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Carosi JM, Hein LK, Sandow JJ, Dang LVP, Hattersley K, Denton D, Kumar S, Sargeant TJ. Autophagy captures the retromer-TBC1D5 complex to inhibit receptor recycling. Autophagy 2024; 20:863-882. [PMID: 37938196 PMCID: PMC11062367 DOI: 10.1080/15548627.2023.2281126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/03/2023] [Indexed: 11/09/2023] Open
Abstract
Retromer prevents the destruction of numerous receptors by recycling them from endosomes to the trans-Golgi network or plasma membrane. This enables retromer to fine-tune the activity of many signaling pathways in parallel. However, the mechanism(s) by which retromer function adapts to environmental fluctuations such as nutrient withdrawal and how this affects the fate of its cargoes remains incompletely understood. Here, we reveal that macroautophagy/autophagy inhibition by MTORC1 controls the abundance of retromer+ endosomes under nutrient-replete conditions. Autophagy activation by chemical inhibition of MTOR or nutrient withdrawal does not affect retromer assembly or its interaction with the RAB7 GAP protein TBC1D5, but rather targets these endosomes for bulk destruction following their capture by phagophores. This process appears to be distinct from amphisome formation. TBC1D5 and its ability to bind to retromer, but not its C-terminal LC3-interacting region (LIR) or nutrient-regulated dephosphorylation, is critical for retromer to be captured by autophagosomes following MTOR inhibition. Consequently, endosomal recycling of its cargoes to the plasma membrane and trans-Golgi network is impaired, leading to their lysosomal turnover. These findings demonstrate a mechanistic link connecting nutrient abundance to receptor homeostasis.Abbreviations: AMPK, 5'-AMP-activated protein kinase; APP, amyloid beta precursor protein; ATG, autophagy related; BafA, bafilomycin A1; CQ, chloroquine; DMEM, Dulbecco's minimum essential medium; DPBS, Dulbecco's phosphate-buffered saline; EBSS, Earle's balanced salt solution; FBS, fetal bovine serum; GAP, GTPase-activating protein; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; LIR, LC3-interacting region; LANDO, LC3-associated endocytosis; LP, leupeptin and pepstatin; MTOR, mechanistic target of rapamycin kinase; MTORC1, MTOR complex 1; nutrient stress, withdrawal of amino acids and serum; PDZ, DLG4/PSD95, DLG1, and TJP1/zo-1; RPS6, ribosomal protein S6; RPS6KB1/S6K1, ribosomal protein S6 kinase B1; SLC2A1/GLUT1, solute carrier family 2 member 1; SORL1, sortillin related receptor 1; SORT1, sortillin 1; SNX, sorting nexin; TBC1D5, TBC1 domain family member 5; ULK1, unc-51 like autophagy activating kinase 1; WASH, WASH complex subunit.
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Affiliation(s)
- Julian M. Carosi
- Lysosomal Health in Ageing, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Centre for Cancer Biology, University of South Australia (UniSA), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, Engineering and Technology, The University of Adelaide, Adelaide, SA, Australia
| | - Leanne K. Hein
- Lysosomal Health in Ageing, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Jarrod J. Sandow
- Walter and Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
- Current Address: IonOpticks, Fitzroy, VIC, Australia
| | - Linh V. P. Dang
- Lysosomal Health in Ageing, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Kathryn Hattersley
- Lysosomal Health in Ageing, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Donna Denton
- Centre for Cancer Biology, University of South Australia (UniSA), Adelaide, SA, Australia
| | - Sharad Kumar
- Centre for Cancer Biology, University of South Australia (UniSA), Adelaide, SA, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Timothy J. Sargeant
- Lysosomal Health in Ageing, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
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2
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Tutzauer J, Serafin DS, Schmidt T, Olde B, Caron KM, Leeb-Lundberg LMF. G protein-coupled estrogen receptor (GPER)/GPR30 forms a complex with the β 1-adrenergic receptor, a membrane-associated guanylate kinase (MAGUK) scaffold protein, and protein kinase A anchoring protein (AKAP) 5 in MCF7 breast cancer cells. Arch Biochem Biophys 2024; 752:109882. [PMID: 38211639 DOI: 10.1016/j.abb.2024.109882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/26/2023] [Accepted: 01/08/2024] [Indexed: 01/13/2024]
Abstract
G protein-coupled receptor 30 (GPR30), also named G protein-coupled estrogen receptor (GPER), and the β1-adrenergic receptor (β1AR) are G protein-coupled receptors (GPCR) that are implicated in breast cancer progression. Both receptors contain PSD-95/Discs-large/ZO-1 homology (PDZ) motifs in their C-terminal tails through which they interact in the plasma membrane with membrane-associated guanylate kinase (MAGUK) scaffold proteins, and in turn protein kinase A anchoring protein (AKAP) 5. GPR30 constitutively and PDZ-dependently inhibits β1AR-mediated cAMP production. We hypothesized that this inhibition is a consequence of a plasma membrane complex of these receptors. Using co-immunoprecipitation, confocal immunofluorescence microscopy, and bioluminescence resonance energy transfer (BRET), we show that GPR30 and β1AR reside in close proximity in a plasma membrane complex when transiently expressed in HEK293. Deleting the GPR30 C-terminal PDZ motif (-SSAV) does not interfere with the receptor complex, indicating that the complex is not PDZ-dependent. MCF7 breast cancer cells express GPR30, β1AR, MAGUKs, and AKAP5 in the plasma membrane, and co-immunoprecipitation revealed that these proteins exist in close proximity also under native conditions. Furthermore, expression of GPR30 in MCF7 cells constitutively and PDZ-dependently inhibits β1AR-mediated cAMP production. AKAP5 also inhibits β1AR-mediated cAMP production, which is not additive with GPR30-promoted inhibition. These results argue that GPR30 and β1AR form a PDZ-independent complex in MCF7 cells through which GPR30 constitutively and PDZ-dependently inhibits β1AR signaling via receptor interaction with MAGUKs and AKAP5.
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Affiliation(s)
- Julia Tutzauer
- Department of Experimental Medical Science, Lund University, 22184, Lund, Sweden
| | - D Stephen Serafin
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Tobias Schmidt
- Wallenberg Center for Molecular Medicine, Department of Clinical Sciences Lund, Division of Pediatrics, Lund University, 22184, Lund, Sweden
| | - Björn Olde
- Department of Clinical Sciences, Division of Cardiology, Lund University, 22184, Lund, Sweden
| | - Kathleen M Caron
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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3
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Janicot R, Maziarz M, Park JC, Luebbers A, Green E, Zhao J, Philibert C, Zhang H, Layne MD, Wu JC, Garcia-Marcos M. Direct interrogation of context-dependent GPCR activity with a universal biosensor platform. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.02.573921. [PMID: 38260348 PMCID: PMC10802303 DOI: 10.1101/2024.01.02.573921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of druggable proteins in the human genome, but progress in understanding and targeting them is hindered by the lack of tools to reliably measure their nuanced behavior in physiologically-relevant contexts. Here, we developed a collection of compact ONE vector G-protein Optical (ONE-GO) biosensor constructs as a scalable platform that can be conveniently deployed to measure G-protein activation by virtually any GPCR with high fidelity even when expressed endogenously in primary cells. By characterizing dozens of GPCRs across many cell types like primary cardiovascular cells or neurons, we revealed new insights into the molecular basis for G-protein coupling selectivity of GPCRs, pharmacogenomic profiles of anti-psychotics on naturally-occurring GPCR variants, and G-protein subtype signaling bias by endogenous GPCRs depending on cell type or upon inducing disease-like states. In summary, this open-source platform makes the direct interrogation of context-dependent GPCR activity broadly accessible.
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Affiliation(s)
- Remi Janicot
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Marcin Maziarz
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Jong-Chan Park
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Alex Luebbers
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Elena Green
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Jingyi Zhao
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Clementine Philibert
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Hao Zhang
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mathew D. Layne
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Joseph C. Wu
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mikel Garcia-Marcos
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
- Department of Biology, College of Arts & Sciences, Boston University, Boston, MA 02115, USA
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4
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Maggio R, Fasciani I, Petragnano F, Coppolino MF, Scarselli M, Rossi M. Unraveling the Functional Significance of Unstructured Regions in G Protein-Coupled Receptors. Biomolecules 2023; 13:1431. [PMID: 37892113 PMCID: PMC10604838 DOI: 10.3390/biom13101431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/29/2023] Open
Abstract
Unstructured regions in functional proteins have gained attention in recent years due to advancements in informatics tools and biophysical methods. G protein-coupled receptors (GPCRs), a large family of cell surface receptors, contain unstructured regions in the form of the i3 loop and C-terminus. This review provides an overview of the functional significance of these regions in GPCRs. GPCRs transmit signals from the extracellular environment to the cell interior, regulating various physiological processes. The i3 loop, located between the fifth and sixth transmembrane helices, and the C-terminus, connected to the seventh transmembrane helix, are determinant of interactions with G proteins and with other intracellular partners such as arrestins. Recent studies demonstrate that the i3 loop and C-terminus play critical roles in allosterically regulating GPCR activation. They can act as autoregulators, adopting conformations that, by restricting G protein access, modulate receptor coupling specificity. The length and unstructured nature of the i3 loop and C-terminus provide unique advantages in GPCR interactions with intracellular protein partners. They act as "fishing lines", expanding the radius of interaction and enabling GPCRs to tether scaffolding proteins, thus facilitating receptor stability during cell membrane movements. Additionally, the i3 loop may be involved in domain swapping between GPCRs, generating novel receptor dimers with distinct binding and coupling characteristics. Overall, the i3 loop and C-terminus are now widely recognized as crucial elements in GPCR function and regulation. Understanding their functional roles enhances our comprehension of GPCR structure and signaling complexity and holds promise for advancements in receptor pharmacology and drug development.
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Affiliation(s)
- Roberto Maggio
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (I.F.); (F.P.); (M.R.)
| | - Irene Fasciani
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (I.F.); (F.P.); (M.R.)
| | - Francesco Petragnano
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (I.F.); (F.P.); (M.R.)
| | - Maria Francesca Coppolino
- Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
| | - Marco Scarselli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy;
| | - Mario Rossi
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (I.F.); (F.P.); (M.R.)
