51
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Gönczi M, Dienes B, Dobrosi N, Fodor J, Balogh N, Oláh T, Csernoch L. Septins, a cytoskeletal protein family, with emerging role in striated muscle. J Muscle Res Cell Motil 2020; 42:251-265. [PMID: 31955380 PMCID: PMC8332580 DOI: 10.1007/s10974-020-09573-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/06/2020] [Indexed: 12/15/2022]
Abstract
Appropriate organization of cytoskeletal components are required for normal distribution and intracellular localization of different ion channels and proteins involved in calcium homeostasis, signal transduction, and contractile function of striated muscle. Proteins of the contractile system are in direct or indirect connection with the extrasarcomeric cytoskeleton. A number of other molecules which have essential role in regulating stretch-, voltage-, and chemical signal transduction from the surface into the cytoplasm or other intracellular compartments are already well characterized. Sarcomere, the basic contractile unit, is comprised of a precisely organized system of thin (actin), and thick (myosin) filaments. Intermediate filaments connect the sarcomeres and other organelles (mitochondria and nucleus), and are responsible for the cellular integrity. Interacting proteins have a very diverse function in coupling of the intracellular assembly components and regulating the normal physiological function. Despite the more and more intense investigations of a new cytoskeletal protein family, the septins, only limited information is available regarding their expression and role in striated, especially in skeletal muscles. In this review we collected basic and specified knowledge regarding this protein group and emphasize the importance of this emerging field in skeletal muscle biology.
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Affiliation(s)
- Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Nóra Dobrosi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - János Fodor
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Norbert Balogh
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary.,Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Tamás Oláh
- Center of Experimental Orthopaedics, Saarland University, 66421, Homburg, Saar, Germany
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary.
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Abstract
Class XVIII myosins represent a branch of the myosin family tree characterized by the presence of large N- and C-terminal extensions flanking a generic myosin core. These myosins display the highest sequence similarity to conventional class II muscle myosins and are compatible with but not restricted to myosin-2 contractile structures. Instead, they fulfill their functions at diverse localities, such as lamella, actomyosin bundles, the Golgi apparatus, focal adhesions, the cell membrane, and within sarcomeres. Sequence comparison of active-site residues and biochemical data available thus far indicate that this myosin class lacks active ATPase-driven motor activity, suggesting that its members function as structural myosins. An emerging body of evidence indicates that this structural capability is essential for the organization, maturation, and regulation of the contractile machinery in both muscle and nonmuscle cells. This is supported by the clear association of myosin-18A (Myo18A) and myosin-18B (Myo18B) dysregulation with diseases such as cancer and various myopathies.
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53
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Cifrová P, Oulehlová D, Kollárová E, Martinek J, Rosero A, Žárský V, Schwarzerová K, Cvrčková F. Division of Labor Between Two Actin Nucleators-the Formin FH1 and the ARP2/3 Complex-in Arabidopsis Epidermal Cell Morphogenesis. FRONTIERS IN PLANT SCIENCE 2020; 11:148. [PMID: 32194585 PMCID: PMC7061858 DOI: 10.3389/fpls.2020.00148] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 01/30/2020] [Indexed: 05/11/2023]
Abstract
The ARP2/3 complex and formins are the only known plant actin nucleators. Besides their actin-related functions, both systems also modulate microtubule organization and dynamics. Loss of the main housekeeping Arabidopsis thaliana Class I membrane-targeted formin FH1 (At3g25500) is known to increase cotyledon pavement cell lobing, while mutations affecting ARP2/3 subunits exhibit an opposite effect. Here we examine the role of FH1 and the ARP2/3 complex subunit ARPC5 (At4g01710) in epidermal cell morphogenesis with focus on pavement cells and trichomes using a model system of single fh1 and arpc5, as well as double fh1 arpc5 mutants. While cotyledon pavement cell shape in double mutants mostly resembled single arpc5 mutants, analysis of true leaf epidermal morphology, as well as actin and microtubule organization and dynamics, revealed a more complex relationship between the two systems and similar, rather than antagonistic, effects on some parameters. Both fh1 and arpc5 mutations increased actin network density and increased cell shape complexity in pavement cells and trichomes of first true leaves, in contrast to cotyledons. Thus, while the two actin nucleation systems have complementary roles in some aspects of cell morphogenesis in cotyledon pavement cells, they may act in parallel in other cell types and developmental stages.
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Affiliation(s)
- Petra Cifrová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Denisa Oulehlová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Eva Kollárová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Jan Martinek
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Amparo Rosero
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Kateřina Schwarzerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
- *Correspondence: Fatima Cvrčková,
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54
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Diaz U, Bergman ZJ, Johnson BM, Edington AR, de Cruz MA, Marshall WF, Riggs B. Microtubules are necessary for proper Reticulon localization during mitosis. PLoS One 2019; 14:e0226327. [PMID: 31877164 PMCID: PMC6932760 DOI: 10.1371/journal.pone.0226327] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 11/25/2019] [Indexed: 01/04/2023] Open
Abstract
During mitosis, the structure of the Endoplasmic Reticulum (ER) displays a dramatic reorganization and remodeling, however, the mechanism driving these changes is poorly understood. Hairpin-containing ER transmembrane proteins that stabilize ER tubules have been identified as possible factors to promote these drastic changes in ER morphology. Recently, the Reticulon and REEP family of ER shaping proteins have been shown to heavily influence ER morphology by driving the formation of ER tubules, which are known for their close proximity with microtubules. Here, we examine the role of microtubules and other cytoskeletal factors in the dynamics of a Drosophila Reticulon, Reticulon-like 1 (Rtnl1), localization to spindle poles during mitosis in the early embryo. At prometaphase, Rtnl1 is enriched to spindle poles just prior to the ER retention motif KDEL, suggesting a possible recruitment role for Rtnl1 in the bulk localization of ER to spindle poles. Using image analysis-based methods and precise temporal injections of cytoskeletal inhibitors in the early syncytial Drosophila embryo, we show that microtubules are necessary for proper Rtnl1 localization to spindles during mitosis. Lastly, we show that astral microtubules, not microfilaments, are necessary for proper Rtnl1 localization to spindle poles, and is largely independent of the minus-end directed motor protein dynein. This work highlights the role of the microtubule cytoskeleton in Rtnl1 localization to spindles during mitosis and sheds light on a pathway towards inheritance of this major organelle.
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Affiliation(s)
- Ulises Diaz
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- Department of Biochemistry & Biophysics, UCSF Mission Bay, San Francisco, California, United States of America
| | - Zane J. Bergman
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Brittany M. Johnson
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Alia R. Edington
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Matthew A. de Cruz
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Wallace F. Marshall
- Department of Biochemistry & Biophysics, UCSF Mission Bay, San Francisco, California, United States of America
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- * E-mail:
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55
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Vajente N, Norante R, Redolfi N, Daga A, Pizzo P, Pendin D. Microtubules Stabilization by Mutant Spastin Affects ER Morphology and Ca 2+ Handling. Front Physiol 2019; 10:1544. [PMID: 31920731 PMCID: PMC6933510 DOI: 10.3389/fphys.2019.01544] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 12/05/2019] [Indexed: 01/21/2023] Open
Abstract
The endoplasmic reticulum (ER) extends as a network of interconnected tubules and sheet-like structures in eukaryotic cells. ER tubules dynamically change their morphology and position within the cells in response to physiological stimuli and these network rearrangements depend on the microtubule (MT) cytoskeleton. Store-operated calcium entry (SOCE) relies on the repositioning of ER tubules to form specific ER-plasma membrane junctions. Indeed, the tips of polymerizing MTs are supposed to provide the anchor for ER tubules to move toward the plasma membrane, however the precise role of the cytoskeleton during SOCE has not been conclusively clarified. Here we exploit an in vivo approach involving the manipulation of MT dynamics in Drosophila melanogaster by neuronal expression of a dominant-negative variant of the MT-severing protein spastin to induce MT hyper-stabilization. We show that MT stabilization alters ER morphology, favoring an enrichment in ER sheets at the expense of tubules. Stabilizing MTs has a negative impact on the process of SOCE and results in a reduced ER Ca2+ content, affecting the flight ability of the flies. Restoring proper MT organization by administering the MT-destabilizing drug vinblastine, chronically or acutely, rescues ER morphology, SOCE and flight ability, indicating that MT dynamics impairment is responsible for all the phenotypes observed.
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Affiliation(s)
- Nicola Vajente
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Rosa Norante
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Andrea Daga
- Laboratory of Molecular Biology, Scientific Institute IRCCS E. Medea, Lecco, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Neuroscience Institute-Italian National Research Council (CNR), Padua, Italy
| | - Diana Pendin
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Neuroscience Institute-Italian National Research Council (CNR), Padua, Italy
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56
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Weeber F, Becher A, Seibold T, Seufferlein T, Eiseler T. Concerted regulation of actin polymerization during constitutive secretion by cortactin and PKD2. J Cell Sci 2019; 132:jcs.232355. [PMID: 31727638 DOI: 10.1242/jcs.232355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 11/07/2019] [Indexed: 12/27/2022] Open
Abstract
Constitutive secretion from the trans-Golgi-network (TGN) is facilitated by a concerted regulation of vesicle biogenesis and fission processes. The protein kinase D family (PKD) has been previously described to enhance vesicle fission by modifying the lipid environment. PKD also phosphorylates the actin regulatory protein cortactin at S298 to impair synergistic actin polymerization. We here report additional functions for PKD2 (also known as PRKD2) and cortactin in the regulation of actin polymerization during the fission of transport carriers from the TGN. Phosphorylation of cortactin at S298 impairs the interaction between WIP (also known as WIPF1) and cortactin. WIP stabilizes the autoinhibited conformation of N-WASP (also known as WASL). This leads to an inhibition of synergistic Arp2/3-complex-dependent actin polymerization at the TGN. PKD2 activity at the TGN is controlled by active CDC42-GTP which directly activates N-WASP, inhibits PKD2 and shifts the balance to non-S298-phosphorylated cortactin, which can in turn sequester WIP from N-WASP. Consequently, synergistic actin polymerization at the TGN and constitutive secretion are enhanced.
