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Xu R, Wan M, Shi X, Ma S, Zhang L, Yi P, Zhang R. A Rab10-ACAP1-Arf6 GTPases cascade modulates M4 muscarinic acetylcholine receptor trafficking and signaling. Cell Mol Life Sci 2023; 80:87. [PMID: 36917255 PMCID: PMC11072986 DOI: 10.1007/s00018-023-04722-x] [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: 11/27/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 03/16/2023]
Abstract
Membrane trafficking processes regulate the G protein-coupled receptor activity. The muscarinic acetylcholine receptors (mAChRs) are highly pursued drug targets for neurological diseases, but the cellular machineries that control the trafficking of these receptors remain largely elusive. Here, we revealed the role of the small GTPase Rab10 as a negative regulator for the post-activation trafficking of M4 mAChR and the underlying mechanism. We show that constitutively active Rab10 arrests the receptor within Rab5-positive early endosomes and significantly hinders the resensitization of M4-mediated Ca2+ signaling. Mechanistically, M4 binds to Rab10-GTP, which requires the motif 386RKKRQMAA393 (R386-A393) within the third intracellular loop. Moreover, Rab10-GTP inactivates Arf6 by recruiting the Arf6 GTPase-activating protein, ACAP1. Strikingly, deletion of the motif R386-A393 causes M4 to bypass the control by Rab10 and switch to the Rab4-facilitated fast recycling pathway, thus reusing the receptor. Therefore, Rab10 couples the cargo sorting and membrane trafficking regulation through cycle between GTP-bound and GDP-bound state. Our findings suggest a model that Rab10 binds to the M4 like a molecular brake and controls the receptor's transport through endosomes, thus modulating the signaling, and this regulation is specific among the mAChR subtypes.
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Affiliation(s)
- Rongmei Xu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Min Wan
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, USA
| | - Xuemeng Shi
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
- College of Life Science, Henan Agricultural University, Zhengzhou, Henan, China
| | - Shumin Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lina Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ping Yi
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Rongying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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Genera M, Colcombet-Cazenave B, Croitoru A, Raynal B, Mechaly A, Caillet J, Haouz A, Wolff N, Caillet-Saguy C. Interactions of the protein tyrosine phosphatase PTPN3 with viral and cellular partners through its PDZ domain: insights into structural determinants and phosphatase activity. Front Mol Biosci 2023; 10:1192621. [PMID: 37200868 PMCID: PMC10185773 DOI: 10.3389/fmolb.2023.1192621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 04/18/2023] [Indexed: 05/20/2023] Open
Abstract
The human protein tyrosine phosphatase non-receptor type 3 (PTPN3) is a phosphatase containing a PDZ (PSD-95/Dlg/ZO-1) domain that has been found to play both tumor-suppressive and tumor-promoting roles in various cancers, despite limited knowledge of its cellular partners and signaling functions. Notably, the high-risk genital human papillomavirus (HPV) types 16 and 18 and the hepatitis B virus (HBV) target the PDZ domain of PTPN3 through PDZ-binding motifs (PBMs) in their E6 and HBc proteins respectively. This study focuses on the interactions between the PTPN3 PDZ domain (PTPN3-PDZ) and PBMs of viral and cellular protein partners. We solved the X-ray structures of complexes between PTPN3-PDZ and PBMs of E6 of HPV18 and the tumor necrosis factor-alpha converting enzyme (TACE). We provide new insights into key structural determinants of PBM recognition by PTPN3 by screening the selectivity of PTPN3-PDZ recognition of PBMs, and by comparing the PDZome binding profiles of PTPN3-recognized PBMs and the interactome of PTPN3-PDZ. The PDZ domain of PTPN3 was known to auto-inhibit the protein's phosphatase activity. We discovered that the linker connecting the PDZ and phosphatase domains is involved in this inhibition, and that the binding of PBMs does not impact this catalytic regulation. Overall, the study sheds light on the interactions and structural determinants of PTPN3 with its cellular and viral partners, as well as on the inhibitory role of its PDZ domain on its phosphatase activity.
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Affiliation(s)
- Mariano Genera
- Institut Pasteur, Université Paris Cité, Channel Receptors Unit, Paris, France
- Sorbonne Université, Complexité du Vivant, F-75005, Paris, France
| | - Baptiste Colcombet-Cazenave
- Institut Pasteur, Université Paris Cité, Channel Receptors Unit, Paris, France
- Sorbonne Université, Complexité du Vivant, F-75005, Paris, France
| | - Anastasia Croitoru
- Institut Pasteur, Université Paris Cité, Channel Receptors Unit, Paris, France
| | - Bertrand Raynal
- Molecular Biophysics Platform-C2RT, CNRS, Institut Pasteur, Université Paris Cité, Paris, France
| | - Ariel Mechaly
- Crystallography Platform-C2RT, Institut Pasteur, Université Paris Cité, Paris, France
| | - Joël Caillet
- CNRS, Institut de Biologie Physico-Chimique, Université Paris Cité, Paris, France
| | - Ahmed Haouz
- Crystallography Platform-C2RT, Institut Pasteur, Université Paris Cité, Paris, France
| | - Nicolas Wolff
- Institut Pasteur, Université Paris Cité, Channel Receptors Unit, Paris, France
| | - Célia Caillet-Saguy
- Institut Pasteur, Université Paris Cité, Channel Receptors Unit, Paris, France
- *Correspondence: Célia Caillet-Saguy,
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Johnson GP, Jonas KC. Mechanistic insight into how gonadotropin hormone receptor complexes direct signaling†. Biol Reprod 2021; 102:773-783. [PMID: 31882999 DOI: 10.1093/biolre/ioz228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/09/2019] [Accepted: 12/17/2019] [Indexed: 12/29/2022] Open
Abstract
Gonadotropin hormones and their receptors play a central role in the control of male and female reproduction. In recent years, there has been growing evidence surrounding the complexity of gonadotropin hormone/receptor signaling, with it increasingly apparent that the Gαs/cAMP/PKA pathway is not the sole signaling pathway that confers their biological actions. Here we review recent literature on the different receptor-receptor, receptor-scaffold, and receptor-signaling molecule complexes formed and how these modulate and direct gonadotropin hormone-dependent intracellular signal activation. We will touch upon the more controversial issue of extragonadal expression of FSHR and the differential signal pathways activated in these tissues, and lastly, highlight the open questions surrounding the role these gonadotropin hormone receptor complexes and how this will shape future research directions.
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Affiliation(s)
| | - Kim Carol Jonas
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London, UK
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4
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Abstract
Gonadotropins are glycoprotein sex hormones regulating development and reproduction and bind to specific G protein–coupled receptors expressed in the gonads. Their effects on multiple signaling cascades and intracellular events have recently been characterized using novel technological and scientific tools. The impact of allosteric modulators on gonadotropin signaling, the role of sugars linked to the hormone backbone, the detection of endosomal compartments supporting signaling modules, and the dissection of different effects mediated by these molecules are areas that have advanced significantly in the last decade. The classic view providing the exclusive activation of the cAMP/protein kinase A (PKA) and the steroidogenic pathway by these hormones has been expanded with the addition of novel signaling cascades as determined by high-resolution imaging techniques. These new findings provided new potential therapeutic applications. Despite these improvements, unanswered issues of gonadotropin physiology, such as the intrinsic pro-apoptotic potential to these hormones, the existence of receptors assembled as heteromers, and their expression in extragonadal tissues, remain to be studied. Elucidating these issues is a challenge for future research.
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Affiliation(s)
- Livio Casarini
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
| | - Manuela Simoni
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
- Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria di Modena, Via P. Giardini 1355, 41126 Modena, Italy
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Ahmed T, Mythreye K, Lee NY. Strength and duration of GIPC-dependent signaling networks as determinants in cancer. Neoplasia 2021; 23:181-188. [PMID: 33360508 PMCID: PMC7773760 DOI: 10.1016/j.neo.2020.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 10/25/2022]
Abstract
GIPC is a PDZ-domain containing adaptor protein that regulates the cell surface expression and endocytic trafficking of numerous transmembrane receptors and signaling complexes. Interactions with over 50 proteins have been reported to date including VEGFR, insulin-like growth factor-1 receptor (IGF-1R), GPCRs, and APPL, many of which have essential roles in neuronal and cardiovascular development. In cancer, a major subset of GIPC-binding receptors and cytoplasmic effectors have been shown to promote tumorigenesis or metastatic progression, while other subsets have demonstrated strong tumor-suppressive effects. Given that these diverse pathways are widespread in normal tissues and human malignancies, precisely how these opposing signals are integrated and regulated within the same tumor setting likely depend on the strength and duration of their interactions with GIPC. This review highlights the major pathways and divergent mechanisms of GIPC signaling in various cancers and provide a rationale for emerging GIPC-targeted cancer therapies.
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Affiliation(s)
- Tasmia Ahmed
- Deparment of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Karthikeyan Mythreye
- Division of Molecular and Cellular Pathology, University of Alabama Birmingham, Birmingham, AL, USA
| | - Nam Y Lee
- Deparment of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, USA; Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA; The University of Arizona Cancer Center, Tucson, AZ, USA.