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5
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Bahouth SW, Nooh MM, Mancarella S. Involvement of SAP97 anchored multiprotein complexes in regulating cardiorenal signaling and trafficking networks. Biochem Pharmacol 2023; 208:115406. [PMID: 36596415 DOI: 10.1016/j.bcp.2022.115406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/02/2023]
Abstract
SAP97 is a member of the MAGUK family of proteins, but unlike other MAGUK proteins that are selectively expressed in the CNS, SAP97 is also expressed in peripheral organs, like the heart and kidneys. SAP97 has several protein binding cassettes, and this review will describe their involvement in creating SAP97-anchored multiprotein networks. SAP97-anchored networks localized at the inner leaflet of the cell membrane play a major role in trafficking and targeting of membrane G protein-coupled receptors (GPCR), channels, and structural proteins. SAP97 plays a major role in compartmentalizing voltage gated sodium and potassium channels to specific cellular compartments of heart cells. SAP97 undergoes extensive alternative splicing. These splice variants give rise to different SAP97 isoforms that alter its cellular localization, networking, signaling and trafficking effects. Regarding GPCR, SAP97 binds to the β1-adrenergic receptor and recruits AKAP5/PKA and PDE4D8 to create a multiprotein complex that regulates trafficking and signaling of cardiac β1-AR. In the kidneys, SAP97 anchored networks played a role in trafficking of aquaporin-2 water channels. Cardiac specific ablation of SAP97 (SAP97-cKO) resulted in cardiac hypertrophy and failure in aging mice. Similarly, instituting transverse aortic constriction (TAC) in young SAP97 c-KO mice exacerbated TAC-induced cardiac remodeling and dysfunction. These findings highlight a critical role for SAP97 in the pathophysiology of a number of cardiac and renal diseases, suggesting that SAP97 is a relevant target for drug discovery.
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Affiliation(s)
- Suleiman W Bahouth
- Department of Pharmacology, Addiction Science and Toxicology, The University of Tennessee-Health Sciences Center, Memphis, TN, United States.
| | - Mohammed M Nooh
- Department of Biochemistry, Faculty of Pharmacy Cairo University, Cairo, Egypt and Biochemistry Department, Faculty of Pharmacy, October 6 University, Giza, Egypt
| | - Salvatore Mancarella
- Department of Physiology, The University of Tennessee-Health Sciences Center, Memphis, TN, United States
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6
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Benton KC, Wheeler DS, Kurtoglu B, Ansari MBZ, Cibich DP, Gonzalez DA, Herbst MR, Khursheed S, Knorr RC, Lobner D, Maglasang JG, Rohr KE, Taylor A, Twining RC, Witt PJ, Gasser PJ. Norepinephrine activates β 1 -adrenergic receptors at the inner nuclear membrane in astrocytes. Glia 2022; 70:1777-1794. [PMID: 35589612 PMCID: PMC9276628 DOI: 10.1002/glia.24219] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 04/18/2022] [Accepted: 05/09/2022] [Indexed: 01/01/2023]
Abstract
Norepinephrine exerts powerful influences on the metabolic, neuroprotective and immunoregulatory functions of astrocytes. Until recently, all effects of norepinephrine were believed to be mediated by receptors localized exclusively to the plasma membrane. However, recent studies in cardiomyocytes have identified adrenergic receptors localized to intracellular membranes, including Golgi and inner nuclear membranes, and have shown that norepinephrine can access these receptors via transporter-mediated uptake. We recently identified a high-capacity norepinephrine transporter, organic cation transporter 3 (OCT3), densely localized to outer nuclear membranes in astrocytes, suggesting that adrenergic signaling may also occur at the inner nuclear membrane in these cells. Here, we used immunofluorescence and western blot to show that β1 -adrenergic receptors are localized to astrocyte inner nuclear membranes; that key adrenergic signaling partners are present in astrocyte nuclei; and that OCT3 and other catecholamine transporters are localized to astrocyte plasma and nuclear membranes. To test the functionality of nuclear membrane β1 -adrenergic receptors, we monitored real-time protein kinase A (PKA) activity in astrocyte nuclei using a fluorescent biosensor. Treatment of astrocytes with norepinephrine induced rapid increases in PKA activity in the nuclear compartment. Pretreatment of astrocytes with inhibitors of catecholamine uptake blocked rapid norepinephrine-induced increases in nuclear PKA activity. These studies, the first to document functional adrenergic receptors at the nuclear membrane in any central nervous system cell, reveal a novel mechanism by which norepinephrine may directly influence nuclear processes. This mechanism may contribute to previously described neuroprotective, metabolic and immunoregulatory actions of norepinephrine.
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Affiliation(s)
| | | | - Beliz Kurtoglu
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | | | - Daniel P. Cibich
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Dante A. Gonzalez
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Matthew R. Herbst
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Saema Khursheed
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Rachel C. Knorr
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Doug Lobner
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Jenree G. Maglasang
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Kayla E. Rohr
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Analisa Taylor
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Robert C. Twining
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Paul J. Witt
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
| | - Paul J. Gasser
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201
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7
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Multivalent interactions between molecular components involved in fast endophilin mediated endocytosis drive protein phase separation. Nat Commun 2022; 13:5017. [PMID: 36028485 PMCID: PMC9418313 DOI: 10.1038/s41467-022-32529-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 08/03/2022] [Indexed: 11/30/2022] Open
Abstract
A specific group of transmembrane receptors, including the β1-adrenergic receptor (β1-AR), is internalized through a non-clathrin pathway known as Fast Endophilin Mediated Endocytosis (FEME). A key question is: how does the endocytic machinery assemble and how is it modulated by activated receptors during FEME. Here we show that endophilin, a major regulator of FEME, undergoes a phase transition into liquid-like condensates, which facilitates the formation of multi-protein assemblies by enabling the phase partitioning of endophilin binding proteins. The phase transition can be triggered by specific multivalent binding partners of endophilin in the FEME pathway such as the third intracellular loop (TIL) of the β1-AR, and the C-terminal domain of lamellipodin (LPD). Other endocytic accessory proteins can either partition into, or target interfacial regions of, these condensate droplets, and LPD also phase separates with the actin polymerase VASP. On the membrane, TIL promotes protein clustering in the presence of endophilin and LPD C-terminal domain. Our results demonstrate how the multivalent interactions between endophilin, LPD, and TIL regulate protein assembly formation on the membrane, providing mechanistic insights into the priming and initiation steps of FEME. Here the authors show that protein phase separation is a key mechanism in cellular receptor internalization via fast endophilin mediated endocytosis (FEME). Phase separation facilitates multivalent FEME-protein assembly in this clathrin-independent pathway.
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8
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MAGED2 Is Required under Hypoxia for cAMP Signaling by Inhibiting MDM2-Dependent Endocytosis of G-Alpha-S. Cells 2022; 11:cells11162546. [PMID: 36010623 PMCID: PMC9406315 DOI: 10.3390/cells11162546] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/14/2022] [Accepted: 08/15/2022] [Indexed: 01/15/2023] Open
Abstract
Mutations in MAGED2 cause transient Bartter syndrome characterized by severe renal salt wasting in fetuses and infants, which leads to massive polyhydramnios causing preterm labor, extreme prematurity and perinatal death. Notably, this condition resolves spontaneously in parallel with developmental increase in renal oxygenation. MAGED2 interacts with G-alpha-S (Gαs). Given the role of Gαs in activating adenylyl cyclase at the plasma membrane and consequently generating cAMP to promote renal salt reabsorption via protein kinase A (PKA), we hypothesized that MAGED2 is required for this signaling pathway under hypoxic conditions such as in fetuses. Consistent with that, under both physical and chemical hypoxia, knockdown of MAGED2 in renal (HEK293) and cancer (HeLa) cell culture models caused internalization of Gαs, which was fully reversible upon reoxygenation. In contrast to Gαs, cell surface expression of the β2-adrenergic receptor, which is coupled to Gαs, was not affected by MAGED2 depletion, demonstrating specific regulation of Gαs by MAGED2. Importantly, the internalization of Gαs due to MAGED2 deficiency significantly reduced cAMP generation and PKA activity. Interestingly, the internalization of Gαs was blocked by preventing its endocytosis with dynasore. Given the role of E3 ubiquitin ligases, which can be regulated by MAGE-proteins, in regulating endocytosis, we assessed the potential role of MDM2-dependent ubiquitination in MAGED2 deficiency-induced internalization of Gαs under hypoxia. Remarkably, MDM2 depletion or its chemical inhibition fully abolished Gαs-endocytosis following MAGED2 knockdown. Moreover, endocytosis of Gαs was also blocked by mutation of ubiquitin acceptor sites in Gαs. Thus, we reveal that MAGED2 is essential for the cAMP/PKA pathway under hypoxia to specifically regulate Gαs endocytosis by blocking MDM2-dependent ubiquitination of Gαs. This may explain, at least in part, the transient nature of Bartter syndrome caused by MAGED2 mutations and opens new avenues for therapy in these patients.
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9
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Structure-guided optimization of light-activated chimeric G-protein-coupled receptors. Structure 2022; 30:1075-1087.e4. [PMID: 35588733 DOI: 10.1016/j.str.2022.04.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/22/2022] [Accepted: 04/22/2022] [Indexed: 01/11/2023]
Abstract
G-protein-coupled receptors (GPCRs) are the largest human receptor family and involved in virtually every physiological process. One hallmark of their function is specific coupling to selected signaling pathways. The ability to tune this coupling would make development of receptors with new capabilities possible. Complexes of GPCRs and G-proteins have recently been resolved at high resolution, but this information was in only few cases harnessed for rational receptor engineering. Here, we demonstrate structure-guided optimization of light-activated OptoXRs. Our hypothesis was that incorporation of GPCR-Gα contacts would lead to improved coupling. We first evaluated structure-based alignments for chimeric receptor fusion. We then show in a light-activated β2AR that including Gα contacts increased signaling 7- to 20-fold compared with other designs. In turn, contact elimination diminished function. Finally, this platform allowed optimization of a further OptoXR and spectral tuning. Our work exemplifies structure-based OptoXR development for targeted cell and network manipulation.
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10
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Andersson L, Cinato M, Mardani I, Miljanovic A, Arif M, Koh A, Lindbom M, Laudette M, Bollano E, Omerovic E, Klevstig M, Henricsson M, Fogelstrand P, Swärd K, Ekstrand M, Levin M, Wikström J, Doran S, Hyötyläinen T, Sinisalu L, Orešič M, Tivesten Å, Adiels M, Bergo MO, Proia R, Mardinoglu A, Jeppsson A, Borén J, Levin MC. Glucosylceramide synthase deficiency in the heart compromises β1-adrenergic receptor trafficking. Eur Heart J 2021; 42:4481-4492. [PMID: 34297830 PMCID: PMC8599074 DOI: 10.1093/eurheartj/ehab412] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/05/2021] [Accepted: 06/18/2021] [Indexed: 12/20/2022] Open
Abstract
Aims Cardiac injury and remodelling are associated with the rearrangement of cardiac lipids. Glycosphingolipids are membrane lipids that are important for cellular structure and function, and cardiac dysfunction is a characteristic of rare monogenic diseases with defects in glycosphingolipid synthesis and turnover. However, it is not known how cardiac glycosphingolipids regulate cellular processes in the heart. The aim of this study is to determine the role of cardiac glycosphingolipids in heart function. Methods and results Using human myocardial biopsies, we showed that the glycosphingolipids glucosylceramide and lactosylceramide are present at very low levels in non-ischaemic human heart with normal function and are elevated during remodelling. Similar results were observed in mouse models of cardiac remodelling. We also generated mice with cardiomyocyte-specific deficiency in Ugcg, the gene encoding glucosylceramide synthase (hUgcg
–/– mice). In 9- to 10-week-old hUgcg
–/– mice, contractile capacity in response to dobutamine stress was reduced. Older hUgcg
–/– mice developed severe heart failure and left ventricular dilatation even under baseline conditions and died prematurely. Using RNA-seq and cell culture models, we showed defective endolysosomal retrograde trafficking and autophagy in Ugcg-deficient cardiomyocytes. We also showed that responsiveness to β-adrenergic stimulation was reduced in cardiomyocytes from hUgcg
–/– mice and that Ugcg knockdown suppressed the internalization and trafficking of β1-adrenergic receptors. Conclusions Our findings suggest that cardiac glycosphingolipids are required to maintain β-adrenergic signalling and contractile capacity in cardiomyocytes and to preserve normal heart function.
