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Taleski M, Jin M, Chapman K, Taylor K, Winning C, Frank M, Imin N, Djordjevic MA. CEP hormones at the nexus of nutrient acquisition and allocation, root development, and plant-microbe interactions. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:538-552. [PMID: 37946363 PMCID: PMC10773996 DOI: 10.1093/jxb/erad444] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 11/04/2023] [Indexed: 11/12/2023]
Abstract
A growing understanding is emerging of the roles of peptide hormones in local and long-distance signalling that coordinates plant growth and development as well as responses to the environment. C-TERMINALLY ENCODED PEPTIDE (CEP) signalling triggered by its interaction with CEP RECEPTOR 1 (CEPR1) is known to play roles in systemic nitrogen (N) demand signalling, legume nodulation, and root system architecture. Recent research provides further insight into how CEP signalling operates, which involves diverse downstream targets and interactions with other hormone pathways. Additionally, there is emerging evidence of CEP signalling playing roles in N allocation, root responses to carbon levels, the uptake of other soil nutrients such as phosphorus and sulfur, root responses to arbuscular mycorrhizal fungi, plant immunity, and reproductive development. These findings suggest that CEP signalling more broadly coordinates growth across the whole plant in response to diverse environmental cues. Moreover, CEP signalling and function appear to be conserved in angiosperms. We review recent advances in CEP biology with a focus on soil nutrient uptake, root system architecture and organogenesis, and roles in plant-microbe interactions. Furthermore, we address knowledge gaps and future directions in this research field.
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Affiliation(s)
- Michael Taleski
- Division of Plant Sciences, Research School of Biology, College of Science, The Australian National University, Canberra, ACT, 2601Australia
| | - Marvin Jin
- Division of Plant Sciences, Research School of Biology, College of Science, The Australian National University, Canberra, ACT, 2601Australia
| | - Kelly Chapman
- Division of Plant Sciences, Research School of Biology, College of Science, The Australian National University, Canberra, ACT, 2601Australia
| | - Katia Taylor
- CSIRO Agriculture and Food, Canberra, ACT, 2601, Australia
| | - Courtney Winning
- Division of Plant Sciences, Research School of Biology, College of Science, The Australian National University, Canberra, ACT, 2601Australia
| | - Manuel Frank
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Nijat Imin
- School of Science, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - Michael A Djordjevic
- Division of Plant Sciences, Research School of Biology, College of Science, The Australian National University, Canberra, ACT, 2601Australia
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2
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Hsu MF, Ito Y, Singh JP, Hsu SF, Wells A, Jen KY, Meng TC, Haj FG. Protein tyrosine phosphatase 1B is a regulator of alpha-actinin4 in the glomerular podocyte. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119590. [PMID: 37730132 PMCID: PMC11060668 DOI: 10.1016/j.bbamcr.2023.119590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/22/2023]
Abstract
Glomerular podocytes are instrumental for the barrier function of the kidney, and podocyte injury contributes to proteinuria and the deterioration of renal function. Protein tyrosine phosphatase 1B (PTP1B) is an established metabolic regulator, and the inactivation of this phosphatase mitigates podocyte injury. However, there is a paucity of data regarding the substrates that mediate PTP1B actions in podocytes. This study aims to uncover novel substrates of PTP1B in podocytes and validate a leading candidate. To this end, using substrate-trapping and mass spectroscopy, we identified putative substrates of this phosphatase and investigated the actin cross-linking cytoskeletal protein alpha-actinin4. PTP1B and alpha-actinin4 co-localized in murine and human glomeruli and transiently transfected E11 podocyte cells. Additionally, podocyte PTP1B deficiency in vivo and culture was associated with elevated tyrosine phosphorylation of alpha-actinin4. Conversely, reconstitution of the knockdown cells with PTP1B attenuated alpha-actinin4 tyrosine phosphorylation. We demonstrated co-association between alpha-actinin4 and the PTP1B substrate-trapping mutant, which was enhanced upon insulin stimulation and disrupted by vanadate, consistent with an enzyme-substrate interaction. Moreover, we identified alpha-actinin4 tandem tyrosine residues 486/487 as mediators of its interaction with PTP1B. Furthermore, knockdown studies in E11 cells suggest that PTP1B and alpha-actinin4 are modulators of podocyte motility. These observations indicate that PTP1B and alpha-actinin4 are likely interacting partners in a signaling node that modulates podocyte function. Targeting PTP1B and plausibly this one of its substrates may represent a new therapeutic approach for podocyte injury that warrants additional investigation.
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Affiliation(s)
- Ming-Fo Hsu
- Department of Nutrition, University of California Davis, Davis, CA, USA
| | - Yoshihiro Ito
- Department of Nutrition, University of California Davis, Davis, CA, USA
| | - Jai Prakash Singh
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - Shu-Fang Hsu
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - Alan Wells
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Kuang-Yu Jen
- Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, CA, USA
| | - Tzu-Ching Meng
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - Fawaz G Haj
- Department of Nutrition, University of California Davis, Davis, CA, USA; Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, University of California Davis, Sacramento, CA, USA.
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3
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Meroterpenoids with inhibitory activity of PTP1B from the fruits of Psidium guajava. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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4
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Gutiérrez-García L, Arró M, Altabella T, Ferrer A, Boronat A. Structural and functional analysis of tomato sterol C22 desaturase. BMC PLANT BIOLOGY 2021; 21:141. [PMID: 33731007 PMCID: PMC7972189 DOI: 10.1186/s12870-021-02898-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/21/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Sterols are structural and functional components of eukaryotic cell membranes. Plants produce a complex mixture of sterols, among which β-sitosterol, stigmasterol, campesterol, and cholesterol in some Solanaceae, are the most abundant species. Many reports have shown that the stigmasterol to β-sitosterol ratio changes during plant development and in response to stresses, suggesting that it may play a role in the regulation of these processes. In tomato (Solanum lycopersicum), changes in the stigmasterol to β-sitosterol ratio correlate with the induction of the only gene encoding sterol C22-desaturase (C22DES), the enzyme specifically involved in the conversion of β-sitosterol to stigmasterol. However, despite the biological interest of this enzyme, there is still a lack of knowledge about several relevant aspects related to its structure and function. RESULTS In this study we report the subcellular localization of tomato C22DES in the endoplasmic reticulum (ER) based on confocal fluorescence microscopy and cell fractionation analyses. Modeling studies have also revealed that C22DES consists of two well-differentiated domains: a single N-terminal transmembrane-helix domain (TMH) anchored in the ER-membrane and a globular (or catalytic) domain that is oriented towards the cytosol. Although TMH is sufficient for the targeting and retention of the enzyme in the ER, the globular domain may also interact and be retained in the ER in the absence of the N-terminal transmembrane domain. The observation that a truncated version of C22DES lacking the TMH is enzymatically inactive revealed that the N-terminal membrane domain is essential for enzyme activity. The in silico analysis of the TMH region of plant C22DES revealed several structural features that could be involved in substrate recognition and binding. CONCLUSIONS Overall, this study contributes to expand the current knowledge on the structure and function of plant C22DES and to unveil novel aspects related to plant sterol metabolism.
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Affiliation(s)
- Laura Gutiérrez-García
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
| | - Montserrat Arró
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Teresa Altabella
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biology, Healthcare and the Environment, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Albert Ferrer
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Albert Boronat
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain.
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain.
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Acharige NPN, Pflum MKH. l-Lactate Dehydrogenase Identified as a Protein Tyrosine Phosphatase 1B Substrate by Using K-BIPS. Chembiochem 2021; 22:186-192. [PMID: 33002308 PMCID: PMC8104301 DOI: 10.1002/cbic.202000499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/30/2020] [Indexed: 11/10/2022]
Abstract
Kinases and phosphatases are major players in a variety of cellular events, including cell signaling. Aberrant activity or mutations in kinases and phosphatases can lead to diseases such as cancer, diabetes, and Alzheimer's. Compared to kinases, phosphatases are understudied; this is partly a result of the limited methods for identifying substrates. As a solution, we developed a proteomics-based method called kinase-catalyzed biotinylation to identify phosphatase substrates (K-BIPS) that previously identified substrates of Ser/Thr phosphatases using small molecule inhibitors. Here, for the first time, K-BIPS was applied to identify substrates of a tyrosine phosphatase, protein tyrosine phosphatase 1B (PTP1B), under siRNA knockdown conditions. Eight possible substrates of PTP1B were discovered in HEK293 cells, including the known substrate pyruvate kinase. In addition, l-lactate dehydrogenase (LDHA) was validated as a novel PTP1B substrate. With the ability to use knockdown conditions with Ser/Thr or Tyr phosphatases, K-BIPS represents a general discovery tool to explore phosphatases biology by identifying unanticipated substrates.