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6
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Sposini S, De Pascali F, Richardson R, Sayers NS, Perrais D, Yu HN, Palmer S, Nataraja S, Reiter E, Hanyaloglu AC. Pharmacological Programming of Endosomal Signaling Activated by Small Molecule Ligands of the Follicle Stimulating Hormone Receptor. Front Pharmacol 2020; 11:593492. [PMID: 33329002 PMCID: PMC7734412 DOI: 10.3389/fphar.2020.593492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/19/2020] [Indexed: 12/23/2022] Open
Abstract
Follicle-stimulating hormone receptor (FSHR) is a G protein-coupled receptor (GPCR) with pivotal roles in reproduction. One key mechanism dictating the signal activity of GPCRs is membrane trafficking. After binding its hormone FSH, FSHR undergoes internalization to very early endosomes (VEEs) for its acute signaling and sorting to a rapid recycling pathway. The VEE is a heterogeneous compartment containing the Adaptor Protein Phosphotyrosine Interacting with Pleckstrin homology Domain and Leucine Zipper 1 (APPL1) with distinct functions in regulating endosomal Gαs/cAMP signaling and rapid recycling. Low molecular weight (LMW) allosteric FSHR ligands were developed for use in assisted reproductive technology yet could also provide novel pharmacological tools to study FSHR. Given the critical nature of receptor internalization and endosomal signaling for FSHR activity, we assessed whether these compounds exhibit differential abilities to alter receptor endosomal trafficking and signaling within the VEE. Two chemically distinct LMW agonists (benzamide, termed B3 and thiazolidinone, termed T1) were employed. T1 was able to induce a greater level of cAMP than FSH and B3. As cAMP signaling drives gonadotrophin hormone receptor recycling, rapid exocytic events were evaluated at single event resolution. Strikingly, T1 was able to induce a 3-fold increase in recycling events compared to FSH and two-fold more compared to B3. As T1-induced internalization was only marginally greater, the dramatic increase in recycling and cAMP signaling may be due to additional mechanisms. All compounds exhibited a similar requirement for receptor internalization to increase cAMP and proportion of FSHR endosomes with active Gαs, suggesting regulation of cAMP signaling induced by T1 may be altered. APPL1 plays a central role for GPCRs targeted to the VEE, and indeed, loss of APPL1 inhibited FSH-induced recycling and increased endosomal cAMP signaling. While T1-induced FSHR recycling was APPL1-dependent, its elevated cAMP signaling was only partially increased following APPL1 knockdown. Unexpectedly, B3 altered the dependence of FSHR to APPL1 in an opposing manner, whereby its endosomal signaling was negatively regulated by APPL1, while B3-induced FSHR recycling was APPL1-independent. Overall, FSHR allosteric compounds have the potential to re-program FSHR activity via altering engagement with VEE machinery and also suggests that these two distinct functions of APPL1 can potentially be selected pharmacologically.
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Affiliation(s)
- Silvia Sposini
- Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Francesco De Pascali
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Université de Tours, Institut Français du Cheval et de l'Equitation (IFCE), Nouzilly, France
| | - Rachel Richardson
- Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Niamh S. Sayers
- Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - David Perrais
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Henry N. Yu
- CanWell Pharma Inc., Wellesley, MA, United States
| | - Stephen Palmer
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, United States
| | | | - Eric Reiter
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Université de Tours, Institut Français du Cheval et de l'Equitation (IFCE), Nouzilly, France
| | - Aylin C. Hanyaloglu
- Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
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Huang C, Yang X, Zeng B, Zeng L, Gong X, Zhou C, Xia J, Lian B, Qin Y, Yang L, Liu L, Xie P. Proteomic analysis of olfactory bulb suggests CACNA1E as a promoter of CREB signaling in microbiota-induced depression. J Proteomics 2019; 194:132-147. [DOI: 10.1016/j.jprot.2018.11.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 11/24/2018] [Accepted: 11/26/2018] [Indexed: 12/18/2022]
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8
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Casarini L, Santi D, Brigante G, Simoni M. Two Hormones for One Receptor: Evolution, Biochemistry, Actions, and Pathophysiology of LH and hCG. Endocr Rev 2018; 39:549-592. [PMID: 29905829 DOI: 10.1210/er.2018-00065] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/08/2018] [Indexed: 01/03/2023]
Abstract
LH and chorionic gonadotropin (CG) are glycoproteins fundamental to sexual development and reproduction. Because they act on the same receptor (LHCGR), the general consensus has been that LH and human CG (hCG) are equivalent. However, separate evolution of LHβ and hCGβ subunits occurred in primates, resulting in two molecules sharing ~85% identity and regulating different physiological events. Pituitary, pulsatile LH production results in an ~90-minute half-life molecule targeting the gonads to regulate gametogenesis and androgen synthesis. Trophoblast hCG, the "pregnancy hormone," exists in several isoforms and glycosylation variants with long half-lives (hours) and angiogenic potential and acts on luteinized ovarian cells as progestational. The different molecular features of LH and hCG lead to hormone-specific LHCGR binding and intracellular signaling cascades. In ovarian cells, LH action is preferentially exerted through kinases, phosphorylated extracellular-regulated kinase 1/2 (pERK1/2) and phosphorylated AKT (also known as protein kinase B), resulting in irreplaceable proliferative/antiapoptotic signals and partial agonism on progesterone production in vitro. In contrast, hCG displays notable cAMP/protein kinase A (PKA)-mediated steroidogenic and proapoptotic potential, which is masked by estrogen action in vivo. In vitro data have been confirmed by a large data set from assisted reproduction, because the steroidogenic potential of hCG positively affects the number of retrieved oocytes, and LH affects the pregnancy rate (per oocyte number). Leydig cell in vitro exposure to hCG results in qualitatively similar cAMP/PKA and pERK1/2 activation compared with LH and testosterone. The supposed equivalence of LH and hCG has been disproved by such data, highlighting their sex-specific functions and thus deeming it an oversight caused by incomplete understanding of clinical data.
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Affiliation(s)
- Livio Casarini
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Daniele Santi
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria, Modena, Italy
| | - Giulia Brigante
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria, Modena, Italy
| | - Manuela Simoni
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy.,Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria, Modena, Italy
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Integration of GPCR Signaling and Sorting from Very Early Endosomes via Opposing APPL1 Mechanisms. Cell Rep 2018; 21:2855-2867. [PMID: 29212031 PMCID: PMC5732320 DOI: 10.1016/j.celrep.2017.11.023] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/18/2017] [Accepted: 11/03/2017] [Indexed: 01/10/2023] Open
Abstract
Endocytic trafficking is a critical mechanism for cells to decode complex signaling pathways, including those activated by G-protein-coupled receptors (GPCRs). Heterogeneity in the endosomal network enables GPCR activity to be spatially restricted between early endosomes (EEs) and the recently discovered endosomal compartment, the very early endosome (VEE). However, the molecular machinery driving GPCR activity from the VEE is unknown. Using luteinizing hormone receptor (LHR) as a prototype GPCR for this compartment, along with additional VEE-localized GPCRs, we identify a role for the adaptor protein APPL1 in rapid recycling and endosomal cAMP signaling without impacting the EE-localized β2-adrenergic receptor. LHR recycling is driven by receptor-mediated Gαs/cAMP signaling from the VEE and PKA-dependent phosphorylation of APPL1 at serine 410. Receptor/Gαs endosomal signaling is localized to microdomains of heterogeneous VEE populations and regulated by APPL1 phosphorylation. Our study uncovers a highly integrated inter-endosomal communication system enabling cells to tightly regulate spatially encoded signaling. GPCRs that internalize to very early endosomes (VEEs) require APPL1 to recycle Receptor recycling is driven by cAMP/PKA to phosphorylate serine 410 on APPL1 cAMP signaling from GPCRs, such as LHR, occurs from distinct VEE microdomains APPL1 limits VEE cAMP signaling via opposing mechanisms required for GPCR sorting
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Hanyaloglu AC. Advances in Membrane Trafficking and Endosomal Signaling of G Protein-Coupled Receptors. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 339:93-131. [PMID: 29776606 DOI: 10.1016/bs.ircmb.2018.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The integration of GPCR signaling with membrane trafficking, as a single orchestrated system, is a theme increasingly evident with the growing reports of GPCR endosomal signaling. Once viewed as a mechanism to regulate cell surface heterotrimeric G protein signaling, the endocytic trafficking system is complex, highly compartmentalized, yet deeply interconnected with cell signaling. The organization of receptors into distinct plasma membrane signalosomes, biochemically distinct endosomal populations, endosomal microdomains, and its communication with distinct subcellular organelles such as the Golgi provides multiple unique signaling platforms that are critical for specifying receptor function physiologically and pathophysiologically. In this chapter I discuss our emerging understanding in the endocytic trafficking systems employed by GPCRs and their novel roles in spatial control of signaling. Given the extensive roles that GPCRs play in vivo, these evolving models are starting to provide mechanistic understanding of distinct diseases and provide novel therapeutic avenues that are proving to be viable targets.
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Affiliation(s)
- Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
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11
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Evolving View of Membrane Trafficking and Signaling Systems for G Protein-Coupled Receptors. ENDOCYTOSIS AND SIGNALING 2018; 57:273-299. [DOI: 10.1007/978-3-319-96704-2_10] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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12
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Sayers N, Hanyaloglu AC. Intracellular Follicle-Stimulating Hormone Receptor Trafficking and Signaling. Front Endocrinol (Lausanne) 2018; 9:653. [PMID: 30450081 PMCID: PMC6225286 DOI: 10.3389/fendo.2018.00653] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 10/17/2018] [Indexed: 12/18/2022] Open
Abstract
Models of G protein-coupled receptor (GPCR) signaling have dramatically altered over the past two decades. Indeed, GPCRs such as the follicle-stimulating hormone receptor (FSHR) have contributed to these new emerging models. We now understand that receptor signaling is highly organized at a spatial level, whereby signaling not only occurs from the plasma membrane but distinct intracellular compartments. Recent studies in the role of membrane trafficking and spatial organization of GPCR signaling in regulating gonadotropin hormone receptor activity has identified novel intracellular compartments, which are tightly linked with receptor signaling and reciprocally regulated by the cellular trafficking machinery. Understanding the impact of these cell biological mechanisms to physiology and pathophysiology is emerging for certain GPCRs. However, for FSHR, the potential impact in both health and disease and the therapeutic possibilities of these newly identified systems is currently unknown, but offers the potential to reassess prior strategies, or unveil novel opportunities, in targeting this receptor.