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Affiliation(s)
- Linda Andersson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Mathieu Cinato
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Ismena Mardani
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Azra Miljanovic
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Muhammad Arif
- Science for Life Laboratory, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Ara Koh
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden.,Department of Precision Medicine, School of Medicine, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Malin Lindbom
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Marion Laudette
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Entela Bollano
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Elmir Omerovic
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Martina Klevstig
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Per Fogelstrand
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Karl Swärd
- Department of Experimental Medical Science, Lund University, SE-221 84 Lund, Sweden
| | - Matias Ekstrand
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Max Levin
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Johannes Wikström
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Pepparedsleden 1, SE-431 83 Mölndal, Sweden
| | - Stephen Doran
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Tuulia Hyötyläinen
- School of Natural Sciences and Technology, Örebro University, Fakultetsgatan 1, SE-701 82 Örebro, Sweden
| | - Lisanna Sinisalu
- School of Natural Sciences and Technology, Örebro University, Fakultetsgatan 1, SE-701 82 Örebro, Sweden
| | - Matej Orešič
- School of Medical Sciences, Örebro University, SE-701 82 Örebro, Sweden.,Turku Bioscience Centre, University of Turku, FIN-20521 Turku, Finland
| | - Åsa Tivesten
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Martin Adiels
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Martin O Bergo
- Department of Biosciences and Nutrition, Karolinska Institute, SE-141 83 Huddinge, Sweden
| | - Richard Proia
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Adil Mardinoglu
- Science for Life Laboratory, KTH-Royal Institute of Technology, Stockholm, Sweden.,Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Anders Jeppsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
| | - Malin C Levin
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg and Sahlgrenska University Hospital, Bruna Stråket 16, SE-413 45 Gothenburg, Sweden
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11
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Ferreira APA, Casamento A, Carrillo Roas S, Halff EF, Panambalana J, Subramaniam S, Schützenhofer K, Chan Wah Hak L, McGourty K, Thalassinos K, Kittler JT, Martinvalet D, Boucrot E. Cdk5 and GSK3β inhibit fast endophilin-mediated endocytosis. Nat Commun 2021; 12:2424. [PMID: 33893293 PMCID: PMC8065113 DOI: 10.1038/s41467-021-22603-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 03/18/2021] [Indexed: 12/12/2022] Open
Abstract
Endocytosis mediates the cellular uptake of micronutrients and cell surface proteins. Fast Endophilin-mediated endocytosis, FEME, is not constitutively active but triggered upon receptor activation. High levels of growth factors induce spontaneous FEME, which can be suppressed upon serum starvation. This suggested a role for protein kinases in this growth factor receptor-mediated regulation. Using chemical and genetic inhibition, we find that Cdk5 and GSK3β are negative regulators of FEME. They antagonize the binding of Endophilin to Dynamin-1 and to CRMP4, a Plexin A1 adaptor. This control is required for proper axon elongation, branching and growth cone formation in hippocampal neurons. The kinases also block the recruitment of Dynein onto FEME carriers by Bin1. As GSK3β binds to Endophilin, it imposes a local regulation of FEME. Thus, Cdk5 and GSK3β are key regulators of FEME, licensing cells for rapid uptake by the pathway only when their activity is low.
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Affiliation(s)
- Antonio P A Ferreira
- Institute of Structural and Molecular Biology, University College London, London, UK
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Alessandra Casamento
- Institute of Structural and Molecular Biology, University College London, London, UK
| | - Sara Carrillo Roas
- Institute of Structural and Molecular Biology, University College London, London, UK
| | - Els F Halff
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - James Panambalana
- Institute of Structural and Molecular Biology, University College London, London, UK
| | - Shaan Subramaniam
- Institute of Structural and Molecular Biology, University College London, London, UK
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK
| | - Kira Schützenhofer
- Institute of Structural and Molecular Biology, University College London, London, UK
| | - Laura Chan Wah Hak
- Institute of Structural and Molecular Biology, University College London, London, UK
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Kieran McGourty
- Institute of Structural and Molecular Biology, University College London, London, UK
- Department of Chemical Sciences, Bernal Institute, University of Limerick, Limerick, Ireland
| | | | - Josef T Kittler
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, UK
| | | | - Emmanuel Boucrot
- Institute of Structural and Molecular Biology, University College London, London, UK.
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK.
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12
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Moo EV, van Senten JR, Bräuner-Osborne H, Møller TC. Arrestin-Dependent and -Independent Internalization of G Protein-Coupled Receptors: Methods, Mechanisms, and Implications on Cell Signaling. Mol Pharmacol 2021; 99:242-255. [PMID: 33472843 DOI: 10.1124/molpharm.120.000192] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/07/2021] [Indexed: 01/05/2023] Open
Abstract
Agonist-induced endocytosis is a key regulatory mechanism for controlling the responsiveness of the cell by changing the density of cell surface receptors. In addition to the role of endocytosis in signal termination, endocytosed G protein-coupled receptors (GPCRs) have been found to signal from intracellular compartments of the cell. Arrestins are generally believed to be the master regulators of GPCR endocytosis by binding to both phosphorylated receptors and adaptor protein 2 (AP-2) or clathrin, thus recruiting receptors to clathrin-coated pits to facilitate the internalization process. However, many other functions have been described for arrestins that do not relate to their role in terminating signaling. Additionally, there are now more than 30 examples of GPCRs that internalize independently of arrestins. Here we review the methods, pharmacological tools, and cellular backgrounds used to determine the role of arrestins in receptor internalization, highlighting their advantages and caveats. We also summarize key examples of arrestin-independent GPCR endocytosis in the literature and their suggested alternative endocytosis pathway (e.g., the caveolae-dependent and fast endophilin-mediated endocytosis pathways). Finally, we consider the possible function of arrestins recruited to GPCRs that are endocytosed independently of arrestins, including the catalytic arrestin activation paradigm. Technological improvements in recent years have advanced the field further, and, combined with the important implications of endocytosis on drug responses, this makes endocytosis an obvious parameter to include in molecular pharmacological characterization of ligand-GPCR interactions. SIGNIFICANCE STATEMENT: G protein-coupled receptor (GPCR) endocytosis is an important means to terminate receptor signaling, and arrestins play a central role in the widely accepted classical paradigm of GPCR endocytosis. In contrast to the canonical arrestin-mediated internalization, an increasing number of GPCRs are found to be endocytosed via alternate pathways, and the process appears more diverse than the previously defined "one pathway fits all."
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Affiliation(s)
- Ee Von Moo
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Jeffrey R van Senten
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Thor C Møller
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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13
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Mondal S, Narayan KB, Powers I, Botterbusch S, Baumgart T. Endophilin recruitment drives membrane curvature generation through coincidence detection of GPCR loop interactions and negative lipid charge. J Biol Chem 2021; 296:100140. [PMID: 33268381 PMCID: PMC7948419 DOI: 10.1074/jbc.ra120.016118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 12/23/2022] Open
Abstract
Endophilin plays key roles during endocytosis of cellular receptors, including generating membrane curvature to drive internalization. Electrostatic interactions between endophilin's BIN/Amphiphysin/Rvs domain and anionic membrane lipids have been considered the major driving force in curvature generation. However, the SH3 domain of endophilin also interacts with the proline-rich third intracellular loop (TIL) of various G-protein-coupled receptors (GPCRs), and it is unclear whether this interaction has a direct role in generating membrane curvature during endocytosis. To examine this, we designed model membranes with a membrane density of 1400 receptors per μm2 represented by a covalently conjugated TIL region from the β1-adrenergic receptor. We observed that TIL recruits endophilin to membranes composed of 95 mol% of zwitterionic lipids via the SH3 domain. More importantly, endophilin recruited via TIL tubulates vesicles and gets sorted onto highly curved membrane tubules. These observations indicate that the cellular membrane bending and curvature sensing activities of endophilin can be facilitated through detection of the TIL of activated GPCRs in addition to binding to anionic lipids. Furthermore, we show that TIL electrostatically interacts with membranes composed of anionic lipids. Therefore, anionic lipids can modulate TIL/SH3 domain binding. Overall, our findings imply that an interplay between TIL, charged membrane lipids, BAR domain, and SH3 domain could exist in the biological system and that these components may act in coordination to regulate the internalization of cellular receptors.
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Affiliation(s)
- Samsuzzoha Mondal
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Karthik B Narayan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Imania Powers
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Samuel Botterbusch
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tobias Baumgart
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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14
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Maziarz M, Park JC, Leyme A, Marivin A, Garcia-Lopez A, Patel PP, Garcia-Marcos M. Revealing the Activity of Trimeric G-proteins in Live Cells with a Versatile Biosensor Design. Cell 2020; 182:770-785.e16. [PMID: 32634377 DOI: 10.1016/j.cell.2020.06.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/21/2020] [Accepted: 06/08/2020] [Indexed: 12/28/2022]
Abstract
Heterotrimeric G-proteins (Gαβγ) are the main transducers of signals from GPCRs, mediating the action of countless natural stimuli and therapeutic agents. However, there are currently no robust approaches to directly measure the activity of endogenous G-proteins in cells. Here, we describe a suite of optical biosensors that detect endogenous active G-proteins with sub-second resolution in live cells. Using a modular design principle, we developed genetically encoded, unimolecular biosensors for endogenous Gα-GTP and free Gβγ: the two active species of heterotrimeric G-proteins. This design was leveraged to generate biosensors with specificity for different heterotrimeric G-proteins or for other G-proteins, such as Rho GTPases. Versatility was further validated by implementing the biosensors in multiple contexts, from characterizing cancer-associated G-protein mutants to neurotransmitter signaling in primary neurons. Overall, the versatile biosensor design introduced here enables studying the activity of endogenous G-proteins in live cells with high fidelity, temporal resolution, and convenience.
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Affiliation(s)
- Marcin Maziarz
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Jong-Chan Park
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Anthony Leyme
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Arthur Marivin
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Alberto Garcia-Lopez
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Prachi P Patel
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Mikel Garcia-Marcos
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA.
