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Saraste J, Prydz K. A New Look at the Functional Organization of the Golgi Ribbon. Front Cell Dev Biol 2019; 7:171. [PMID: 31497600 PMCID: PMC6713163 DOI: 10.3389/fcell.2019.00171] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/07/2019] [Indexed: 12/14/2022] Open
Abstract
A characteristic feature of vertebrate cells is a Golgi ribbon consisting of multiple cisternal stacks connected into a single-copy organelle next to the centrosome. Despite numerous studies, the mechanisms that link the stacks together and the functional significance of ribbon formation remain poorly understood. Nevertheless, these questions are of considerable interest, since there is increasing evidence that Golgi fragmentation – the unlinking of the stacks in the ribbon – is intimately connected not only to normal physiological processes, such as cell division and migration, but also to pathological states, including neurodegeneration and cancer. Challenging a commonly held view that ribbon architecture involves the formation of homotypic tubular bridges between the Golgi stacks, we present an alternative model, based on direct interaction between the biosynthetic (pre-Golgi) and endocytic (post-Golgi) membrane networks and their connection with the centrosome. We propose that the central domains of these permanent pre- and post-Golgi networks function together in the biogenesis and maintenance of the more transient Golgi stacks, and thereby establish “linker compartments” that dynamically join the stacks together. This model provides insight into the reversible fragmentation of the Golgi ribbon that takes place in dividing and migrating cells and its regulation along a cell surface – Golgi – centrosome axis. Moreover, it helps to understand transport pathways that either traverse or bypass the Golgi stacks and the positioning of the Golgi apparatus in differentiated neuronal, epithelial, and muscle cells.
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Affiliation(s)
- Jaakko Saraste
- Department of Biomedicine and Molecular Imaging Center, University of Bergen, Bergen, Norway
| | - Kristian Prydz
- Department of Biosciences, University of Oslo, Oslo, Norway
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2
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Fourriere L, Divoux S, Roceri M, Perez F, Boncompain G. Microtubule-independent secretion requires functional maturation of Golgi elements. J Cell Sci 2016; 129:3238-50. [DOI: 10.1242/jcs.188870] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 07/08/2016] [Indexed: 12/17/2022] Open
Abstract
The Golgi apparatus is responsible for processing and sorting of secretory cargos. Microtubules are known to accelerate the transport of proteins from the endoplasmic reticulum to the Golgi apparatus and from the Golgi to the plasma membrane. However, whether post-Golgi transport strictly requires microtubules is still unclear. Using the retention using selective hooks (RUSH) system to synchronize the trafficking of cargos, we show that anterograde transport of tumor necrosis factor (TNF) is strongly reduced without microtubules. We show that two populations of Golgi elements co-exist in these cells. A centrally located and giantin-positive Golgi complex sustains trafficking while newly formed peripheral Golgi mini-stacks accumulate cargos in cells without microtubules. Using a genome-edited GFP-giantin cell line, we observe that the trafficking-competent Golgi population corresponds to the pre-existing one that was present before removal of microtubules. All Golgi elements support trafficking after long-term microtubules depletion or after relocation of Golgi proteins in the endoplasmic reticulum using Brefeldin A. Our results demonstrate that functional maturation of Golgi elements is needed to ensure post-Golgi trafficking and that microtubule-driven post-Golgi transport is not strictly required.