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13
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Zenko D, Hislop JN. Regulation and trafficking of muscarinic acetylcholine receptors. Neuropharmacology 2017; 136:374-382. [PMID: 29138081 DOI: 10.1016/j.neuropharm.2017.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/02/2017] [Accepted: 11/10/2017] [Indexed: 12/31/2022]
Abstract
Fidelity of signal transduction relies on cells expressing the appropriate number of functional receptors. Fluctuation in the total number of muscarinic acetylcholine receptors has been implicated in a range of physiological and pathophysiological processes, and the mechanisms responsible for this regulation represent potential molecular targets for therapeutic intervention. This article will review the current literature on the endocytic trafficking of muscarinic receptors and how knowledge of the trafficking of related receptors might influence future studies. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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Affiliation(s)
- Dmitry Zenko
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - James N Hislop
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom.
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Spatial encryption of G protein-coupled receptor signaling in endosomes; Mechanisms and applications. Biochem Pharmacol 2017; 143:1-9. [DOI: 10.1016/j.bcp.2017.04.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/25/2017] [Indexed: 01/14/2023]
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15
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De novo sequencing and comparative analysis of testicular transcriptome from different reproductive phases in freshwater spotted snakehead Channa punctatus. PLoS One 2017; 12:e0173178. [PMID: 28253373 PMCID: PMC5333912 DOI: 10.1371/journal.pone.0173178] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 02/16/2017] [Indexed: 12/14/2022] Open
Abstract
The spotted snakehead Channa punctatus is a seasonally breeding teleost widely distributed in the Indian subcontinent and economically important due to high nutritional value. The declining population of C. punctatus prompted us to focus on genetic regulation of its reproduction. The present study carried out de novo testicular transcriptome sequencing during the four reproductive phases and correlated differential expression of transcripts with various testicular events in C. punctatus. The Illumina paired-end sequencing of testicular transcriptome from resting, preparatory, spawning and postspawning phases generated 41.94, 47.51, 61.81 and 44.45 million reads, and 105526, 105169, 122964 and 106544 transcripts, respectively. Transcripts annotated using Rattus norvegicus reference protein sequences and classified under various subcategories of biological process, molecular function and cellular component showed that the majority of the subcategories had highest number of transcripts during spawning phase. In addition, analysis of transcripts exhibiting differential expression during the four phases revealed an appreciable increase in upregulated transcripts of biological processes such as cell proliferation and differentiation, cytoskeleton organization, response to vitamin A, transcription and translation, regulation of angiogenesis and response to hypoxia during spermatogenically active phases. The study also identified significant differential expression of transcripts relevant to spermatogenesis (mgat3, nqo1, hes2, rgs4, cxcl2, alcam, agmat), steroidogenesis (star, tkt, gipc3), cell proliferation (eef1a2, btg3, pif1, myo16, grik3, trim39, plbd1), cytoskeletal organization (espn, wipf3, cd276), sperm development (klhl10, mast1, hspa1a, slc6a1, ros1, foxj1, hipk1), and sperm transport and motility (hint1, muc13). Analysis of functional annotation and differential expression of testicular transcripts depending on reproductive phases of C. punctatus helped in developing a comprehensive understanding on genetic regulation of spermatogenic and steroidogenic events in seasonally breeding teleosts. Our findings provide the basis for future investigation on the precise role of testicular genes in regulation of seasonal reproduction in male teleosts.
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James CD, Roberts S. Viral Interactions with PDZ Domain-Containing Proteins-An Oncogenic Trait? Pathogens 2016; 5:pathogens5010008. [PMID: 26797638 PMCID: PMC4810129 DOI: 10.3390/pathogens5010008] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/14/2016] [Accepted: 01/15/2016] [Indexed: 02/06/2023] Open
Abstract
Many of the human viruses with oncogenic capabilities, either in their natural host or in experimental systems (hepatitis B and C, human T cell leukaemia virus type 1, Kaposi sarcoma herpesvirus, human immunodeficiency virus, high-risk human papillomaviruses and adenovirus type 9), encode in their limited genome the ability to target cellular proteins containing PSD95/ DLG/ZO-1 (PDZ) interaction modules. In many cases (but not always), the viruses have evolved to bind the PDZ domains using the same short linear peptide motifs found in host protein-PDZ interactions, and in some cases regulate the interactions in a similar fashion by phosphorylation. What is striking is that the diverse viruses target a common subset of PDZ proteins that are intimately involved in controlling cell polarity and the structure and function of intercellular junctions, including tight junctions. Cell polarity is fundamental to the control of cell proliferation and cell survival and disruption of polarity and the signal transduction pathways involved is a key event in tumourigenesis. This review focuses on the oncogenic viruses and the role of targeting PDZ proteins in the virus life cycle and the contribution of virus-PDZ protein interactions to virus-mediated oncogenesis. We highlight how many of the viral associations with PDZ proteins lead to deregulation of PI3K/AKT signalling, benefitting virus replication but as a consequence also contributing to oncogenesis.
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Affiliation(s)
- Claire D James
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
- Present address; Virginia Commonwealth University, School of Dentistry, W. Baxter Perkinson Jr. Building, 521 North 11th Street, P.O. Box 980566, Richmond, VA 23298-0566, USA.
| | - Sally Roberts
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
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Song J, Li J, Liu HD, Liu W, Feng Y, Zhou XT, Li JD. Snapin interacts with G-protein coupled receptor PKR2. Biochem Biophys Res Commun 2015; 469:501-6. [PMID: 26687946 DOI: 10.1016/j.bbrc.2015.12.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 12/06/2015] [Indexed: 01/21/2023]
Abstract
Mutations in Prokineticin receptor 2 (PKR2), a G-protein-coupled receptor, have been identified in patients with Kallmann syndrome and/or idiopathic hypogonadotropic hypogonadism, characterized by delayed puberty and infertility. In this study, we performed yeast two-hybrid screening by using PKR2 C-terminus (amino acids 333-384) as a bait, and identified Snapin as a novel interaction partner for PKR2. The interaction of Snapin and PKR2 was confirmed in GST pull-down and co-immunoprecipitation studies. We further demonstrated that two α-helix domains in Snapin are required for the interaction. And the interactive motifs of PKR2 were mapped to YFK (343-345) and HWR (351-353), which shared a similar sequence of two aromatic amino acids followed by a basic amino acid. Disruption of Snapin-PKR2 interaction did not affect PKR2 signaling, but increased the ligand-induced degradation, implying a role of Snapin in the trafficking of PKR2.
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Affiliation(s)
- Jian Song
- The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China; Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
| | - Jie Li
- The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Hua-die Liu
- The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Wei Liu
- The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yong Feng
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
| | - Xiao-Tao Zhou
- The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China; Department of Immunology, Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, China.
| | - Jia-Da Li
- The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
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West C, Hanyaloglu AC. Minireview: Spatial Programming of G Protein-Coupled Receptor Activity: Decoding Signaling in Health and Disease. Mol Endocrinol 2015; 29:1095-106. [PMID: 26121235 DOI: 10.1210/me.2015-1065] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Probing the multiplicity of hormone signaling via G protein-coupled receptors (GPCRs) has demonstrated the complex signal pathways that underlie the multiple functions these receptors play in vivo. This is highly pertinent for the GPCRs key in reproduction and pregnancy that are exposed to cyclical and dynamic changes in their extracellular milieu. How such functional pleiotropy in GPCR signaling is translated to specific downstream cellular responses, however, is largely unknown. Emerging data strongly support mechanisms for a central role of receptor location in signal regulation via membrane trafficking. In this review, we discuss current progress in our understanding of the role membrane trafficking plays in location control of GPCR signaling, from organized plasma membrane signaling microdomains, potentially provided by both distinct endocytic and exocytic pathways, to more recent evidence for spatial control within the endomembrane system. Application of these emerging mechanisms in their relevance to GPCR activity in physiological and pathophysiological conditions will also be discussed, and in improving therapeutic strategies that exploits these mechanisms in order to program highly regulated and distinct signaling profiles.
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Affiliation(s)
- Camilla West
- Institute of Reproductive Biology and Development, Department of Surgery and Cancer, Imperial College London, London, W12 0NN, United Kingdom
| | - Aylin C Hanyaloglu
- Institute of Reproductive Biology and Development, Department of Surgery and Cancer, Imperial College London, London, W12 0NN, United Kingdom
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19
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Bowman SL, Puthenveedu MA. Postendocytic Sorting of Adrenergic and Opioid Receptors: New Mechanisms and Functions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 132:189-206. [PMID: 26055059 DOI: 10.1016/bs.pmbts.2015.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The endocytic pathway tightly regulates the activity of G protein-coupled receptors (GPCRs). Much of our understanding of this relationship between GPCR endocytic trafficking and signaling comes from studies done on catecholamine and opioid receptors. After ligand-induced endocytosis, a key sorting step in the endosome determines whether receptors are recycled back to the cell surface, leading to recovery of signaling, or are degraded in the lysosome, leading to desensitization. Recycling of GPCRs, unlike that of many other proteins, is an active process driven by specific sequences on the receptor and proteins that interact with this sequence. Recent data suggest that sequence-dependent recycling plays complex roles in regulating both the timing and location of GPCR signaling. This chapter will describe our current understanding of the mechanisms regulating GPCR sorting in the endosome and discuss emerging ideas on their role in GPCR signaling, focusing on adrenergic and opioid receptors as prototypes.