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Affiliation(s)
- Nuwan P N Acharige
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - Mary Kay H Pflum
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
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6
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Zaman MF, Nenadic A, Radojičić A, Rosado A, Beh CT. Sticking With It: ER-PM Membrane Contact Sites as a Coordinating Nexus for Regulating Lipids and Proteins at the Cell Cortex. Front Cell Dev Biol 2020; 8:675. [PMID: 32793605 PMCID: PMC7387695 DOI: 10.3389/fcell.2020.00675] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/03/2020] [Indexed: 12/31/2022] Open
Abstract
Membrane contact sites between the cortical endoplasmic reticulum (ER) and the plasma membrane (PM) provide a direct conduit for small molecule transfer and signaling between the two largest membranes of the cell. Contact is established through ER integral membrane proteins that physically tether the two membranes together, though the general mechanism is remarkably non-specific given the diversity of different tethering proteins. Primary tethers including VAMP-associated proteins (VAPs), Anoctamin/TMEM16/Ist2p homologs, and extended synaptotagmins (E-Syts), are largely conserved in most eukaryotes and are both necessary and sufficient for establishing ER-PM association. In addition, other species-specific ER-PM tether proteins impart unique functional attributes to both membranes at the cell cortex. This review distils recent functional and structural findings about conserved and species-specific tethers that form ER-PM contact sites, with an emphasis on their roles in the coordinate regulation of lipid metabolism, cellular structure, and responses to membrane stress.
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Affiliation(s)
- Mohammad F Zaman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Aleksa Nenadic
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Ana Radojičić
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.,Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Abel Rosado
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Christopher T Beh
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.,The Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
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Bohnert M. Tether Me, Tether Me Not—Dynamic Organelle Contact Sites in Metabolic Rewiring. Dev Cell 2020; 54:212-225. [DOI: 10.1016/j.devcel.2020.06.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/17/2020] [Accepted: 06/20/2020] [Indexed: 02/04/2023]
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8
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Petit JD, Immel F, Lins L, Bayer EM. Lipids or Proteins: Who Is Leading the Dance at Membrane Contact Sites? FRONTIERS IN PLANT SCIENCE 2019; 10:198. [PMID: 30846999 PMCID: PMC6393330 DOI: 10.3389/fpls.2019.00198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/05/2019] [Indexed: 05/19/2023]
Abstract
Understanding the mode of action of membrane contact sites (MCSs) across eukaryotic organisms at the near-atomic level to infer function at the cellular and tissue levels is a challenge scientists are currently facing. These peculiar systems dedicated to inter-organellar communication are perfect examples of cellular processes where the interplay between lipids and proteins is critical. In this mini review, we underline the link between membrane lipid environment, the recruitment of proteins at specialized membrane domains and the function of MCSs. More precisely, we want to give insights on the crucial role of lipids in defining the specificity of plant endoplasmic reticulum (ER)-plasma membrane (PM) MCSs and we further propose approaches to study them at multiple scales. Our goal is not so much to go into detailed description of MCSs, as there are numerous focused reviews on the subject, but rather try to pinpoint the critical elements defining those structures and give an original point of view by considering the subject from a near-atomic angle with a focus on lipids. We review current knowledge as to how lipids can define MCS territories, play a role in the recruitment and function of the MCS-associated proteins and in turn, how the lipid environment can be modified by proteins.
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Affiliation(s)
- Jules D. Petit
- UMR5200 CNRS, Laboratory of Membrane Biogenesis, University of Bordeaux, Villenave d’Ornon, France
- Laboratoire de Biophysique Moléculaire aux Interfaces, TERRA Research Centre, GX ABT, Université de Liège, Liège, Belgium
| | - Françoise Immel
- UMR5200 CNRS, Laboratory of Membrane Biogenesis, University of Bordeaux, Villenave d’Ornon, France
| | - Laurence Lins
- Laboratoire de Biophysique Moléculaire aux Interfaces, TERRA Research Centre, GX ABT, Université de Liège, Liège, Belgium
| | - Emmanuelle M. Bayer
- UMR5200 CNRS, Laboratory of Membrane Biogenesis, University of Bordeaux, Villenave d’Ornon, France
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9
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Huebinger J, Spindler J, Holl KJ, Koos B. Quantification of protein mobility and associated reshuffling of cytoplasm during chemical fixation. Sci Rep 2018; 8:17756. [PMID: 30532039 PMCID: PMC6288139 DOI: 10.1038/s41598-018-36112-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/14/2018] [Indexed: 01/21/2023] Open
Abstract
To understand cellular functionalities, it is essential to unravel spatio-temporal patterns of molecular distributions and interactions within living cells. The technological progress in fluorescence microscopy now allows in principle to measure these patterns with sufficient spatial resolution. However, high resolution imaging comes with long acquisition times and high phototoxicity. Therefore, physiological live cell imaging is often unfeasible and chemical fixation is employed. Yet, fixation methods have not been rigorously investigated, in terms of pattern preservation, at the resolution at which cells can now be imaged. A key parameter for this is the time required until fixation is complete. During this time, cells are under unphysiological conditions and patterns decay. We demonstrate here that formaldehyde fixation takes more than one hour for cytosolic proteins in cultured cells. Other small aldehydes, glyoxal and acrolein, did not perform better. Associated with this, we found a distinct displacement of proteins and lipids, including their loss from cells. Fixations using glutaraldehyde were faster than four minutes and retained most cytoplasmic proteins. Surprisingly, autofluorescence produced by glutaraldehyde was almost completely absent with supplementary addition of formaldehyde without compromising fixation speed. These findings indicate, which cellular processes can actually be reliably imaged after a certain chemical fixation.
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Affiliation(s)
- Jan Huebinger
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str.11, 44227, Dortmund, Germany.
| | - Jessica Spindler
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str.11, 44227, Dortmund, Germany
| | - Kristin J Holl
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str.11, 44227, Dortmund, Germany
| | - Björn Koos
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str.11, 44227, Dortmund, Germany
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10
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Stallaert W, Brüggemann Y, Sabet O, Baak L, Gattiglio M, Bastiaens PIH. Contact inhibitory Eph signaling suppresses EGF-promoted cell migration by decoupling EGFR activity from vesicular recycling. Sci Signal 2018; 11:11/541/eaat0114. [DOI: 10.1126/scisignal.aat0114] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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11
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Rentero C, Blanco-Muñoz P, Meneses-Salas E, Grewal T, Enrich C. Annexins-Coordinators of Cholesterol Homeostasis in Endocytic Pathways. Int J Mol Sci 2018; 19:E1444. [PMID: 29757220 PMCID: PMC5983649 DOI: 10.3390/ijms19051444] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/09/2018] [Accepted: 05/10/2018] [Indexed: 02/07/2023] Open
Abstract
The spatiotemporal regulation of calcium (Ca2+) storage in late endosomes (LE) and lysosomes (Lys) is increasingly recognized to influence a variety of membrane trafficking events, including endocytosis, exocytosis, and autophagy. Alterations in Ca2+ homeostasis within the LE/Lys compartment are implicated in human diseases, ranging from lysosomal storage diseases (LSDs) to neurodegeneration and cancer, and they correlate with changes in the membrane binding behaviour of Ca2+-binding proteins. This also includes Annexins (AnxA), which is a family of Ca2+-binding proteins participating in membrane traffic and tethering, microdomain organization, cytoskeleton interactions, Ca2+ signalling, and LE/Lys positioning. Although our knowledge regarding the way Annexins contribute to LE/Lys functions is still incomplete, recruitment of Annexins to LE/Lys is greatly influenced by the availability of Annexin bindings sites, including acidic phospholipids, such as phosphatidylserine (PS) and phosphatidic acid (PA), cholesterol, and phosphatidylinositol (4,5)-bisphosphate (PIP2). Moreover, the cytosolic portion of LE/Lys membrane proteins may also, directly or indirectly, determine the recruitment of Annexins to LE. Strikingly, within LE/Lys, AnxA1, A2, A6, and A8 differentially contribute to cholesterol transport along the endocytic route, in particular, cholesterol transfer between LE and other compartments, positioning Annexins at the centre of major pathways mediating cellular cholesterol homeostasis. Underlying mechanisms include the formation of membrane contact sites (MCS) and intraluminal vesicles (ILV), as well as the modulation of LE-cholesterol transporter activity. In this review, we will summarize the current understanding how Annexins contribute to influence LE/Lys membrane transport and associated functions.
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Affiliation(s)
- Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona. 08036 Barcelona. Spain.
| | - Patricia Blanco-Muñoz
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona. 08036 Barcelona. Spain.
| | - Elsa Meneses-Salas
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona. 08036 Barcelona. Spain.
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia.
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona. 08036 Barcelona. Spain.
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain.