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Affiliation(s)
- Lou Fourriere
- Institut Curie, Centre de Recherche, PSL research University, Paris, France
- CNRS UMR144, Paris, France
- UPMC, Paris, France
| | - Severine Divoux
- Institut Curie, Centre de Recherche, PSL research University, Paris, France
- CNRS UMR144, Paris, France
| | - Mila Roceri
- Institut Curie, Centre de Recherche, PSL research University, Paris, France
- CNRS UMR144, Paris, France
| | - Franck Perez
- Institut Curie, Centre de Recherche, PSL research University, Paris, France
- CNRS UMR144, Paris, France
| | - Gaelle Boncompain
- Institut Curie, Centre de Recherche, PSL research University, Paris, France
- CNRS UMR144, Paris, France
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3
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Schuberth CE, Tängemo C, Coneva C, Tischer C, Pepperkok R. Self-organization of core Golgi material is independent of COPII-mediated endoplasmic reticulum export. J Cell Sci 2015; 128:1279-93. [PMID: 25717003 DOI: 10.1242/jcs.154443] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The Golgi is a highly organized and dynamic organelle that receives and distributes material from and to the endoplasmic reticulum (ER) and the endocytic pathway. One open question about Golgi organization is whether it is solely based on ER-to-Golgi transport. Here, we analyzed the kinetics of Golgi breakdown in the absence of COPII-dependent ER export with high temporal and spatial resolution using quantitative fluorescence microscopy. We found that Golgi breakdown occurred in two phases. While Golgi enzymes continuously redistributed to the ER, we consistently observed extensive Golgi fragmentation at the beginning of the breakdown, followed by microtubule-dependent formation of a Golgi remnant structure (phase 1). Further Golgi disintegration occurred less uniformly (phase 2). Remarkably, cisternal Golgi morphology was lost early in phase 1 and Golgi fragments instead corresponded to variably sized vesicle clusters. These breakdown intermediates were devoid of COPI-dependent recycling material, but contained typical 'core' Golgi components. Furthermore, Golgi breakdown intermediates were able to disassemble and reassemble following cell division, indicating that they retained important regulatory capabilities. Taken together, these findings support the view that Golgi self-organization exists independently of ER-to-Golgi transport.
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Affiliation(s)
- Christian E Schuberth
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany Institute of Cell Dynamics and Imaging, University of Muenster, von-Esmarch-Str. 56, 48149 Muenster, Germany Cells in Motion Cluster of Excellence (EXC1003-CiM), University of Muenster, von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Carolina Tängemo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Cvetalina Coneva
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Christian Tischer
- Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Rainer Pepperkok
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
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Fraisier V, Kasri A, Miserey-Lenkei S, Sibarita JB, Nair D, Mayeux A, Bardin S, Toyoda Y, Poser I, Poznyakovskiy A, Goud B, Hyman AA, Dimitrov A. C11ORF24 is a novel type I membrane protein that cycles between the Golgi apparatus and the plasma membrane in Rab6-positive vesicles. PLoS One 2013; 8:e82223. [PMID: 24312644 PMCID: PMC3846831 DOI: 10.1371/journal.pone.0082223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 10/21/2013] [Indexed: 01/03/2023] Open
Abstract
The Golgi apparatus is an intracellular compartment necessary for post-translational modification, sorting and transport of proteins. It plays a key role in mitotic entry through the Golgi mitotic checkpoint. In order to identify new proteins involved in the Golgi mitotic checkpoint, we combine the results of a knockdown screen for mitotic phenotypes and a localization screen. Using this approach, we identify a new Golgi protein C11ORF24 (NP_071733.1). We show that C11ORF24 has a signal peptide at the N-terminus and a transmembrane domain in the C-terminal region. C11ORF24 is localized on the Golgi apparatus and on the trans-Golgi network. A large part of the protein is present in the lumen of the Golgi apparatus whereas only a short tail extends into the cytosol. This cytosolic tail is well conserved in evolution. By FRAP experiments we show that the dynamics of C11ORF24 in the Golgi membrane are coherent with the presence of a transmembrane domain in the protein. C11ORF24 is not only present on the Golgi apparatus but also cycles to the plasma membrane via endosomes in a pH sensitive manner. Moreover, via video-microscopy studies we show that C11ORF24 is found on transport intermediates and is colocalized with the small GTPase RAB6, a GTPase involved in anterograde transport from the Golgi to the plasma membrane. Knocking down C11ORF24 does not lead to a mitotic phenotype or an intracellular transport defect in our hands. All together, these data suggest that C11ORF24 is present on the Golgi apparatus, transported to the plasma membrane and cycles back through the endosomes by way of RAB6 positive carriers.