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Affiliation(s)
- Shanna L Bowman
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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20
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Dunn HA, Ferguson SSG. PDZ Protein Regulation of G Protein–Coupled Receptor Trafficking and Signaling Pathways. Mol Pharmacol 2015; 88:624-39. [DOI: 10.1124/mol.115.098509] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/25/2015] [Indexed: 01/03/2023] Open
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Chak K, Kolodkin AL. Function of the Drosophila receptor guanylyl cyclase Gyc76C in PlexA-mediated motor axon guidance. Development 2014; 141:136-47. [PMID: 24284209 PMCID: PMC3865755 DOI: 10.1242/dev.095968] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 09/26/2013] [Indexed: 12/17/2022]
Abstract
The second messengers cAMP and cGMP modulate attraction and repulsion mediated by neuronal guidance cues. We find that the Drosophila receptor guanylyl cyclase Gyc76C genetically interacts with Semaphorin 1a (Sema-1a) and physically associates with the Sema-1a receptor plexin A (PlexA). PlexA regulates Gyc76C catalytic activity in vitro, and each distinct Gyc76C protein domain is crucial for regulating Gyc76C activity in vitro and motor axon guidance in vivo. The cytosolic protein dGIPC interacts with Gyc76C and facilitates Sema-1a-PlexA/Gyc76C-mediated motor axon guidance. These findings provide an in vivo link between semaphorin-mediated repulsive axon guidance and alteration of intracellular neuronal cGMP levels.
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Affiliation(s)
- Kayam Chak
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alex L. Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Jean-Alphonse F, Bowersox S, Chen S, Beard G, Puthenveedu MA, Hanyaloglu AC. Spatially restricted G protein-coupled receptor activity via divergent endocytic compartments. J Biol Chem 2013; 289:3960-77. [PMID: 24375413 PMCID: PMC3924264 DOI: 10.1074/jbc.m113.526350] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Postendocytic sorting of G protein-coupled receptors (GPCRs) is driven by their interactions between highly diverse receptor sequence motifs with their interacting proteins, such as postsynaptic density protein (PSD95), Drosophila disc large tumor suppressor (Dlg1), zonula occludens-1 protein (zo-1) (PDZ) domain proteins. However, whether these diverse interactions provide an underlying functional specificity, in addition to driving sorting, is unknown. Here we identify GPCRs that recycle via distinct PDZ ligand/PDZ protein pairs that exploit their recycling machinery primarily for targeted endosomal localization and signaling specificity. The luteinizing hormone receptor (LHR) and β2-adrenergic receptor (B2AR), two GPCRs sorted to the regulated recycling pathway, underwent divergent trafficking to distinct endosomal compartments. Unlike B2AR, which traffics to early endosomes (EE), LHR internalizes to distinct pre-early endosomes (pre-EEs) for its recycling. Pre-EE localization required interactions of the LHR C-terminal tail with the PDZ protein GAIP-interacting protein C terminus, inhibiting its traffic to EEs. Rerouting the LHR to EEs, or EE-localized GPCRs to pre-EEs, spatially reprograms MAPK signaling. Furthermore, LHR-mediated activation of MAPK signaling requires internalization and is maintained upon loss of the EE compartment. We propose that combinatorial specificity between GPCR sorting sequences and interacting proteins dictates an unprecedented spatiotemporal control in GPCR signal activity.
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Affiliation(s)
- Frederic Jean-Alphonse
- From the Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, London W12 0NN, United Kingdom and
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Andrisse S, Patel GD, Chen JE, Webber AM, Spears LD, Koehler RM, Robinson-Hill RM, Ching JK, Jeong I, Fisher JS. ATM and GLUT1-S490 phosphorylation regulate GLUT1 mediated transport in skeletal muscle. PLoS One 2013; 8:e66027. [PMID: 23776597 PMCID: PMC3679034 DOI: 10.1371/journal.pone.0066027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 05/04/2013] [Indexed: 12/24/2022] Open
Abstract
Objective The glucose and dehydroascorbic acid (DHA) transporter GLUT1 contains a phosphorylation site, S490, for ataxia telangiectasia mutated (ATM). The objective of this study was to determine whether ATM and GLUT1-S490 regulate GLUT1. Research Design and Methods L6 myoblasts and mouse skeletal muscles were used to study the effects of ATM inhibition, ATM activation, and S490 mutation on GLUT1 localization, trafficking, and transport activity. Results In myoblasts, inhibition of ATM significantly diminished cell surface GLUT1, glucose and DHA transport, GLUT1 externalization, and association of GLUT1 with Gα-interacting protein-interacting protein, C-terminus (GIPC1), which has been implicated in recycling of endosomal proteins. In contrast, ATM activation by doxorubicin (DXR) increased DHA transport, cell surface GLUT1, and the GLUT1/GIPC1 association. S490A mutation decreased glucose and DHA transport, cell surface GLUT1, and interaction of GLUT1 with GIPC1, while S490D mutation increased transport, cell surface GLUT1, and the GLUT1/GIPC1 interaction. ATM dysfunction or ATM inhibition reduced DHA transport in extensor digitorum longus (EDL) muscles and decreased glucose transport in EDL and soleus. In contrast, DXR increased DHA transport in EDL. Conclusions These results provide evidence that ATM and GLUT1-S490 promote cell surface GLUT1 and GLUT1-mediated transport in skeletal muscle associated with upregulation of the GLUT1/GIPC1 interaction.
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Affiliation(s)
- Stanley Andrisse
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Gaytri D. Patel
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Joseph E. Chen
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Andrea M. Webber
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Larry D. Spears
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Rikki M. Koehler
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Rona M. Robinson-Hill
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - James K. Ching
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Imju Jeong
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Jonathan S. Fisher
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
- * E-mail:
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24
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Katoh M. Functional proteomics, human genetics and cancer biology of GIPC family members. Exp Mol Med 2013; 45:e26. [PMID: 23743496 PMCID: PMC3701287 DOI: 10.1038/emm.2013.49] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 04/04/2013] [Indexed: 12/24/2022] Open
Abstract
GIPC1, GIPC2 and GIPC3 consist of GIPC homology 1 (GH1) domain, PDZ domain and GH2 domain. The regions around the GH1 and GH2 domains of GIPC1 are involved in dimerization and interaction with myosin VI (MYO6), respectively. The PDZ domain of GIPC1 is involved in interactions with transmembrane proteins [IGF1R, NTRK1, ADRB1, DRD2, TGFβR3 (transforming growth factorβ receptor type III), SDC4, SEMA4C, LRP1, NRP1, GLUT1, integrin α5 and VANGL2], cytosolic signaling regulators (APPL1 and RGS19) and viral proteins (HBc and HPV-18 E6). GIPC1 is an adaptor protein with dimerizing ability that loads PDZ ligands as cargoes for MYO6-dependent endosomal trafficking. GIPC1 is required for cell-surface expression of IGF1R and TGFβR3. GIPC1 is also required for integrin recycling during cell migration, angiogenesis and cytokinesis. On early endosomes, GIPC1 assembles receptor tyrosine kinases (RTKs) and APPL1 for activation of PI3K-AKT signaling, and G protein-coupled receptors (GPCRs) and RGS19 for attenuation of inhibitory Gα signaling. GIPC1 upregulation in breast, ovarian and pancreatic cancers promotes tumor proliferation and invasion, whereas GIPC1 downregulation in cervical cancer with human papillomavirus type 18 infection leads to resistance to cytostatic transforming growth factorβ signaling. GIPC2 is downregulated in acute lymphocytic leukemia owing to epigenetic silencing, while Gipc2 is upregulated in estrogen-induced mammary tumors. Somatic mutations of GIPC2 occur in malignant melanoma, and colorectal and ovarian cancers. Germ-line mutations of the GIPC3 or MYO6 gene cause nonsyndromic hearing loss. As GIPC proteins are involved in trafficking, signaling and recycling of RTKs, GPCRs, integrins and other transmembrane proteins, dysregulation of GIPCs results in human pathologies, such as cancer and hereditary deafness.
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Affiliation(s)
- Masaru Katoh
- Division of Integrative Omics and Bioinformatics, National Cancer Centre, Tokyo, Japan.
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25
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Varsano T, Taupin V, Guo L, Baterina OY, Farquhar MG. The PDZ protein GIPC regulates trafficking of the LPA1 receptor from APPL signaling endosomes and attenuates the cell's response to LPA. PLoS One 2012; 7:e49227. [PMID: 23145131 PMCID: PMC3493537 DOI: 10.1371/journal.pone.0049227] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 10/07/2012] [Indexed: 12/21/2022] Open
Abstract
Lysophosphatidic acid (LPA) mediates diverse cellular responses through the activation of at least six LPA receptors – LPA1–6, but the interacting proteins and signaling pathways that mediate the specificity of these receptors are largely unknown. We noticed that LPA1 contains a PDZ binding motif (SVV) identical to that present in two other proteins that interact with the PDZ protein GIPC. GIPC is involved in endocytic trafficking of several receptors including TrkA, VEGFR2, lutropin and dopamine D2 receptors. Here we show that GIPC binds directly to the PDZ binding motif of LPA1 but not that of other LPA receptors. LPA1 colocalizes and coimmunoprecipitates with GIPC and its binding partner APPL, an activator of Akt signaling found on APPL signaling endosomes. GIPC depletion by siRNA disturbed trafficking of LPA1 to EEA1 early endosomes and promoted LPA1 mediated Akt signaling, cell proliferation, and cell motility. We propose that GIPC binds LPA1 and promotes its trafficking from APPL-containing signaling endosomes to EEA1 early endosomes and thus attenuates LPA-mediated Akt signaling from APPL endosomes.