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12
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The EphA2 receptor is activated through induction of distinct, ligand-dependent oligomeric structures. Commun Biol 2018; 1:15. [PMID: 30271902 PMCID: PMC6123813 DOI: 10.1038/s42003-018-0017-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/28/2018] [Indexed: 01/19/2023] Open
Abstract
The EphA2 receptor tyrosine kinase is capable of activating multiple diverse signaling pathways with roles in processes such as tissue homeostasis and cancer. EphA2 is known to form activated oligomers in the presence of ephrin-A ligands. Here, we characterize the lateral interactions between full-length EphA2 molecules in the plasma membrane in the presence of three types of ligands (dimeric ephrinA1-Fc, monomeric ephrinA1, and an engineered peptide ligand) as well as in the absence of ligand, using a quantitative FRET technique. The data show that EphA2 forms higher-order oligomers and two different types of dimers that all lead to increased EphA2 tyrosine phosphorylation, which is indicative of increased kinase-dependent signaling. We find that different ligands stabilize conformationally distinct oligomers that are assembled through two different interfaces. Our results suggest that these different oligomeric assemblies could have distinct signaling properties, contributing to the diverse activities of the EphA2 receptor. Deo Singh et al. use Fully Quantified Spectral Imaging-FRET to show that the EphA2 receptor forms dimers or higher order oligomers depending on the type of ligand, and that different ligands stabilize EphA2 dimers through distinct interfaces. These findings may explain how EphA2 activates diverse signaling pathways.
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13
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Caldieri G, Malabarba MG, Di Fiore PP, Sigismund S. EGFR Trafficking in Physiology and Cancer. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2018; 57:235-272. [PMID: 30097778 DOI: 10.1007/978-3-319-96704-2_9] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Signaling from the epidermal growth factor receptor (EGFR) elicits multiple biological responses, including cell proliferation, migration, and survival. Receptor endocytosis and trafficking are critical physiological processes that control the strength, duration, diversification, and spatial restriction of EGFR signaling through multiple mechanisms, which we review in this chapter. These mechanisms include: (i) regulation of receptor density and activation at the cell surface; (ii) concentration of receptors into distinct nascent endocytic structures; (iii) commitment of the receptor to different endocytic routes; (iv) endosomal sorting and postendocytic trafficking of the receptor through distinct pathways, and (v) recycling to restricted regions of the cell surface. We also highlight how communication between organelles controls EGFR activity along the endocytic route. Finally, we illustrate how abnormal trafficking of EGFR oncogenic mutants, as well as alterations of the endocytic machinery, contributes to aberrant EGFR signaling in cancer.
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Affiliation(s)
- Giusi Caldieri
- Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Via Santa Sofia 9/1, 20122, Milan, Italy
- Istituto Europeo di Oncologia, Via Ripamonti 435, 20141, Milan, Italy
| | - Maria Grazia Malabarba
- Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Via Santa Sofia 9/1, 20122, Milan, Italy
- Istituto Europeo di Oncologia, Via Ripamonti 435, 20141, Milan, Italy
| | - Pier Paolo Di Fiore
- Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Via Santa Sofia 9/1, 20122, Milan, Italy
- Istituto Europeo di Oncologia, Via Ripamonti 435, 20141, Milan, Italy
| | - Sara Sigismund
- Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Via Santa Sofia 9/1, 20122, Milan, Italy.
- Istituto Europeo di Oncologia, Via Ripamonti 435, 20141, Milan, Italy.
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Lara JA, Burciaga-Monge A, Chávez A, Revés M, Lavilla R, Arró M, Boronat A, Altabella T, Ferrer A. Identification and Characterization of Sterol Acyltransferases Responsible for Steryl Ester Biosynthesis in Tomato. FRONTIERS IN PLANT SCIENCE 2018; 9:588. [PMID: 29868054 PMCID: PMC5952233 DOI: 10.3389/fpls.2018.00588] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 04/16/2018] [Indexed: 05/17/2023]
Abstract
Steryl esters (SEs) serve as a storage pool of sterols that helps to maintain proper levels of free sterols (FSs) in cell membranes throughout plant growth and development, and participates in the recycling of FSs and fatty acids released from cell membranes in aging tissues. SEs are synthesized by sterol acyltransferases, a family of enzymes that catalyze the transfer of fatty acil groups to the hydroxyl group at C-3 position of the sterol backbone. Sterol acyltransferases are categorized into acyl-CoA:sterol acyltransferases (ASAT) and phospholipid:sterol acyltransferases (PSAT) depending on whether the fatty acyl donor substrate is a long-chain acyl-CoA or a phospolipid. Until now, only Arabidopsis ASAT and PSAT enzymes (AtASAT1 and AtPSAT1) have been cloned and characterized in plants. Here we report the identification, cloning, and functional characterization of the tomato (Solanum lycopersicum cv. Micro-Tom) orthologs. SlPSAT1 and SlASAT1 were able to restore SE to wild type levels in the Arabidopsis psat1-2 and asat1-1 knock-out mutants, respectively. Expression of SlPSAT1 in the psat1-2 background also prevented the toxicity caused by an external supply of mevalonate and the early senescence phenotype observed in detached leaves of this mutant, whereas expression of SlASAT1 in the asat1-1 mutant revealed a clear substrate preference of the tomato enzyme for the sterol precursors cycloartenol and 24-methylene cycloartanol. Subcellular localization studies using fluorescently tagged SlPSAT1 and SlASAT1 proteins revealed that SlPSAT1 localize in cytoplasmic lipid droplets (LDs) while, in contrast to the endoplasmic reticulum (ER) localization of AtASAT1, SlASAT1 resides in the plasma membrane (PM). The possibility that PM-localized SlASAT1 may act catalytically in trans on their sterol substrates, which are presumably embedded in the ER membrane, is discussed. The widespread expression of SlPSAT1 and SlASAT1 genes in different tomato organs together with their moderate transcriptional response to several stresses suggests a dual role of SlPSAT1 and SlASAT1 in tomato plant and fruit development and the adaptive responses to stress. Overall, this study contributes to enlarge the current knowledge on plant sterol acyltransferases and set the basis for further studies aimed at understanding the role of SE metabolism in tomato plant growth and development.
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Affiliation(s)
- Juan A. Lara
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG) (CSIC-IRTA-UAB-UB), Campus Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
- Present address: Juan A. Lara, School of Agritechnological Sciences (Extensión Cuauhtémoc), Autonomous University of Chihuahua, Chihuahua, Mexico
| | - Alma Burciaga-Monge
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG) (CSIC-IRTA-UAB-UB), Campus Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
| | - Angel Chávez
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG) (CSIC-IRTA-UAB-UB), Campus Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
| | - Marc Revés
- Laboratory of Medicinal Chemistry, Institute of Biomedicine University of Barcelona, Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain
| | - Rodolfo Lavilla
- Laboratory of Medicinal Chemistry, Institute of Biomedicine University of Barcelona, Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain
| | - Monserrat Arró
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG) (CSIC-IRTA-UAB-UB), Campus Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain
| | - Albert Boronat
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG) (CSIC-IRTA-UAB-UB), Campus Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Teresa Altabella
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG) (CSIC-IRTA-UAB-UB), Campus Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
- Department of Biology, Healthcare, and the Environment, Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain
- *Correspondence: Teresa Altabella, Albert Ferrer,
| | - Albert Ferrer
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG) (CSIC-IRTA-UAB-UB), Campus Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain
- *Correspondence: Teresa Altabella, Albert Ferrer,
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15
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Nicolas WJ, Grison MS, Bayer EM. Shaping intercellular channels of plasmodesmata: the structure-to-function missing link. JOURNAL OF EXPERIMENTAL BOTANY 2017; 69:91-103. [PMID: 28992136 DOI: 10.1093/jxb/erx225] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Plasmodesmata (PD) are a hallmark of the plant kingdom and a cornerstone of plant biology and physiology, forming the conduits for the cell-to-cell transfer of proteins, RNA and various metabolites, including hormones. They connect the cytosols and endomembranes of cells, which allows enhanced cell-to-cell communication and synchronization. Because of their unique position as intercellular gateways, they are at the frontline of plant defence and signalling and constitute the battleground for virus replication and spreading. The membranous organization of PD is remarkable, where a tightly furled strand of endoplasmic reticulum comes into close apposition with the plasma membrane, the two connected by spoke-like elements. The role of these structural features is, to date, still not completely understood. Recent data on PD seem to point in an unexpected direction, establishing a close parallel between PD and membrane contact sites and defining plasmodesmal membranes as microdomains. However, the implications of this new viewpoint are not fully understood. Aided by available phylogenetic data, this review attempts to reassess the function of the different elements comprising the PD and the relevance of membrane lipid composition and biophysics in defining specialized microdomains of PD, critical for their function.
