1
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Polacco BJ, Lobingier BT, Blythe EE, Abreu N, Khare P, Howard MK, Gonzalez-Hernandez AJ, Xu J, Li Q, Novy B, Naing ZZC, Shoichet BK, Coyote-Maestas W, Levitz J, Krogan NJ, Von Zastrow M, Hüttenhain R. Profiling the proximal proteome of the activated μ-opioid receptor. Nat Chem Biol 2024:10.1038/s41589-024-01588-3. [PMID: 38528119 DOI: 10.1038/s41589-024-01588-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 02/22/2024] [Indexed: 03/27/2024]
Abstract
The μ-opioid receptor (μOR) represents an important target of therapeutic and abused drugs. So far, most understanding of μOR activity has focused on a subset of known signal transducers and regulatory molecules. Yet μOR signaling is coordinated by additional proteins in the interaction network of the activated receptor, which have largely remained invisible given the lack of technologies to interrogate these networks systematically. Here we describe a proteomics and computational approach to map the proximal proteome of the activated μOR and to extract subcellular location, trafficking and functional partners of G-protein-coupled receptor (GPCR) activity. We demonstrate that distinct opioid agonists exert differences in the μOR proximal proteome mediated by endocytosis and endosomal sorting. Moreover, we identify two new μOR network components, EYA4 and KCTD12, which are recruited on the basis of receptor-triggered G-protein activation and might form a previously unrecognized buffering system for G-protein activity broadly modulating cellular GPCR signaling.
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Affiliation(s)
- Benjamin J Polacco
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Braden T Lobingier
- Department of Chemical Physiology and Biochemistry, Oregon Health and Sciences University, Portland, OR, USA
| | - Emily E Blythe
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
- Department of Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Nohely Abreu
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Prachi Khare
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Matthew K Howard
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
- TETRAD Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | | | - Jiewei Xu
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Qiongyu Li
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Brandon Novy
- Department of Chemical Physiology and Biochemistry, Oregon Health and Sciences University, Portland, OR, USA
| | - Zun Zar Chi Naing
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Brian K Shoichet
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Willow Coyote-Maestas
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Nevan J Krogan
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
- J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Mark Von Zastrow
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA.
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.
- Department of Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, CA, USA.
| | - Ruth Hüttenhain
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA.
- J. David Gladstone Institutes, San Francisco, CA, USA.
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
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2
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Zhong X, Li Q, Polacco BJ, Patil T, DiBerto JF, Vartak R, Xu J, Marley A, Foussard H, Roth BL, Eckhardt M, Von Zastrow M, Krogan NJ, Hüttenhain R. An automated proximity proteomics pipeline for subcellular proteome and protein interaction mapping. bioRxiv 2023:2023.04.11.536358. [PMID: 37090610 PMCID: PMC10120663 DOI: 10.1101/2023.04.11.536358] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Proximity labeling (PL) coupled with mass spectrometry has emerged as a powerful technique to map proximal protein interactions in living cells. Large-scale sample processing for proximity proteomics necessitates a high-throughput workflow to reduce hands-on time and increase quantitative reproducibility. To address this issue, we developed a scalable and automated PL pipeline, including generation and characterization of monoclonal cell lines, automated enrichment of biotinylated proteins in a 96-well format, and optimization of the quantitative mass spectrometry (MS) acquisition method. Combined with data-independent acquisition (DIA) MS, our pipeline outperforms manual enrichment and data-dependent acquisition (DDA) MS regarding reproducibility of protein identification and quantification. We apply the pipeline to map subcellular proteomes for endosomes, late endosomes/lysosomes, the Golgi apparatus, and the plasma membrane. Moreover, using serotonin receptor (5HT2A) as a model, we investigated agonist-induced dynamics in protein-protein interactions. Importantly, the approach presented here is universally applicable for PL proteomics using all biotinylation-based PL enzymes, increasing both throughput and reproducibility of standard protocols.