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Affiliation(s)
- Tal Varsano
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Vanessa Taupin
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Lixia Guo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Oscar Y. Baterina
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Marilyn G. Farquhar
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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Mu Y, Huang H, Liu S, Cai P, Gao Y. Molecular characterization and ligand binding specificity of the PDZ domain-containing protein GIPC3 from Schistosoma japonicum. Parasit Vectors 2012; 5:227. [PMID: 23050840 PMCID: PMC3504512 DOI: 10.1186/1756-3305-5-227] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 10/05/2012] [Indexed: 01/09/2023] Open
Abstract
Background Schistosomiasis is a serious global health problem that afflicts more than 230 million people in 77 countries. Long-term mass treatments with the only available drug, praziquantel, have caused growing concerns about drug resistance. PSD-95/Dlg/ZO-1 (PDZ) domain-containing proteins are recognized as potential targets for the next generation of drug development. However, the PDZ domain-containing protein family in parasites has largely been unexplored. Methods We present the molecular characteristics of a PDZ domain-containing protein, GIPC3, from Schistosoma japonicum (SjGIPC3) according to bioinformatics analysis and experimental approaches. The ligand binding specificity of the PDZ domain of SjGIPC3 was confirmed by screening an arbitrary peptide library in yeast two-hybrid (Y2H) assays. The native ligand candidates were predicted by Tailfit software based on the C-terminal binding specificity, and further validated by Y2H assays. Results SjGIPC3 is a single PDZ domain-containing protein comprised of 328 amino acid residues. Structural prediction revealed that a conserved PDZ domain was presented in the middle region of the protein. Phylogenetic analysis revealed that SjGIPC3 and other trematode orthologues clustered into a well-defined cluster but were distinguishable from those of other phyla. Transcriptional analysis by quantitative RT-PCR revealed that the SjGIPC3 gene was relatively highly expressed in the stages within the host, especially in male adult worms. By using Y2H assays to screen an arbitrary peptide library, we confirmed the C-terminal binding specificity of the SjGIPC3-PDZ domain, which could be deduced as a consensus sequence, -[SDEC]-[STIL]-[HSNQDE]-[VIL]*. Furthermore, six proteins were predicted to be native ligand candidates of SjGIPC3 based on the C-terminal binding properties and other biological information; four of these were confirmed to be potential ligands using the Y2H system. Conclusions In this study, we first characterized a PDZ domain-containing protein GIPC3 in S. japonicum. The SjGIPC3-PDZ domain is able to bind both type I and II ligand C-terminal motifs. The identification of native ligand will help reveal the potential biological function of SjGIPC3. These data will facilitate the identification of novel drug targets against S. japonicum infections.
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Affiliation(s)
- Yi Mu
- National Key Laboratory of Medical Molecular Biology, Dept, of Physiology and Pathophysiology, School of Basic Medicine, Peking Union Medical College, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing 100005, P,R, China
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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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Arey BJ, López FJ. Are circulating gonadotropin isoforms naturally occurring biased agonists? Basic and therapeutic implications. Rev Endocr Metab Disord 2011; 12:275-88. [PMID: 21706143 DOI: 10.1007/s11154-011-9188-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The gonadotropins, luteinizing hormone, human chorionic gonadotropin and follicle-stimulating hormone, are key regulators of reproduction. As a result of this function, they have been the focus of research for many years. Isolated or recombinant proteins have been successfully used therapeutically for the treatment of infertility; and, in the case of compounds that block gonadotropin activity, for their potential utility in contraception. Until recently, selective small molecules modulating gonadotropin receptor activity have proven difficult to identify. The gonadotropins are glycoproteins that are released into the plasma as differently glycosylated isoforms and bind to specific G protein-coupled receptors. The degree of glycosylation on the gonadotropins has been shown to be important for the biological activities of these hormones and is differentially regulated depending on the steroidal status. Recent data from the study of glycosylated variants of LH, hCG and FSH have revealed that these isoforms have distinct signaling properties that allow for gonadotropin pleiotropic signals to be transduced effectively at the level of the receptor. Thus, glycosylated variants of the gonadotropins behave as biased agonists. Recently, newly developed, small molecule, synthetic allosteric compounds have been identified that are capable of mimicking this biased signaling. This opens the door to development of orally available, drug-like therapies for reproductive disorders that offer similar pleiotropic richness as that offered by the complex, endogenous hormones.
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Affiliation(s)
- Brian J Arey
- Metabolic and Cardiovascular Drug Discovery, Research and Development, Bristol-Myers Squibb Co., 311 Pennington-Rocky Hill Rd., Mail Stop- 21-1.08, Hopewell, NJ 08543, USA.
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Kedlaya R, Kandala G, Liu TF, Maddodi N, Devi S, Setaluri V. Interactions between GIPC-APPL and GIPC-TRP1 regulate melanosomal protein trafficking and melanogenesis in human melanocytes. Arch Biochem Biophys 2011; 508:227-33. [PMID: 21291857 DOI: 10.1016/j.abb.2011.01.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 01/23/2011] [Accepted: 01/28/2011] [Indexed: 02/02/2023]
Abstract
By virtue of the presence of multiple protein-protein interaction and signaling domains, PDZ proteins play important roles in assembling protein complexes that participate in diverse cell biological processes. GIPC is a versatile PDZ protein that binds a variety of target proteins in different cell types. In previous studies we showed that, in epidermal melanocytes, GIPC interacts with newly synthesized melanosomal protein TRP1 in the Golgi region and proposed that this interaction may facilitate intracellular trafficking of TRP1. However, since GIPC contains a single PDZ domain and no other known protein interaction motifs, it is not known how GIPC-TRP1 interaction affects melanosome biogenesis and/or melanin pigmentation. Here, we show that in human primary melanocytes GIPC interacts with AKT-binding protein APPL (adaptor protein containing pleckstrin homology, leucine zipper and phosphotyrosine binding domains), which readily co-precipitates with newly synthesized TRP1. Knockdown of either GIPC or APPL inhibits melanogenesis by decreasing tyrosinase protein levels and enzyme activity. In melanocytes, APPL exists in a complex with GIPC and phospho-AKT. Inhibition of AKT phosphorylation using a PI3-kinase inhibitor abolishes this interaction and results in retardation TRP1 in the Golgi. These data suggest that interactions between TRP1-GIPC and GIPC-APPL-AKT provide a potential link between melanogenesis and PI3 kinase signaling.
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Affiliation(s)
- Rajendra Kedlaya
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA
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Romero G, von Zastrow M, Friedman PA. Role of PDZ proteins in regulating trafficking, signaling, and function of GPCRs: means, motif, and opportunity. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 62:279-314. [PMID: 21907913 DOI: 10.1016/b978-0-12-385952-5.00003-8] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PDZ proteins, named for the common structural domain shared by the postsynaptic density protein (PSD95), Drosophila disc large tumor suppressor (DlgA), and zonula occludens-1 protein (ZO-1), constitute a family of 200-300 recognized members. These cytoplasmic adapter proteins are capable of assembling a variety of membrane-associated proteins and signaling molecules in short-lived functional units. Here, we review PDZ proteins that participate in the regulation of signaling, trafficking, and function of G protein-coupled receptors. Salient structural features of PDZ proteins that allow them to recognize targeted GPCRs are considered. Scaffolding proteins harboring PDZ domains may contain single or multiple PDZ modules and may also include other protein-protein interaction modules. PDZ proteins may impact receptor signaling by diverse mechanisms that include retaining the receptor at the cell membrane, thereby increasing the duration of ligand binding, as well as importantly influencing GPCR internalization, trafficking, recycling, and intracellular sorting. PDZ proteins are also capable of modifying the assembled complex of accessory proteins such as β-arrestins that themselves regulate GPCR signaling. Additionally, PDZ proteins may modulate GPCR signaling by altering the G protein to which the receptor binds, or affect other regulatory proteins that impact GTPase activity, protein kinase A, phospholipase C, or modify downstream signaling events. Small molecules targeting the PDZ protein-GPCR interaction are being developed and may become important and selective drug candidates.
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Affiliation(s)
- Guillermo Romero
- Laboratory for G Protein-Coupled Receptor Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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31
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Dias JA, Mahale SD, Nechamen CA, Davydenko O, Thomas RM, Ulloa-Aguirre A. Emerging roles for the FSH receptor adapter protein APPL1 and overlap of a putative 14-3-3τ interaction domain with a canonical G-protein interaction site. Mol Cell Endocrinol 2010; 329:17-25. [PMID: 20600589 PMCID: PMC2946492 DOI: 10.1016/j.mce.2010.05.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 05/20/2010] [Accepted: 05/20/2010] [Indexed: 12/13/2022]
Abstract
The interaction of cytoplasmic proteins with intracellular domains of membrane receptors can occur at several opportunities, including: during biosynthesis, while in membrane residency and during internalization and recycling following ligand binding. Since the initial discovery that it interacts with the FSH receptor (FSHR) together with additional members of a potential signaling complex, APPL1 has been shown to interact with a variety of membrane receptors. Recent subcellular localizations of APPL1 place it in dynamic and varied venues in the cell, including at the cell membrane, the nucleus and the early endosomes. Another adapter protein family the 14-3-3 proteins, are largely recognized as binding to phosphorylation sites but recent work demonstrated that in the case of FSHR, the 14-3-3 site overlaps with the canonical G-protein binding site. G-proteins appear to sample the environment and exchange between the membrane and intracellular locales and this binding could be mediated by or modulated by receptor interactions at the 14-3-3 binding site. Observations that multiple proteins can interact with cytoplasmic domains of GPCRs leads to the inescapable conclusion that either the interactions occur via orderly replacement or exchange, or that receptors are simultaneously occupied by a variety of adapters and effectors or even that oligomers of dimeric GPCRs provide for platforms that can simultaneously interact with effectors and adaptors.
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Affiliation(s)
- James A Dias
- Wadsworth Center, New York State Dept of Health, Albany, NY, United States.