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Affiliation(s)
- Vincent Fraisier
- UMR144, Institut Curie/ CNRS, Cell and Tissue Imaging Platform, Paris, France
| | - Amal Kasri
- UMR144, Institut Curie/CNRS, Molecular Mechanisms of Intracellular Transport, Paris, France
| | | | - Jean-Baptiste Sibarita
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, Bordeaux, France
- CNRS, UMR 5297, Bordeaux, France
| | - Deepak Nair
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, Bordeaux, France
- CNRS, UMR 5297, Bordeaux, France
| | - Adeline Mayeux
- UMR144, Institut Curie/CNRS, Molecular Mechanisms of Intracellular Transport, Paris, France
| | - Sabine Bardin
- UMR144, Institut Curie/CNRS, Molecular Mechanisms of Intracellular Transport, Paris, France
| | - Yusuke Toyoda
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | | | - Bruno Goud
- UMR144, Institut Curie/CNRS, Molecular Mechanisms of Intracellular Transport, Paris, France
| | - Anthony A. Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ariane Dimitrov
- UMR144, Institut Curie/CNRS, Molecular Mechanisms of Intracellular Transport, Paris, France
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail:
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Marie M, Dale HA, Kouprina N, Saraste J. Division of the intermediate compartment at the onset of mitosis provides a mechanism for Golgi inheritance. J Cell Sci 2012; 125:5403-16. [PMID: 22946056 DOI: 10.1242/jcs.108100] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
As mammalian cells prepare for mitosis, the Golgi ribbon is first unlinked into its constituent stacks and then transformed into spindle-associated, pleiomorphic membrane clusters in a process that remains enigmatic. Also, it remains unclear whether Golgi inheritance involves the incorporation of Golgi enzymes into a pool of coat protein I (COPI) vesicles, or their COPI-independent transfer to the endoplasmic reticulum (ER). Based on the observation that the intermediate compartment (IC) at the ER-Golgi boundary is connected to the centrosome, we examined its mitotic fate and possible role in Golgi breakdown. The use of multiple imaging techniques and markers revealed that the IC elements persist during the M phase, maintain their compositional and structural properties and remain associated with the mitotic spindle, forming circular arrays at the spindle poles. At G2/M transition, the movement of the pericentrosomal domain of the IC (pcIC) to the cell centre and its expansion coincide with the unlinking of the Golgi ribbon. At prophase, coupled to centrosome separation, the pcIC divides together with recycling endosomes, providing novel landmarks for mitotic entry. We provide evidence that the permanent IC elements function as way stations during the COPI-dependent dispersal of Golgi components at prometa- and metaphase, indicating that they correspond to the previously described Golgi clusters. In addition, they continue to communicate with the vesicular 'Golgi haze' and thus are likely to provide templates for Golgi reassembly. These results implicate the IC in mitotic Golgi inheritance, resulting in a model that integrates key features of the two previously proposed pathways.
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Affiliation(s)
- Michaël Marie
- Department of Biomedicine and Molecular Imaging Center, University of Bergen, Jonas Lies Vei 91, N-5009 Bergen, Norway
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Vielemeyer O, Nizak C, Jimenez AJ, Echard A, Goud B, Camonis J, Rain JC, Perez F. Characterization of single chain antibody targets through yeast two hybrid. BMC Biotechnol 2010; 10:59. [PMID: 20727208 PMCID: PMC2936416 DOI: 10.1186/1472-6750-10-59] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 08/22/2010] [Indexed: 05/12/2023] Open
Abstract
Background Due to their unique ability to bind their targets with high fidelity, antibodies are used widely not only in biomedical research, but also in many clinical applications. Recombinant antibodies, including single chain variable fragments (scFv), are gaining momentum because they allow powerful in vitro selection and manipulation without loss of function. Regardless of the ultimate application or type of antibody used, precise understanding of the interaction between the antibody's binding site and its specific target epitope(s) is of great importance. However, such data is frequently difficult to obtain. Results We describe an approach that allows detailed characterization of a given antibody's target(s) using the yeast two-hybrid system. Several recombinant scFv were used as bait and screened against highly complex cDNA libraries. Systematic sequencing of all retained clones and statistical analysis allowed efficient ranking of the prey fragments. Multiple alignment of the obtained cDNA fragments provided a selected interacting domain (SID), efficiently narrowing the epitope-containing region. Interactions between antibodies and their respective targets were characterized for several scFv. For AA2 and ROF7, two conformation-specific sensors that exclusively bind the activated forms of the small GTPases Rab6 and Rab1 respectively, only fragments expressing the entire target protein's core region were retained. This strongly suggested interaction with a non-linear epitope. For two other scFv, TA10 and SF9, which recognize the large proteins giantin and non-muscle myosin IIA, respectively, precise antibody-binding regions within the target were defined. Finally, for some antibodies, secondary targets within and across species could be revealed. Conclusions Our method, utilizing the yeast two-hybrid technology and scFv as bait, is a simple yet powerful approach for the detailed characterization of antibody targets. It allows precise domain mapping for linear epitopes, confirmation of non-linear epitopes for conformational sensors, and detection of secondary binding partners. This approach may thus prove to be an elegant and rapid method for the target characterization of newly obtained scFv antibodies. It may be considered prior to any research application and particularly before any use of such recombinant antibodies in clinical medicine.