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Affiliation(s)
- Xiaofang Zhong
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Qiongyu Li
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Benjamin J Polacco
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Trupti Patil
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jeffrey F DiBerto
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rasika Vartak
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jiewei Xu
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Aaron Marley
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA 94158, USA
| | - Helene Foussard
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Bryan L Roth
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Manon Eckhardt
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Mark Von Zastrow
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA 94158, USA
| | - Nevan J Krogan
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ruth Hüttenhain
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
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3
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Lazar AM, Irannejad R, Baldwin TA, Sundaram AB, Gutkind JS, Inoue A, Dessauer CW, Von Zastrow M. G protein-regulated endocytic trafficking of adenylyl cyclase type 9. eLife 2020; 9:e58039. [PMID: 32515353 PMCID: PMC7332294 DOI: 10.7554/elife.58039] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [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: 04/20/2020] [Accepted: 06/08/2020] [Indexed: 12/14/2022] Open
Abstract
GPCRs are increasingly recognized to initiate signaling via heterotrimeric G proteins as they move through the endocytic network, but little is known about how relevant G protein effectors are localized. Here we report selective trafficking of adenylyl cyclase type 9 (AC9) from the plasma membrane to endosomes while adenylyl cyclase type 1 (AC1) remains in the plasma membrane, and stimulation of AC9 trafficking by ligand-induced activation of Gs-coupled GPCRs. AC9 transits a similar, dynamin-dependent early endocytic pathway as ligand-activated GPCRs. However, unlike GPCR traffic control which requires β-arrestin but not Gs, AC9 traffic control requires Gs but not β-arrestin. We also show that AC9, but not AC1, mediates cAMP production stimulated by endogenous receptor activation in endosomes. These results reveal dynamic and isoform-specific trafficking of adenylyl cyclase in the endocytic network, and a discrete role of a heterotrimeric G protein in regulating the subcellular distribution of a relevant effector.
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Affiliation(s)
- André M Lazar
- Program in Biochemistry and Cell Biology, University of California San FranciscoSan FranciscoUnited States
| | - Roshanak Irannejad
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
| | - Tanya A Baldwin
- Department of Integrative Biology and Pharmacology, University of Texas Health Science CenterHoustonUnited States
| | - Aparna B Sundaram
- Lung Biology Center, Department of Medicine, University of California San FranciscoSan FranciscoUnited States
| | - J Silvio Gutkind
- Department of Pharmacology and Moores Cancer Center, University of California San DiegoSan DiegoUnited States
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-kuSendaiJapan
| | - Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, University of Texas Health Science CenterHoustonUnited States
| | - Mark Von Zastrow
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
- Department of Psychiatry and Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
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4
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Siljee JE, Wang Y, Bernard AA, Ersoy BA, Zhang S, Marley A, Von Zastrow M, Reiter JF, Vaisse C. Subcellular localization of MC4R with ADCY3 at neuronal primary cilia underlies a common pathway for genetic predisposition to obesity. Nat Genet 2018; 50:180-185. [PMID: 29311635 PMCID: PMC5805646 DOI: 10.1038/s41588-017-0020-9] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/15/2017] [Indexed: 02/01/2023]
Affiliation(s)
- Jacqueline E Siljee
- Department of Medicine and Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Yi Wang
- Department of Medicine and Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Adelaide A Bernard
- Department of Medicine and Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Baran A Ersoy
- Department of Medicine and Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.,Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Sumei Zhang
- Department of Medicine and Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Aaron Marley
- Department of Psychiatry and Cellular & Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | - Mark Von Zastrow
- Department of Psychiatry and Cellular & Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Christian Vaisse
- Department of Medicine and Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.
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5
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Leaf A, Von Zastrow M. Dopamine receptors reveal an essential role of IFT-B, KIF17, and Rab23 in delivering specific receptors to primary cilia. eLife 2015; 4. [PMID: 26182404 PMCID: PMC4547097 DOI: 10.7554/elife.06996] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [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: 02/13/2015] [Accepted: 07/15/2015] [Indexed: 01/05/2023] Open
Abstract
Appropriate physiological signaling by primary cilia depends on the specific targeting of particular receptors to the ciliary membrane, but how this occurs remains poorly understood. In this study, we show that D1-type dopaminergic receptors are delivered to cilia from the extra-ciliary plasma membrane by a mechanism requiring the receptor cytoplasmic tail, the intraflagellar transport complex-B (IFT-B), and ciliary kinesin KIF17. This targeting mechanism critically depends on Rab23, a small guanine nucleotide binding protein that has important effects on physiological signaling from cilia but was not known previously to be essential for ciliary delivery of any cargo. Depleting Rab23 prevents dopamine receptors from accessing the ciliary membrane. Conversely, fusion of Rab23 to a non-ciliary receptor is sufficient to drive robust, nucleotide-dependent mis-localization to the ciliary membrane. Dopamine receptors thus reveal a previously unrecognized mechanism of ciliary receptor targeting and functional role of Rab23 in promoting this process.