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Kim J, Lee S, Ko S, Kim-Ha J. dGIPC is required for the locomotive activity and longevity in Drosophila. Biochem Biophys Res Commun 2010; 402:565-70. [PMID: 21029723 DOI: 10.1016/j.bbrc.2010.10.095] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 10/20/2010] [Indexed: 11/19/2022]
Abstract
To identify genes that function in the adult neural system, we screened pools of P element-mediated mutants and tested locomotor activity of homozygous flies. Of 1014 P element-mutagenized lines, 638 were homozygous viable. These lines were tested for climbing ability and lifespan. We isolated dGIPC, a Drosophila homolog of GIPC, that produced a 50% premature loss of locomotor activity and a 30% reduction in life span. We found that dGIPC is expressed in the central brain of adult flies, especially in glia and dopaminergic (DA) neurons. Inhibition of dGIPC expression in DA neurons significantly affected climbing ability and survival. In vertebrates, interactions between GIPC with dopamine receptors have been reported. Our findings, together with those obtained from vertebrate models, suggest that DrosophiladGIPC acts in the adult central nervous system and may be required to regulate the trafficking of dopamine receptors needed for proper functioning of dopaminergic neurons.
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Affiliation(s)
- Jihyun Kim
- Department of Molecular Biology, College of Life Sciences, Sejong University, 98 Kunja-Dong, Kwangjin-ku, Seoul 143-747, Republic of Korea
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Klenk C, Vetter T, Zürn A, Vilardaga JP, Friedman PA, Wang B, Lohse MJ. Formation of a ternary complex among NHERF1, beta-arrestin, and parathyroid hormone receptor. J Biol Chem 2010; 285:30355-62. [PMID: 20656684 DOI: 10.1074/jbc.m110.114900] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
β-Arrestins are crucial regulators of G-protein coupled receptor (GPCR) signaling, desensitization, and internalization. Despite the long-standing paradigm that agonist-promoted receptor phosphorylation is required for β-arrestin2 recruitment, emerging evidence suggests that phosphorylation-independent mechanisms play a role in β-arrestin2 recruitment by GPCRs. Several PDZ proteins are known to interact with GPCRs and serve as cytosolic adaptors to modulate receptor signaling and trafficking. Na(+)/H(+) exchange regulatory factors (NHERFs) exert a major role in GPCR signaling. By combining imaging and biochemical and biophysical methods we investigated the interplay among NHERF1, β-arrestin2, and the parathyroid hormone receptor type 1 (PTHR). We show that NHERF1 and β-arrestin2 can independently bind to the PTHR and form a ternary complex in cultured human embryonic kidney cells and Chinese hamster ovary cells. Although NHERF1 interacts constitutively with the PTHR, β-arrestin2 binding is promoted by receptor activation. NHERF1 interacts directly with β-arrestin2 without using the PTHR as an interface. Fluorescence resonance energy transfer studies revealed that the kinetics of PTHR and β-arrestin2 interactions were modulated by NHERF1. These findings suggest a model in which NHERF1 may serve as an adaptor, bringing β-arrestin2 into close proximity to the PTHR, thereby facilitating β-arrestin2 recruitment after receptor activation.
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Affiliation(s)
- Christoph Klenk
- Institute of Pharmacology and Toxicology, University of Würzburg, 97078 Würzburg, Germany
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Wu D, Haruta A, Wei Q. GIPC1 interacts with MyoGEF and promotes MDA-MB-231 breast cancer cell invasion. J Biol Chem 2010; 285:28643-50. [PMID: 20634288 DOI: 10.1074/jbc.m110.107649] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
GIPC1/synectin, a single PDZ domain-containing protein, binds to numerous proteins and is involved in multiple biological processes, including cell migration. We reported previously that MyoGEF, a guanine nucleotide exchange factor, plays a role in regulating breast cancer cell polarization and invasion. Here, we identify GIPC1 as an interacting partner of MyoGEF. Both in vitro and in vivo binding assays show that the GIPC1 PDZ domain binds to the PDZ-binding motif at the C terminus of MyoGEF. Immunofluorescence analysis shows that GIPC1 and MyoGEF colocalize to the cell leading edge. Depletion of GIPC1 by RNAi in MDA-MB-231 cells causes cells to shift from a polarized to a rounded morphology. Matrigel invasion assays show that RNAi-mediated depletion of GIPC1 dramatically decreases MDA-MB-231 cell invasion. Notably, an anti-MyoGEF peptide antibody, whose epitope is located at the C terminus of MyoGEF, interferes with GIPC1-MyoGEF complex formation. Treatment of MDA-MB-231 cells with the anti-MyoGEF peptide antibody disrupts cell polarization and invasion. Thus, our results suggest that GIPC1-MyoGEF complex formation plays an important role in regulating MDA-MB-231 breast cancer cell polarization and invasion.
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Affiliation(s)
- Di Wu
- Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506, USA
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Djiane A, Mlodzik M. The Drosophila GIPC homologue can modulate myosin based processes and planar cell polarity but is not essential for development. PLoS One 2010; 5:e11228. [PMID: 20574526 PMCID: PMC2888583 DOI: 10.1371/journal.pone.0011228] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 06/01/2010] [Indexed: 01/20/2023] Open
Abstract
Epithelia often show, in addition to the ubiquitous apico-basal (A/B) axis, a polarization within the plane of the epithelium, perpendicular to the A/B axis. Such planar cell polarity (PCP) is for example evident in the regular arrangement of the stereocilia in the cochlea of the mammalian inner ear or in (almost) all Drosophila adult external structures. GIPCs (GAIP interacting protein, C terminus) were first identified in mammals and bind to the Gαi GTPase activating protein RGS-GAIP. They have been proposed to act in a G-protein coupled complex controlling vesicular trafficking. Although GIPCs have been found to bind to numerous proteins including Frizzled receptors, which participate in PCP establishment, there is little in vivo evidence for the functional role(s) of GIPCs. We show here that overexpressed Drosophila dGIPC alters PCP generation in the wing. We were however unable to find any binding between dGIPC and the Drosophila receptors Fz1 and Fz2. The effect of overexpressed dGIPC is likely due to an effect on the actin cytoskeleton via myosins, since it is almost entirely suppressed by removing a genomic copy of the Myosin VI/jaguar gene. Surprisingly, although dGIPC can interfere with PCP generation and myosin based processes, the complete loss-of-function of dGIPC gives viable adults with no PCP or other detectable defects arguing for a non-essential role of dGIPC in viability and normal Drosophila development.
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Affiliation(s)
- Alexandre Djiane
- Department of Physiology Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Marek Mlodzik
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, United States of America
- * E-mail:
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Muders MH, Vohra PK, Dutta SK, Wang E, Ikeda Y, Wang L, Udugamasooriya DG, Memic A, Rupasinghe CN, Rupashinghe CN, Baretton GB, Aust DE, Langer S, Datta K, Simons M, Spaller MR, Mukhopadhyay D. Targeting GIPC/synectin in pancreatic cancer inhibits tumor growth. Clin Cancer Res 2009; 15:4095-103. [PMID: 19509165 DOI: 10.1158/1078-0432.ccr-08-2837] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE Various studies have shown the importance of the GAIP interacting protein, COOH-terminus (GIPC, also known as Synectin) as a central adaptor molecule in different signaling pathways and as an important mediator of receptor stability. GIPC/Synectin is associated with different growth-promoting receptors such as insulin-like growth factor receptor I (IGF-IR) and integrins. These interactions were mediated through its PDZ domain. GIPC/Synectin has been shown to be overexpressed in pancreatic and breast cancer. The goal of this study was to show the importance of GIPC/Synectin in pancreatic cancer growth and to evaluate a possible therapeutic strategy by using a GIPC-PDZ domain inhibitor. Furthermore, the effect of targeting GIPC on the IGF-I receptor as one of its associated receptors was tested. EXPERIMENTAL DESIGN The in vivo effects of GIPC/Synectin knockdown were studied after lentiviral transduction of luciferase-expressing pancreatic cancer cells with short hairpin RNA against GIPC/Synectin. Additionally, a GIPC-PDZ--targeting peptide was designed. This peptide was tested for its influence on pancreatic cancer growth in vitro and in vivo. RESULTS Knockdown of GIPC/Synectin led to a significant inhibition of pancreatic adenocarcinoma growth in an orthotopic mouse model. Additionally, a cell-permeable GIPC-PDZ inhibitor was able to block tumor growth significantly without showing toxicity in a mouse model. Targeting GIPC was accompanied by a significant reduction in IGF-IR expression in pancreatic cancer cells. CONCLUSIONS Our findings show that targeting GIPC/Synectin and its PDZ domain inhibits pancreatic carcinoma growth and is a potential strategy for therapeutic intervention of pancreatic cancer.
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Affiliation(s)
- Michael H Muders
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA
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An essential role for the Glut1 PDZ-binding motif in growth factor regulation of Glut1 degradation and trafficking. Biochem J 2009; 418:345-67. [PMID: 19016655 DOI: 10.1042/bj20081422] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cell surface localization of the Glut (glucose transporter), Glut1, is a cytokine-controlled process essential to support the metabolism and survival of haemopoietic cells. Molecular mechanisms that regulate Glut1 trafficking, however, are not certain. In the present study, we show that a C-terminal PDZ-binding motif in Glut1 is critical to promote maximal cytokine-stimulated Glut1 cell surface localization and prevent Glut1 lysosomal degradation in the absence of growth factor. Disruption of this PDZ-binding sequence through deletion or point mutation sharply decreased surface Glut1 levels and led to rapid targeting of internalized Glut1 to lysosomes for proteolysis, particularly in growth factor-deprived cells. The PDZ-domain protein, GIPC (G(alpha)-interacting protein-interacting protein, C-terminus), bound to Glut1 in part via the Glut1 C-terminal PDZ-binding motif, and we found that GIPC deficiency decreased Glut1 surface levels and glucose uptake. Unlike the Glut1 degradation observed on mutation of the Glut1 PDZ-binding domain, however, GIPC deficiency resulted in accumulation of intracellular Glut1 in a pool distinct from the recycling pathway of the TfR (transferrin receptor). Blockade of Glut1 lysosomal targeting after growth factor withdrawal also led to intracellular accumulation of Glut1, a portion of which could be rapidly restored to the cell surface after growth factor stimulation. These results indicate that the C-terminal PDZ-binding motif of Glut1 plays a key role in growth factor regulation of glucose uptake by both allowing GIPC to promote Glut1 trafficking to the cell surface and protecting intracellular Glut1 from lysosomal degradation after growth factor withdrawal, thus allowing the potential for a rapid return of intracellular Glut1 to the cell surface on restimulation.