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Affiliation(s)
- William J Nicolas
- Laboratoire de Biogénèse Membranaire, UMR 5200 CNRS, University of Bordeaux, France
| | - Magali S Grison
- Laboratoire de Biogénèse Membranaire, UMR 5200 CNRS, University of Bordeaux, France
| | - Emmanuelle M Bayer
- Laboratoire de Biogénèse Membranaire, UMR 5200 CNRS, University of Bordeaux, France
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16
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Sorokoumov VN, Shpakov AO. Protein phosphotyrosine phosphatase 1B: Structure, function, role in the development of metabolic disorders and their correction by the enzyme inhibitors. J EVOL BIOCHEM PHYS+ 2017. [DOI: 10.1134/s0022093017040020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Yamashita N, Joshi R, Zhang S, Zhang ZY, Kuruvilla R. Phospho-Regulation of Soma-to-Axon Transcytosis of Neurotrophin Receptors. Dev Cell 2017; 42:626-639.e5. [PMID: 28919207 DOI: 10.1016/j.devcel.2017.08.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 07/07/2017] [Accepted: 08/11/2017] [Indexed: 01/12/2023]
Abstract
Axonal targeting of signaling receptors is essential for neuronal responses to extracellular cues. Here, we report that retrograde signaling by target-derived nerve growth factor (NGF) is necessary for soma-to-axon transcytosis of TrkA receptors in sympathetic neurons, and we define the molecular underpinnings of this positive feedback regulation that enhances neuronal sensitivity to trophic factors. Activated TrkA receptors are retrogradely transported in signaling endosomes from distal axons to cell bodies, where they are inserted on soma surfaces and promote phosphorylation of resident naive receptors, resulting in their internalization. Endocytosed TrkA receptors are then dephosphorylated by PTP1B, an ER-resident protein tyrosine phosphatase, prior to axonal transport. PTP1B inactivation prevents TrkA exit from soma and causes receptor degradation, suggesting a "gatekeeper" mechanism that ensures targeting of inactive receptors to axons to engage with ligand. In mice, PTP1B deletion reduces axonal TrkA levels and attenuates neuron survival and target innervation under limiting NGF (NGF+/-) conditions.
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Affiliation(s)
- Naoya Yamashita
- Department of Biology, Johns Hopkins University, 3400 N. Charles St, 227 Mudd Hall, Baltimore, MD 21218, USA
| | - Rajshri Joshi
- Department of Biology, Johns Hopkins University, 3400 N. Charles St, 227 Mudd Hall, Baltimore, MD 21218, USA
| | - Sheng Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, Robert E. Heine Pharmacy Building, Room 202A, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Zhong-Yin Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, Robert E. Heine Pharmacy Building, Room 202A, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Rejji Kuruvilla
- Department of Biology, Johns Hopkins University, 3400 N. Charles St, 227 Mudd Hall, Baltimore, MD 21218, USA.
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18
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IRE1α links Nck1 deficiency to attenuated PTP1B expression in HepG2 cells. Cell Signal 2017; 36:79-90. [DOI: 10.1016/j.cellsig.2017.04.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/11/2017] [Accepted: 04/23/2017] [Indexed: 12/23/2022]
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19
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Takasugi M, Okada R, Takahashi A, Virya Chen D, Watanabe S, Hara E. Small extracellular vesicles secreted from senescent cells promote cancer cell proliferation through EphA2. Nat Commun 2017; 8:15729. [PMID: 28585531 PMCID: PMC5467215 DOI: 10.1038/ncomms15728] [Citation(s) in RCA: 237] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 04/24/2017] [Indexed: 12/28/2022] Open
Abstract
Cellular senescence prevents the proliferation of cells at risk for neoplastic transformation. However, the altered secretome of senescent cells can promote the growth of the surrounding cancer cells. Although extracellular vesicles (EVs) have emerged as new players in intercellular communication, their role in the function of senescent cell secretome has been largely unexplored. Here, we show that exosome-like small EVs (sEVs) are important mediators of the pro-tumorigenic function of senescent cells. sEV-associated EphA2 secreted from senescent cells binds to ephrin-A1, that is, highly expressed in several types of cancer cells and promotes cell proliferation through EphA2/ephrin-A1 reverse signalling. sEV sorting of EphA2 is increased in senescent cells because of its enhanced phosphorylation resulting from oxidative inactivation of PTP1B phosphatase. Our results demonstrate a novel mechanism of reactive oxygen species (ROS)-regulated cargo sorting into sEVs, which is critical for the potentially deleterious growth-promoting effect of the senescent cell secretome. Although senescent cell secretome can promote the growth of surrounding cancer cells, the role of extracellular vesicles in this process has not been well understood. Here the authors show that ROS increase the sorting of EphA2 into extracellular vesicles in senescent cells, which promotes proliferation of cancer cells.
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Affiliation(s)
- Masaki Takasugi
- Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Ryo Okada
- Division of Cancer Biology, Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo 135-8550, Japan
| | - Akiko Takahashi
- Division of Cancer Biology, Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo 135-8550, Japan
| | - David Virya Chen
- Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Sugiko Watanabe
- Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Eiji Hara
- Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.,Division of Cancer Biology, Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo 135-8550, Japan
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20
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Rodriguez Lanzi C, de Rosas I, Perdicaro DJ, Ponce MT, Martinez L, Miatello RM, Cavagnaro B, Vazquez Prieto MA. Effects of salicylic acid-induced wine rich in anthocyanins on metabolic parameters and adipose insulin signaling in high-fructose fed rats. Int J Food Sci Nutr 2016; 67:969-76. [DOI: 10.1080/09637486.2016.1207060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Hsu MF, Pan KT, Chang FY, Khoo KH, Urlaub H, Cheng CF, Chang GD, Haj FG, Meng TC. S-nitrosylation of endogenous protein tyrosine phosphatases in endothelial insulin signaling. Free Radic Biol Med 2016; 99:199-213. [PMID: 27521458 PMCID: PMC5514559 DOI: 10.1016/j.freeradbiomed.2016.08.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 08/03/2016] [Accepted: 08/09/2016] [Indexed: 01/08/2023]
Abstract
Nitric oxide (NO) exerts its biological function through S-nitrosylation of cellular proteins. Due to the labile nature of this modification under physiological condition, identification of S-nitrosylated residue in enzymes involved in signaling regulation remains technically challenging. The present study investigated whether intrinsic NO produced in endothelium-derived MS-1 cells response to insulin stimulation might target endogenous protein tyrosine phosphatases (PTPs). For this, we have developed an approach using a synthetic reagent that introduces a phenylacetamidyl moiety on S-nitrosylated Cys, followed by detection with anti-phenylacetamidyl Cys (PAC) antibody. Coupling with sequential blocking of free thiols with multiple iodoacetyl-based Cys-reactive chemicals, we employed this PAC-switch method to show that endogenous SHP-2 and PTP1B were S-nitrosylated in MS-1 cells exposed to insulin. The mass spectrometry detected a phenylacetamidyl moiety specifically present on the active-site Cys463 of SHP-2. Focusing on the regulatory role of PTP1B, we showed S-nitrosylation to be the principal Cys reversible redox modification in endothelial insulin signaling. The PAC-switch method in an imaging format illustrated that a pool of S-nitrosylated PTP1B was colocalized with activated insulin receptor to the cell periphery, and that such event was endothelial NO synthase (eNOS)-dependent. Moreover, ectopic expression of the C215S mutant of PTP1B that mimics the active-site Cys215 S-nitrosylated form restored insulin responsiveness in eNOS-ablated cells, which was otherwise insensitive to insulin stimulation. This work not only introduces a new method that explores the role of physiological NO in regulating signal transduction, but also highlights a positive NO effect on promoting insulin responsiveness through S-nitrosylation of PTP1B's active-site Cys215.
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Affiliation(s)
- Ming-Fo Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Kuan-Ting Pan
- Bioanalytical Mass Spectrometry Group, Max Plank Institute for Biophysical Chemistry, Göttingen, Germany
| | - Fan-Yu Chang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, College of Life Sciences, National Taiwan University, Taipei, Taiwan
| | - Kay-Hooi Khoo
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, College of Life Sciences, National Taiwan University, Taipei, Taiwan
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Plank Institute for Biophysical Chemistry, Göttingen, Germany; Bioanalytics Research Group, Department of Clinical Chemistry, University Medical Center, Göttingen, Germany
| | - Ching-Feng Cheng
- Department of Medical Research, Tzu Chi University and Department of Pediatrics, Tzu Chi General Hospital, Hualien, Taiwan; Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Geen-Dong Chang
- Institute of Biochemical Sciences, College of Life Sciences, National Taiwan University, Taipei, Taiwan.
| | - Fawaz G Haj
- Department of Nutrition, University of California Davis, Davis, CA, USA.
| | - Tzu-Ching Meng
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, College of Life Sciences, National Taiwan University, Taipei, Taiwan.
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22
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Ho CM, Paciorek T, Abrash E, Bergmann D. Modulators of Stomatal Lineage Signal Transduction Alter Membrane Contact Sites and Reveal Specialization among ERECTA Kinases. Dev Cell 2016; 38:345-57. [DOI: 10.1016/j.devcel.2016.07.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 05/18/2016] [Accepted: 07/21/2016] [Indexed: 11/29/2022]
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23
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Gallo A, Vannier C, Galli T. Endoplasmic Reticulum-Plasma Membrane Associations:Structures and Functions. Annu Rev Cell Dev Biol 2016; 32:279-301. [PMID: 27298092 DOI: 10.1146/annurev-cellbio-111315-125024] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Inside eukaryotic cells, membrane contact sites (MCSs), regions where two membrane-bound organelles are apposed at less than 30 nm, generate regions of important lipid and calcium exchange. This review principally focuses on the structure and the function of MCSs between the endoplasmic reticulum (ER) and the plasma membrane (PM). Here we describe how tethering structures form and maintain these junctions and, in some instances, participate in their function. We then discuss recent insights into the mechanisms by which specific classes of proteins mediate nonvesicular lipid exchange between the ER and PM and how such phenomena, already known to be crucial for maintaining organelle identity, are also emerging as regulators of cell growth and development.