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Affiliation(s)
- Alison Leaf
- Program in Cell Biology, University of California, San Francisco, San Francisco, United States
| | - Mark Von Zastrow
- Program in Cell Biology, University of California, San Francisco, San Francisco, United States
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6
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Wang Y, Lauffer B, Von Zastrow M, Kobilka BK, Xiang Y. N-ethylmaleimide-sensitive factor regulates beta2 adrenoceptor trafficking and signaling in cardiomyocytes. Mol Pharmacol 2007; 72:429-39. [PMID: 17510209 DOI: 10.1124/mol.107.037747] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recycling of G protein-coupled receptors determines the functional resensitization of receptors and is implicated in switching beta2 adrenoceptor (beta2AR) G protein specificity in cardiomyocytes. The human beta2AR carboxyl end binds to the N-ethylmaleimide-sensitive factor (NSF), an ATPase integral to membrane trafficking machinery. It is interesting that the human beta2AR (hbeta2AR) carboxyl end pulled down NSF from mouse heart lysates, whereas the murine one did not. Despite this difference, both beta2ARs exhibited substantial agonist-induced internalization, recycling, and Gi coupling in cardiomyocytes. The hbeta2AR, however, displayed faster rates of agonist-induced internalization and recycling compared with the murine beta2AR (mbeta2AR) and a more profound Gi component in its contraction response. Replacing the mbeta2AR proline (-1) with a leucine generated a gain-of-function mutation, mbeta2AR-P417L, with a rescued ability to bind NSF, faster internalization and recycling than the mbeta2AR, and a significant enhancement in Gi signaling, which mimics the hbeta2AR. Selective disruption of the mbeta2AR-P417L binding to NSF inhibited the receptor coupling to Gi. Mean-while, inhibiting NSF with N-ethylmaleimide blocked the mbeta2AR recycling after agonist-induced endocytosis. Expressing the NSF-E329Q mutant lacking ATPase activity inhibited the mbeta2AR coupling to Gi in cardiomyocytes. Our results revealed a dual regulation on hbeta2AR trafficking and signaling by NSF through direct binding to cargo receptor and its ATPase activity and uncovered an unprecedented role for the receptor binding to NSF in regulating G protein specificity that has diverged between mouse and human beta2ARs.
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Affiliation(s)
- Yongyu Wang
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, B523 Burrill Hall, MC-114, 407 S. Goodwin Avenue, Urbana, IL 61801, USA
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7
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Abstract
A critical event determining the functional consequences of G protein-coupled receptor (GPCR) endocytosis is the molecular sorting of internalized receptors between divergent recycling and degradative membrane pathways. The D1 dopamine receptor recycles rapidly and efficiently to the plasma membrane after agonist-induced endocytosis and is remarkably resistant to proteolytic down-regulation. Whereas the mechanism mediating agonist-induced endocytosis of D1 receptors has been investigated in some detail, little is known about how receptors are sorted after endocytosis. We have identified a sequence present in the carboxyl-terminal cytoplasmic domain of the human D1 dopamine receptor that is specifically required for the efficient recycling of endocytosed receptors back to the plasma membrane. This sequence is distinct from previously identified membrane trafficking signals and is located in a proximal portion of the carboxyl-terminal cytoplasmic domain, in contrast to previously identified GPCR recycling signals present at the distal tip. Nevertheless, fusion of this sequence to the carboxyl terminus of a chimeric mutant delta opioid neuropeptide receptor is sufficient to re-route internalized receptors from lysosomal to recycling membrane pathways, defining this sequence as a bona fide endocytic recycling signal that can function in both proximal and distal locations. These results identify a novel sorting signal controlling the endocytic trafficking itinerary of a physiologically important dopamine receptor, provide the first example of such a sorting signal functioning in a proximal portion of the carboxyl-terminal cytoplasmic domain, and suggest the existence of a diverse array of sorting signals in the GPCR superfamily that mediate subtype-specific regulation of receptors via endocytic membrane trafficking.