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38
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Zhang X, Wang F, Chen X, Chen Y, Ma L. Post-endocytic fates of -opioid receptor are regulated by GRK2-mediated receptor phosphorylation and distinct -arrestin isoforms. J Neurochem 2008; 106:781-92. [DOI: 10.1111/j.1471-4159.2008.05431.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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39
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Wang F, Chen X, Zhang X, Ma L. Phosphorylation state of mu-opioid receptor determines the alternative recycling of receptor via Rab4 or Rab11 pathway. Mol Endocrinol 2008; 22:1881-92. [PMID: 18550774 DOI: 10.1210/me.2007-0496] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Agonist-induced phosphorylation, internalization, and intracellular trafficking of G protein-coupled receptors are critical in regulating both cellular responsiveness and signal transduction. The current study investigated the role of receptor phosphorylation state in regulation of agonist-induced internalization and intracellular trafficking of mu-opioid receptor (MOR). Our results showed that after agonist stimulation, the recycle of a mutant MOR that lacks the C-terminal residues after Asn(362) (MOR362T) was greatly decreased, whereas a C-terminal phosphorylation sites-mutated MOR (MOR3A), which is deficient in agonist-induced phosphorylation recycled back to the membrane at a level comparable to that of the wild-type receptor, however, interestingly at a slower rate. Inhibition of functions of either Rab4 or Rab11 by dominant-negative mutants and small interfering RNA both significantly impaired the recycling of the wild-type MOR, whereas the recycling of the phosphorylation-deficient mutant was only inhibited by the dominant-negative mutant and small interfering RNA of Rab11, suggesting that the recycling of nonphosphorylated MOR is exclusively via Rab11-mediated pathway. Furthermore, phosphorylated MOR was observed accumulated in Rab5- and Rab4-, but not Rab11-positive vesicles. Our data indicate that both phosphorylated and nonphosphorylated MOR internalize via Rab5-dependent pathway after agonist stimulation, and the phosphorylated and nonphosphorylated MORs recycle through distinct vesicular trafficking pathways mediated by Rab4 and Rab11, respectively, which may ultimately lead to differential cellular responsiveness or downstream signaling.
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Affiliation(s)
- Feifei Wang
- Pharmacology Research Center, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, People's Republic of China
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40
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Hanyaloglu AC, von Zastrow M. Regulation of GPCRs by endocytic membrane trafficking and its potential implications. Annu Rev Pharmacol Toxicol 2008; 48:537-68. [PMID: 18184106 DOI: 10.1146/annurev.pharmtox.48.113006.094830] [Citation(s) in RCA: 447] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The endocytic pathway tightly controls the activity of G protein-coupled receptors (GPCRs). Ligand-induced endocytosis can drive receptors into divergent lysosomal and recycling pathways, producing essentially opposite effects on the strength and duration of cellular signaling via heterotrimeric G proteins, and may also promote distinct signaling events from intracellular membranes. This chapter reviews recent developments toward understanding the molecular machinery and functional implications of GPCR sorting in the endocytic pathway, focusing on mammalian GPCRs whose ligand-induced endocytosis is mediated primarily by clathrin-coated pits. Lysosomal sorting of a number of GPCRs occurs via a highly conserved mechanism requiring covalent tagging of receptors with ubiquitin. There is increasing evidence that additional, noncovalent mechanisms control the sorting of endocytosed GPCRs to lysosomes in mammalian cells. Recycling of several GPCRs to the plasma membrane is also specifically sorted, via a mechanism requiring both receptor-specific and shared sorting proteins. The current data reveal an unprecedented degree of specificity and plasticity in the cellular regulation of mammalian GPCRs by endocytic membrane trafficking. These developments have fundamental implications for GPCR pharmacology, and suggest new mechanisms that could be exploited in GPCR-directed pharmacotherapy.
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Affiliation(s)
- Aylin C Hanyaloglu
- Institute of Reproductive Biology and Development, Imperial College London, Hammersmith Campus, London, United Kingdom
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41
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Buss F, Kendrick-Jones J. How are the cellular functions of myosin VI regulated within the cell? Biochem Biophys Res Commun 2007; 369:165-75. [PMID: 18068125 PMCID: PMC2635068 DOI: 10.1016/j.bbrc.2007.11.150] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Accepted: 11/22/2007] [Indexed: 12/31/2022]
Abstract
This review, dedicated to the memory of Professor Setsuro Ebashi, focuses on our current work investigating the cellular functions and regulation of the unique unconventional motor, myosin VI. This myosin, unlike all the other myosins so far studied, moves towards the minus end of actin filaments and has been implicated in a wide range of cellular processes such as endocytosis, exocytosis, cell migration, cell division and cytokinesis. Myosin VI’s involvement in these cellular pathways is mediated by its interaction with specific adaptor proteins and is regulated by multiple regulatory signals and modifications such as calcium ions, PtdIns(4,5)P2 (PIP2) and phosphorylation. Understanding the functions of myosin VI within the cell and how it is regulated is now of utmost importance given the recent observations that it is associated with a number of human disorders such as deafness and cancers.
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Affiliation(s)
- Folma Buss
- Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK
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42
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Abstract
The NMDA receptor is an important component of excitatory synapses in the CNS. In addition to its synaptic localization, the NMDA receptor is also present at extrasynaptic sites where it may have functions distinct from those at the synapse. Little is known about how the number, composition, and localization of extrasynaptic receptors are regulated. We identified a novel NMDA receptor-interacting protein, GIPC (GAIP-interacting protein, C terminus), that associates with surface as well as internalized NMDA receptors when expressed in heterologous cells. In neurons, GIPC colocalizes with a population of NMDA receptors on the cell surface, and changes in GIPC expression alter the number of surface receptors. GIPC is mainly excluded from the synapse, and changes in GIPC expression do not change the total number of synaptic receptors. Our results suggest that GIPC may be preferentially associated with extrasynaptic NMDA receptors and may play a role in the organization and trafficking of this population of receptors.
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43
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Kato AS, Zhou W, Milstein AD, Knierman MD, Siuda ER, Dotzlaf JE, Yu H, Hale JE, Nisenbaum ES, Nicoll RA, Bredt DS. New transmembrane AMPA receptor regulatory protein isoform, gamma-7, differentially regulates AMPA receptors. J Neurosci 2007; 27:4969-77. [PMID: 17475805 PMCID: PMC6672084 DOI: 10.1523/jneurosci.5561-06.2007] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AMPA-type glutamate receptors (GluRs) mediate most excitatory signaling in the brain and are composed of GluR principal subunits and transmembrane AMPA receptor regulatory protein (TARP) auxiliary subunits. Previous studies identified four mammalian TARPs, gamma-2 (or stargazin), gamma-3, gamma-4, and gamma-8, that control AMPA receptor trafficking, gating, and pharmacology. Here, we explore roles for the homologous gamma-5 and gamma-7 proteins, which were previously suggested not to serve as TARPs. Western blotting reveals high levels of gamma-5 and gamma-7 in the cerebellum, where gamma-7 is enriched in Purkinje neurons in the molecular layer and glomerular synapses in the granule cell layer. Immunoprecipitation proteomics shows that cerebellar gamma-7 avidly and selectively binds to AMPA receptor GluR subunits and also binds to the AMPA receptor clustering protein, postsynaptic density-95 (PSD-95). Furthermore, gamma-7 occurs together with PSD-95 and AMPA receptor subunits in purified postsynaptic densities. In heterologous cells, gamma-7 but not gamma-5 greatly enhances AMPA receptor glutamate-evoked currents and modulates channel gating. In granule cells from stargazer mice, transfection of gamma-7 but not gamma-5 increases AMPA receptor-mediated currents. Compared with stargazin, gamma-7 differentially modulates AMPA receptor glutamate affinity and kainate efficacy. These studies define gamma-7 as a new member of the TARP family that can differentially influence AMPA receptors in cerebellar neurons.
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Affiliation(s)
| | - Wei Zhou
- Departments of Physiology, and Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, California 94143
| | - Aaron D. Milstein
- Departments of Physiology, and Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, California 94143
| | | | | | | | | | | | | | - Roger A. Nicoll
- Departments of Physiology, and Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, California 94143
| | - David S. Bredt
- Neuroscience Discovery and
- Integrated Biology, Lilly Research Laboratories
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Varsano T, Dong MQ, Niesman I, Gacula H, Lou X, Ma T, Testa JR, Yates JR, Farquhar MG. GIPC is recruited by APPL to peripheral TrkA endosomes and regulates TrkA trafficking and signaling. Mol Cell Biol 2006; 26:8942-52. [PMID: 17015470 PMCID: PMC1636811 DOI: 10.1128/mcb.00305-06] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
GIPC is a PDZ protein located on peripheral endosomes that binds to the juxtamembrane region of the TrkA nerve growth factor (NGF) receptor and has been implicated in NGF signaling. We establish here that endogenous GIPC binds to the C terminus of APPL, a Rab5 binding protein, which is a marker for signaling endosomes. When PC12(615) cells are treated with either NGF or antibody agonists to activate TrkA, GIPC and APPL translocate from the cytoplasm and bind to incoming, endocytic vesicles carrying TrkA concentrated at the tips of the cell processes. GIPC, but not APPL, dissociates from these peripheral endosomes prior to or during their trafficking from the cell periphery to the juxtanuclear region, where they acquire EEA1. GIPC's interaction with APPL is essential for recruitment of GIPC to peripheral endosomes and for TrkA signaling, because a GIPC PDZ domain mutant that cannot bind APPL or APPL knockdown with small interfering RNA inhibits NGF-induced GIPC recruitment, mitogen-activated protein kinase activation, and neurite outgrowth. GIPC is also required for efficient endocytosis and trafficking of TrkA because depletion of GIPC slows down endocytosis and trafficking of TrkA and APPL to the early EEA1 endosomes in the juxtanuclear region. We conclude that GIPC, following its recruitment to TrkA by APPL, plays a key role in TrkA trafficking and signaling from endosomes.