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Affiliation(s)
- Ole Vielemeyer
- Institut Curie-Research Center, 26 rue d'Ulm, Paris cedex 05, France
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Phosphorylation and membrane dissociation of the ARF exchange factor GBF1 in mitosis. Biochem J 2010; 427:401-12. [PMID: 20175751 DOI: 10.1042/bj20091681] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Secretory protein trafficking is arrested and the Golgi apparatus fragmented when mammalian cells enter mitosis. These changes are thought to facilitate cell-cycle progression and Golgi inheritance, and are brought about through the actions of mitotically active protein kinases. To better understand how the Golgi apparatus undergoes mitotic fragmentation we have sought to identify novel Golgi targets for mitotic kinases. We report in the present paper the identification of the ARF (ADP-ribosylation factor) exchange factor GBF1 (Golgi-specific brefeldin A-resistant guanine nucleotide-exchange factor 1) as a Golgi phosphoprotein. GBF1 is phosphorylated by CDK1 (cyclin-dependent kinase 1)-cyclin B in mitosis, which results in its dissociation from Golgi membranes. Consistent with a reduced level of GBF1 activity at the Golgi membrane there is a reduction in levels of membrane-associated GTP-bound ARF in mitotic cells. Despite the reduced levels of membrane-bound GBF1 and ARF, COPI (coat protein I) binding to the Golgi membrane appears unaffected in mitotic cells. Surprisingly, this pool of COPI is dependent upon GBF1 for its recruitment to the membrane, suggesting that a low level of GBF1 activity persists in mitosis. We propose that the phosphorylation and membrane dissociation of GBF1 and the consequent reduction in ARF-GTP levels in mitosis are important for changes in Golgi dynamics and possibly other mitotic events mediated through effectors other than the COPI vesicle coat.
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Jollivet F, Raposo G, Dimitrov A, Sougrat R, Goud B, Perez F. Analysis of de novo Golgi complex formation after enzyme-based inactivation. Mol Biol Cell 2007; 18:4637-47. [PMID: 17855505 PMCID: PMC2043539 DOI: 10.1091/mbc.e07-08-0799] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The Golgi complex is characterized by its unique morphology of closely apposed flattened cisternae that persists despite the large quantity of lipids and proteins that transit bidirectionally. Whether such a structure is maintained through endoplasmic reticulum (ER)-based recycling and auto-organization or whether it depends on a permanent Golgi structure is strongly debated. To further study Golgi maintenance in interphase cells, we developed a method allowing for a drug-free inactivation of Golgi dynamics and function in living cells. After Golgi inactivation, a new Golgi-like structure, containing only certain Golgi markers and newly synthesized cargoes, was produced. However, this structure did not acquire a normal Golgi architecture and was unable to ensure a normal trafficking activity. This suggests an integrative model for Golgi maintenance in interphase where the ER is able to autonomously produce Golgi-like structures that need pre-existing Golgi complexes to be organized as morphologically normal and active Golgi elements.
