interactions but, instead, inhibits (directly or indirectly) RGS14 nuclear import and nucleocytoplasmic shuttling. Together, our findings describe a novel mechanism of negative regulation of RGS14 functions, specifically interactions with active Gαi and nuclear import, while leaving the function of other RGS14 domains intact. Ongoing studies will further elucidate the physiological function of this interaction between RGS14 and 14-3-3γ, providing insight into the functions of both RGS14 and 14-3-3 in their roles in modulating synaptic plasticity in the hippocampus.
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Affiliation(s)
- Kyle J Gerber
- From the Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Katherine E Squires
- From the Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - John R Hepler
- From the Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322
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Praktiknjo SD, Saad F, Maier D, Ip P, Hipfner DR. Activation of Smoothened in the Hedgehog pathway unexpectedly increases Gα s-dependent cAMP levels in Drosophila. J Biol Chem 2018; 293:13496-13508. [PMID: 30018136 DOI: 10.1074/jbc.ra118.001953] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 07/13/2018] [Indexed: 12/28/2022] Open
Abstract
Hedgehog (Hh) signaling plays a key role in the development and maintenance of animal tissues. This signaling is mediated by the atypical G protein-coupled receptor (GPCR) Smoothened (Smo). Smo activation leads to signaling through several well-characterized effectors to activate Hh target gene expression. Recent studies have implicated activation of the heterotrimeric G protein subunit Gαi and the subsequent decrease in cellular cAMP levels in promoting the Hh response in flies and mammals. Although Hh stimulation decreases cAMP levels in some insect cell lines, here using a bioluminescence resonance energy transfer (BRET)-based assay we found that this stimulation had no detectable effect in Drosophila S2-R+ cells. However, we observed an unexpected and significant Gαs-dependent increase in cAMP levels in response to strong Smo activation in Smo-transfected cells. This effect was mediated by Smo's broadly conserved core, and was specifically activated in response to phosphorylation of the Smo C-terminus by GPCR kinase 2 (Gprk2). Genetic analysis of heterotrimeric G protein function in the developing Drosophila wing revealed a positive role for cAMP in the endogenous Hh response. Specifically, we found that mutation or depletion of Gαs diminished low-threshold Hh responses in Drosophila, whereas depletion of Gαi potentiated them (in contrast to previous findings). Our analysis suggested that regulated cAMP production is important for controlling the sensitivity of cellular responses to Hh in Drosophila.
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Affiliation(s)
- Samantha D Praktiknjo
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7.,the Departments of Anatomy and Cell Biology and
| | - Farah Saad
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7.,Biology, McGill University, Montreal, Quebec H3A 0C7, and
| | - Dominic Maier
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7.,the Departments of Anatomy and Cell Biology and
| | - Pamela Ip
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7.,the Departments of Anatomy and Cell Biology and
| | - David R Hipfner
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7, .,the Departments of Anatomy and Cell Biology and.,Biology, McGill University, Montreal, Quebec H3A 0C7, and.,the Département de médecine, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
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48
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Podyma B, Sun H, Wilson EA, Carlson B, Pritikin E, Gavrilova O, Weinstein LS, Chen M. The stimulatory G protein G sα is required in melanocortin 4 receptor-expressing cells for normal energy balance, thermogenesis, and glucose metabolism. J Biol Chem 2018; 293:10993-11005. [PMID: 29794140 DOI: 10.1074/jbc.ra118.003450] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/21/2018] [Indexed: 01/05/2023] Open
Abstract
Central melanocortin 4 receptors (MC4Rs) stimulate energy expenditure and inhibit food intake. MC4Rs activate the G protein Gsα, but whether Gsα mediates all MC4R actions has not been established. Individuals with Albright hereditary osteodystrophy (AHO), who have heterozygous Gsα-inactivating mutations, only develop obesity when the Gsα mutation is present on the maternal allele because of tissue-specific genomic imprinting. Furthermore, evidence in mice implicates Gsα imprinting within the central nervous system (CNS) in this disorder. In this study, we examined the effects of Gsα in MC4R-expressing cells on metabolic regulation. Mice with homozygous Gsα deficiency in MC4R-expressing cells (MC4RGsKO) developed significant obesity with increased food intake and decreased energy expenditure, along with impaired insulin sensitivity and cold-induced thermogenesis. Moreover, the ability of the MC4R agonist melanotan-II (MTII) to stimulate energy expenditure and to inhibit food intake was impaired in MC4RGsKO mice. MTII failed to stimulate the secretion of the anorexigenic hormone peptide YY (PYY) from enteroendocrine L cells, a physiological response mediated by MC4R-Gsα signaling, even though baseline PYY levels were elevated in these mice. In Gsα heterozygotes, mild obesity and reduced energy expenditure were present only in mice with a Gsα deletion on the maternal allele in MC4R-expressing cells, whereas food intake was unaffected. These results demonstrate that Gsα signaling in MC4R-expressing cells is required for controlling energy balance, thermogenesis, and peripheral glucose metabolism. They further indicate that Gsα imprinting in MC4R-expressing cells contributes to obesity in Gsα knockout mice and probably in individuals with Albright hereditary osteodystrophy as well.