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Affiliation(s)
- Tal Varsano
- Department of Cellular and Molecular Medicine, University of California-San Diego, George Palade Laboratories Room 210, 9500 Gilman Drive, La Jolla, CA 92093-0651, USA
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Wu J, O'Donnell M, Gitler AD, Klein PS. Kermit 2/XGIPC, an IGF1 receptor interacting protein, is required for IGF signaling in Xenopus eye development. Development 2006; 133:3651-60. [PMID: 16914488 DOI: 10.1242/dev.02547] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
GIPC is a PDZ-domain-containing protein identified in vertebrate and invertebrate organisms through its interaction with a variety of binding partners including many membrane proteins. Despite the multiple reports identifying GIPC, its endogenous function and the physiological significance of these interactions are much less studied. We have previously identified the Xenopus GIPC homolog kermit as a frizzled 3 interacting protein that is required for frizzled 3 induction of neural crest in ectodermal explants. We identified a second Xenopus GIPC homolog, named kermit 2 (also recently described as an IGF receptor interacting protein and named XGIPC). Despite its high amino acid similarity with kermit, kermit 2/XGIPC has a distinct function in Xenopus embryos. Loss-of-function analysis indicates that kermit 2/XGIPC is specifically required for Xenopus eye development. Kermit 2/XGIPC functions downstream of IGF in eye formation and is required for maintaining IGF-induced AKT activation. A constitutively active PI3 kinase partially rescues the Kermit 2/XGIPC loss-of-function phenotype. Our results provide the first in vivo loss of function analysis of GIPC in embryonic development and also indicate that kermit 2/XGIPC is a novel component of the IGF pathway, potentially functioning through modulation of the IGF1 receptor.
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Affiliation(s)
- Jinling Wu
- Cell and Molecular Biology Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Galet C, Ascoli M. A constitutively active mutant of the human lutropin receptor (hLHR-L457R) escapes lysosomal targeting and degradation. Mol Endocrinol 2006; 20:2931-45. [PMID: 16803865 PMCID: PMC1626098 DOI: 10.1210/me.2006-0138] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Using biochemical and imaging approaches, we examined the postendocytotic fate of the complex formed by human choriogonadotropin (hCG) and a constitutively active mutant of the human lutropin receptor (hLHR-L457R) found in a boy with precocious puberty and Leydig cell hyperplasia. After internalization, some of the complex formed by the hLHR-wild type (hLHR-wt) and hCG recycles to the cell surface, and some is found in lysosomes where the hormone is degraded. In contrast, the complex formed by the hLHR-L457R and hCG is not routed to the lysosomes, most of it is recycled to the cell surface and hormone degradation is barely detectable. For both, hLHR-wt and -L457R, there is an hCG-induced loss of cell surface receptors that accompanies internalization but this loss cannot be prevented by leupeptin. The removal of recycling motifs of the hLHR by truncation of the C-terminal tail at residue 682 greatly enhances the lysosomal accumulation of the hormone-receptor complexes formed by the hLHR-wt or the L457R mutant, the degradation of the internalized hormone, and the loss of cell surface receptors. The degradation of the hormone internalized by these mutants as well as the loss of cell surface receptors is largely prevented by leupeptin. These results highlight a previously unrecognized complexity in the postendocytotic trafficking of the hLHR and document a clear difference between the properties of the constitutively active mutant and the agonist-activated hLHR-wt. This lack of lysosomal degradation of the L457R mutant could contribute to its constitutive activity by prolonging the duration of signaling.
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Affiliation(s)
- Colette Galet
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, 2-319B Bowen Science Building, 51 Newton Road, Iowa City, Iowa 52242-1109, USA
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Weinman EJ, Hall RA, Friedman PA, Liu-Chen LY, Shenolikar S. The association of NHERF adaptor proteins with g protein-coupled receptors and receptor tyrosine kinases. Annu Rev Physiol 2006; 68:491-505. [PMID: 16460281 DOI: 10.1146/annurev.physiol.68.040104.131050] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The sodium-hydrogen exchanger regulatory factors (NHERF-1 and NHERF-2) are a family of adaptor proteins characterized by the presence of two tandem PDZ protein interaction domains and a C-terminal domain that binds the cytoskeleton proteins ezrin, radixin, moesin, and merlin. The NHERF proteins are highly expressed in the kidney, small intestine, and other organs, where they associate with a number of transporters and ion channels, signaling proteins, and transcription factors. Recent evidence has revealed important associations between the NHERF proteins and several G protein-coupled receptors such as the beta2-adrenergic receptor, the kappa-opioid receptor, and the parathyroid hormone receptor, as well as growth factor tyrosine kinase receptors such as the platelet-derived growth factor receptor and the epidermal growth factor receptor. This review summarizes the emerging data on the biochemical mechanisms, physiologic outcomes, and potential clinical implications of the assembly and disassembly of receptor/NHERF complexes.
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Affiliation(s)
- Edward J Weinman
- Department of Medicine, University of Maryland School of Medicine, and Medical Service, Department of Veterans Affairs Medical Center, Baltimore, Maryland 21201, USA.
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Neitzel KL, Hepler JR. Cellular mechanisms that determine selective RGS protein regulation of G protein-coupled receptor signaling. Semin Cell Dev Biol 2006; 17:383-9. [PMID: 16647283 DOI: 10.1016/j.semcdb.2006.03.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Regulators of G protein signaling (RGS proteins) bind directly to activated Galpha subunits to inhibit their signaling. However, recent findings show that RGS proteins selectively regulate signaling by certain G protein-coupled receptors (GPCRs) in cells, irrespective of the coupled G protein. New studies support an emerging model that suggests RGS proteins utilize both direct and indirect mechanisms to form stable functional pairs with preferred GPCRs to selectively modulate the signaling functions of those receptors and linked G proteins. Here, we discuss these findings and their implications for established models of GPCR signaling.
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Affiliation(s)
- Karen L Neitzel
- Department of Pharmacology, Emory University School of Medicine, G205 Rollins Research Center, 1510 Clifton Road, Atlanta, GA 30322, USA
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Nunn C, Mao H, Chidiac P, Albert PR. RGS17/RGSZ2 and the RZ/A family of regulators of G-protein signaling. Semin Cell Dev Biol 2006; 17:390-9. [PMID: 16765607 DOI: 10.1016/j.semcdb.2006.04.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Regulators of G-protein signaling (RGS proteins) comprise over 20 different proteins that have been classified into subfamilies on the basis of structural homology. The RZ/A family includes RGSZ2/RGS17 (the most recently discovered member of this family), GAIP/RGS19, RGSZ1/RGS20, and the RGSZ1 variant Ret-RGS. The RGS proteins are GTPase activating proteins (GAPs) that turn off G-proteins and thus negatively regulate the signaling of G-protein coupled receptors (GPCRs). In addition, some RZ/A family RGS proteins are able to modify signaling through interactions with adapter proteins (such as GIPC and GIPN). The RZ/A proteins have a simple structure that includes a conserved amino-terminal cysteine string motif, RGS box and short carboxyl-terminal, which confer GAP activity (RGS box) and the ability to undergo covalent modification and interact with other proteins (amino-terminal). This review focuses on RGS17 and its RZ/A sibling proteins and discusses the similarities and differences among these proteins in terms of their palmitoylation, phosphorylation, intracellular localization and interactions with GPCRs and adapter proteins. The specificity of these RGS protein for different Galpha proteins and receptors, and the consequences for signaling are discussed. The tissue and brain distribution, and the evolving understanding of the roles of this family of RGS proteins in receptor signaling and brain function are highlighted.
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Affiliation(s)
- Caroline Nunn
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ont., Canada, N6A 5C1
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Huang H, Gao Y. A method for generation of arbitrary peptide libraries using genomic DNA. Mol Biotechnol 2005; 30:135-42. [PMID: 15920283 DOI: 10.1385/mb:30:2:135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Random peptide libraries can be constructed either by in vitro synthesis of random peptides, or through translation of DNA sequences from synthetic random oligonucleotides. Here we describe an alternative way of making arbitrary peptide libraries with high diversity that can be used in screening as random peptide libraries. Genomic DNA digested with a frequent-cutting restriction enzyme recognizing four nucleotides will theoretically consist of small DNA pieces with average length of 256 nucleotides, and on average around 107 fragments can be generated from a genome of 3 x 109 bases. A peptide library translated from these fragments will have sufficient diversity for some protein interaction screening experiments. Moreover, the same genome digested with a different four-cutter enzyme or ligated into different reading frames will result in different nonoverlapping libraries. A series of such libraries could be generated with genomic DNAs from different species. In this study, human genomic DNA was digested with four-cutter restriction enzymes DpnII and Tsp509I, respectively, and cloned into yeast expression vector pGADT7 to generate arbitrary peptide libraries. These libraries were used in yeast two-hybrid assays to screen for binding motifs of the PDZ domain containing protein synectin. Our results showed that in addition to various native carboxy-terminal tails, synectin could also bind to many artificial ones, some of which contained a consensus sequence--(S/T)XC-COOH.
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Affiliation(s)
- Haiming Huang
- Department of Pathophysiology, National Key Laboratory of Medical Molecular Biology, Proteomics Research Center, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, PR China
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