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Affiliation(s)
- Florian Weeber
- Department of Internal Medicine I, Ulm University, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Alexander Becher
- Department of Internal Medicine I, Ulm University, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Tanja Seibold
- Department of Internal Medicine I, Ulm University, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Thomas Seufferlein
- Department of Internal Medicine I, Ulm University, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Tim Eiseler
- Department of Internal Medicine I, Ulm University, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
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57
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Ravichandran Y, Goud B, Manneville JB. The Golgi apparatus and cell polarity: Roles of the cytoskeleton, the Golgi matrix, and Golgi membranes. Curr Opin Cell Biol 2019; 62:104-113. [PMID: 31751898 DOI: 10.1016/j.ceb.2019.10.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/02/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022]
Abstract
Membrane trafficking plays a crucial role in cell polarity by directing lipids and proteins to specific subcellular locations in the cell and sustaining a polarized state. The Golgi apparatus, the master organizer of membrane trafficking, can be subdivided into three layers that play different mechanical roles: a cytoskeletal layer, the so-called Golgi matrix, and the Golgi membranes. First, the outer regions of the Golgi apparatus interact with cytoskeletal elements, mainly actin and microtubules, which shape, position, and orient the organelle. Closer to the Golgi membranes, a matrix of long coiled-coiled proteins not only selectively captures transport intermediates but also participates in signaling events during polarization of membrane trafficking. Finally, the Golgi membranes themselves serve as active signaling platforms during cell polarity events. We review here the recent findings that link the Golgi apparatus to cell polarity, focusing on the roles of the cytoskeleton, the Golgi matrix, and the Golgi membranes.
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Affiliation(s)
- Yamini Ravichandran
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm F-75005, Paris, France; Sorbonne Université, UPMC University Paris 06, CNRS, UMR 144, 26 rue d'Ulm F-75005, Paris, France; Institut Pasteur, CNRS, UMR 3691, 25 rue du Docteur Roux F-75014, Paris, France
| | - Bruno Goud
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm F-75005, Paris, France; Sorbonne Université, UPMC University Paris 06, CNRS, UMR 144, 26 rue d'Ulm F-75005, Paris, France
| | - Jean-Baptiste Manneville
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm F-75005, Paris, France; Sorbonne Université, UPMC University Paris 06, CNRS, UMR 144, 26 rue d'Ulm F-75005, Paris, France.
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58
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Ma J, Williams J, Eastwood D, Lin S, Qian X, Fang Q, Cope D, Yuan Z, Cao L, An J. High-dose Propofol Anesthesia Reduces the Occurrence of Postoperative Cognitive Dysfunction via Maintaining Cytoskeleton. Neuroscience 2019; 421:136-143. [PMID: 31682819 DOI: 10.1016/j.neuroscience.2019.09.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/15/2022]
Abstract
Postoperative cognitive dysfunction (POCD) is a common postoperative complication observed in patients following. Here we tested the molecular mechanisms of memory loss in hippocampus of rat POCD model. We found that high-dose propofol anesthesia significantly alleviated spatial memory loss. The proteomes and transcriptomes in hippocampus showed that hippocampal cytoskeleton related pathways were abnormal in low group while not in high group. The protein assays confirmed that hippocampal actin cytoskeleton was depolymerized in low group while maintained in high group. This study confirms that high-dose propofol anesthesia could mitigate the development of POCD and provides evidences for actin cytoskeleton associated with this syndrome.
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Affiliation(s)
- Jun Ma
- Department of Anesthesiology, Pain Medicine & CCM, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China; Laboratory of Medical Cell Biology, College of Translational Medicine, China Medical University, Shenyang, China
| | - John Williams
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Derek Eastwood
- Murrayfield Hospital Wirral, Royal College of Anaesthetists, London, UK
| | - Siyu Lin
- Department of Anesthesiology, Pain Medicine & CCM, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China
| | - Xiaoyan Qian
- Department of Anesthesiology, Pain Medicine & CCM, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China
| | - Qiwu Fang
- Department of Anesthesiology, Pain Medicine & CCM, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China
| | - Doris Cope
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Zengqiang Yuan
- Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Liu Cao
- Laboratory of Medical Cell Biology, College of Translational Medicine, China Medical University, Shenyang, China
| | - Jianxiong An
- Department of Anesthesiology, Pain Medicine & CCM, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China.
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59
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Will L, Portegies S, van Schelt J, van Luyk M, Jaarsma D, Hoogenraad CC. Dynein activating adaptor BICD2 controls radial migration of upper-layer cortical neurons in vivo. Acta Neuropathol Commun 2019; 7:162. [PMID: 31655624 PMCID: PMC6815425 DOI: 10.1186/s40478-019-0827-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/03/2019] [Indexed: 01/19/2023] Open
Abstract
For the proper organization of the six-layered mammalian neocortex it is required that neurons migrate radially from their place of birth towards their designated destination. The molecular machinery underlying this neuronal migration is still poorly understood. The dynein-adaptor protein BICD2 is associated with a spectrum of human neurological diseases, including malformations of cortical development. Previous studies have shown that knockdown of BICD2 interferes with interkinetic nuclear migration in radial glial progenitor cells, and that Bicd2-deficient mice display an altered laminar organization of the cerebellum and the neocortex. However, the precise in vivo role of BICD2 in neocortical development remains unclear. By comparing cell-type specific conditional Bicd2 knock-out mice, we found that radial migration in the cortex predominantly depends on BICD2 function in post-mitotic neurons. Neuron-specific Bicd2 cKO mice showed severely impaired radial migration of late-born upper-layer neurons. BICD2 depletion in cortical neurons interfered with proper Golgi organization, and neuronal maturation and survival of cortical plate neurons. Single-neuron labeling revealed a specific role of BICD2 in bipolar locomotion. Rescue experiments with wildtype and disease-related mutant BICD2 constructs revealed that a point-mutation in the RAB6/RANBP2-binding-domain, associated with cortical malformation in patients, fails to restore proper cortical neuron migration. Together, these findings demonstrate a novel, cell-intrinsic role of BICD2 in cortical neuron migration in vivo and provide new insights into BICD2-dependent dynein-mediated functions during cortical development.
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60
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Khalaf B, Roncador A, Pischedda F, Casini A, Thomas S, Piccoli G, Kiebler M, Macchi P. Ankyrin-G induces nucleoporin Nup358 to associate with the axon initial segment of neurons. J Cell Sci 2019; 132:jcs.222802. [PMID: 31427429 DOI: 10.1242/jcs.222802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 08/12/2019] [Indexed: 12/11/2022] Open
Abstract
Nup358 (also known as RanBP2) is a member of the large nucleoporin family that constitutes the nuclear pore complex. Depending on the cell type and the physiological state, Nup358 interacts with specific partner proteins and influences distinct mechanisms independent of its role in nucleocytoplasmic transport. Here, we provide evidence that Nup358 associates selectively with the axon initial segment (AIS) of mature neurons, mediated by the AIS scaffold protein ankyrin-G (AnkG, also known as Ank3). The N-terminus of Nup358 is demonstrated to be sufficient for its localization at the AIS. Further, we show that Nup358 is expressed as two isoforms, one full-length and another shorter form of Nup358. These isoforms differ in their subcellular distribution in neurons and expression level during neuronal development. Overall, the present study highlights an unprecedented localization of Nup358 within the AIS and suggests its involvement in neuronal function.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Bouchra Khalaf
- Laboratory of Molecular and Cellular Neurobiology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy
| | - Alessandro Roncador
- Laboratory of Molecular and Cellular Neurobiology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy
| | - Francesca Pischedda
- Dulbecco Telethon Laboratory of Biology of Synapses, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy
| | - Antonio Casini
- Laboratory of Molecular Virology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy
| | - Sabine Thomas
- Department for Cell Biology, Biomedical Center, Medical Faculty, Ludwig-Maximilian University of Munich, Großhaderner Straße 9, 82152 Planegg-Martinsried, Germany
| | - Giovanni Piccoli
- Dulbecco Telethon Laboratory of Biology of Synapses, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy
| | - Michael Kiebler
- Department for Cell Biology, Biomedical Center, Medical Faculty, Ludwig-Maximilian University of Munich, Großhaderner Straße 9, 82152 Planegg-Martinsried, Germany
| | - Paolo Macchi
- Laboratory of Molecular and Cellular Neurobiology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy
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61
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Karabasheva D, Smyth JT. A novel, dynein-independent mechanism focuses the endoplasmic reticulum around spindle poles in dividing Drosophila spermatocytes. Sci Rep 2019; 9:12456. [PMID: 31462700 PMCID: PMC6713755 DOI: 10.1038/s41598-019-48860-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 08/14/2019] [Indexed: 01/04/2023] Open
Abstract
In dividing animal cells the endoplasmic reticulum (ER) concentrates around the poles of the spindle apparatus by associating with astral microtubules (MTs), and this association is essential for proper ER partitioning to progeny cells. The mechanisms that associate the ER with astral MTs are unknown. Because astral MT minus-ends are anchored by centrosomes at spindle poles, we hypothesized that the MT minus-end motor dynein mediates ER concentration around spindle poles. Live in vivo imaging of Drosophila spermatocytes revealed that dynein is required for ER concentration around centrosomes during late interphase. In marked contrast, however, dynein suppression had no effect on ER association with astral MTs and concentration around spindle poles in early M-phase. In fact, there was a sudden onset of ER association with astral MTs in dynein RNAi cells, revealing activation of an M-phase specific mechanism of ER-MT association. ER redistribution to spindle poles also did not require non-claret disjunctional (ncd), the other known Drosophila MT minus-end motor, nor Klp61F, a MT plus-end motor that generates spindle poleward forces. Collectively, our results suggest that a novel, M-phase specific mechanism of ER-MT association that is independent of MT minus-end motors is required for proper ER partitioning in dividing cells.
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Affiliation(s)
- Darya Karabasheva
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD, 20814, USA
| | - Jeremy T Smyth
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD, 20814, USA.
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62
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Popa S, Villeneuve J, Stewart S, Perez Garcia E, Petrunkina Harrison A, Moreau K. Genome-wide CRISPR screening identifies new regulators of glycoprotein secretion. Wellcome Open Res 2019; 4:119. [PMID: 32030357 PMCID: PMC6979480 DOI: 10.12688/wellcomeopenres.15232.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2019] [Indexed: 01/08/2024] Open
Abstract
Background: The fundamental process of protein secretion from eukaryotic cells has been well described for many years, yet gaps in our understanding of how this process is regulated remain. Methods: With the aim of identifying novel genes involved in the secretion of glycoproteins, we used a screening pipeline consisting of a pooled genome-wide CRISPR screen, followed by secondary siRNA screening of the hits to identify and validate several novel regulators of protein secretion. Results: We present approximately 50 novel genes not previously associated with protein secretion, many of which also had an effect on the structure of the Golgi apparatus. We further studied a small selection of hits to investigate their subcellular localisation. One of these, GPR161, is a novel Golgi-resident protein that we propose maintains Golgi structure via an interaction with golgin A5. Conclusions: This study has identified new factors for protein secretion involved in Golgi homeostasis.