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Affiliation(s)
- Alessandra Gallo
- Membrane Traffic in Health & Disease Group (INSERM ERL U950), F-75013 Paris, France;
| | - Christian Vannier
- Membrane Traffic in Health & Disease Group (INSERM ERL U950), F-75013 Paris, France;
| | - Thierry Galli
- Membrane Traffic in Health & Disease Group (INSERM ERL U950), F-75013 Paris, France;
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24
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Okeke E, Dingsdale H, Parker T, Voronina S, Tepikin AV. Endoplasmic reticulum-plasma membrane junctions: structure, function and dynamics. J Physiol 2016; 594:2837-47. [PMID: 26939537 DOI: 10.1113/jp271142] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/13/2016] [Indexed: 12/20/2022] Open
Abstract
Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are contact sites between the ER and the PM; the distance between the two organelles in the junctions is below 40 nm and the membranes are connected by protein tethers. A number of molecular tools and technical approaches have been recently developed to visualise, modify and characterise properties of ER-PM junctions. The junctions serve as the platforms for lipid exchange between the organelles and for cell signalling, notably Ca(2+) and cAMP signalling. Vice versa, signalling events regulate the development and properties of the junctions. Two Ca(2+) -dependent mechanisms of de novo formation of ER-PM junctions have been recently described and characterised. The junction-forming proteins and lipids are currently the focus of vigorous investigation. Junctions can be relatively short-lived and simple structures, forming and dissolving on the time scale of a few minutes. However, complex, sophisticated and multifunctional ER-PM junctions, capable of attracting numerous protein residents and other cellular organelles, have been described in some cell types. The road from simplicity to complexity, i.e. the transformation from simple 'nascent' ER-PM junctions to advanced stable multiorganellar complexes, is likely to become an attractive research avenue for current and future junctologists. Another area of considerable research interest is the downstream cellular processes that can be activated by specific local signalling events in the ER-PM junctions. Studies of the cell physiology and indeed pathophysiology of ER-PM junctions have already produced some surprising discoveries, likely to expand with advances in our understanding of these remarkable organellar contact sites.
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Affiliation(s)
- Emmanuel Okeke
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK
| | - Hayley Dingsdale
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK
| | - Tony Parker
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK
| | - Svetlana Voronina
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK
| | - Alexei V Tepikin
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK
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25
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Abstract
Spatiotemporal aspects of protein-tyrosine phosphatase (PTP) activity and interaction partners for many PTPs are elusive. We describe here an elegant and relatively simple method, in situ proximity ligation assay (in situ PLA), which can be used to address these issues. The possibility to detect endogenous unmodified proteins in situ and to visualize individual interactions with spatial resolution is the major advantage of this technique. We provide protocols suitable to monitor association of the transmembrane PTPs PTPRJ/DEP-1/CD148 and PTPRB/VE-PTP with their substrates, the receptor tyrosine kinases FMS-like tyrosine kinase 3 (FLT3/CD135), and Tie2 and vascular endothelial growth factor receptor 2 (VEGFR2), respectively. Detailed description of method development and reagents as well as highlighting of critical factors will enable the reader to apply the method successfully to other PTP-protein interactions.
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26
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González Wusener AE, González Á, Nakamura F, Arregui CO. PTP1B triggers integrin-mediated repression of myosin activity and modulates cell contractility. Biol Open 2015; 5:32-44. [PMID: 26700725 PMCID: PMC4728310 DOI: 10.1242/bio.015883] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cell contractility and migration by integrins depends on precise regulation of protein tyrosine kinase and Rho-family GTPase activities in specific spatiotemporal patterns. Here we show that protein tyrosine phosphatase PTP1B cooperates with β3 integrin to activate the Src/FAK signalling pathway which represses RhoA-myosin-dependent contractility. Using PTP1B null (KO) cells and PTP1B reconstituted (WT) cells, we determined that some early steps following cell adhesion to fibronectin and vitronectin occurred robustly in WT cells, including aggregation of β3 integrins and adaptor proteins, and activation of Src/FAK-dependent signalling at small puncta in a lamellipodium. However, these events were significantly impaired in KO cells. We established that cytoskeletal strain and cell contractility was highly enhanced at the periphery of KO cells compared to WT cells. Inhibition of the Src/FAK signalling pathway or expression of constitutive active RhoA in WT cells induced a KO cell phenotype. Conversely, expression of constitutive active Src or myosin inhibition in KO cells restored the WT phenotype. We propose that this novel function of PTP1B stimulates permissive conditions for adhesion and lamellipodium assembly at the protruding edge during cell spreading and migration. Summary: Here we show that protein tyrosine phosphatase PTP1B cooperates with β3 integrin to transiently repress RhoA-myosin-dependent contractility, stimulating adhesion and lamellipodium assembly during cell spreading and migration.
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Affiliation(s)
- Ana E González Wusener
- IIB-INTECH, Universidad Nacional de San Martín, 1650 San Martín, Buenos Aires, Argentina
| | - Ángela González
- IIB-INTECH, Universidad Nacional de San Martín, 1650 San Martín, Buenos Aires, Argentina
| | - Fumihiko Nakamura
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02445, USA
| | - Carlos O Arregui
- IIB-INTECH, Universidad Nacional de San Martín, 1650 San Martín, Buenos Aires, Argentina
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27
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Fueller J, Egorov MV, Walther KA, Sabet O, Mallah J, Grabenbauer M, Kinkhabwala A. Subcellular Partitioning of Protein Tyrosine Phosphatase 1B to the Endoplasmic Reticulum and Mitochondria Depends Sensitively on the Composition of Its Tail Anchor. PLoS One 2015; 10:e0139429. [PMID: 26431424 PMCID: PMC4592070 DOI: 10.1371/journal.pone.0139429] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 09/14/2015] [Indexed: 01/15/2023] Open
Abstract
The canonical protein tyrosine phosphatase PTP1B is an important regulator of diverse cellular signaling networks. PTP1B has long been thought to exert its influence solely from its perch on the endoplasmic reticulum (ER); however, an additional subpopulation of PTP1B has recently been detected in mitochondria extracted from rat brain tissue. Here, we show that PTP1B’s mitochondrial localization is general (observed across diverse mammalian cell lines) and sensitively dependent on the transmembrane domain length, C-terminal charge and hydropathy of its short (≤35 amino acid) tail anchor. Our electron microscopy of specific DAB precipitation revealed that PTP1B localizes via its tail anchor to the outer mitochondrial membrane (OMM), with fluorescence lifetime imaging microscopy establishing that this OMM pool contributes to the previously reported cytoplasmic interaction of PTP1B with endocytosed epidermal growth factor receptor. We additionally examined the mechanism of PTP1B’s insertion into the ER membrane through heterologous expression of PTP1B’s tail anchor in wild-type yeast and yeast mutants of major conserved ER insertion pathways: In none of these yeast strains was ER targeting significantly impeded, providing in vivo support for the hypothesis of spontaneous membrane insertion (as previously demonstrated in vitro). Further functional elucidation of the newly recognized mitochondrial pool of PTP1B will likely be important for understanding its complex roles in cellular responses to external stimuli, cell proliferation and diseased states.
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Affiliation(s)
- Julia Fueller
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany
- Center for Molecular Biology (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany
| | - Mikhail V. Egorov
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany
- Institute of Anatomy and Cell Biology, Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
| | - Kirstin A. Walther
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany
| | - Ola Sabet
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany
| | - Jana Mallah
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany
| | - Markus Grabenbauer
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany
- Institute of Anatomy and Cell Biology, Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
| | - Ali Kinkhabwala
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany
- * E-mail:
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28
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Fluorescence recovery after photobleaching in material and life sciences: putting theory into practice. Q Rev Biophys 2015; 48:323-87. [PMID: 26314367 DOI: 10.1017/s0033583515000013] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
AbstractFluorescence recovery after photobleaching (FRAP) is a versatile tool for determining diffusion and interaction/binding properties in biological and material sciences. An understanding of the mechanisms controlling the diffusion requires a deep understanding of structure–interaction–diffusion relationships. In cell biology, for instance, this applies to the movement of proteins and lipids in the plasma membrane, cytoplasm and nucleus. In industrial applications related to pharmaceutics, foods, textiles, hygiene products and cosmetics, the diffusion of solutes and solvent molecules contributes strongly to the properties and functionality of the final product. All these systems are heterogeneous, and accurate quantification of the mass transport processes at the local level is therefore essential to the understanding of the properties of soft (bio)materials. FRAP is a commonly used fluorescence microscopy-based technique to determine local molecular transport at the micrometer scale. A brief high-intensity laser pulse is locally applied to the sample, causing substantial photobleaching of the fluorescent molecules within the illuminated area. This causes a local concentration gradient of fluorescent molecules, leading to diffusional influx of intact fluorophores from the local surroundings into the bleached area. Quantitative information on the molecular transport can be extracted from the time evolution of the fluorescence recovery in the bleached area using a suitable model. A multitude of FRAP models has been developed over the years, each based on specific assumptions. This makes it challenging for the non-specialist to decide which model is best suited for a particular application. Furthermore, there are many subtleties in performing accurate FRAP experiments. For these reasons, this review aims to provide an extensive tutorial covering the essential theoretical and practical aspects so as to enable accurate quantitative FRAP experiments for molecular transport measurements in soft (bio)materials.