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15
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Casamento A, Boucrot E. Molecular mechanism of Fast Endophilin-Mediated Endocytosis. Biochem J 2020; 477:2327-2345. [PMID: 32589750 PMCID: PMC7319585 DOI: 10.1042/bcj20190342] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/11/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022]
Abstract
Endocytosis mediates the cellular uptake of micronutrients and cell surface proteins. Clathrin-mediated endocytosis (CME) is the housekeeping pathway in resting cells but additional Clathrin-independent endocytic (CIE) routes, including Fast Endophilin-Mediated Endocytosis (FEME), internalize specific cargoes and support diverse cellular functions. FEME is part of the Dynamin-dependent subgroup of CIE pathways. Here, we review our current understanding of the molecular mechanism of FEME. Key steps are: (i) priming, (ii) cargo selection, (iii) membrane curvature and carrier formation, (iv) membrane scission and (v) cytosolic transport. All steps are controlled by regulatory mechanisms mediated by phosphoinositides and by kinases such as Src, LRRK2, Cdk5 and GSK3β. A key feature of FEME is that it is not constitutively active but triggered upon the stimulation of selected cell surface receptors by their ligands. In resting cells, there is a priming cycle that concentrates Endophilin into clusters on discrete locations of the plasma membrane. In the absence of receptor activation, the patches quickly abort and new cycles are initiated nearby, constantly priming the plasma membrane for FEME. Upon activation, receptors are swiftly sorted into pre-existing Endophilin clusters, which then bud to form FEME carriers within 10 s. We summarize the hallmarks of FEME and the techniques and assays required to identify it. Next, we review similarities and differences with other CIE pathways and proposed cargoes that may use FEME to enter cells. Finally, we submit pending questions and future milestones and discuss the exciting perspectives that targeting FEME may boost treatments against cancer and neurodegenerative diseases.
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Affiliation(s)
- Alessandra Casamento
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, U.K
| | - Emmanuel Boucrot
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, U.K
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, U.K
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16
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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] [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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17
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Walpole GFW, Grinstein S. Endocytosis and the internalization of pathogenic organisms: focus on phosphoinositides. F1000Res 2020; 9. [PMID: 32494357 PMCID: PMC7233180 DOI: 10.12688/f1000research.22393.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
Despite their comparatively low abundance in biological membranes, phosphoinositides are key to the regulation of a diverse array of signaling pathways and direct membrane traffic. The role of phosphoinositides in the initiation and progression of endocytic pathways has been studied in considerable depth. Recent advances have revealed that distinct phosphoinositide species feature prominently in clathrin-dependent and -independent endocytosis as well as in phagocytosis and macropinocytosis. Moreover, a variety of intracellular and cell-associated pathogens have developed strategies to commandeer host cell phosphoinositide metabolism to gain entry and/or metabolic advantage, thereby promoting their survival and proliferation. Here, we briefly survey the current knowledge on the involvement of phosphoinositides in endocytosis, phagocytosis, and macropinocytosis and highlight several examples of molecular mimicry employed by pathogens to either “hitch a ride” on endocytic pathways endogenous to the host or create an entry path of their own.
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Affiliation(s)
- Glenn F W Walpole
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
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18
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Braadland PR, Ramberg H, Grytli HH, Urbanucci A, Nielsen HK, Guldvik IJ, Engedal A, Ketola K, Wang W, Svindland A, Mills IG, Bjartell A, Taskén KA. The β 2-Adrenergic Receptor Is a Molecular Switch for Neuroendocrine Transdifferentiation of Prostate Cancer Cells. Mol Cancer Res 2019; 17:2154-2168. [PMID: 31395667 DOI: 10.1158/1541-7786.mcr-18-0605] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 04/25/2019] [Accepted: 08/06/2019] [Indexed: 11/16/2022]
Abstract
The incidence of treatment-related neuroendocrine prostate cancer (t-NEPC) is rising as more potent drugs targeting the androgen signaling axis are clinically implemented. Neuroendocrine transdifferentiation (NEtD), an putative initial step in t-NEPC development, is induced by androgen-deprivation therapy (ADT) or anti-androgens, and by activation of the β2-adrenergic receptor (ADRB2) in prostate cancer cell lines. Thus, understanding whether ADRB2 is involved in ADT-initiated NEtD may assist in developing treatment strategies that can prevent or reverse t-NEPC emergence, thereby prolonging therapeutic responses. Here we found that in primary, treatment-naïve prostate cancers, ADRB2 mRNA was positively correlated with expression of luminal differentiation markers, and ADRB2 protein levels were inversely correlated with Gleason grade. ADRB2 mRNA was upregulated in metastatic prostate cancer, and progressively downregulated during ADT and t-NEPC emergence. In androgen-deprivated medium, high ADRB2 was required for LNCaP cells to undergo NEtD, measured as increased neurite outgrowth and expression of neuron differentiation and neuroendocrine genes. ADRB2 overexpression induced a neuroendocrine-like morphology in both androgen receptor (AR)-positive and -negative prostate cancer cell lines. ADRB2 downregulation in LNCaP cells increased canonical Wnt signaling, and GSK3α/β inhibition reduced the expression of neuron differentiation and neuroendocrine genes. In LNCaP xenografts, more pronounced castration-induced NEtD was observed in tumors derived from high than low ADRB2 cells. In conclusion, high ADRB2 expression is required for ADT-induced NEtD, characterized by ADRB2 downregulation and t-NEPC emergence. IMPLICATIONS: This data suggest a potential application of β-blockers to prevent cancer cells committed to a neuroendocrine lineage from evolving into t-NEPC.
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Affiliation(s)
- Peder R Braadland
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Håkon Ramberg
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Helene Hartvedt Grytli
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Alfonso Urbanucci
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo, Oslo, Norway.,Department of Core Facilities, Institute of Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Heidi Kristin Nielsen
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Ingrid Jenny Guldvik
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Andreas Engedal
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Kirsi Ketola
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Wanzhong Wang
- Clinical Pathology/Cytology, Karolinska University Hospital, Stockholm, Sweden
| | - Aud Svindland
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - Ian G Mills
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo, Oslo, Norway.,Movember FASTMAN Centre of Excellence, Centre for Cancer Research & Cell Biology, Queen's University Belfast, Belfast, United Kingdom.,Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Anders Bjartell
- Department of Urology, Skåne University Hospital, Malmö, Sweden.,Department of Translational Medicine, Division of Urological Cancers, Lund University, Malmø, Sweden
| | - Kristin Austlid Taskén
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway. .,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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19
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Civciristov S, Ellisdon AM, Suderman R, Pon CK, Evans BA, Kleifeld O, Charlton SJ, Hlavacek WS, Canals M, Halls ML. Preassembled GPCR signaling complexes mediate distinct cellular responses to ultralow ligand concentrations. Sci Signal 2018; 11:eaan1188. [PMID: 30301787 PMCID: PMC7416780 DOI: 10.1126/scisignal.aan1188] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest class of cell surface signaling proteins, participate in nearly all physiological processes, and are the targets of 30% of marketed drugs. Typically, nanomolar to micromolar concentrations of ligand are used to activate GPCRs in experimental systems. We detected GPCR responses to a wide range of ligand concentrations, from attomolar to millimolar, by measuring GPCR-stimulated production of cyclic adenosine monophosphate (cAMP) with high spatial and temporal resolution. Mathematical modeling showed that femtomolar concentrations of ligand activated, on average, 40% of the cells in a population provided that a cell was activated by one to two binding events. Furthermore, activation of the endogenous β2-adrenergic receptor (β2AR) and muscarinic acetylcholine M3 receptor (M3R) by femtomolar concentrations of ligand in cell lines and human cardiac fibroblasts caused sustained increases in nuclear translocation of extracellular signal-regulated kinase (ERK) and cytosolic protein kinase C (PKC) activity, respectively. These responses were spatially and temporally distinct from those that occurred in response to higher concentrations of ligand and resulted in a distinct cellular proteomic profile. This highly sensitive signaling depended on the GPCRs forming preassembled, higher-order signaling complexes at the plasma membrane. Recognizing that GPCRs respond to ultralow concentrations of neurotransmitters and hormones challenges established paradigms of drug action and provides a previously unappreciated aspect of GPCR activation that is quite distinct from that typically observed with higher ligand concentrations.
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Affiliation(s)
- Srgjan Civciristov
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Andrew M Ellisdon
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Ryan Suderman
- Theoretical Biology and Biophysics Group, Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Cindy K Pon
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Bronwyn A Evans
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Oded Kleifeld
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Steven J Charlton
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
- Excellerate Bioscience Ltd, MediCity, Nottingham NG90 6BH, UK
| | - William S Hlavacek
- Theoretical Biology and Biophysics Group, Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Meritxell Canals
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
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20
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Bertot L, Grassart A, Lagache T, Nardi G, Basquin C, Olivo-Marin JC, Sauvonnet N. Quantitative and Statistical Study of the Dynamics of Clathrin-Dependent and -Independent Endocytosis Reveal a Differential Role of EndophilinA2. Cell Rep 2018; 22:1574-1588. [DOI: 10.1016/j.celrep.2018.01.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 01/03/2018] [Accepted: 01/12/2018] [Indexed: 01/13/2023] Open
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21
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Alfadda AA, Sallam RM, Gul R, Hwang I, Ka S. Endophilin A2: A Potential Link to Adiposity and Beyond. Mol Cells 2017; 40:855-863. [PMID: 29113429 PMCID: PMC5712515 DOI: 10.14348/molcells.2017.0137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 09/07/2017] [Accepted: 09/20/2017] [Indexed: 12/11/2022] Open
Abstract
Adipose tissue plays a central role in regulating dynamic crosstalk between tissues and organs. A detailed description of molecules that are differentially expressed upon changes in adipose tissue mass is expected to increase our understanding of the molecular mechanisms that underlie obesity and related metabolic co-morbidities. Our previous studies suggest a possible link between endophilins (SH3Grb2 proteins) and changes in body weight. To explore this further, we sought to assess the distribution of endophilin A2 (EA2) in human adipose tissue and experimental animals. Human paired adipose tissue samples (subcutaneous and visceral) were collected from subjects undergoing elective abdominal surgery and abdominal liposuction. We observed elevated EA2 gene expression in the subcutaneous compared to that in the visceral human adipose tissue. EA2 gene expression negatively correlated with adiponectin and chemerin in visceral adipose tissue, and positively correlated with TNF-α in subcutaneous adipose tissue. EA2 gene expression was significantly downregulated during differentiation of preadipocytes in vitro. In conclusion, this study provides a description of EA2 distribution and emphasizes a need to study the roles of this protein during the progression of obesity.