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Affiliation(s)
- Stephanie Popa
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Julien Villeneuve
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Sarah Stewart
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Esther Perez Garcia
- NIHR Cambridge BRC Cell Phenotyping Hub, Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Anna Petrunkina Harrison
- NIHR Cambridge BRC Cell Phenotyping Hub, Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Kevin Moreau
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
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63
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Popa S, Villeneuve J, Stewart S, Perez Garcia E, Petrunkina Harrison A, Moreau K. Genome-wide CRISPR screening identifies new regulators of glycoprotein secretion. Wellcome Open Res 2019; 4:119. [PMID: 32030357 PMCID: PMC6979480 DOI: 10.12688/wellcomeopenres.15232.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2019] [Indexed: 12/14/2022] Open
Abstract
Background: The fundamental process of protein secretion from eukaryotic cells has been well described for many years, yet gaps in our understanding of how this process is regulated remain. Methods: With the aim of identifying novel genes involved in the secretion of glycoproteins, we used a screening pipeline consisting of a pooled genome-wide CRISPR screen, followed by secondary siRNA screening of the hits to identify and validate several novel regulators of protein secretion. Results: We present approximately 50 novel genes not previously associated with protein secretion, many of which also had an effect on the structure of the Golgi apparatus. We further studied a small selection of hits to investigate their subcellular localisation. One of these, GPR161, is a novel Golgi-resident protein that we propose maintains Golgi structure via an interaction with golgin A5. Conclusions: This study has identified new factors for protein secretion involved in Golgi homeostasis.
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Affiliation(s)
- Stephanie Popa
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Julien Villeneuve
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Sarah Stewart
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Esther Perez Garcia
- NIHR Cambridge BRC Cell Phenotyping Hub, Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Anna Petrunkina Harrison
- NIHR Cambridge BRC Cell Phenotyping Hub, Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Kevin Moreau
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
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64
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Gatenby RA. The Role of Cell Membrane Information Reception, Processing, and Communication in the Structure and Function of Multicellular Tissue. Int J Mol Sci 2019; 20:ijms20153609. [PMID: 31344783 PMCID: PMC6696332 DOI: 10.3390/ijms20153609] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 07/18/2019] [Indexed: 01/12/2023] Open
Abstract
Investigations of information dynamics in eukaryotic cells focus almost exclusively on heritable information in the genome. Gene networks are modeled as “central processors” that receive, analyze, and respond to intracellular and extracellular signals with the nucleus described as a cell’s control center. Here, we present a model in which cellular information is a distributed system that includes non-genomic information processing in the cell membrane that may quantitatively exceed that of the genome. Within this model, the nucleus largely acts a source of macromolecules and processes information needed to synchronize their production with temporal variations in demand. However, the nucleus cannot produce microsecond responses to acute, life-threatening perturbations and cannot spatially resolve incoming signals or direct macromolecules to the cellular regions where they are needed. In contrast, the cell membrane, as the interface with its environment, can rapidly detect, process, and respond to external threats and opportunities through the large amounts of potential information encoded within the transmembrane ion gradient. Our model proposes environmental information is detected by specialized protein gates within ion-specific transmembrane channels. When the gate receives a specific environmental signal, the ion channel opens and the received information is communicated into the cell via flow of a specific ion species (i.e., K+, Na+, Cl−, Ca2+, Mg2+) along electrochemical gradients. The fluctuation of an ion concentration within the cytoplasm adjacent to the membrane channel can elicit an immediate, local response by altering the location and function of peripheral membrane proteins. Signals that affect a larger surface area of the cell membrane and/or persist over a prolonged time period will produce similarly cytoplasmic changes on larger spatial and time scales. We propose that as the amplitude, spatial extent, and duration of changes in cytoplasmic ion concentrations increase, the information can be communicated to the nucleus and other intracellular structure through ion flows along elements of the cytoskeleton to the centrosome (via microtubules) or proteins in the nuclear membrane (via microfilaments). These dynamics add spatial and temporal context to the more well-recognized information communication from the cell membrane to the nucleus following ligand binding to membrane receptors. Here, the signal is transmitted and amplified through transduction by the canonical molecular (e.g., Mitogen Activated Protein Kinases (MAPK) pathways. Cytoplasmic diffusion allows this information to be broadly distributed to intracellular organelles but at the cost of loss of spatial and temporal information also contained in ligand binding.
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Affiliation(s)
- Robert A Gatenby
- Departments of Radiology and Integrated Mathematical Oncology, Moffitt Cancer Center, Tampa, FL 33612, USA.
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65
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Golgi Fragmentation in Neurodegenerative Diseases: Is There a Common Cause? Cells 2019; 8:cells8070748. [PMID: 31331075 PMCID: PMC6679019 DOI: 10.3390/cells8070748] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/17/2019] [Accepted: 07/17/2019] [Indexed: 02/06/2023] Open
Abstract
In most mammalian cells, the Golgi complex forms a continuous ribbon. In neurodegenerative diseases, the Golgi ribbon of a specific group of neurons is typically broken into isolated elements, a very early event which happens before clinical and other pathological symptoms become evident. It is not known whether this phenomenon is caused by mechanisms associated with cell death or if, conversely, it triggers apoptosis. When the phenomenon was studied in diseases such as Parkinson’s and Alzheimer’s or amyotrophic lateral sclerosis, it was attributed to a variety of causes, including the presence of cytoplasmatic protein aggregates, malfunctioning of intracellular traffic and/or alterations in the cytoskeleton. In the present review, we summarize the current findings related to these and other neurodegenerative diseases and try to search for clues on putative common causes.
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66
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Facchin F, Canaider S, Tassinari R, Zannini C, Bianconi E, Taglioli V, Olivi E, Cavallini C, Tausel M, Ventura C. Physical energies to the rescue of damaged tissues. World J Stem Cells 2019; 11:297-321. [PMID: 31293714 PMCID: PMC6600852 DOI: 10.4252/wjsc.v11.i6.297] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/24/2019] [Accepted: 05/29/2019] [Indexed: 02/06/2023] Open
Abstract
Rhythmic oscillatory patterns sustain cellular dynamics, driving the concerted action of regulatory molecules, microtubules, and molecular motors. We describe cellular microtubules as oscillators capable of synchronization and swarming, generating mechanical and electric patterns that impact biomolecular recognition. We consider the biological relevance of seeing the inside of cells populated by a network of molecules that behave as bioelectronic circuits and chromophores. We discuss the novel perspectives disclosed by mechanobiology, bioelectromagnetism, and photobiomodulation, both in term of fundamental basic science and in light of the biomedical implication of using physical energies to govern (stem) cell fate. We focus on the feasibility of exploiting atomic force microscopy and hyperspectral imaging to detect signatures of nanomotions and electromagnetic radiation (light), respectively, generated by the stem cells across the specification of their multilineage repertoire. The chance is reported of using these signatures and the diffusive features of physical waves to direct specifically the differentiation program of stem cells in situ, where they already are resident in all the tissues of the human body. We discuss how this strategy may pave the way to a regenerative and precision medicine without the needs for (stem) cell or tissue transplantation. We describe a novel paradigm based upon boosting our inherent ability for self-healing.
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Affiliation(s)
- Federica Facchin
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), School of Medicine, University of Bologna, Bologna 40100, Italy
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Silvia Canaider
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), School of Medicine, University of Bologna, Bologna 40100, Italy
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Riccardo Tassinari
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Chiara Zannini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Eva Bianconi
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Valentina Taglioli
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Elena Olivi
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Claudia Cavallini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | | | - Carlo Ventura
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), School of Medicine, University of Bologna, Bologna 40100, Italy
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
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67
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Resolvin D1 promotes the targeting and clearance of necroptotic cells. Cell Death Differ 2019; 27:525-539. [PMID: 31222041 DOI: 10.1038/s41418-019-0370-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/30/2019] [Accepted: 05/28/2019] [Indexed: 02/07/2023] Open
Abstract
Inflammation-resolution is a protective response that is mediated by specialized pro-resolving mediators (SPMs). The clearance of dead cells or efferocytosis is a critical cellular program of inflammation-resolution. Impaired efferocytosis can lead to tissue damage in prevalent human diseases, like atherosclerosis. Therefore understanding mechanisms associated with swift clearance of dead cells is of utmost clinical importance. Recently, the accumulation of necroptotic cells (NCs) was observed in human plaques and we postulated that this is due to defective clearance programs. Here we present evidence that NCs are inefficiently taken up by macrophages because they have increased surface expression of a well-known "don't eat me" signal called CD47. High levels of CD47 on NCs stimulated RhoA-pMLC signaling in macrophages that promoted "nibbling", rather than whole-cell engulfment of NCs. Anti-CD47 blocking antibodies limited RhoA-p-MLC signaling and promoted whole-cell NC engulfment. Treatment with anti-CD47 blocking antibodies to Ldlr-/- mice with established atherosclerosis decreased necrotic cores, limited the accumulation of plaque NCs and increased lesional SPMs, including Resolvin D1 (RvD1) compared with IgG controls. Mechanistically, RvD1 promoted whole-cell engulfment of NCs by decreasing RhoA signaling and activating CDC42. RvD1 specifically targeted NCs for engulfment by facilitating the release of the well-known "eat me signal" called calreticulin from macrophages in a CDC42 dependent manner. Lastly, RvD1 enhanced the clearance of NCs in advanced murine plaques. Together, these results suggest new molecules and signaling associated with the clearance of NCs, provide a new paradigm for the regulation of inflammation-resolution, and offer a potential treatment strategy for diseases where NCs underpin the pathology.
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Abstract
This chapter reviews our current knowledge about the spatiotemporal assembly of filoviral particles. We will follow particles from nucleocapsid entry into the cytoplasm until the nucleocapsids are enveloped at the plasma membrane. We will also highlight the currently open scientific questions surrounding filovirus assembly.