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Ubiquitination switches EphA2 vesicular traffic from a continuous safeguard to a finite signalling mode. Nat Commun 2015; 6:8047. [PMID: 26292967 PMCID: PMC4560775 DOI: 10.1038/ncomms9047] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/11/2015] [Indexed: 01/15/2023] Open
Abstract
Autocatalytic phosphorylation of receptor tyrosine kinases (RTKs) enables diverse, context-dependent responses to extracellular signals but comes at the price of autonomous, ligand-independent activation. Using a conformational biosensor that reports on the kinase activity of the cell guidance ephrin receptor type-A (EphA2) in living cells, we observe that autonomous EphA2 activation is suppressed by vesicular recycling and dephosphorylation by protein tyrosine phosphatases 1B (PTP1B) near the pericentriolar recycling endosome. This spatial segregation of catalytically superior PTPs from RTKs at the plasma membrane is essential to preserve ligand responsiveness. Ligand-induced clustering, on the other hand, promotes phosphorylation of a c-Cbl docking site and ubiquitination of the receptor, thereby redirecting it to the late endosome/lysosome. We show that this switch from cyclic to unidirectional receptor trafficking converts a continuous suppressive safeguard mechanism into a transient ligand-responsive signalling mode.
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30
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Three-dimensional architecture of extended synaptotagmin-mediated endoplasmic reticulum-plasma membrane contact sites. Proc Natl Acad Sci U S A 2015; 112:E2004-13. [PMID: 25787254 DOI: 10.1073/pnas.1503191112] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The close apposition between the endoplasmic reticulum (ER) and the plasma membrane (PM) plays important roles in Ca(2+) homeostasis, signaling, and lipid metabolism. The extended synaptotagmins (E-Syts; tricalbins in yeast) are ER-anchored proteins that mediate the tethering of the ER to the PM and are thought to mediate lipid transfer between the two membranes. E-Syt cytoplasmic domains comprise a synaptotagmin-like mitochondrial-lipid-binding protein (SMP) domain followed by five C2 domains in E-Syt1 and three C2 domains in E-Syt2/3. Here, we used cryo-electron tomography to study the 3D architecture of E-Syt-mediated ER-PM contacts at molecular resolution. In vitrified frozen-hydrated mammalian cells overexpressing individual E-Syts, in which E-Syt-dependent contacts were by far the predominant contacts, ER-PM distance (19-22 nm) correlated with the amino acid length of the cytosolic region of E-Syts (i.e., the number of C2 domains). Elevation of cytosolic Ca(2+) shortened the ER-PM distance at E-Syt1-dependent contacts sites. E-Syt-mediated contacts displayed a characteristic electron-dense layer between the ER and the PM. These features were strikingly different from those observed in cells exposed to conditions that induce contacts mediated by the stromal interaction molecule 1 (STIM1) and the Ca(2+) channel Orai1 as well as store operated Ca(2+) entry. In these cells the gap between the ER and the PM was spanned by filamentous structures perpendicular to the membranes. Our results define specific ultrastructural features of E-Syt-dependent ER-PM contacts and reveal their structural plasticity, which may impact on the cross-talk between the ER and the PM and the functions of E-Syts in lipid transport between the two bilayers.
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31
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Gomez GA, McLachlan RW, Wu SK, Caldwell BJ, Moussa E, Verma S, Bastiani M, Priya R, Parton RG, Gaus K, Sap J, Yap AS. An RPTPα/Src family kinase/Rap1 signaling module recruits myosin IIB to support contractile tension at apical E-cadherin junctions. Mol Biol Cell 2015; 26:1249-62. [PMID: 25631816 PMCID: PMC4454173 DOI: 10.1091/mbc.e14-07-1223] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Cell-cell adhesion couples the contractile cortices of epithelial cells together, generating tension to support a range of morphogenetic processes. E-cadherin adhesion plays an active role in generating junctional tension by promoting actin assembly and cortical signaling pathways that regulate myosin II. Multiple myosin II paralogues accumulate at mammalian epithelial cell-cell junctions. Earlier, we found that myosin IIA responds to Rho-ROCK signaling to support junctional tension in MCF-7 cells. Although myosin IIB is also found at the zonula adherens (ZA) in these cells, its role in junctional contractility and its mode of regulation are less well understood. We now demonstrate that myosin IIB contributes to tension at the epithelial ZA. Further, we identify a receptor type-protein tyrosine phosphatase alpha-Src family kinase-Rap1 pathway as responsible for recruiting myosin IIB to the ZA and supporting contractile tension. Overall these findings reinforce the concept that orthogonal E-cadherin-based signaling pathways recruit distinct myosin II paralogues to generate the contractile apparatus at apical epithelial junctions.
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Affiliation(s)
- Guillermo A Gomez
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Robert W McLachlan
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Selwin K Wu
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Benjamin J Caldwell
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Elliott Moussa
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Suzie Verma
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Michele Bastiani
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Rashmi Priya
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Robert G Parton
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Katharina Gaus
- UNSW Australia, ARC Centre of Excellence in Advanced Molecular Imaging and Australian Centre for Nanomedicine, Sydney 2052, Australia
| | - Jan Sap
- Université Paris Diderot, Sorbonne Paris Cité, Epigenetics and Cell Fate, UMR 7216 CNRS Bâtiment Lamarck, F-75205 Paris Cedex 13, France
| | - Alpha S Yap
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
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32
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St-Germain JR, Taylor P, Zhang W, Li Z, Ketela T, Moffat J, Neel BG, Trudel S, Moran MF. Differential regulation of FGFR3 by PTPN1 and PTPN2. Proteomics 2014; 15:419-33. [PMID: 25311528 DOI: 10.1002/pmic.201400259] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/04/2014] [Accepted: 10/08/2014] [Indexed: 11/06/2022]
Abstract
Aberrant expression and activation of FGFR3 is associated with disease states including bone dysplasia and malignancies of bladder, cervix, and bone marrow. MS analysis of protein-phosphotyrosine in multiple myeloma cells revealed a prevalent phosphorylated motif, D/EYYR/K, derived from the kinase domain activation loops of tyrosine kinases including FGFR3 corresponding to a recognition sequence of protein-tyrosine phosphatase PTPN1. Knockdown of PTPN1 or the related enzyme PTPN2 by RNAi resulted in ligand-independent activation of FGFR3. Modulation of FGFR3 activation loop phosphorylation by both PTPN1 and PTPN2 was a function of receptor trafficking and phosphotyrosine phosphatase (PTP) compartmentalization. The FGFR3 activation loop motif DYYKK(650) is altered to DYYKE(650) in the oncogenic variant FGFR3(K650E) , and consequently it is constitutively fully activated and unaffected by activation loop phosphorylation. FGFR3(K650E) was nevertheless remarkably sensitive to negative regulation by PTPN1 and PTPN2. This suggests that in addition to modulating FGFR3 phosphorylation, PTPN1 and PTPN2 constrain the kinase domain by fostering an inactive-state. Loss of this constraint in response to ligand or impaired PTPN1/N2 may initiate FGFR3 activation. These results suggest a model wherein PTP expression levels may define conditions that select for ectopic FGFR3 expression and activation during tumorigenesis.
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Affiliation(s)
- Jonathan R St-Germain
- Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, Canada; Department of Molecular Genetics, University of Toronto, Canada
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Apical localization of inositol 1,4,5-trisphosphate receptors is independent of extended synaptotagmins in hepatocytes. PLoS One 2014; 9:e114043. [PMID: 25437447 PMCID: PMC4250053 DOI: 10.1371/journal.pone.0114043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 11/03/2014] [Indexed: 12/12/2022] Open
Abstract
Extended synaptotagmins (E-Syts) are a recently identified family of proteins that tether the endoplasmic reticulum (ER) to the plasma membrane (PM) in part by conferring regulation of cytosolic calcium (Ca2+) at these contact sites (Cell, 2013). However, the mechanism by which E-Syts link this tethering to Ca2+ signaling is unknown. Ca2+ waves in polarized epithelia are initiated by inositol 1,4,5-trisphosphate receptors (InsP3Rs), and these waves begin in the apical region because InsP3Rs are targeted to the ER adjacent to the apical membrane. In this study we investigated whether E-Syts are responsible for this targeting. Primary rat hepatocytes were used as a model system, because a single InsP3R isoform (InsP3R-II) is tethered to the peri-apical ER in these cells. Additionally, it has been established in hepatocytes that the apical localization of InsP3Rs is responsible for Ca2+ waves and secretion and is disrupted in disease states in which secretion is impaired. We found that rat hepatocytes express two of the three identified E-Syts (E-Syt1 and E-Syt2). Individual or simultaneous siRNA knockdown of these proteins did not alter InsP3R-II expression levels, apical localization or average InsP3R-II cluster size. Moreover, apical secretion of the organic anion 5-chloromethylfluorescein diacetate (CMFDA) was not changed in cells lacking E-Syts but was reduced in cells in which cytosolic Ca2+ was buffered. These data provide evidence that E-Syts do not participate in the targeting of InsP3Rs to the apical region. Identifying tethers that bring InsP3Rs to the apical region remains an important question, since mis-targeting of InsP3Rs leads to impaired secretory activity.