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Affiliation(s)
- Assim A. Alfadda
- Obesity Research Center, College of Medicine, King Saud University, Riyadh 11461,
Saudi Arabia
- Department of Medicine, College of Medicine, King Saud University, Riyadh 11461,
Saudi Arabia
| | - Reem M. Sallam
- Obesity Research Center, College of Medicine, King Saud University, Riyadh 11461,
Saudi Arabia
- Clinical Chemistry Unit, Pathology Department, College of Medicine, King Saud University, Riyadh 11461,
Saudi Arabia
| | - Rukhsana Gul
- Obesity Research Center, College of Medicine, King Saud University, Riyadh 11461,
Saudi Arabia
| | - Injae Hwang
- Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826,
Korea
| | - Sojeong Ka
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
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22
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Purcell RH, Toro C, Gahl WA, Hall RA. A disease-associated mutation in the adhesion GPCR BAI2 (ADGRB2) increases receptor signaling activity. Hum Mutat 2017; 38:1751-1760. [PMID: 28891236 DOI: 10.1002/humu.23336] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/01/2017] [Accepted: 09/03/2017] [Indexed: 12/15/2022]
Abstract
Mutations in G protein-coupled receptors (GPCRs) that increase constitutive signaling activity can cause human disease. A de novo C-terminal mutation (R1465W) in the adhesion GPCR BAI2 (also known as ADGRB2) was identified in a patient suffering from progressive spastic paraparesis and other neurological symptoms. In vitro studies revealed that this mutation strongly increases the constitutive signaling activity of an N-terminally cleaved form of BAI2, which represents the activated form of the receptor. Further studies dissecting the mechanism(s) underling this effect revealed that wild-type BAI2 primarily couples to Gαz , with the R1465W mutation conferring increased coupling to Gαi . The R1465W mutation also increases the total and surface expression of BAI2. The mutation has no effect on receptor binding to β-arrestins, but does perturb binding to the endocytic protein endophilin A1, identified here as a novel interacting partner for BAI2. These studies provide new insights into the signaling capabilities of the adhesion GPCR BAI2/ADGRB2 and shed light on how an apparent gain-of-function mutation to the receptor's C-terminus may lead to human disease.
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Affiliation(s)
- Ryan H Purcell
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia
| | - Camilo Toro
- NIH Undiagnosed Diseases Program, Office of the Director, NIH, Bethesda, Maryland
| | - William A Gahl
- NIH Undiagnosed Diseases Program, Office of the Director, NIH, Bethesda, Maryland
| | - Randy A Hall
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia
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23
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Felce JH, Latty SL, Knox RG, Mattick SR, Lui Y, Lee SF, Klenerman D, Davis SJ. Receptor Quaternary Organization Explains G Protein-Coupled Receptor Family Structure. Cell Rep 2017; 20:2654-2665. [PMID: 28903045 PMCID: PMC5608970 DOI: 10.1016/j.celrep.2017.08.072] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/14/2017] [Accepted: 08/23/2017] [Indexed: 12/15/2022] Open
Abstract
The organization of Rhodopsin-family G protein-coupled receptors (GPCRs) at the cell surface is controversial. Support both for and against the existence of dimers has been obtained in studies of mostly individual receptors. Here, we use a large-scale comparative study to examine the stoichiometric signatures of 60 receptors expressed by a single human cell line. Using bioluminescence resonance energy transfer- and single-molecule microscopy-based assays, we found that a relatively small fraction of Rhodopsin-family GPCRs behaved as dimers and that these receptors otherwise appear to be monomeric. Overall, the analysis predicted that fewer than 20% of ∼700 Rhodopsin-family receptors form dimers. The clustered distribution of the dimers in our sample and a striking correlation between receptor organization and GPCR family size that we also uncover each suggest that receptor stoichiometry might have profoundly influenced GPCR expansion and diversification.
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Affiliation(s)
- James H Felce
- Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Sarah L Latty
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Rachel G Knox
- Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Susan R Mattick
- Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Yuan Lui
- Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Steven F Lee
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.
| | - Simon J Davis
- Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
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24
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Zhu Y, Zhang X, Wang L, Ji Z, Xie M, Zhou X, Liu Z, Shi H, Yu R. Loss of SH3GL2 promotes the migration and invasion behaviours of glioblastoma cells through activating the STAT3/MMP2 signalling. J Cell Mol Med 2017; 21:2685-2694. [PMID: 28470949 PMCID: PMC5661104 DOI: 10.1111/jcmm.13184] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/06/2017] [Indexed: 12/22/2022] Open
Abstract
SH3GL2 (Src homology 3 (SH3) domain GRB2‐like 2) is mainly expressed in the central nervous system and regarded as a tumour suppressor in human glioma. However, the molecular mechanism of the SH3GL2 protein involved in malignant behaviours of human glioma has not been elucidated. In this study, we tried to investigate the role of SH3GL2 in glioma cell migration and invasion and explore its underlined molecular mechanism. Firstly, we discovered that the protein level of SH3GL2 was widely decreased in the human glioma patients, especially in high‐grade glioma tissues. Then, we determined the role of SH3GL2 in migration and invasion of glioma cells upon SH3GL2 knocking down and overexpressing. It was showed that knocking down of SH3GL2 promoted the migration and invasion of glioma cells, whereas overexpression of SH3GL2 inhibited them. Further study on molecular mechanism disclosed that silencing of SH3GL2 obviously activated the STAT3 (signal transducer and activator of transcription 3) signalling thereby promoting the expression and secretion of MMP2. On the contrary, overexpression of SH3GL2 had opposite effect. Taken together, the above results suggest that SH3GL2 suppresses migration and invasion behaviours of glioma cells through negatively regulating STAT3/MMP2 signalling and that loss of SH3GL2 may intensify the STAT3/MMP2 signalling thereby contributing to the migration and invasion of glioma cells.
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Affiliation(s)
- Yufu Zhu
- Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou, China.,Brain Hospital, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Xiang Zhang
- Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou, China.,The Graduate School, Xuzhou Medical University, Xuzhou, China
| | - Lei Wang
- Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou, China.,Brain Hospital, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Zhe Ji
- Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou, China.,The Graduate School, Xuzhou Medical University, Xuzhou, China
| | - Manyi Xie
- Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou, China.,Brain Hospital, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Xinyu Zhou
- The Graduate School, Xuzhou Medical University, Xuzhou, China.,Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Zhiyi Liu
- The Graduate School, Xuzhou Medical University, Xuzhou, China.,Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Hengliang Shi
- Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou, China.,Brain Hospital, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Rutong Yu
- Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou, China.,Brain Hospital, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
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25
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Braadland PR, Grytli HH, Ramberg H, Katz B, Kellman R, Gauthier-Landry L, Fazli L, Krobert KA, Wang W, Levy FO, Bjartell A, Berge V, Rennie PS, Mellgren G, Mælandsmo GM, Svindland A, Barbier O, Taskén KA. Low β₂-adrenergic receptor level may promote development of castration resistant prostate cancer and altered steroid metabolism. Oncotarget 2016; 7:1878-94. [PMID: 26646591 PMCID: PMC4811504 DOI: 10.18632/oncotarget.6479] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 11/21/2015] [Indexed: 11/25/2022] Open
Abstract
The underlying mechanisms responsible for the development of castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy are not fully understood. This is the first study to address whether β2-adrenergic receptor (ADRB2)- mediated signaling may affect CRPC progression in vivo. By immunohistochemical analyses, we observed that low levels of ADRB2 is associated with a more rapid development of CRPC in a Norwegian patient cohort. To elucidate mechanisms by which ADRB2 may affect CRPC development, we stably transfected LNCaP cells with shRNAs to mimic low and high expression of ADRB2. Two UDP-glucuronosyltransferases, UGT2B15 and UGT2B17, involved in phase II metabolism of androgens, were strongly downregulated in two LNCaP shADRB2 cell lines. The low-ADRB2 LNCaP cell lines displayed lowered glucuronidation activities towards androgens than high-ADRB2 cells. Furthermore, increased levels of testosterone and enhanced androgen responsiveness were observed in LNCaP cells expressing low level of ADRB2. Interestingly, these cells grew faster than high-ADRB2 LNCaP cells, and sustained their low glucuronidation activity in castrated NOD/SCID mice. ADRB2 immunohistochemical staining intensity correlated with UGT2B15 staining intensity in independent TMA studies and with UGT2B17 in one TMA study. Similar to ADRB2, we show that low levels of UGT2B15 are associated with a more rapid CRPC progression. We propose a novel mechanism by which ADRB2 may affect the development of CRPC through downregulation of UGT2B15 and UGT2B17.
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Affiliation(s)
- Peder Rustøen Braadland
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Helene Hartvedt Grytli
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Håkon Ramberg
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Betina Katz
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - Ralf Kellman
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
| | - Louis Gauthier-Landry
- Laboratory of Molecular Pharmacology, CHU-Québec Research Center and Faculty of Pharmacy, Laval University, Québec, Canada
| | - Ladan Fazli
- The Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada
| | - Kurt Allen Krobert
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Wanzhong Wang
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Finn Olav Levy
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Anders Bjartell
- Department of Urology, Skåne University Hospital, Malmø, Sweden.,Department of Clinical Sciences Malmø, Division of Urological Cancers, Lund University, Lund, Sweden
| | - Viktor Berge
- Department of Urology, Oslo University Hospital, Oslo, Norway
| | - Paul S Rennie
- The Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada
| | - Gunnar Mellgren
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Gunhild Mari Mælandsmo
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Institute for Pharmacy, Faculty of Health Science, University of Tromsø, Tromsø, Norway
| | - Aud Svindland
- Department of Pathology, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Olivier Barbier
- Laboratory of Molecular Pharmacology, CHU-Québec Research Center and Faculty of Pharmacy, Laval University, Québec, Canada
| | - Kristin Austlid Taskén
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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26
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Endophilin-A2-mediated increase in scavenger receptor expression contributes to macrophage-derived foam cell formation. Atherosclerosis 2016; 254:133-141. [PMID: 27741419 DOI: 10.1016/j.atherosclerosis.2016.10.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 09/08/2016] [Accepted: 10/05/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND AIMS Macrophage-derived foam cell formation (MFCF) is a crucial step in the pathogenesis of atherosclerosis. Uptake of oxidized low-density lipoprotein (oxLDL) by scavenger receptors is indispensable for MFCF. Endophilin-A2 has been reported to regulate clathrin-mediated endocytosis (CME). In this study, we tested the hypothesis that endophilin-A2 regulates oxLDL uptake and MFCF by mediating CME of oxLDL-scavenger receptor complexes. METHODS In vitro MFCF was induced by oxLDL treatment. Involvement of endophilin-A2 in oxLDL cytomembrane binding, cellular uptake, and MFCF was evaluated by manipulation of endophilin-A2. RESULTS Endophilin-A2 was involved in MFCF via scavenger receptor CD36 and scavenger receptor-A (SR-A)-mediated positive feedback pathways. We observed that oxLDL triggered interaction of endophilin-A2 with CD36 or SR-A, and induced an endophilin-A2-dependent activation of the apoptosis signal-regulating kinase-1 (ASK1)/Jun N-terminal kinase (JNK)/p38 signaling pathway. The activation of ASK1-JNK/p38 signal increased expression of both CD36 and SR-A, which promoted oxLDL cytomembrane binding, cellular uptake, and MFCF. In the absence of oxLDL, endophilin-A2 up-regulated the expression of receptors and Dil-oxLDL binding and uptake, but not the intracellular accumulation of lipids. In the presence of oxLDL, the CME inhibitors pitstop2 and ikarugamycin mimicked the inhibiting effect of endophilin-A2 knockdown and eliminated the elevating effect of endophilin-A2 overexpression on oxLDL uptake and MFCF. CONCLUSIONS Endophilin-A2 was identified as a novel molecule regulating MFCF by mechanisms attributable to CME and beyond CME.