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69
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Wurzer H, Hoffmann C, Al Absi A, Thomas C. Actin Cytoskeleton Straddling the Immunological Synapse between Cytotoxic Lymphocytes and Cancer Cells. Cells 2019; 8:cells8050463. [PMID: 31100864 PMCID: PMC6563383 DOI: 10.3390/cells8050463] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/08/2019] [Accepted: 05/13/2019] [Indexed: 02/06/2023] Open
Abstract
The immune system is a fundamental part of the tumor microenvironment. In particular, cytotoxic lymphocytes, such as cytolytic T cells and natural killer cells, control tumor growth and disease progression by interacting and eliminating tumor cells. The actin cytoskeleton of cytotoxic lymphocytes engaged in an immunological synapse has received considerable research attention. It has been recognized as a central mediator of the formation and maturation of the immunological synapse, and its signaling and cytolytic activities. In comparison, fewer studies have explored the organization and function of actin filaments on the target cancer cell side of the immunological synapse. However, there is growing evidence that the actin cytoskeleton of cancer cells also undergoes extensive remodeling upon cytotoxic lymphocyte attack, and that such remodeling can alter physical and functional interactions at the immunological synapse. In this article, we review the current knowledge of actin organization and functions at both sides of the immunological synapse between cytotoxic lymphocytes and cancer cells, with particular focus on synapse formation, signaling and cytolytic activity, and immune evasion.
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Affiliation(s)
- Hannah Wurzer
- Cytoskeleton and Cancer Progression; Laboratory of Experimental Cancer Research, Department of Oncology 84 Val Fleuri, L-1526 Luxembourg City, Luxembourg.
- University of Luxembourg, Faculty of Science, Technology and Communication, 2 Avenue de l'Université, L-4365 Esch-sur-Alzette, Luxembourg.
| | - Céline Hoffmann
- Cytoskeleton and Cancer Progression; Laboratory of Experimental Cancer Research, Department of Oncology 84 Val Fleuri, L-1526 Luxembourg City, Luxembourg.
| | - Antoun Al Absi
- Cytoskeleton and Cancer Progression; Laboratory of Experimental Cancer Research, Department of Oncology 84 Val Fleuri, L-1526 Luxembourg City, Luxembourg.
- University of Strasbourg, 67081 Strasbourg, France.
| | - Clément Thomas
- Cytoskeleton and Cancer Progression; Laboratory of Experimental Cancer Research, Department of Oncology 84 Val Fleuri, L-1526 Luxembourg City, Luxembourg.
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70
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Frieden BR, Gatenby RA. Signal transmission through elements of the cytoskeleton form an optimized information network in eukaryotic cells. Sci Rep 2019; 9:6110. [PMID: 30992457 PMCID: PMC6467984 DOI: 10.1038/s41598-019-42343-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/25/2019] [Indexed: 11/23/2022] Open
Abstract
Multiple prior empirical and theoretical studies have demonstrated wire-like flow of electrons and ions along elements of the cytoskeleton but this has never been linked to a biological function. Here we propose that eukaryotes use this mode of signal transmission to convey spatial and temporal environmental information from the cell membrane to the nucleus. The cell membrane, as the interface between intra- and extra-cellular environments, is the site at which much external information is received. Prior studies have demonstrated that transmembrane ion gradients permit information acquisition when an environmental signal interacts with specialized protein gates in membrane ion channels and producing specific ions to flow into or out of the cell along concentration gradients. The resulting localized change in cytoplasmic ion concentrations and charge density can alter location and enzymatic function of peripheral membrane proteins. This allows the cell to process the information and rapidly deploy a local response. Here we investigate transmission of information received and processed in and around the cell membrane by elements of the cytoskeleton to the nucleus to alter gene expression. We demonstrate signal transmission by ion flow along the cytoskeleton is highly optimized. In particular, microtubules, with diameters of about 30 nm, carry coarse-grained Shannon information to the centrosome adjacent to the nucleus with minimum loss of input source information. And, microfilaments, with diameters of about 4 nm, transmit maximum Fisher (fine-grained) information to protein complexes in the nuclear membrane. These previously unrecognized information dynamics allow continuous integration of spatial and temporal environmental signals with inherited information in the genome.
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Affiliation(s)
- B R Frieden
- College of Optical Science, University of Arizona, Tucson, AZ, USA
| | - R A Gatenby
- Department of Integrated Mathematical Biology, Moffitt Cancer Center, Tampa, FL, USA.
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71
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A M, Fung TS, Kettenbach AN, Chakrabarti R, Higgs HN. A complex containing lysine-acetylated actin inhibits the formin INF2. Nat Cell Biol 2019; 21:592-602. [PMID: 30962575 PMCID: PMC6501848 DOI: 10.1038/s41556-019-0307-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 02/28/2019] [Indexed: 11/10/2022]
Abstract
Inverted formin 2 (INF2) is a member of the formin family of actin assembly factors. Dominant missense mutations in INF2 are linked to two diseases: focal segmental glomerulosclerosis, a kidney disease, and Charcot-Marie-Tooth disease, a neuropathy. All of the disease mutations map to the autoinhibitory diaphanous inhibitory domain. Interestingly, purified INF2 is not autoinhibited, suggesting the existence of other cellular inhibitors. Here, we purified an INF2 inhibitor from mouse brain tissue, and identified it as a complex of lysine-acetylated actin (KAc-actin) and cyclase-associated protein (CAP). Inhibition of INF2 by CAP-KAc-actin is dependent on the INF2 diaphanous inhibitory domain (DID). Treatment of CAP-KAc-actin-inhibited INF2 with histone deacetylase 6 releases INF2 inhibition, whereas inhibitors of histone deacetylase 6 block the activation of cellular INF2. Disease-associated INF2 mutants are poorly inhibited by CAP-KAc-actin, suggesting that focal segmental glomerulosclerosis and Charcot-Marie-Tooth disease result from reduced CAP-KAc-actin binding. These findings reveal a role for KAc-actin in the regulation of an actin assembly factor by a mechanism that we call facilitated autoinhibition.
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Affiliation(s)
- Mu A
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA.
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72
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Fattouh N, Cazevieille C, Landmann F. Wolbachia endosymbionts subvert the endoplasmic reticulum to acquire host membranes without triggering ER stress. PLoS Negl Trop Dis 2019; 13:e0007218. [PMID: 30893296 PMCID: PMC6426186 DOI: 10.1371/journal.pntd.0007218] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/05/2019] [Indexed: 12/15/2022] Open
Abstract
The reproductive parasites Wolbachia are the most common endosymbionts on earth, present in a plethora of arthropod species. They have been introduced into mosquitos to successfully prevent the spread of vector-borne diseases, yet the strategies of host cell subversion underlying their obligate intracellular lifestyle remain to be explored in depth in order to gain insights into the mechanisms of pathogen-blocking. Like some other intracellular bacteria, Wolbachia reside in a host-derived vacuole in order to replicate and escape the immune surveillance. Using here the pathogen-blocking Wolbachia strain from Drosophila melanogaster, introduced into two different Drosophila cell lines, we show that Wolbachia subvert the endoplasmic reticulum to acquire their vacuolar membrane and colonize the host cell at high density. Wolbachia redistribute the endoplasmic reticulum, and time lapse experiments reveal tight coupled dynamics suggesting important signalling events or nutrient uptake. Wolbachia infection however does not affect the tubular or cisternal morphologies. A fraction of endoplasmic reticulum becomes clustered, allowing the endosymbionts to reside in between the endoplasmic reticulum and the Golgi apparatus, possibly modulating the traffic between these two organelles. Gene expression analyses and immunostaining studies suggest that Wolbachia achieve persistent infections at very high titers without triggering endoplasmic reticulum stress or enhanced ERAD-driven proteolysis, suggesting that amino acid salvage is achieved through modulation of other signalling pathways. Wolbachia are a genus of intracellular bacteria living in symbiosis with millions of arthropod species. They have the ability to block the transmission of arboviruses when introduced into mosquito vectors, by interfering with the cellular resources exploited by these viruses. Despite the biomedical interest of this symbiosis, little is known about the mechanisms by which Wolbachia survive and replicate in the host cell. We show here that the membrane composing the Wolbachia vacuole is acquired from the endoplasmic reticulum, a central organelle required for protein and lipid synthesis, and from which originates a vesicular trafficking toward the Golgi apparatus and the secretory pathway. Wolbachia modify the distribution of this organelle which is a potential source of membrane and likely of nutrients as well. In contrast to some intracellular pathogenic bacteria, the effect of Wolbachia on the cell homeostasis does not induce a stress on the endoplasmic reticulum. One of the consequences of such a stress would be an increased proteolysis used to relieve the cell from an excess of misfolded proteins. Incidentally, this suggests that Wolbachia do not acquire amino acids from the host cell through this strategy.
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Affiliation(s)
| | - Chantal Cazevieille
- MRI-COMET, Plateau de microscopie électronique, U1051 INM, Hôpital Saint Eloi, Montpellier, France
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73
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Mather IH, Masedunskas A, Chen Y, Weigert R. Symposium review: Intravital imaging of the lactating mammary gland in live mice reveals novel aspects of milk-lipid secretion. J Dairy Sci 2019; 102:2760-2782. [PMID: 30471915 PMCID: PMC7094374 DOI: 10.3168/jds.2018-15459] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 09/21/2018] [Indexed: 12/22/2022]
Abstract
Milk fat comprises membrane-coated droplets of neutral lipid, which constitute the predominant source of lipids for survival of the suckling neonate. From the perspective of the dairy industry, they are the basis for the manufacture of butter and essential ingredients in the production of cheese, yogurt, and specialty dairy produce. To provide mechanistic insight into the assembly and secretion of lipid droplets during lactation, we developed novel intravital imaging techniques using transgenic mice, which express fluorescently tagged marker proteins. The number 4 mammary glands were surgically prepared under a deep plane of anesthesia and the exposed glands positioned as a skin flap with intact vascular supply on the stage of a laser-scanning confocal microscope. Lipid droplets were stained by prior exposure of the glands to hydrophobic fluorescent BODIPY (boron-dipyrromethene) dyes and their formation and secretion monitored by time-lapse subcellular microscopy over periods of 1 to 2 h. Droplets were transported to the cell apex by directed (superdiffusive) motion at relatively slow and intermittent rates (0-2 µm/min). Regardless of size, droplets grew by numerous fusion events during transport and as they were budding from the cell enveloped by apical membranes. Surprisingly, droplet secretion was not constitutive but required an injection of oxytocin to induce contraction of the myoepithelium with subsequent release of droplets into luminal spaces. These novel results are discussed in the context of the current paradigm for milk fat synthesis and secretion and as a template for future innovations in the dairy industry.