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Affiliation(s)
| | - Hui Sun
- From the Metabolic Diseases Branch and
| | | | | | | | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | | | - Min Chen
- From the Metabolic Diseases Branch and
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Tunc‐Ozdemir M, Liao K, Ross‐Elliott TJ, Elston TC, Jones AM. Long-distance communication in Arabidopsis involving a self-activating G protein. Plant Direct 2018; 2:e00037. [PMID: 31245704 PMCID: PMC6508511 DOI: 10.1002/pld3.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/18/2017] [Accepted: 12/31/2017] [Indexed: 05/06/2023]
Abstract
In plant cells, heterotrimeric G protein signaling mediates development, biotic/abiotic stress responsiveness, hormone signaling, and extracellular sugar sensing. The amount of sugar in plant cells fluctuates from nanomolar to high millimolar concentrations over time depending on changes in the light environment. Arabidopsis thaliana Regulator of G Signaling protein 1 (AtRGS1) modulates G protein activation and detects the concentration and the exposure time of sugars. This is called dose-duration reciprocity in sugar sensing and occurs through AtRGS1 internalization which is directly proportional to G protein activation. One source of sugars is from CO 2 fixation by photosynthesis. Through a simple set of experiments, we show that sugars made in cotyledons that are undergoing photomorphogenesis activate G signaling in cells distal to the nascent photosynthesis center. This occurs with sufficient speed to enable distal cells to monitor changes in photosynthetic activity in the leaves.
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Affiliation(s)
- Meral Tunc‐Ozdemir
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Kang‐Ling Liao
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | | | - Timothy C. Elston
- Department of PharmacologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Alan M. Jones
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
- Department of PharmacologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
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50
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Ferrero-Serrano Á, Su Z, Assmann SM. Illuminating the role of the Gα heterotrimeric G protein subunit, RGA1, in regulating photoprotection and photoavoidance in rice. Plant Cell Environ 2018; 41:451-468. [PMID: 29216416 DOI: 10.1111/pce.13113] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/19/2017] [Accepted: 11/21/2017] [Indexed: 05/22/2023]
Abstract
We studied physiological mechanisms of photoavoidance and photoprotection of a dwarf rice mutant with erect leaves, d1, in which the RGA1 gene, which encodes the Gα subunit of the heterotrimeric G protein, is non-functional. Leaves of d1 exhibit lower leaf temperature and higher photochemical reflectance index relative to wild type (WT), indicative of increased photoavoidance and more efficient light harvesting. RNA sequencing analysis of flag leaves revealed that messenger RNA levels of genes encoding heat shock proteins, enzymes associated with chlorophyll breakdown, and ROS scavengers were down-regulated in d1. By contrast, genes encoding proteins associated with light harvesting, Photosystem II, cyclic electron transport, Photosystem I, and chlorophyll biosynthesis were up-regulated in d1. Consistent with these observations, when WT and d1 plants were experimentally subjected to the same light intensity, d1 plants exhibited a greater capacity to dissipate excess irradiance (increased nonphotochemical quenching) relative to WT. The increased capacity in d1 for both photoavoidance and photoprotection reduced sustained photoinhibitory damage, as revealed by a higher Fv /Fm . We therefore propose RGA1 as a regulator of photoavoidance and photoprotection mechanisms in rice and highlight the prospect of exploiting modulation of heterotrimeric G protein signalling to increase these characteristics and improve the yield of cereals in the event of abiotic stress.
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Affiliation(s)
- Ángel Ferrero-Serrano
- Biology Department, Penn State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
| | - Zhao Su
- Biology Department, Penn State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
| | - Sarah M Assmann
- Biology Department, Penn State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
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