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27
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Liu Y, Gao M, Ma MM, Tang YB, Zhou JG, Wang GL, Du YH, Guan YY. Endophilin A2 protects H2O2-induced apoptosis by blockade of Bax translocation in rat basilar artery smooth muscle cells. J Mol Cell Cardiol 2016; 92:122-33. [DOI: 10.1016/j.yjmcc.2016.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 01/25/2016] [Accepted: 02/04/2016] [Indexed: 12/31/2022]
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28
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Deming JD, Shin JA, Lim K, Lee EJ, Van Craenenbroeck K, Craft CM. Dopamine receptor D4 internalization requires a beta-arrestin and a visual arrestin. Cell Signal 2015; 27:2002-13. [PMID: 26169958 DOI: 10.1016/j.cellsig.2015.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 06/30/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE The G-protein coupled receptor (GPCR) Dopamine Receptor D4 (DRD4) plays an essential role in cAMP regulation and gap junctional coupling in the photoreceptors, where DRD4 expression is under circadian control. Previous in vitro transfection studies of human DRD4 desensitization have reported that DRD4 is not internalized upon dopamine stimulation when beta-arrestin is co-transfected with DRD4. We hypothesized that the visual arrestins, ARR1 and ARR4, play a modulatory role in DRD4 desensitization in the photoreceptors. METHODS To test this hypothesis, immunohistochemistry analysis of mouse retinas was used to determine the cellular localization of beta-arrestins and DRD4 in photoreceptors. In vitro studies were performed in HEK293T cells transiently transfected with human DRD4 and arrestins. First, co-immunoprecipitation experiments were executed to test protein-protein interactions and to investigate the effect of dopamine stimulation. Second, immunohistochemistry analysis was implemented to study DRD4 internalization and translocation of ARR4. RESULTS Immunohistochemistry studies of mouse retinas confirmed the expression of beta-arrestin 2, ARR1 and ARR4, as well as DRD4 in mouse cone photoreceptor inner segments. Co-immunoprecipitation experiments revealed a dopamine-dependent protein-protein interaction between human DRD4 and ARR4. In vitro internalization experiments showed that no detectable internalization of DRD4 was observed with any single arrestin co-transfected. However, a dopamine-dependent internalization of DRD4 was observed with three out of six sets of two arrestins co-transfected with DRD4. Each of these pairs of arrestins contained one visual arrestin and one beta-arrestin, and no internalization was observed with either two visual arrestins or two beta-arrestins. Additional time-course experiments revealed that in vitro, ARR4 translocates to co-localize with DRD4 at the plasma membrane in response to 30min of dopamine stimulation. CONCLUSIONS The results have functional implications and we hypothesize that the desensitization and internalization of DRD4 in photoreceptors are synergistically mediated by both visual and beta-arrestins. These results are additionally unique because they demonstrate for the first time that at least one G-protein coupled receptor, DRD4, requires two arrestins for desensitization and internalization, and opens up the possibility that other G-protein coupled receptors may require more than one arrestin for desensitization and/or internalization.
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Affiliation(s)
- Janise D Deming
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA.
| | - Jung-A Shin
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA; Department of Anatomy, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea.
| | - Kayleen Lim
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA.
| | - Eun-Jin Lee
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA; Department of Biomedical Engineering, University of Southern California Viterbi School of Engineering, 1042 Downey Way, Los Angeles, CA 90089-1111, USA.
| | - Kathleen Van Craenenbroeck
- Laboratory of GPCR Expression and Signal Transduction (L-GEST), Ghent University-UGent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
| | - Cheryl Mae Craft
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Annex 215, Los Angeles, CA 90033, USA; Department of Cell & Neurobiology, Keck School of Medicine of the University of Southern California, 2250 Alcazar Street, Clinical Science Center 135H, Los Angeles, CA 90033, USA.
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29
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Trafficking of β-Adrenergic Receptors: Implications in Intracellular Receptor Signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 132:151-88. [PMID: 26055058 DOI: 10.1016/bs.pmbts.2015.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
β-Adrenergic receptors (βARs), prototypical G-protein-coupled receptors, play a pivotal role in regulating neuronal and cardiovascular responses to catecholamines during stress. Agonist-induced receptor endocytosis is traditionally considered as a primary mechanism to turn off the receptor signaling (or receptor desensitization). However, recent progress suggests that intracellular trafficking of βAR presents a mean to translocate receptor signaling machinery to intracellular organelles/compartments while terminating the signaling at the cell surface. Moreover, the apparent multidimensionality of ligand efficacy in space and time in a cell has forecasted exciting pathophysiological implications, which are just beginning to be explored. As we begin to understand how these pathways impact downstream cellular programs, this will have significant implications for a number of pathophysiological conditions in heart and other systems, that in turn open up new therapeutic opportunities.
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30
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Johannes L, Parton RG, Bassereau P, Mayor S. Building endocytic pits without clathrin. Nat Rev Mol Cell Biol 2015; 16:311-21. [PMID: 25857812 DOI: 10.1038/nrm3968] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
How endocytic pits are built in clathrin- and caveolin-independent endocytosis still remains poorly understood. Recent insight suggests that different forms of clathrin-independent endocytosis might involve the actin-driven focusing of membrane constituents, the lectin-glycosphingolipid-dependent construction of endocytic nanoenvironments, and Bin-Amphiphysin-Rvs (BAR) domain proteins serving as scaffolding modules. We discuss the need for different types of internalization processes in the context of diverse cellular functions, the existence of clathrin-independent mechanisms of cargo recruitment and membrane bending from a biological and physical perspective, and finally propose a generic scheme for the formation of clathrin-independent endocytic pits.
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Affiliation(s)
- Ludger Johannes
- Institut Curie, PSL Research University, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, 75248 Paris Cedex 05, France; Centre National de la Recherche Scientifique UMR3666, 75005 Paris, France; and INSERM U1143, 75005 Paris, France
| | - Robert G Parton
- University of Queensland, Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, St Lucia QLD 4072, Australia
| | - Patricia Bassereau
- Institut Curie, PSL Research University, Membrane and Cell Functions Group, 26 rue d'Ulm, 75248 Paris Cedex 05, France; Centre National de la Recherche Scientifique UMR168, 75005 Paris, France; and Université Pierre et Marie Curie, 75252 Paris, France
| | - Satyajit Mayor
- National Centre for Biological Sciences, Cellular Organization and Signaling Group, and at Institute for Stem Cell Biology and Regenerative Medicine, UAS-GKVK Campus, 560 065 Bangalore, India
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31
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Boucrot E, Ferreira APA, Almeida-Souza L, Debard S, Vallis Y, Howard G, Bertot L, Sauvonnet N, McMahon HT. Endophilin marks and controls a clathrin-independent endocytic pathway. Nature 2014; 517:460-5. [PMID: 25517094 DOI: 10.1038/nature14067] [Citation(s) in RCA: 373] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 11/17/2014] [Indexed: 01/08/2023]
Abstract
Endocytosis is required for internalization of micronutrients and turnover of membrane components. Endophilin has been assigned as a component of clathrin-mediated endocytosis. Here we show in mammalian cells that endophilin marks and controls a fast-acting tubulovesicular endocytic pathway that is independent of AP2 and clathrin, activated upon ligand binding to cargo receptors, inhibited by inhibitors of dynamin, Rac, phosphatidylinositol-3-OH kinase, PAK1 and actin polymerization, and activated upon Cdc42 inhibition. This pathway is prominent at the leading edges of cells where phosphatidylinositol-3,4-bisphosphate-produced by the dephosphorylation of phosphatidylinositol-3,4,5-triphosphate by SHIP1 and SHIP2-recruits lamellipodin, which in turn engages endophilin. This pathway mediates the ligand-triggered uptake of several G-protein-coupled receptors such as α2a- and β1-adrenergic, dopaminergic D3 and D4 receptors and muscarinic acetylcholine receptor 4, the receptor tyrosine kinases EGFR, HGFR, VEGFR, PDGFR, NGFR and IGF1R, as well as interleukin-2 receptor. We call this new endocytic route fast endophilin-mediated endocytosis (FEME).
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Affiliation(s)
- Emmanuel Boucrot
- 1] MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK [2] Institute of Structural and Molecular Biology, University College London &Birkbeck College, London WC1E 6BT, UK
| | - Antonio P A Ferreira
- Institute of Structural and Molecular Biology, University College London &Birkbeck College, London WC1E 6BT, UK
| | | | - Sylvain Debard
- 1] Institute of Structural and Molecular Biology, University College London &Birkbeck College, London WC1E 6BT, UK [2] Department of Biology, Ecole Normale Supérieure de Cachan, 94235 Cachan, France
| | - Yvonne Vallis
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Gillian Howard
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Laetitia Bertot
- Institut Pasteur, Unité de Pathogenie Moleculaire Microbienne, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Nathalie Sauvonnet
- Institut Pasteur, Unité de Pathogenie Moleculaire Microbienne, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Harvey T McMahon
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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32
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Affiliation(s)
- Volker Haucke
- Leibniz Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
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33
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Liu W, Wang P, Shang C, Chen L, Cai H, Ma J, Yao Y, Shang X, Xue Y. Endophilin-1 regulates blood–brain barrier permeability by controlling ZO-1 and occludin expression via the EGFR–ERK1/2 pathway. Brain Res 2014; 1573:17-26. [DOI: 10.1016/j.brainres.2014.05.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/07/2014] [Accepted: 05/13/2014] [Indexed: 01/07/2023]
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Gilbert CE, Zuckerman DM, Currier PL, Machamer CE. Three basic residues of intracellular loop 3 of the beta-1 adrenergic receptor are required for golgin-160-dependent trafficking. Int J Mol Sci 2014; 15:2929-45. [PMID: 24566136 PMCID: PMC3958891 DOI: 10.3390/ijms15022929] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/24/2014] [Accepted: 02/12/2014] [Indexed: 12/14/2022] Open
Abstract
Golgin-160 is a member of the golgin family of proteins, which have been implicated in the maintenance of Golgi structure and in vesicle tethering. Golgin-160 is atypical; it promotes post-Golgi trafficking of specific cargo proteins, including the β-1 adrenergic receptor (β1AR), a G protein-coupled receptor. Here we show that golgin-160 binds directly to the third intracellular loop of β1AR and that this binding depends on three basic residues in this loop. Mutation of the basic residues does not affect trafficking of β1AR from the endoplasmic reticulum through the Golgi complex, but results in reduced steady-state levels at the plasma membrane. We hypothesize that golgin-160 promotes incorporation of β1AR into specific transport carriers at the trans-Golgi network to ensure efficient delivery to the cell surface. These results add to our understanding of the biogenesis of β1AR, and suggest a novel point of regulation for its delivery to the plasma membrane.