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34
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Bakke J, Haj FG. Protein-tyrosine phosphatase 1B substrates and metabolic regulation. Semin Cell Dev Biol 2014; 37:58-65. [PMID: 25263014 DOI: 10.1016/j.semcdb.2014.09.020] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/15/2014] [Accepted: 09/21/2014] [Indexed: 01/19/2023]
Abstract
Metabolic homeostasis requires integration of complex signaling networks which, when deregulated, contribute to metabolic syndrome and related disorders. Protein-tyrosine phosphatase 1B (PTP1B) has emerged as a key regulator of signaling networks that are implicated in metabolic diseases such as obesity and type 2 diabetes. In this review, we examine mechanisms that regulate PTP1B-substrate interaction, enzymatic activity and experimental approaches to identify PTP1B substrates. We then highlight findings that implicate PTP1B in metabolic regulation. In particular, insulin and leptin signaling are discussed as well as recently identified PTP1B substrates that are involved in endoplasmic reticulum stress response, cell-cell communication, energy balance and vesicle trafficking. In summary, PTP1B exhibits exquisite substrate specificity and is an outstanding pharmaceutical target for obesity and type 2 diabetes.
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Affiliation(s)
- Jesse Bakke
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States
| | - Fawaz G Haj
- Department of Nutrition, University of California Davis, One Shields Ave, Davis, CA 95616, United States; Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of California Davis, Sacramento, CA 95817, United States; Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, United States.
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35
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Liu S, Xi Y, Bettaieb A, Matsuo K, Matsuo I, Kulkarni RN, Haj FG. Disruption of protein-tyrosine phosphatase 1B expression in the pancreas affects β-cell function. Endocrinology 2014; 155:3329-38. [PMID: 24956127 PMCID: PMC4138572 DOI: 10.1210/en.2013-2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and energy balance. However, the role of PTP1B in pancreatic endocrine function remains largely unknown. To investigate the metabolic role of pancreatic PTP1B, we generated mice with pancreas PTP1B deletion (panc-PTP1B KO). Mice were fed regular chow or a high-fat diet, and metabolic parameters, insulin secretion and glucose tolerance were determined. On regular chow, panc-PTP1B KO and control mice exhibited comparable glucose tolerance whereas aged panc-PTP1B KO exhibited mild glucose intolerance. Furthermore, high-fat feeding promoted earlier impairment of glucose tolerance and attenuated glucose-stimulated insulin secretion in panc-PTP1B KO mice. The secretory defect in glucose-stimulated insulin secretion was recapitulated in primary islets ex vivo, suggesting that the effects were likely cell-autonomous. At the molecular level, PTP1B deficiency in vivo enhanced basal and glucose-stimulated tyrosyl phosphorylation of EphA5 in islets. Consistently, PTP1B overexpression in the glucose-responsive MIN6 β-cell line attenuated EphA5 tyrosyl phosphorylation, and substrate trapping identified EphA5 as a PTP1B substrate. In summary, these studies identify a novel role for PTP1B in pancreatic endocrine function.
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Affiliation(s)
- Siming Liu
- Nutrition Department (S.L., Y.X., A.B., K.M., I.M., F.G.H.), University of California Davis, Davis, California 95616; Joslin Diabetes Center (R.N.K.), Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215; and Division of Endocrinology, Diabetes and Metabolism (F.G.H.), Department of Internal Medicine, and Comprehensive Cancer Center, University of California Davis, Sacramento, California 95817
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36
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Prinz WA. Bridging the gap: membrane contact sites in signaling, metabolism, and organelle dynamics. ACTA ACUST UNITED AC 2014; 205:759-69. [PMID: 24958771 PMCID: PMC4068136 DOI: 10.1083/jcb.201401126] [Citation(s) in RCA: 295] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Regions of close apposition between two organelles, often referred to as membrane contact sites (MCSs), mostly form between the endoplasmic reticulum and a second organelle, although contacts between mitochondria and other organelles have also begun to be characterized. Although these contact sites have been noted since cells first began to be visualized with electron microscopy, the functions of most of these domains long remained unclear. The last few years have witnessed a dramatic increase in our understanding of MCSs, revealing the critical roles they play in intracellular signaling, metabolism, the trafficking of metabolites, and organelle inheritance, division, and transport.
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Affiliation(s)
- William A Prinz
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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37
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Roda-Navarro P, Bastiaens PI. Dynamic recruitment of protein tyrosine phosphatase PTPD1 to EGF stimulation sites potentiates EGFR activation. PLoS One 2014; 9:e103203. [PMID: 25062045 PMCID: PMC4111557 DOI: 10.1371/journal.pone.0103203] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 06/26/2014] [Indexed: 11/25/2022] Open
Abstract
Balanced activity of protein tyrosine kinases and phosphatases (PTPs) controls tyrosine phosphorylation levels and, consequently, is needed to prevent pathologies like cancer. Phosphatase activity is tightly regulated in space and time. Thus, in order to understand how phospho-tyrosine signalling is regulated, the intracellular dynamics of PTPs should be investigated. Here, we have studied the intracellular dynamics of PTPD1, a FERM (four-point-one, ezrin, radixin, moesin) domain-containing PTP that is over expressed in cancer cells and potentiates EGFR signalling. Whereas PTPD1 was excluded from E-cadherin rich cell-cell adhesions in epithelial cell monolayers, it diffused from the cytoplasm to those membranes in contact with the extracellular medium. Localisation of PTPD1 at the plasma membrane was mediated by its FERM domain and enabled the formation of EGFR/PTPD1-containing signalling complexes that pre-existed at the plasma membrane before EGF stimulation. PTPD1 and EGFR transiently co-localised at EGF stimulation sites until the formation of macropinosomes containing active species of EGFR. Interference of PTPD1 expression caused a decrease in EGFR phosphorylated species at the periphery of the cell. Presented data suggest that the transient formation of dynamic PTPD1/EGFR signalling complexes strengthens EGF signalling by promoting the spatial propagation of EGFR phosphorylated species.
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Affiliation(s)
- Pedro Roda-Navarro
- Department of Immunology, School of Medicine, Complutense University and ‘12 de Octubre’ Health Research Institute, Madrid, Spain
- * E-mail: (PR-N); (PIB)
| | - Philippe I. Bastiaens
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
- * E-mail: (PR-N); (PIB)
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38
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Arregui CO, González Á, Burdisso JE, González Wusener AE. Protein tyrosine phosphatase PTP1B in cell adhesion and migration. Cell Adh Migr 2013; 7:418-23. [PMID: 24104540 DOI: 10.4161/cam.26375] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cell migration requires a highly coordinated interplay between specialized plasma membrane adhesion complexes and the cytoskeleton. Protein phosphorylation/dephosphorylation modifications regulate many aspects of the integrin-cytoskeleton interdependence, including their coupling, dynamics, and organization to support cell movement. The endoplasmic reticulum-bound protein tyrosine phosphatase PTP1B has been implicated as a regulator of cell adhesion and migration. Recent results from our laboratory shed light on potential mechanisms, such as Src/FAK signaling through Rho GTPases and integrin-cytoskeletal coupling.
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Affiliation(s)
- Carlos O Arregui
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH); Universidad Nacional de San Martín; Consejo Nacional de Investigaciones Científicas y Técnicas; Buenos Aires, Argentina
| | - Ángela González
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH); Universidad Nacional de San Martín; Consejo Nacional de Investigaciones Científicas y Técnicas; Buenos Aires, Argentina
| | - Juan E Burdisso
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH); Universidad Nacional de San Martín; Consejo Nacional de Investigaciones Científicas y Técnicas; Buenos Aires, Argentina
| | - Ana E González Wusener
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH); Universidad Nacional de San Martín; Consejo Nacional de Investigaciones Científicas y Técnicas; Buenos Aires, Argentina
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Lisabeth EM, Falivelli G, Pasquale EB. Eph receptor signaling and ephrins. Cold Spring Harb Perspect Biol 2013; 5:5/9/a009159. [PMID: 24003208 DOI: 10.1101/cshperspect.a009159] [Citation(s) in RCA: 281] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Eph receptors are the largest of the RTK families. Like other RTKs, they transduce signals from the cell exterior to the interior through ligand-induced activation of their kinase domain. However, the Eph receptors also have distinctive features. Instead of binding soluble ligands, they generally mediate contact-dependent cell-cell communication by interacting with surface-associated ligands-the ephrins-on neighboring cells. Eph receptor-ephrin complexes emanate bidirectional signals that affect both receptor- and ephrin-expressing cells. Intriguingly, ephrins can also attenuate signaling by Eph receptors coexpressed in the same cell. Additionally, Eph receptors can modulate cell behavior independently of ephrin binding and kinase activity. The Eph/ephrin system regulates many developmental processes and adult tissue homeostasis. Its abnormal function has been implicated in various diseases, including cancer. Thus, Eph receptors represent promising therapeutic targets. However, more research is needed to better understand the many aspects of their complex biology that remain mysterious.