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Affiliation(s)
- Ian H Mather
- Department of Animal and Avian Sciences, University of Maryland, College Park 20742; National Cancer Institute and National Institute of Craniofacial and Dental Research, National Institutes of Health, Bethesda, MD 20892.
| | - Andrius Masedunskas
- National Cancer Institute and National Institute of Craniofacial and Dental Research, National Institutes of Health, Bethesda, MD 20892
| | - Yun Chen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21205
| | - Roberto Weigert
- National Cancer Institute and National Institute of Craniofacial and Dental Research, National Institutes of Health, Bethesda, MD 20892
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74
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Omrane M, Camara AS, Taveneau C, Benzoubir N, Tubiana T, Yu J, Guérois R, Samuel D, Goud B, Poüs C, Bressanelli S, Garratt RC, Thiam AR, Gassama-Diagne A. Septin 9 has Two Polybasic Domains Critical to Septin Filament Assembly and Golgi Integrity. iScience 2019; 13:138-153. [PMID: 30831549 PMCID: PMC6403118 DOI: 10.1016/j.isci.2019.02.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 10/12/2018] [Accepted: 02/13/2019] [Indexed: 12/11/2022] Open
Abstract
Septins are GTP-binding proteins involved in several membrane remodeling mechanisms. They associate with membranes, presumably using a polybasic domain (PB1) that interacts with phosphoinositides (PIs). Membrane-bound septins assemble into microscopic structures that regulate membrane shape. How septins interact with PIs and then assemble and shape membranes is poorly understood. Here, we found that septin 9 has a second polybasic domain (PB2) conserved in the human septin family. Similar to PB1, PB2 binds specifically to PIs, and both domains are critical for septin filament formation. However, septin 9 membrane association is not dependent on these PB domains, but on putative PB-adjacent amphipathic helices. The presence of PB domains guarantees protein enrichment in PI-contained membranes, which is critical for PI-enriched organelles. In particular, we found that septin 9 PB domains control the assembly and functionality of the Golgi apparatus. Our findings offer further insight into the role of septins in organelle morphology. Two polybasic domains mediate septin 9 interactions with PIs Human septins have amphipathic helices suitable for membrane binding Septin 9 polybasic domains mediate the formation of septin higher-order structures The mutation or depletion of septin polybasic domains induces Golgi fragmentation
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Affiliation(s)
- Mohyeddine Omrane
- INSERM, Unité 1193, Villejuif 94800, France; Université Paris-Sud, UMR-S 1193, Villejuif 94800, France; Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Amanda Souza Camara
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil
| | - Cyntia Taveneau
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif Sur Yvette Cedex, France
| | - Nassima Benzoubir
- INSERM, Unité 1193, Villejuif 94800, France; Université Paris-Sud, UMR-S 1193, Villejuif 94800, France
| | - Thibault Tubiana
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif Sur Yvette Cedex, France
| | - Jinchao Yu
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif Sur Yvette Cedex, France; Commissariat à l'Energie Atomique et aux Energies Alternatives, 91191 Gif-Sur- Yvette Cedex, France
| | - Raphaël Guérois
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif Sur Yvette Cedex, France; Commissariat à l'Energie Atomique et aux Energies Alternatives, 91191 Gif-Sur- Yvette Cedex, France
| | - Didier Samuel
- INSERM, Unité 1193, Villejuif 94800, France; Université Paris-Sud, UMR-S 1193, Villejuif 94800, France
| | - Bruno Goud
- Institute Curie, PSL Research University, CNRS UMR 144, Paris, France
| | - Christian Poüs
- INSERM, Unité 1193, Villejuif 94800, France; Université Paris-Sud, UMR-S 1193, Villejuif 94800, France
| | - Stéphane Bressanelli
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif Sur Yvette Cedex, France
| | | | - Abdou Rachid Thiam
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France.
| | - Ama Gassama-Diagne
- INSERM, Unité 1193, Villejuif 94800, France; Université Paris-Sud, UMR-S 1193, Villejuif 94800, France.
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75
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Farías GG, Fréal A, Tortosa E, Stucchi R, Pan X, Portegies S, Will L, Altelaar M, Hoogenraad CC. Feedback-Driven Mechanisms between Microtubules and the Endoplasmic Reticulum Instruct Neuronal Polarity. Neuron 2019; 102:184-201.e8. [PMID: 30772082 DOI: 10.1016/j.neuron.2019.01.030] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 11/29/2018] [Accepted: 01/15/2019] [Indexed: 12/20/2022]
Abstract
Establishment of neuronal polarity depends on local microtubule (MT) reorganization. The endoplasmic reticulum (ER) consists of cisternae and tubules and, like MTs, forms an extensive network throughout the entire cell. How the two networks interact and control neuronal development is an outstanding question. Here we show that the interplay between MTs and the ER is essential for neuronal polarity. ER tubules localize within the axon, whereas ER cisternae are retained in the somatodendritic domain. MTs are essential for axonal ER tubule stabilization, and, reciprocally, the ER is required for stabilizing and organizing axonal MTs. Recruitment of ER tubules into one minor neurite initiates axon formation, whereas ER retention in the perinuclear area or disruption of ER tubules prevent neuronal polarization. The ER-shaping protein P180, present in axonal ER tubules, controls axon specification by regulating local MT remodeling. We propose a model in which feedback-driven regulation between the ER and MTs instructs neuronal polarity.
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Affiliation(s)
- Ginny G Farías
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands.
| | - Amélie Fréal
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Elena Tortosa
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Riccardo Stucchi
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands; Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Xingxiu Pan
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Sybren Portegies
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Lena Will
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands.
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76
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Romani P, Brian I, Santinon G, Pocaterra A, Audano M, Pedretti S, Mathieu S, Forcato M, Bicciato S, Manneville JB, Mitro N, Dupont S. Extracellular matrix mechanical cues regulate lipid metabolism through Lipin-1 and SREBP. Nat Cell Biol 2019; 21:338-347. [DOI: 10.1038/s41556-018-0270-5] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 12/20/2018] [Indexed: 12/15/2022]
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77
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Song K, Gras C, Capin G, Gimber N, Lehmann M, Mohd S, Puchkov D, Rödiger M, Wilhelmi I, Daumke O, Schmoranzer J, Schürmann A, Krauss M. A SEPT1-based scaffold is required for Golgi integrity and function. J Cell Sci 2019; 132:132/3/jcs225557. [PMID: 30709970 PMCID: PMC6382012 DOI: 10.1242/jcs.225557] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/17/2018] [Indexed: 12/13/2022] Open
Abstract
Compartmentalization of membrane transport and signaling processes is of pivotal importance to eukaryotic cell function. While plasma membrane compartmentalization and dynamics are well known to depend on the scaffolding function of septin GTPases, the roles of septins at intracellular membranes have remained largely elusive. Here, we show that the structural and functional integrity of the Golgi depends on its association with a septin 1 (SEPT1)-based scaffold, which promotes local microtubule nucleation and positioning of the Golgi. SEPT1 function depends on the Golgi matrix protein GM130 (also known as GOLGA2) and on centrosomal proteins, including CEP170 and components of γ-tubulin ring complex (γ-Turc), to facilitate the perinuclear concentration of Golgi membranes. Accordingly, SEPT1 depletion triggers a massive fragmentation of the Golgi ribbon, thereby compromising anterograde membrane traffic at the level of the Golgi.
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Affiliation(s)
- Kyungyeun Song
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Claudia Gras
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Gabrielle Capin
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Niclas Gimber
- Charité Universitätsmedizin Berlin, Advanced Medical Bioimaging Core Facility - AMBIO, 10117 Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Cellular Imaging Facility, 13125 Berlin, Germany
| | - Saif Mohd
- Max-Delmbrück-Centrum für Molekulare Medizin, 13125 Berlin, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Cellular Imaging Facility, 13125 Berlin, Germany
| | - Maria Rödiger
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Ilka Wilhelmi
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Oliver Daumke
- Max-Delmbrück-Centrum für Molekulare Medizin, 13125 Berlin, Germany
| | - Jan Schmoranzer
- Charité Universitätsmedizin Berlin, Advanced Medical Bioimaging Core Facility - AMBIO, 10117 Berlin, Germany
| | - Annette Schürmann
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Michael Krauss
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
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78
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Bedi S, Ono A. Friend or Foe: The Role of the Cytoskeleton in Influenza A Virus Assembly. Viruses 2019; 11:v11010046. [PMID: 30634554 PMCID: PMC6356976 DOI: 10.3390/v11010046] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 01/02/2019] [Accepted: 01/08/2019] [Indexed: 12/12/2022] Open
Abstract
Influenza A Virus (IAV) is a respiratory virus that causes seasonal outbreaks annually and pandemics occasionally. The main targets of the virus are epithelial cells in the respiratory tract. Like many other viruses, IAV employs the host cell’s machinery to enter cells, synthesize new genomes and viral proteins, and assemble new virus particles. The cytoskeletal system is a major cellular machinery, which IAV exploits for its entry to and exit from the cell. However, in some cases, the cytoskeleton has a negative impact on efficient IAV growth. In this review, we highlight the role of cytoskeletal elements in cellular processes that are utilized by IAV in the host cell. We further provide an in-depth summary of the current literature on the roles the cytoskeleton plays in regulating specific steps during the assembly of progeny IAV particles.
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Affiliation(s)
- Sukhmani Bedi
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Akira Ono
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
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79
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Specific Modification of Aged Proteasomes Revealed by Tag-Exchangeable Knock-In Mice. Mol Cell Biol 2018; 39:MCB.00426-18. [PMID: 30348842 DOI: 10.1128/mcb.00426-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/10/2018] [Indexed: 01/02/2023] Open
Abstract
The proteasome is the proteolytic machinery at the center of regulated intracellular protein degradation and participates in various cellular processes. Maintaining the quality of the proteasome is therefore important for proper cell function. It is unclear, however, how proteasomes change over time and how aged proteasomes are disposed. Here, we show that the proteasome undergoes specific biochemical alterations as it ages. We generated Rpn11-Flag/enhanced green fluorescent protein (EGFP) tag-exchangeable knock-in mice and established a method for selective purification of old proteasomes in terms of their molecular age at the time after synthesis. The half-life of proteasomes in mouse embryonic fibroblasts isolated from these knock-in mice was about 16 h. Using this tool, we found increased association of Txnl1, Usp14, and actin with the proteasome and specific phosphorylation of Rpn3 at Ser 6 in 3-day-old proteasomes. We also identified CSNK2A2 encoding the catalytic α' subunit of casein kinase II (CK2α') as a responsible gene that regulates the phosphorylation and turnover of old proteasomes. These findings will provide a basis for understanding the mechanism of molecular aging of the proteasome.