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Affiliation(s)
- Catherine E Gilbert
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA.
| | - David M Zuckerman
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA.
| | - Pamela L Currier
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA.
| | - Carolyn E Machamer
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA.
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35
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Zhang J, Fan J, Tian Q, Song Z, Zhang JF, Chen Y. Characterization of two distinct modes of endophilin in clathrin-mediated endocytosis. Cell Signal 2012; 24:2043-50. [DOI: 10.1016/j.cellsig.2012.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 05/24/2012] [Accepted: 06/16/2012] [Indexed: 10/28/2022]
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Cotecchia S, Stanasila L, Diviani D. Protein-protein interactions at the adrenergic receptors. Curr Drug Targets 2012; 13:15-27. [PMID: 21777184 PMCID: PMC3290771 DOI: 10.2174/138945012798868489] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 02/12/2011] [Accepted: 02/16/2011] [Indexed: 01/07/2023]
Abstract
The adrenergic receptors are among the best characterized G protein-coupled receptors (GPCRs) and knowledge on this receptor family has provided several important paradigms about GPCR function and regulation. One of the most recent paradigms initially supported by studies on adrenergic receptors is that both βarrestins and G protein-coupled receptors themselves can act as scaffolds binding a variety of proteins and this can result in growing complexity of the receptor-mediated cellular effects. In this review we will briefly summarize the main features of βarrestin binding to the adrenergic receptor subtypes and we will review more in detail the main proteins found to selectively interact with distinct AR subtype. At the end, we will review the main findings on oligomerization of the AR subtypes.
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Affiliation(s)
- Susanna Cotecchia
- Départment de Pharmacologie et de Toxicologie, Université de Lausanne, Switzerland.
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37
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Pálfy M, Reményi A, Korcsmáros T. Endosomal crosstalk: meeting points for signaling pathways. Trends Cell Biol 2012; 22:447-56. [PMID: 22796207 PMCID: PMC3430897 DOI: 10.1016/j.tcb.2012.06.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 12/30/2022]
Abstract
Endocytosis participates in downregulating incoming signals, but 'signaling endosomes' may also serve as physical platforms for crosstalk between signaling pathways. Here, we briefly review the role of endosomes in signaling crosstalk and suggest that endosome-associated scaffold proteins mediate this crosstalk. In addition, using a proteome-wide in silico approach - in which we analyze endosome-binding properties and the capacity of candidates to recruit signaling proteins from more than one distinct pathway - we extend the list of putative crosstalk-mediating endosomal scaffolds. Because endosomal crosstalk may be an important systems-level regulator of pathway communication, scaffold proteins that mediate this crosstalk could be potential targets for pharmacological intervention and synthetic engineering.
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Affiliation(s)
- Máté Pálfy
- Department of Genetics, Eötvös Loránd University, Pázmány P. s. 1/C, Budapest, H-1117, Hungary
| | - Attila Reményi
- Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/C, Budapest, H-1117, Hungary
| | - Tamás Korcsmáros
- Department of Genetics, Eötvös Loránd University, Pázmány P. s. 1/C, Budapest, H-1117, Hungary
- Department of Medical Chemistry, Semmelweis University, Tűzoltó u. 37-47, Budapest, H-1094, Hungary
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38
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Molecular Mechanisms of G Protein-Independent Signaling Mediated by 7-Transmembrane Receptors. NEUROPHYSIOLOGY+ 2012. [DOI: 10.1007/s11062-012-9295-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Magalhaes AC, Dunn H, Ferguson SS. Regulation of GPCR activity, trafficking and localization by GPCR-interacting proteins. Br J Pharmacol 2012; 165:1717-1736. [PMID: 21699508 DOI: 10.1111/j.1476-5381.2011.01552.x] [Citation(s) in RCA: 252] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
GPCRs represent the largest family of integral membrane proteins and were first identified as receptor proteins that couple via heterotrimeric G-proteins to regulate a vast variety of effector proteins to modulate cellular function. It is now recognized that GPCRs interact with a myriad of proteins that not only function to attenuate their signalling but also function to couple these receptors to heterotrimeric G-protein-independent signalling pathways. In addition, intracellular and transmembrane proteins associate with GPCRs and regulate their processing in the endoplasmic reticulum, trafficking to the cell surface, compartmentalization to plasma membrane microdomains, endocytosis and trafficking between intracellular membrane compartments. The present review will overview the functional consequence of β-arrestin, receptor activity-modifying proteins (RAMPS), regulators of G-protein signalling (RGS), GPCR-associated sorting proteins (GASPs), Homer, small GTPases, PSD95/Disc Large/Zona Occludens (PDZ), spinophilin, protein phosphatases, calmodulin, optineurin and Src homology 3 (SH3) containing protein interactions with GPCRs.
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Affiliation(s)
- Ana C Magalhaes
- J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, London, ON, CanadaThe Department of Physiology & Pharmacology, the University of Western Ontario, London, ON, Canada
| | - Henry Dunn
- J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, London, ON, CanadaThe Department of Physiology & Pharmacology, the University of Western Ontario, London, ON, Canada
| | - Stephen Sg Ferguson
- J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, London, ON, CanadaThe Department of Physiology & Pharmacology, the University of Western Ontario, London, ON, Canada
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40
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Burns RN, Moniri NH. Agonist- and hydrogen peroxide-mediated oxidation of the β2 adrenergic receptor: evidence of receptor s-sulfenation as detected by a modified biotin-switch assay. J Pharmacol Exp Ther 2011; 339:914-21. [PMID: 21917560 DOI: 10.1124/jpet.111.185975] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Reactive oxygen species (ROS), including hydrogen peroxide (H(2)O(2)), have recently been shown to be generated upon agonism of several members of the G protein-coupled receptor (GPCR) superfamily, including β(2)-adrenergic receptors (β(2)ARs). Previously, we have demonstrated that inhibition of intracellular ROS generation mitigates β(2)AR signaling, suggesting that β(2)AR-mediated ROS generation is capable of feeding back to regulate receptor function. Given that ROS, specifically H(2)O(2), are able to post-translationally oxidize protein cysteine sulfhydryls to cysteine-sulfenic acids, the goal of the current study was to assess whether ROS are capable of S-sulfenating β(2)AR. Using a modified biotin-switch assay that is selective for cysteine-sulfenic acids, our results demonstrate for the first time that H(2)O(2) treatment facilitates S-sulfenation of transiently overexpressed β(2)AR in human embryonic kidney 293 cells. It is noteworthy that stimulation of cells with the β-agonist isoproterenol produces both dose- and time-dependent S-sulfenation of β(2)AR, an effect that is receptor-dependent, and demonstrates that receptor-generated ROS are also capable of oxidizing the β(2)AR. Receptor-dependent S-sulfenation was inhibited by the chemoselective sulfenic acid alkylator dimedone and the cysteine antioxidant N-acetyl-l-cysteine. Moreover, our results reveal that receptor oxidation occurs in cells that endogenously express physiologically relevant levels of β(2)AR, because treatment of human alveolar epithelial A549 cells with either H(2)O(2) or the β(2)-selective agonist formoterol promoted receptor S-sulfenation. These findings provide the first evidence, to our knowledge, that a mammalian GPCR can be oxidized by S-sulfenation and signify an important first step toward shedding light on the overlooked role of ROS in the regulation of β(2)AR function.
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Affiliation(s)
- Rebecca N Burns
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Mercer University, 3001 Mercer University Drive, Atlanta, GA 30341, USA
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41
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Valentine CD, Haggie PM. Confinement of β(1)- and β(2)-adrenergic receptors in the plasma membrane of cardiomyocyte-like H9c2 cells is mediated by selective interactions with PDZ domain and A-kinase anchoring proteins but not caveolae. Mol Biol Cell 2011; 22:2970-82. [PMID: 21680711 PMCID: PMC3154891 DOI: 10.1091/mbc.e11-01-0034] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The presence of stable multiprotein complexes containing adrenergic receptors is verified in live H9c2 cardiomyocyte-like cells by single-particle tracking. The immobilization of β-adrenergic receptors presumably contributes to the specificity of cardiac adrenergic responses. The sympathetic nervous system regulates cardiac output by activating adrenergic receptors (ARs) in cardiac myocytes. The predominant cardiac ARs, β1- and β2AR, are structurally similar but mediate distinct signaling responses. Scaffold protein–mediated compartmentalization of ARs into discrete, multiprotein complexes has been proposed to dictate differential signaling responses. To test the hypothesis that βARs integrate into complexes in live cells, we measured receptor diffusion and interactions by single-particle tracking. Unstimulated β1- and β2AR were highly confined in the membrane of H9c2 cardiomyocyte-like cells, indicating that receptors are tethered and presumably integrated into protein complexes. Selective disruption of interactions with postsynaptic density protein 95/disks large/zonula occludens-1 (PDZ)–domain proteins and A-kinase anchoring proteins (AKAPs) increased receptor diffusion, indicating that these scaffold proteins participate in receptor confinement. In contrast, modulation of interactions between the putative scaffold caveolae and β2AR did not alter receptor dynamics, suggesting that these membrane domains are not involved in β2AR confinement. For both β1- and β2AR, the receptor carboxy-terminus was uniquely responsible for scaffold interactions. Our data formally demonstrate that distinct and stable protein complexes containing β1- or β2AR are formed in the plasma membrane of cardiomyocyte-like cells and that selective PDZ and AKAP interactions are responsible for the integration of receptors into complexes.