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Affiliation(s)
- Gabriel A Vargas
- Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California 94143-2140, USA.
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8
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Hislop JN, Marley A, Von Zastrow M. Role of mammalian vacuolar protein-sorting proteins in endocytic trafficking of a non-ubiquitinated G protein-coupled receptor to lysosomes. J Biol Chem 2004; 279:22522-31. [PMID: 15024011 DOI: 10.1074/jbc.m311062200] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many signaling receptors require covalent modification by ubiquitin for agonist-induced down-regulation via endocytic trafficking to lysosomes, a process that is mediated by a conserved set of endosome-associating proteins also required for vacuolar protein-sorting (VPS) in yeast. The delta opioid receptor (DOR) is a G protein-coupled receptor that can undergo agonist-induced proteolysis via endocytic trafficking to lysosomes but does not require covalent modification by ubiquitin to do so. This raises the question of whether lysosomal down-regulation of this "ubiquitination-independent" GPCR is mediated by a completely distinct biochemical mechanism or if similar VPS machinery is involved. Agonist-induced proteolysis of DOR was significantly inhibited by dominant negative mutant versions of Vps4/Skd1, an AAA-family ATPase required for a late step in lysosomal sorting of ubiquitinated membrane cargo. Furthermore, overexpression and interfering RNA-mediated knockdown indicated that lysosomal trafficking of opioid receptors is also dependent on Hrs, a VPS protein that mediates an early step in lysosomal sorting of ubiquitinated cargo. However, interfering RNA-mediated knockdown of Tsg101, a VPS protein that is essential for an intermediate step of the conserved lysosomal sorting mechanism, did not detectably affect agonist-induced proteolysis of DOR in the same cells in which (ubiquitination-dependent) lysosomal trafficking of epidermal growth factor receptors was clearly inhibited. These results indicate that opioid receptors, despite their ability to undergo efficient agonist-induced trafficking to lysosomes in the absence of covalent modification by ubiquitin, utilize some (Vps4 and Hrs) but perhaps not all (Tsg101) of the VPS machinery required for lysosomal sorting of ubiquitinated membrane cargo.
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Affiliation(s)
- James N Hislop
- Department of Psychiatry, University of California, San Francisco, California 94143-2140, USA.
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9
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Elenko E, Fischer T, Niesman I, Harding T, McQuistan T, Von Zastrow M, Farquhar MG. Spatial regulation of Galphai protein signaling in clathrin-coated membrane microdomains containing GAIP. Mol Pharmacol 2003; 64:11-20. [PMID: 12815156 DOI: 10.1124/mol.64.1.11] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Regulators of G-protein signaling (RGS) proteins are GTPase-activating proteins (GAPs) that bind to Galpha subunits and attenuate G protein signaling, but where these events occur in the cell is not yet established. Here we investigated, by immunofluorescence labeling and deconvolution analysis, the site at which endogenous Galpha-interacting protein (GAIP) (RGS19) binds to Galphai3-YFP and its fate after activation of delta-opioid receptor (DOR). In the absence of agonist, GAIP is spatially segregated from Galphai3 and DOR in clathrin-coated domains (CCPs) of the cell membrane (PM), whereas Galphai3-YPF and DOR are located in non-clathrin-coated microdomains of the PM. Upon addition of agonist, Galphai3 partially colocalizes with GAIP in CCPs at the PM. When endocytosis is blocked by expression of a dynamin mutant [dyn(K44A)], there is a striking overlap in the distribution of DOR and Galphai3-YFP with GAIP in CCPs. Moreover, Galphai3-YFP and GAIP form a coprecipitable complex. Our results support a model whereby, after agonist addition, DOR and Galphai3 move together into CCPs where Galphai3 and GAIP meet and turn off G protein signaling. Subsequently, Galphai3 returns to non-clathrin-coated microdomains of the PM, GAIP remains stably associated with CCPs, and DOR is internalized via clathrin-coated vesicles. This constitutes a novel mechanism for regulation of Galpha signaling through spatial segregation of a GAP in clathrin-coated pits.