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80
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Chua MD, Liou CH, Bogdan AC, Law HT, Yeh KM, Lin JC, Siu LK, Guttman JA. Klebsiella pneumoniae disassembles host microtubules in lung epithelial cells. Cell Microbiol 2018; 21:e12977. [PMID: 30415487 DOI: 10.1111/cmi.12977] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 01/21/2023]
Abstract
Klebsiella pneumoniae raises significant concerns to the health care industry as these microbes are the source of widespread contamination of medical equipment, cause pneumonia as well as other multiorgan metastatic infections and have gained multidrug resistance. Despite soaring mortality rates, the host cell alterations occurring during these infections remain poorly understood. Here, we show that during in vitro and in vivo K. pneumoniae infections of lung epithelia, microtubules are severed and then eliminated. This destruction does not require direct association of K. pneumoniae with the host cells, as microtubules are disassembled in cells that are distant from the infecting bacteria. This microtubule dismantling is dependent on the K. pneumoniae (Kp) gene ytfL as non-pathogenic Escherichia coli expressing Kp ytfL disassemble microtubules in the absence of K. pneumoniae itself. Our data points to the host katanin catalytic subunit A like 1 protein (KATNAL1) and the katanin regulatory subunit B1 protein (KATNB1) as the gatekeepers to the microtubule severing event as both proteins localise specifically to microtubule cut sites. Infected cells that had either of these proteins knocked out maintained intact microtubules. Taken together, we have identified a novel mechanism that a bacterial pathogen has exploited to cause microtubule destruction within the host epithelia.
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Affiliation(s)
- Michael Dominic Chua
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Ci-Hong Liou
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | | | - Hong T Law
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kuo-Ming Yeh
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Jung-Chung Lin
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - L Kristopher Siu
- Division of Infection Diseases, National Health Research Institutes, Miaoli, Taiwan
| | - Julian Andrew Guttman
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
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81
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Chang B, Svoboda KKH, Liu X. Cell polarization: From epithelial cells to odontoblasts. Eur J Cell Biol 2018; 98:1-11. [PMID: 30473389 DOI: 10.1016/j.ejcb.2018.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/04/2018] [Accepted: 11/16/2018] [Indexed: 12/29/2022] Open
Abstract
Cell polarity identifies the asymmetry of a cell. Various types of cells, including odontoblasts and epithelial cells, polarize to fulfil their destined functions. Odontoblast polarization is a prerequisite and fundamental step for tooth development and tubular dentin formation. Current knowledge of odontoblast polarization, however, is very limited, which greatly impedes the development of novel approaches for regenerative endodontics. Compared to odontoblasts, epithelial cell polarization has been extensively studied over the last several decades. The knowledge obtained from epithelia polarization has been found applicable to other cell types, which is particularly useful considering the remarkable similarities of the morphological and compositional features between polarized odontoblasts and epithelia. In this review, we first discuss the characteristics, the key regulatory factors, and the process of epithelial polarity. Next, we compare the known facts of odontoblast polarization with epithelial cells. Lastly, we clarify knowledge gaps in odontoblast polarization and propose the directions for future research to fill the gaps, leading to the advancement of regenerative endodontics.
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Affiliation(s)
- Bei Chang
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX, 75246, USA
| | - Kathy K H Svoboda
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX, 75246, USA
| | - Xiaohua Liu
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX, 75246, USA.
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82
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Biwi J, Biot C, Guerardel Y, Vercoutter-Edouart AS, Lefebvre T. The Many Ways by Which O-GlcNAcylation May Orchestrate the Diversity of Complex Glycosylations. Molecules 2018; 23:molecules23112858. [PMID: 30400201 PMCID: PMC6278486 DOI: 10.3390/molecules23112858] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/25/2018] [Accepted: 10/30/2018] [Indexed: 12/31/2022] Open
Abstract
Unlike complex glycosylations, O-GlcNAcylation consists of the addition of a single N-acetylglucosamine unit to serine and threonine residues of target proteins, and is confined within the nucleocytoplasmic and mitochondrial compartments. Nevertheless, a number of clues tend to show that O-GlcNAcylation is a pivotal regulatory element of its complex counterparts. In this perspective, we gather the evidence reported to date regarding this connection. We propose different levels of regulation that encompass the competition for the nucleotide sugar UDP-GlcNAc, and that control the wide class of glycosylation enzymes via their expression, catalytic activity, and trafficking. We sought to better envision that nutrient fluxes control the elaboration of glycans, not only at the level of their structure composition, but also through sweet regulating actors.
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Affiliation(s)
- James Biwi
- Unité de Glycobiologie Structurale et Fonctionnelle, Université de Lille, CNRS, UMR 8576, UGSF, 59000 Lille, France.
| | - Christophe Biot
- Unité de Glycobiologie Structurale et Fonctionnelle, Université de Lille, CNRS, UMR 8576, UGSF, 59000 Lille, France.
| | - Yann Guerardel
- Unité de Glycobiologie Structurale et Fonctionnelle, Université de Lille, CNRS, UMR 8576, UGSF, 59000 Lille, France.
| | | | - Tony Lefebvre
- Unité de Glycobiologie Structurale et Fonctionnelle, Université de Lille, CNRS, UMR 8576, UGSF, 59000 Lille, France.
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83
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Igamberdiev AU. Hyper-restorative non-equilibrium state as a driving force of biological morphogenesis. Biosystems 2018; 173:104-113. [DOI: 10.1016/j.biosystems.2018.09.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/20/2018] [Accepted: 09/25/2018] [Indexed: 12/13/2022]
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84
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Abstract
ABSTRACT
The intracellular environment of eukaryotic cells is highly complex and compact. The limited volume of the cell, usually a few hundred femtoliters, is not only occupied by numerous complicated, diverse membranous and proteinaceous structures, these structures are also highly dynamic due to constant remodeling and trafficking events. Consequently, intracellular interactions are more than just opportunities to exchange molecules; they also involve components physically navigating around each other in a highly confined space. While the biochemical interactions between organelles have been intensely studied in the past decades, the mechanical properties of organelles and the physical interactions between them are only beginning to be unraveled. Indeed, recent studies show that intracellular organelles are, at times, under extreme mechanical strain both in widely used experimental systems as well as in vivo. In this Hypothesis, we highlight known examples of intracellular mechanical challenges in biological systems and focus on the coping mechanisms of two important organelles, the nucleus and mitochondria, for they are the best studied in this aspect. In the case of mitochondria, we propose that ER–mitochondrial contact sites at thin cell peripheries may induce mitochondrial fission by mechanically constricting mitochondrial tubules. We also briefly discuss the mechano-responsiveness of other organelles and interesting directions for future research.
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Affiliation(s)
- Qian Feng
- Institute of Biochemistry, ETH Zurich, 8093 Zürich, Switzerland
| | - Benoît Kornmann
- Institute of Biochemistry, ETH Zurich, 8093 Zürich, Switzerland
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85
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Schoenherr C, Frame MC, Byron A. Trafficking of Adhesion and Growth Factor Receptors and Their Effector Kinases. Annu Rev Cell Dev Biol 2018; 34:29-58. [PMID: 30110558 DOI: 10.1146/annurev-cellbio-100617-062559] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cell adhesion to macromolecules in the microenvironment is essential for the development and maintenance of tissues, and its dysregulation can lead to a range of disease states, including inflammation, fibrosis, and cancer. The biomechanical and biochemical mechanisms that mediate cell adhesion rely on signaling by a range of effector proteins, including kinases and associated scaffolding proteins. The intracellular trafficking of these must be tightly controlled in space and time to enable effective cell adhesion and microenvironmental sensing and to integrate cell adhesion with, and compartmentalize it from, other cellular processes, such as gene transcription, protein degradation, and cell division. Delivery of adhesion receptors and signaling proteins from the plasma membrane to unanticipated subcellular locales is revealing novel biological functions. Here, we review the expected and unexpected trafficking, and sites of activity, of adhesion and growth factor receptors and intracellular kinase partners as we begin to appreciate the complexity and diversity of their spatial regulation.
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Affiliation(s)
- Christina Schoenherr
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, United Kingdom;
| | - Margaret C Frame
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, United Kingdom;
| | - Adam Byron
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, United Kingdom;
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86
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Pan ZN, Lu Y, Tang F, Pan MH, Wan X, Lan M, Zhang Y, Sun SC. RAB8A GTPase regulates spindle migration and Golgi apparatus distribution via ROCK-mediated actin assembly in mouse oocyte meiosis†. Biol Reprod 2018; 100:711-720. [DOI: 10.1093/biolre/ioy217] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/03/2018] [Accepted: 09/30/2018] [Indexed: 12/13/2022] Open
Affiliation(s)
- Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yujie Lu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Feng Tang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiang Wan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Mei Lan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
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87
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Reagan BC, Ganusova EE, Fernandez JC, McCray TN, Burch-Smith TM. RNA on the move: The plasmodesmata perspective. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 275:1-10. [PMID: 30107876 DOI: 10.1016/j.plantsci.2018.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/25/2018] [Accepted: 07/04/2018] [Indexed: 05/11/2023]
Abstract
It is now widely accepted that plant RNAs can have effects at sites far away from their sites of synthesis. Cellular mRNA transcripts, endogenous small RNAs and defense-related small RNAs all move from cell to cell via plasmodesmata (PD), and may even move long distances in the phloem. Despite their small size, PD have complicated substructures, and the area of the pore available for RNA trafficking can be remarkably small. The intent of this review is to bring into focus the role of PD in cell-to-cell and long distance communication in plants. We consider how cellular RNAs could move through the cell to the PD and thence through PD. The protein composition of PD and the possible roles of PD proteins in RNA trafficking are also discussed. Recent evidence for RNA metabolism in organelles acting as a factor in controlling PD flux is also presented, highlighting new aspects of plant intra- and intercellular communication. It is clear that while the phenomenon of RNA mobility is common and essential, many questions remain, and these have been highlighted throughout this review.