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Affiliation(s)
- Cathleen D Valentine
- Division of Nephrology, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
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42
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Temkin P, Lauffer B, Jäger S, Cimermancic P, Krogan NJ, von Zastrow M. SNX27 mediates retromer tubule entry and endosome-to-plasma membrane trafficking of signalling receptors. Nat Cell Biol 2011; 13:715-21. [PMID: 21602791 PMCID: PMC3113693 DOI: 10.1038/ncb2252] [Citation(s) in RCA: 367] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 04/05/2011] [Indexed: 01/02/2023]
Abstract
Endocytic sorting of signalling receptors between recycling and degradative pathways is a key cellular process controlling the surface complement of receptors and, accordingly, the cell's ability to respond to specific extracellular stimuli. The β2 adrenergic receptor (β2AR) is a prototypical seven-transmembrane signalling receptor that recycles rapidly and efficiently to the plasma membrane after ligand-induced endocytosis. β2AR recycling is dependent on the receptor's carboxy-terminal PDZ ligand and Rab4. This active sorting process is required for functional resensitization of β2AR-mediated signalling. Here we show that sequence-directed sorting occurs at the level of entry into retromer tubules and that retromer tubules are associated with Rab4. Furthermore, we show that sorting nexin 27 (SNX27) serves as an essential adaptor protein linking β2ARs to the retromer tubule. SNX27 does not seem to directly interact with the retromer core complex, but does interact with the retromer-associated Wiskott-Aldrich syndrome protein and SCAR homologue (WASH) complex. The present results identify a role for retromer in endocytic trafficking of signalling receptors, in regulating a receptor-linked signalling pathway, and in mediating direct endosome-to-plasma membrane traffic.
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Affiliation(s)
- Paul Temkin
- Department of Psychiatry, University of California at San Francisco, San Francisco, California 94158, USA
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Björk K, Svenningsson P. Modulation of monoamine receptors by adaptor proteins and lipid rafts: role in some effects of centrally acting drugs and therapeutic agents. Annu Rev Pharmacol Toxicol 2011; 51:211-42. [PMID: 20887195 DOI: 10.1146/annurev-pharmtox-010510-100520] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The monoamines and their cognate receptors are widespread in the central nervous system and are vital for normal brain function. Dysfunction in these systems underlies several psychiatric and neurological disease states, and consequently monoamines are targets of a host of pharmacotherapies. This review provides an overview on how monoamine receptors are regulated by adaptor proteins and lipid rafts with emphasis on interactions in nerve cells. Monoamine receptors have prominent intracellular loops that provide binding sites for adaptor proteins. Receptor function is further modulated by cholesterol and submembranous microdomains termed lipid rafts. These interactions determine several facets of G protein-coupled receptor (GPCR) function including trafficking, localization, and signaling. Possible roles of adaptor proteins and lipid rafts in disease states and in mediating actions of drugs and therapeutic agents are also discussed.
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Affiliation(s)
- Karl Björk
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
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44
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Evans BA, Sato M, Sarwar M, Hutchinson DS, Summers RJ. Ligand-directed signalling at beta-adrenoceptors. Br J Pharmacol 2010; 159:1022-38. [PMID: 20132209 DOI: 10.1111/j.1476-5381.2009.00602.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
beta-Adrenoceptors (ARs) classically mediate responses to the endogenous ligands adrenaline and noradrenaline by coupling to Gsalpha and stimulating cAMP production; however, drugs designed as beta-AR agonists or antagonists can activate alternative cell signalling pathways, with the potential to influence clinical efficacy. Furthermore, drugs acting at beta-ARs have differential capacity for pathway activation, described as stimulus trafficking, biased agonism, functional selectivity or ligand-directed signalling. These terms refer to responses where drug A has higher efficacy than drug B for one signalling pathway, but a lower efficacy than drug B for a second pathway. The accepted explanation for such responses is that drugs A and B have the capacity to induce or stabilize distinct active conformations of the receptor that in turn display altered coupling efficiency to different effectors. This is consistent with biophysical studies showing that drugs can indeed promote distinct conformational states. Agonists acting at beta-ARs display ligand-directed signalling, but many drugs acting as cAMP antagonists are also able to activate signalling pathways central to cell survival and proliferation or cell death. The observed complexity of drug activity at beta-ARs, prototypical G protein-coupled receptors, necessitates rethinking of the approaches used for screening and characterization of novel therapeutic agents. Most studies of ligand-directed signalling employ recombinant cell systems with high receptor abundance. While such systems are valid for examining upstream signalling events, such as receptor conformational changes and G protein activation, they are less robust when comparing downstream signalling outputs as these are likely to be affected by complex pathway interactions.
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Affiliation(s)
- Bronwyn A Evans
- Monash Institute of Pharmaceutical Sciences & Department of Pharmacology, Parkville, Vic, Australia
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45
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Ferguson SM, Ferguson S, Raimondi A, Paradise S, Shen H, Mesaki K, Ferguson A, Destaing O, Ko G, Takasaki J, Cremona O, O' Toole E, De Camilli P. Coordinated actions of actin and BAR proteins upstream of dynamin at endocytic clathrin-coated pits. Dev Cell 2010; 17:811-22. [PMID: 20059951 DOI: 10.1016/j.devcel.2009.11.005] [Citation(s) in RCA: 326] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Revised: 11/02/2009] [Accepted: 11/17/2009] [Indexed: 01/30/2023]
Abstract
The GTPase dynamin, a key player in endocytic membrane fission, interacts with numerous proteins that regulate actin dynamics and generate/sense membrane curvature. To determine the functional relationship between these proteins and dynamin, we have analyzed endocytic intermediates that accumulate in cells that lack dynamin (derived from dynamin 1 and 2 double conditional knockout mice). In these cells, actin-nucleating proteins, actin, and BAR domain proteins accumulate at the base of arrested endocytic clathrin-coated pits, where they support the growth of dynamic long tubular necks. These results, which we show reflect the sequence of events in wild-type cells, demonstrate a concerted action of these proteins prior to, and independent of, dynamin and emphasize similarities between clathrin-mediated endocytosis in yeast and higher eukaryotes. Our data also demonstrate that the relationship between dynamin and actin is intimately connected to dynamin's endocytic role and that dynamin terminates a powerful actin- and BAR protein-dependent tubulating activity.
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Affiliation(s)
- Shawn M Ferguson
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA
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46
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The β1-adrenergic receptor mediates extracellular signal-regulated kinase activation via Gαs. Amino Acids 2008; 38:75-84. [DOI: 10.1007/s00726-008-0207-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 11/03/2008] [Indexed: 01/14/2023]
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47
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Le HY, Zhang Y, Liu H, Ma LH, Jin Y, Huang QH, Chen Y, Deng M, Chen Z, Chen SJ, Liu TX. eena Promotes Myeloid Proliferation through Stimulating ERK1/2 Phosphorylation in Zebrafish. J Biol Chem 2008; 283:17652-61. [DOI: 10.1074/jbc.m710517200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Morisco C, Marrone C, Galeotti J, Shao D, Vatner DE, Vatner SF, Sadoshima J. Endocytosis machinery is required for beta1-adrenergic receptor-induced hypertrophy in neonatal rat cardiac myocytes. Cardiovasc Res 2008; 78:36-44. [PMID: 18194989 DOI: 10.1093/cvr/cvn008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIMS Cardiac hypertrophy by activation of the beta-adrenergic receptor (beta AR) is mediated more efficiently by the beta1-AR than by the beta2-AR. We investigated the signalling mechanism by which the beta1-AR mediates cardiac hypertrophy. METHODS AND RESULTS Experiments were performed in cultured neonatal rat cardiomyocytes. Hypertrophy was determined by the protein/DNA content and atrial natriuretic factor transcription. Phosphorylation of Akt and Src was assessed by immunoblotting. Isoproterenol (ISO, 10 microM), a non-selective beta-AR agonist, caused selective downregulation of the beta1-AR (control beta1 vs. beta2: 35 vs. 65%, Bmax 78 +/- 4 fmol/mg; 4 h, 10 vs. 90%, 61 +/- 5 fmol/mg). Concanavalin A (Con A, 0.5 microg/mL), an inhibitor of endocytosis, prevented downregulation of beta1-ARs by ISO treatment (4 h, 35 vs. 65%, 73 +/- 8 fmol/mg), suggesting that beta1-ARs selectively undergo endocytosis. Interference with beta1-AR endocytosis by Con A, carboxyl terminal peptide of beta-AR kinase-1, dominant negative (DN) beta-arrestin-1, or DN dynamin inhibited beta-adrenergic hypertrophy, suggesting that the endocytosis machinery plays a key role in mediating beta-adrenergic hypertrophy. Activation of Akt by the beta1-AR was blocked by inhibition of the endocytosis machinery, suggesting that endocytosis mediates activation of Akt. Akt plays a critical role in beta-adrenergic hypertrophy, since DN Akt blocked ISO-induced hypertrophy. beta-Adrenergic activation of Akt is mediated by Src, which associates with the endocytosis machinery and is necessary and sufficient to mediate beta-adrenergic hypertrophy. CONCLUSION Activation of the endocytosis machinery is required for activation of Akt, which, in turn, critically mediates beta1-AR-induced cardiac hypertrophy.
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Affiliation(s)
- Carmine Morisco
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, UMDNJ, New Jersey Medical School, 185 South Orange Avenue, MSB G-609, Newark, NJ 07103, USA
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Perera RM, Zoncu R, Lucast L, De Camilli P, Toomre D. Two synaptojanin 1 isoforms are recruited to clathrin-coated pits at different stages. Proc Natl Acad Sci U S A 2006; 103:19332-7. [PMID: 17158794 PMCID: PMC1693868 DOI: 10.1073/pnas.0609795104] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phosphoinositides are thought to play an important role in clathrin-coated pit (CCP) dynamics. Biochemical and structural studies have shown a direct interaction of phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] with endocytic clathrin adaptors, whereas functional studies using cell-free systems or intact cells have demonstrated the importance of PI(4,5)P2 synthesis and dephosphorylation in clathrin coating and uncoating, respectively. Furthermore, genetic manipulations of kinases and phosphatases involved in PI(4,5)P2 metabolism result in major defects in synaptic vesicle recycling and other forms of clathrin-dependent endocytosis. However, live imaging studies of these enzymes at CCPs have not been conducted. We have used multicolor total internal reflection fluorescence microscopy (TIRFM) to visualize the spatial-temporal recruitment of synaptojanin 1 (SJ1), a polyphosphoinositide phosphatase, and its binding partner endophilin to CCPs. Strikingly, we observed differential temporal recruitment of the two major SJ1 splice variants to CCPs. The 145-kDa isoform, the predominant isoform expressed in the brain, was rapidly recruited as a "burst," together with endophilin, at a late stage of CCP formation. In contrast, the nonneuronal ubiquitously expressed 170-kDa isoform of SJ1 was present at all stages of CCP formation. These results raise the possibility that dynamic phosphoinositide metabolism may occur throughout the lifetime of a CCP.
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Affiliation(s)
| | - Roberto Zoncu
- *Department of Cell Biology and
- Howard Hughes Medical Institute, Kavli Institute for Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510
| | - Louise Lucast
- *Department of Cell Biology and
- Howard Hughes Medical Institute, Kavli Institute for Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510
| | - Pietro De Camilli
- *Department of Cell Biology and
- Howard Hughes Medical Institute, Kavli Institute for Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510
- To whom correspondence may be addressed. E-mail:
or
| | - Derek Toomre
- *Department of Cell Biology and
- To whom correspondence may be addressed. E-mail:
or
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