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Affiliation(s)
- Eric Elenko
- Department of Cellular and Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0651, USA
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10
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Abstract
Ubiquitination of cytoplasmic lysine residues can target G protein-coupled receptors (GPCRs) to proteasomes and has recently been shown to also be required for sorting of certain GPCRs to lysosomes following ligand-induced endocytosis. We addressed the generality of this mechanism by examining regulated proteolysis of the murine delta opioid receptor (DOR) expressed in human embryonic kidney 293 cells, a well characterized model system in which receptors are sorted to lysosomes. Incubation of cells in the presence of the highly specific proteasome inhibitor lactacystin did not detectably affect ligand-induced proteolysis of DOR but significantly delayed ligand-induced proteolysis of epidermal growth factor receptors. Mutation of all cytoplasmic lysine residues in DOR, creating a mutant opioid receptor that is unable to be ubiquitinated, did not detectably inhibit either ligand-induced endocytosis or proteolytic degradation of endocytosed receptors. Furthermore, the lysine-mutated DOR, like its wild type counterpart, colocalized extensively with lysosomes after ligand-induced endocytosis. These results demonstrate that ubiquitination of DOR is not required either for its ligand-induced endocytosis or for postendocytic trafficking to lysosomes.
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Affiliation(s)
- Michael Tanowitz
- Department of Psychiatry, University of California, San Francisco, California 94143-0984, USA.
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11
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Abstract
Binding of hormones, growth factors and other cell modulators to cell-surface receptors triggers a complex array of signal-transduction events. The activation of many receptors also accelerates their endocytosis. Endocytic transport is important in regulating signal transduction and in mediating the formation of specialized signalling complexes. Conversely, signal-transduction events modulate specific components of the endocytic machinery. Recent studies of protein tyrosine kinases and G-protein-coupled receptors have shed new light on the mechanisms and functional consequences of this bidirectional interplay between signalling and membrane-transport networks.
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Affiliation(s)
- Alexander Sorkin
- Department of Pharmacology, University of Colorado Health Sciences Center, Denver, Colorado 80111, USA.
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12
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Whistler JL, Enquist J, Marley A, Fong J, Gladher F, Tsuruda P, Murray SR, Von Zastrow M. Modulation of postendocytic sorting of G protein-coupled receptors. Science 2002; 297:615-20. [PMID: 12142540 DOI: 10.1126/science.1073308] [Citation(s) in RCA: 249] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Recycling of the mu opioid receptor to the plasma membrane after endocytosis promotes rapid resensitization of signal transduction, whereas targeting of the delta opioid receptor (DOR) to lysosomes causes proteolytic down-regulation. We identified a protein that binds preferentially to the cytoplasmic tail of the DOR as a candidate heterotrimeric GTP-binding protein (G protein)-coupled receptor-associated sorting protein (GASP). Disruption of the DOR-GASP interaction through receptor mutation or overexpression of a dominant negative fragment of GASP inhibited receptor trafficking to lysosomes and promoted recycling. The GASP family of proteins may modulate lysosomal sorting and functional down-regulation of a variety of G protein-coupled receptors.
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Affiliation(s)
- Jennifer L Whistler
- Department of Neurology, Ernest Gallo Clinic and Research Center, University of California, San Francisco, Emeryville, CA 94608, USA.
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13
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Abstract
Activity-dependent modulation of synaptic efficacy in the brain contributes to neural circuit development and experience-dependent plasticity. Although glia are affected by activity and ensheathe synapses, their influence on synaptic strength has largely been ignored. Here, we show that a protein produced by glia, tumor necrosis factor alpha (TNFalpha), enhances synaptic efficacy by increasing surface expression of AMPA receptors. Preventing the actions of endogenous TNFalpha has the opposite effects. Thus, the continual presence of TNFalpha is required for preservation of synaptic strength at excitatory synapses. Through its effects on AMPA receptor trafficking, TNFalpha may play roles in synaptic plasticity and modulating responses to neural injury.
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Affiliation(s)
- Eric C Beattie
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA 94304, USA.
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