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Affiliation(s)
- Brandon C Reagan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Elena E Ganusova
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Jessica C Fernandez
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tyra N McCray
- School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tessa M Burch-Smith
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States; School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, United States.
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88
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Saraste J, Marie M. Intermediate compartment (IC): from pre-Golgi vacuoles to a semi-autonomous membrane system. Histochem Cell Biol 2018; 150:407-430. [PMID: 30173361 PMCID: PMC6182704 DOI: 10.1007/s00418-018-1717-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2018] [Indexed: 12/19/2022]
Abstract
Despite its discovery more than three decades ago and well-established role in protein sorting and trafficking in the early secretory pathway, the intermediate compartment (IC) has remained enigmatic. The prevailing view is that the IC evolved as a specialized organelle to mediate long-distance endoplasmic reticulum (ER)–Golgi communication in metazoan cells, but is lacking in other eukaryotes, such as plants and fungi. However, this distinction is difficult to reconcile with the high conservation of the core machineries that regulate early secretory trafficking from yeast to man. Also, it has remained unclear whether the pleiomorphic IC components—vacuoles, tubules and vesicles—represent transient transport carriers or building blocks of a permanent pre-Golgi organelle. Interestingly, recent studies have revealed that the IC maintains its compositional, structural and spatial properties throughout the cell cycle, supporting a model that combines the dynamic and stable aspects of the organelle. Moreover, the IC has been assigned novel functions, such as cell signaling, Golgi-independent trafficking and autophagy. The emerging permanent nature of the IC and its connections with the centrosome and the endocytic recycling system encourage reconsideration of its relationship with the Golgi ribbon, role in Golgi biogenesis and ubiquitous presence in eukaryotic cells.
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Affiliation(s)
- Jaakko Saraste
- Department of Biomedicine and Molecular Imaging Center (MIC), University of Bergen, Jonas Lies vei 91, 5009, Bergen, Norway.
| | - Michaël Marie
- Department of Biomedicine and Molecular Imaging Center (MIC), University of Bergen, Jonas Lies vei 91, 5009, Bergen, Norway
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89
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Singh V, Erady C, Balasubramanian N. Cell-matrix adhesion controls Golgi organization and function through Arf1 activation in anchorage-dependent cells. J Cell Sci 2018; 131:jcs.215855. [PMID: 30054383 PMCID: PMC6127727 DOI: 10.1242/jcs.215855] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/27/2018] [Indexed: 12/15/2022] Open
Abstract
Cell-matrix adhesion regulates membrane trafficking controlling anchorage-dependent signaling. While a dynamic Golgi complex can contribute to this pathway, its regulation by adhesion remains unclear. Here we report that loss of adhesion dramatically disorganized the Golgi in mouse and human fibroblast cells. Golgi integrity is restored rapidly upon integrin-mediated re-adhesion to FN and is disrupted by integrin blocking antibody. In suspended cells, the cis, cis-medial and trans-Golgi networks differentially disorganize along the microtubule network but show no overlap with the ER, making this disorganization distinct from known Golgi fragmentation. This pathway is regulated by an adhesion-dependent reduction and recovery of Arf1 activation. Constitutively active Arf1 disrupts this regulation and prevents Golgi disorganization due to loss of adhesion. Adhesion-dependent Arf1 activation regulates its binding to the microtubule minus-end motor protein dynein to control Golgi reorganization, which is blocked by ciliobrevin. Adhesion-dependent Golgi organization controls its function, regulating cell surface glycosylation due to loss of adhesion, which is blocked by constitutively active Arf1. This study, hence, identified integrin-dependent cell-matrix adhesion to be a novel regulator of Arf1 activation, controlling Golgi organization and function in anchorage-dependent cells.
This article has an associated First Person interview with the first author of the paper. Summary: Integrin-dependent cell-matrix adhesion activates Arf1, which then recruits dynein to regulate Golgi organization and function along the microtubule network.
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Affiliation(s)
- Vibha Singh
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India
| | - Chaitanya Erady
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India
| | - Nagaraj Balasubramanian
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India
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90
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Müller GDAES, Lüchmann KH, Razzera G, Toledo-Silva G, Bebianno MJ, Marques MRF, Bainy ACD. Proteomic response of gill microsomes of Crassostrea brasiliana exposed to diesel fuel water-accommodated fraction. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 201:109-118. [PMID: 29906693 DOI: 10.1016/j.aquatox.2018.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 05/28/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
Diesel fuel water-accommodated fraction (diesel-WAF) is a complex mixture of organic compounds that may cause harmful effects to marine invertebrates. Expression of microsomal proteins can be changed by oil exposure, causing functional alterations in endoplasmic reticulum (ER). The aim of this study was to investigate changes in protein expression signatures in microsomes of oysterl Crassostrea brasiliana (=C.gasar) gill after exposure to 10% diesel-WAF for 24 and 72 h. Protein expression signatures of gills of oysters exposed to diesel-WAF were compared to those of unexposed oysters using two-dimensional electrophoresis (2-DE) to identify differentially expressed proteins. A total of 458 protein spots with molecular weights between 30-75 kDa were detected by 2-DE in six replicates of exposed oyster proteomes compared to unexposed ones. Fourteen differentially expressed proteins (six up-regulated and eight down-regulated) were identified. They are: proteins related to xenobiotic biotransformation (cytochrome P450 6 A, NADPH-cytochrome P450 reductase); cytoskeleton (α-tubulin, β-tubulin, gelsolin); processing and degradation of proteins pathways (thioredoxin domain-containing protein E3 ubiquitin-protein ligase MIB2); involved in the biosynthesis of glycolipids and glycoproteins (beta-1,3-galactosyltransferase 1); associated with stress responses (glutamate receptor 4 and 14-3-3 protein zeta, corticotropin-releasing factor-binding protein); plasmalogen biosynthesis (fatty acyl-CoA reductase 1), and sodium-and chloride-dependent glycine transporter 2 and glyoxylate reductase/hydroxypyruvate reductase. Different patterns of protein responses were observed between 24 and 72 h-exposed groups. Expression pattern of microsomal proteins provided a first insight on the potential diesel-WAF effects at protein level in microsomal fraction of oyster gills and indicated new potential biomarkers of exposure and effect. The present work can be a basis for future ecotoxicological studies in oysters aiming to elucidate the molecular mechanisms behind diesel-WAF toxicity and for environmental monitoring programs.
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Affiliation(s)
- Gabrielle do Amaral E Silva Müller
- Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Biochemistry Department, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil
| | - Karim Hahn Lüchmann
- Laboratory of Biochemistry and Molecular Biology - LBBM, Fishery Engineering Department, Santa Catarina State University, Laguna, 88790-000, Brazil
| | - Guilherme Razzera
- Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Biochemistry Department, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil
| | - Guilherme Toledo-Silva
- Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Biochemistry Department, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil
| | - Maria João Bebianno
- Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Biochemistry Department, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil; Centre of Marine and Environmental Research (CIMA), University of Algarve, Campus de Gambelas, 8000-139 Faro, Portugal
| | - Maria Risoleta Freire Marques
- Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Biochemistry Department, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil
| | - Afonso Celso Dias Bainy
- Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Biochemistry Department, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil.
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91
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Pathak D, Thakur S, Mallik R. Fluorescence microscopy applied to intracellular transport by microtubule motors. J Biosci 2018; 43:437-445. [PMID: 30002263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Long-distance transport of many organelles inside eukaryotic cells is driven by the dynein and kinesin motors on microtubule filaments. More than 30 years since the discovery of these motors, unanswered questions include motor- organelle selectivity, structural determinants of processivity, collective behaviour of motors and track selection within the complex cytoskeletal architecture, to name a few. Fluorescence microscopy has been invaluable in addressing some of these questions. Here we present a review of some efforts to understand these sub-microscopic machines using fluorescence.
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Affiliation(s)
- Divya Pathak
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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92
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Abstract
Microtubules act as "railways" for motor-driven intracellular transport, interact with accessory proteins to assemble into larger structures such as the mitotic spindle, and provide an organizational framework to the rest of the cell. Key to these functions is the fact that microtubules are "dynamic." As with actin, the polymer dynamics are driven by nucleotide hydrolysis and influenced by a host of specialized regulatory proteins, including microtubule-associated proteins. However, microtubule turnover involves a surprising behavior-termed dynamic instability-in which individual polymers switch stochastically between growth and depolymerization. Dynamic instability allows microtubules to explore intracellular space and remodel in response to intracellular and extracellular cues. Here, we review how such instability is central to the assembly of many microtubule-based structures and to the robust functioning of the microtubule cytoskeleton.
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Affiliation(s)
- Holly V Goodson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Erin M Jonasson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
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93
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94
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Muraleedharan S, Sam A, Skaer H, Inamdar MS. Networks that link cytoskeletal regulators and diaphragm proteins underpin filtration function in Drosophila nephrocytes. Exp Cell Res 2018; 364:234-242. [PMID: 29458174 PMCID: PMC5883325 DOI: 10.1016/j.yexcr.2018.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 02/06/2018] [Accepted: 02/15/2018] [Indexed: 11/25/2022]
Abstract
Insect nephrocytes provide a valuable model for kidney disease, as they are structurally and functionally homologous to mammalian kidney podocytes. They possess an exceptional macromolecular assembly, the nephrocyte diaphragm (ND), which serves as a filtration barrier and helps maintain tissue homeostasis by filtering out wastes and toxic products. However, the elements that maintain nephrocyte architecture and the ND are not understood. We show that Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin, which is maintained by the microtubule cytoskeleton and Rho-GTPases. A balance of Rac1 and Cdc42 activity as well as proper microtubule organization and endoplasmic reticulum structure, are required to position the actin cluster. Further, ND proteins Sns and Duf also localize to this cluster and regulate organization of the actin and microtubule cytoskeleton. Perturbation of any of these inter-dependent components impairs nephrocyte ultrafiltration. Thus cytoskeletal components, Rho-GTPases and ND proteins work in concert to maintain the specialized nephrocyte architecture and function. Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin. Microtubules, Rho-GTPases and endoplasmic reticulum position the actin cluster. Nephrocyte diaphragm proteins localize to and regulate actin cluster organization. Perturbation of any of these inter-dependent components impairs ultrafiltration.
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Affiliation(s)
- Simi Muraleedharan
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Aksah Sam
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Helen Skaer
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Maneesha S Inamdar
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India; Institute for Stem Cell Biology and Regenerative Medicine, GKVK, Bellary Road, Bangalore 560065, India.