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Affiliation(s)
- Erika M Lisabeth
- Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA
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40
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Bettaieb A, Bakke J, Nagata N, Matsuo K, Xi Y, Liu S, AbouBechara D, Melhem R, Stanhope K, Cummings B, Graham J, Bremer A, Zhang S, Lyssiotis CA, Zhang ZY, Cantley LC, Havel PJ, Haj FG. Protein tyrosine phosphatase 1B regulates pyruvate kinase M2 tyrosine phosphorylation. J Biol Chem 2013; 288:17360-71. [PMID: 23640882 PMCID: PMC3682537 DOI: 10.1074/jbc.m112.441469] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 04/24/2013] [Indexed: 11/06/2022] Open
Abstract
Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and adiposity and is a drug target for the treatment of obesity and diabetes. Here we identify pyruvate kinase M2 (PKM2) as a novel PTP1B substrate in adipocytes. PTP1B deficiency leads to increased PKM2 total tyrosine and Tyr(105) phosphorylation in cultured adipocytes and in vivo. Substrate trapping and mutagenesis studies identify PKM2 Tyr-105 and Tyr-148 as key sites that mediate PTP1B-PKM2 interaction. In addition, in vitro analyses illustrate a direct effect of Tyr-105 phosphorylation on PKM2 activity in adipocytes. Importantly, PTP1B pharmacological inhibition increased PKM2 Tyr-105 phosphorylation and decreased PKM2 activity. Moreover, PKM2 Tyr-105 phosphorylation is regulated nutritionally, decreasing in adipose tissue depots after high-fat feeding. Further, decreased PKM2 Tyr-105 phosphorylation correlates with the development of glucose intolerance and insulin resistance in rodents, non-human primates, and humans. Together, these findings identify PKM2 as a novel substrate of PTP1B and provide new insights into the regulation of adipose PKM2 activity.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kimber Stanhope
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - Bethany Cummings
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - James Graham
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - Andrew Bremer
- the Department of Pediatrics, Vanderbilt University, Nashville, Tennessee 37232
| | - Sheng Zhang
- the Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202
| | - Costas A. Lyssiotis
- the Beth Israel Deaconess Medical Center, Department of Medicine, and
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Zhong-Yin Zhang
- the Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202
| | - Lewis C. Cantley
- the Beth Israel Deaconess Medical Center, Department of Medicine, and
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Peter J. Havel
- From the Nutrition Department and
- Department of Molecular Biosciences, University of California Davis, Davis, California 95616
| | - Fawaz G. Haj
- From the Nutrition Department and
- the Department of Internal Medicine and
- Comprehensive Cancer Center, University of California Davis, Sacramento, California 95817
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41
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Stefan CJ, Manford AG, Emr SD. ER-PM connections: sites of information transfer and inter-organelle communication. Curr Opin Cell Biol 2013; 25:434-42. [PMID: 23522446 DOI: 10.1016/j.ceb.2013.02.020] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 02/25/2013] [Accepted: 02/28/2013] [Indexed: 11/18/2022]
Abstract
Eukaryotic cells are divided into distinct membrane-bound organelles with unique identities and specialized metabolic functions. Communication between organelles must take place to regulate the size, shape, and composition of individual organelles, as well as to coordinate transport between organelles. The endoplasmic reticulum (ER) forms an expansive membrane network that contacts and participates in crosstalk with several other organelles in the cell, most notably the plasma membrane (PM). ER-PM junctions have well-established functions in the movement of small molecules, such as lipids and ions, between the ER and PM. Recent discoveries have revealed additional exciting roles for ER-PM junctions in the regulation of cell signaling, ER shape and architecture, and PM domain organization.
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Affiliation(s)
- Christopher J Stefan
- Weill Institute for Cell & Molecular Biology, Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY 14853, United States.
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42
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The nucleus- and endoplasmic reticulum-targeted forms of protein tyrosine phosphatase 61F regulate Drosophila growth, life span, and fecundity. Mol Cell Biol 2013; 33:1345-56. [PMID: 23339871 DOI: 10.1128/mcb.01411-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The protein tyrosine phosphatases (PTPs) T cell PTP (TCPTP) and PTP1B share a high level of catalytic domain sequence and structural similarity yet display distinct differences in substrate recognition and function. Their noncatalytic domains contribute to substrate selectivity and function by regulating TCPTP nucleocytoplasmic shuttling and targeting PTP1B to the endoplasmic reticulum (ER). The Drosophila TCPTP/PTP1B orthologue PTP61F has two variants with identical catalytic domains that are differentially targeted to the ER and nucleus. Here we demonstrate that the PTP61F variants differ in their ability to negatively regulate insulin signaling in vivo, with the nucleus-localized form (PTP61Fn) being more effective than the ER-localized form (PTP61Fm). We report that PTP61Fm is reliant on the adaptor protein Dock to attenuate insulin signaling in vivo. Also, we show that the PTP61F variants differ in their capacities to regulate growth, with PTP61Fn but not PTP61Fm attenuating cellular proliferation. Furthermore, we generate a mutant lacking both PTP61F variants, which displays a reduction in median life span and a decrease in female fecundity, and show that both variants are required to rescue these mutant phenotypes. Our findings define the role of PTP61F in life span and fecundity and reinforce the importance of subcellular localization in mediating PTP function in vivo.
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Burdisso JE, González Á, Arregui CO. PTP1B promotes focal complex maturation, lamellar persistence and directional migration. J Cell Sci 2013; 126:1820-31. [DOI: 10.1242/jcs.118828] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Previous findings established that ER-bound PTP1B targets peripheral cell-matrix adhesions and regulates positively cell adhesion to fibronectin. Here we show that PTP1B enhances focal complex lifetime at the lamellipodium base, delaying their turnover and facilitating α-actinin incorporation. We demonstrate the presence of catalytic PTP1BD181A-α-actinin complexes at focal complexes. Kymograph analysis reveals that PTP1B contributes to lamellar protrusion persistence and directional cell migration. Pull down and FRET analysis also shows that PTP1B is required for efficient integrin-dependent downregulation of RhoA and upregulation of Rac1 during spreading. A substrate trap strategy revealed that FAK/Src recruitment and Src activity were essential for the generation of PTP1B substrates in adhesions. PTP1B targets the negative regulatory site of Src (phosphotyrosine 529), paxillin and p130Cas at peripheral cell-matrix adhesions. We postulate that PTP1B modulates more than one pathway required for focal complex maturation and membrane protrusion, including α-actinin-mediated cytoskeletal anchorage, integrin-dependent activation of the FAK/Src signaling pathway, and RhoA and Rac1 GTPase activity. By doing so, PTP1B contributes to coordinate adhesion turnover, lamellar stability and directional cell migration.
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Berdnikovs S, Abdala-Valencia H, Cook-Mills JM. Endothelial cell PTP1B regulates leukocyte recruitment during allergic inflammation. Am J Physiol Lung Cell Mol Physiol 2012; 304:L240-9. [PMID: 23275627 DOI: 10.1152/ajplung.00375.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary eosinophilia is a consistent hallmark of allergic lung inflammation. Infiltration of eosinophils into ovalbumin (OVA)-challenged lungs is dependent on the adhesion molecule vascular cell adhesion molecule-1 (VCAM-1) on endothelial cells. Ligation of VCAM-1 activates endothelial cell protein tyrosine phosphatase 1B (PTP1B), which is required for VCAM-1-dependent leukocyte migration in vitro. To examine whether nonhematopoietic PTP1B modulates eosinophil recruitment in vivo, mice deficient in PTP1B were irradiated and received wild-type hematopoietic cells to generate chimeric PTP1B-/- mice. In response to OVA challenge, the chimeric PTP1B-/- mice had reduced eosinophilia in the lung tissue and bronchoalveolar lavage, indicating a role for PTP1B in nonhematopoietic cells during leukocyte recruitment. To determine whether endothelial cell PTP1B modulates eosinophil recruitment, mice with an inducible endothelial cell-specific PTP1B deletion (iePTP1B mice) were generated and the PTP1B deletion was induced after antigen sensitization before antigen challenge. In response to OVA challenge, the iePTP1B mice with the endothelial cell PTP1B deletion had an increased accumulation of eosinophils bound to the luminal surface of the endothelium in the lung vasculature and had a decrease in leukocyte recruitment into the lung tissue. In the iePTP1B mice, expression of adhesion molecules, cytokines, or chemokines that regulate leukocyte recruitment during inflammation was not altered, consistent with other studies that deletion of endothelial adhesion molecule signals does not alter lung cytokines and chemokines. In summary, these data suggest that VCAM-1 activation of PTP1B in the endothelium is necessary for eosinophil recruitment during allergic inflammation. Moreover, these studies provide a basis for targeting VCAM-1-dependent signaling pathways in allergy therapies.
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Affiliation(s)
- Sergejs Berdnikovs
- Division of Allergy and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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