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95
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ATF6α regulates morphological changes associated with senescence in human fibroblasts. Oncotarget 2018; 7:67699-67715. [PMID: 27563820 PMCID: PMC5356513 DOI: 10.18632/oncotarget.11505] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/02/2016] [Indexed: 12/14/2022] Open
Abstract
Cellular senescence is known as an anti-tumor barrier and is characterized by a number of determinants including cell cycle arrest, senescence associated β-galactosidase activity and secretion of pro-inflammatory mediators. Senescent cells are also subjected to enlargement, cytoskeleton-mediated shape changes and organelle alterations. However, the underlying molecular mechanisms responsible for these last changes remain still uncharacterized. Herein, we have identified the Unfolded Protein Response (UPR) as a player controlling some morphological aspects of the senescent phenotype. We show that senescent fibroblasts exhibit ER expansion and mild UPR activation, but conserve an ER stress adaptive capacity similar to that of exponentially growing cells. By genetically invalidating the three UPR sensors in senescent fibroblasts, we demonstrated that ATF6α signaling dictates senescence-associated cell shape modifications. We also show that ER expansion and increased secretion of the pro-inflammatory mediator IL6 were partly reversed by silencing ATF6α in senescent cells. Moreover, ATF6α drives the increase of senescence associated-β-galactosidase activity. Collectively, these findings unveil a novel and central role for ATF6α in the establishment of morphological features of senescence in normal human primary fibroblasts.
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96
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Howes SC, Geyer EA, LaFrance B, Zhang R, Kellogg EH, Westermann S, Rice LM, Nogales E. Structural and functional differences between porcine brain and budding yeast microtubules. Cell Cycle 2018; 17:278-287. [PMID: 29278985 PMCID: PMC5914886 DOI: 10.1080/15384101.2017.1415680] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The cytoskeleton of eukaryotic cells relies on microtubules to perform many essential functions. We have previously shown that, in spite of the overall conservation in sequence and structure of tubulin subunits across species, there are differences between mammalian and budding yeast microtubules with likely functional consequences for the cell. Here we expand our structural and function comparison of yeast and porcine microtubules to show different distribution of protofilament number in microtubules assembled in vitro from these two species. The different geometry at lateral contacts between protofilaments is likely due to a more polar interface in yeast. We also find that yeast tubulin forms longer and less curved oligomers in solution, suggesting stronger tubulin:tubulin interactions along the protofilament. Finally, we observed species-specific plus-end tracking activity for EB proteins: yeast Bim1 tracked yeast but not mammalian MTs, and human EB1 tracked mammalian but not yeast MTs. These findings further demonstrate that subtle sequence differences in tubulin sequence can have significant structural and functional consequences in microtubule structure and behavior.
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Affiliation(s)
- Stuart C Howes
- a Biophysics Graduate Group , UC Berkeley , CA 94720 , USA and Department of Molecular Cell Biology , Leiden University Medical Center , 2333 ZC Leiden , Netherlands
| | - Elisabeth A Geyer
- b UT Southwestern Medical Center , Departments of Biophysics and Biochemistry , Dallas , TX 75390 , USA
| | - Benjamin LaFrance
- c Molecular and Cell Biology Graduate Program , UC Berkeley , CA 94720 , USA
| | - Rui Zhang
- d Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , CA 94720 , USA.,e Howard Hughes Medical Institute , UC Berkeley , CA 94720-3220 , USA.,f Department of Biochemistry and Molecular Biophysics , Washington University School of Medicine , St. Louis , MO 63110 , USA
| | - Elizabeth H Kellogg
- d Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , CA 94720 , USA.,e Howard Hughes Medical Institute , UC Berkeley , CA 94720-3220 , USA
| | - Stefan Westermann
- g Research Institute of Molecular Pathology , Dr. Bohr-Gasse 7, 1030 Vienna , Austria
| | - Luke M Rice
- b UT Southwestern Medical Center , Departments of Biophysics and Biochemistry , Dallas , TX 75390 , USA
| | - Eva Nogales
- d Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , CA 94720 , USA.,e Howard Hughes Medical Institute , UC Berkeley , CA 94720-3220 , USA.,h Molecular and Cell Biology Department and QB3 Institute , UC Berkeley , CA 94720 , USA
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97
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McIntosh BB, Pyrpassopoulos S, Holzbaur ELF, Ostap EM. Opposing Kinesin and Myosin-I Motors Drive Membrane Deformation and Tubulation along Engineered Cytoskeletal Networks. Curr Biol 2018; 28:236-248.e5. [PMID: 29337076 DOI: 10.1016/j.cub.2017.12.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 09/29/2017] [Accepted: 12/07/2017] [Indexed: 01/22/2023]
Abstract
Microtubule and actin filament molecular motors such as kinesin-1 and myosin-Ic (Myo1c) transport and remodel membrane-bound vesicles; however, it is unclear how they coordinate to accomplish these tasks. We introduced kinesin-1- and Myo1c-bound giant unilamellar vesicles (GUVs) into a micropatterned in vitro cytoskeletal matrix modeled after the subcellular architecture where vesicular sorting and membrane remodeling are observed. This array was composed of sparse microtubules intersecting regions dense with actin filaments, and revealed that Myo1c-dependent tethering of GUVs enabled kinesin-1-driven membrane deformation and tubulation. Membrane remodeling at actin/microtubule intersections was modulated by lipid composition and the addition of the Bin-Amphiphysin-Rvs-domain (BAR-domain) proteins endophilin or FCH-domain-only (FCHo). Myo1c not only tethered microtubule-transported cargo, but also transported, deformed, and tubulated GUVs along actin filaments in a lipid-composition- and BAR-protein-responsive manner. These results suggest a mechanism for actin-based involvement in vesicular transport and remodeling of intracellular membranes, and implicate lipid composition as a key factor in determining whether vesicles will undergo transport, deformation, or tubulation driven by opposing actin and microtubule motors and BAR-domain proteins.
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Affiliation(s)
- Betsy B McIntosh
- The Pennsylvania Muscle Institute and Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA; Center for Engineering MechanoBiology, University of Pennsylvania, Philadelphia, PA 19104-6085, USA
| | - Serapion Pyrpassopoulos
- The Pennsylvania Muscle Institute and Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA; Center for Engineering MechanoBiology, University of Pennsylvania, Philadelphia, PA 19104-6085, USA
| | - Erika L F Holzbaur
- The Pennsylvania Muscle Institute and Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA; Center for Engineering MechanoBiology, University of Pennsylvania, Philadelphia, PA 19104-6085, USA.
| | - E Michael Ostap
- The Pennsylvania Muscle Institute and Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA; Center for Engineering MechanoBiology, University of Pennsylvania, Philadelphia, PA 19104-6085, USA.
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98
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Spiliotis ET. Spatial effects - site-specific regulation of actin and microtubule organization by septin GTPases. J Cell Sci 2018; 131:jcs207555. [PMID: 29326311 PMCID: PMC5818061 DOI: 10.1242/jcs.207555] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The actin and microtubule cytoskeletons comprise a variety of networks with distinct architectures, dynamics and protein composition. A fundamental question in eukaryotic cell biology is how these networks are spatially and temporally controlled, so they are positioned in the right intracellular places at the right time. While significant progress has been made in understanding the self-assembly of actin and microtubule networks, less is known about how they are patterned and regulated in a site-specific manner. In mammalian systems, septins are a large family of GTP-binding proteins that multimerize into higher-order structures, which associate with distinct subsets of actin filaments and microtubules, as well as membranes of specific curvature and lipid composition. Recent studies have shed more light on how septins interact with actin and microtubules, and raised the possibility that the cytoskeletal topology of septins is determined by their membrane specificity. Importantly, new functions have emerged for septins regarding the generation, maintenance and positioning of cytoskeletal networks with distinct organization and biochemical makeup. This Review presents new and past findings, and discusses septins as a unique regulatory module that instructs the local differentiation and positioning of distinct actin and microtubule networks.
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Affiliation(s)
- Elias T Spiliotis
- Drexel University, Department of Biology, Drexel University, Philadelphia, PA 19104, USA
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99
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Luarte A, Cornejo VH, Bertin F, Gallardo J, Couve A. The axonal endoplasmic reticulum: One organelle-many functions in development, maintenance, and plasticity. Dev Neurobiol 2017; 78:181-208. [PMID: 29134778 DOI: 10.1002/dneu.22560] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/02/2017] [Accepted: 11/07/2017] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) is highly conserved in eukaryotes and neurons. Indeed, the localization of the organelle in axons has been known for nearly half a century. However, the relevance of the axonal ER is only beginning to emerge. In this review, we discuss the structure of the ER in axons, examining the role of ER-shaping proteins and highlighting reticulons. We analyze the multiple functions of the ER and their potential contribution to axonal physiology. First, we examine the emerging roles of the axonal ER in lipid synthesis, protein translation, processing, quality control, and secretory trafficking of transmembrane proteins. We also review the impact of the ER on calcium dynamics, focusing on intracellular mechanisms and functions. We describe the interactions between the ER and endosomes, mitochondria, and synaptic vesicles. Finally, we analyze available proteomic data of axonal preparations to reveal the dynamic functionality of the ER in axons during development. We suggest that the dynamic proteome and a validated axonal interactome, together with state-of-the-art methodologies, may provide interesting research avenues in axon physiology that may extend to pathology and regeneration. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 181-208, 2018.
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Affiliation(s)
- Alejandro Luarte
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Víctor Hugo Cornejo
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Francisca Bertin
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Javiera Gallardo
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Andrés Couve
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
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100
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A new insight into the three-dimensional architecture of the Golgi complex: Characterization of unusual structures in epididymal principal cells. PLoS One 2017; 12:e0185557. [PMID: 28957389 PMCID: PMC5619803 DOI: 10.1371/journal.pone.0185557] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/14/2017] [Indexed: 12/01/2022] Open
Abstract
Principal epididymal cells have one of the largest and more developed Golgi complex of mammalian cells. In the present study, we have used this cell as model for the study of the three-dimensional architecture of the Golgi complex of highly secretory and endocytic cells. Electron tomography demonstrated the presence in this cell type of some unknown or very unusual Golgi structures such as branched cisternae, pocket-like cisternal invaginations or tubular connections. In addition, we have used this methodology and immunoelectron microscopy to analyze the close relationship between this organelle and both the endoplasmic reticulum and microtubules, and to describe in detail how these elements interact with compact and non-compact regions of the ribbon.
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