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Affiliation(s)
- Florence Jollivet
- *Centre National de la Recherche Scientifique Unité Mixte de Recherche 144, 75248 Paris Cedex 05, France
- Institut Curie, 75248 Paris Cedex 05, France; and
| | - Graça Raposo
- *Centre National de la Recherche Scientifique Unité Mixte de Recherche 144, 75248 Paris Cedex 05, France
- Institut Curie, 75248 Paris Cedex 05, France; and
| | - Ariane Dimitrov
- *Centre National de la Recherche Scientifique Unité Mixte de Recherche 144, 75248 Paris Cedex 05, France
- Institut Curie, 75248 Paris Cedex 05, France; and
| | - Rachid Sougrat
- Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-5430
| | - Bruno Goud
- *Centre National de la Recherche Scientifique Unité Mixte de Recherche 144, 75248 Paris Cedex 05, France
- Institut Curie, 75248 Paris Cedex 05, France; and
| | - Franck Perez
- *Centre National de la Recherche Scientifique Unité Mixte de Recherche 144, 75248 Paris Cedex 05, France
- Institut Curie, 75248 Paris Cedex 05, France; and
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Théry M, Racine V, Piel M, Pépin A, Dimitrov A, Chen Y, Sibarita JB, Bornens M. Anisotropy of cell adhesive microenvironment governs cell internal organization and orientation of polarity. Proc Natl Acad Sci U S A 2006; 103:19771-6. [PMID: 17179050 PMCID: PMC1750916 DOI: 10.1073/pnas.0609267103] [Citation(s) in RCA: 411] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Control of the establishment of cell polarity is an essential function in tissue morphogenesis and renewal that depends on spatial cues provided by the extracellular environment. The molecular role of cell-cell or cell-extracellular matrix (ECM) contacts on the establishment of cell polarity has been well characterized. It has been hypothesized that the geometry of the cell adhesive microenvironment was directing cell surface polarization and internal organization. To define how the extracellular environment affects cell polarity, we analyzed the organization of individual cells plated on defined micropatterned substrates imposing cells to spread on various combinations of adhesive and nonadhesive areas. The reproducible normalization effect on overall cell compartmentalization enabled quantification of the spatial organization of the actin network and associated proteins, the spatial distribution of microtubules, and the positioning of nucleus, centrosome, and Golgi apparatus. By using specific micropatterns and statistical analysis of cell compartment positions, we demonstrated that ECM geometry determines the orientation of cell polarity axes. The nucleus-centrosome orientations were reproducibly directed toward cell adhesive edges. The anisotropy of the cell cortex in response to the adhesive conditions did not affect the centrosome positioning at the cell centroid. Based on the quantification of microtubule plus end distribution we propose a working model that accounts for that observation. We conclude that, in addition to molecular composition and mechanical properties, ECM geometry plays a key role in developmental processes.
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Affiliation(s)
- Manuel Théry
- *Biologie du Cycle Cellulaire et de la Motilité, and
| | - Victor Racine
- Service d'Imagerie, Unité Mixte de Recherche 144, Centre National de la Recherche Scientifique, Institut Curie, 26 Rue d'Ulm, 75248 Paris Cedex 5, France; and
| | - Matthieu Piel
- *Biologie du Cycle Cellulaire et de la Motilité, and
| | - Anne Pépin
- Groupe Nanotechnologie et Dispositifs Microfluidiques, Unité Propre de Recherche 20, Laboratoire Photonique et Nanostructures, Centre National de la Recherche Scientifique, Route de Nozay, 91460 Marcoussis, France
| | | | - Yong Chen
- Groupe Nanotechnologie et Dispositifs Microfluidiques, Unité Propre de Recherche 20, Laboratoire Photonique et Nanostructures, Centre National de la Recherche Scientifique, Route de Nozay, 91460 Marcoussis, France
| | - Jean-Baptiste Sibarita
- Service d'Imagerie, Unité Mixte de Recherche 144, Centre National de la Recherche Scientifique, Institut Curie, 26 Rue d'Ulm, 75248 Paris Cedex 5, France; and
| | - Michel Bornens
- *Biologie du Cycle Cellulaire et de la Motilité, and
- To whom correspondence should be addressed. E-mail:
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Miserey-Lenkei S, Couëdel-Courteille A, Del Nery E, Bardin S, Piel M, Racine V, Sibarita JB, Perez F, Bornens M, Goud B. A role for the Rab6A' GTPase in the inactivation of the Mad2-spindle checkpoint. EMBO J 2006; 25:278-89. [PMID: 16395330 PMCID: PMC1383512 DOI: 10.1038/sj.emboj.7600929] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 11/30/2005] [Indexed: 12/21/2022] Open
Abstract
The two isoforms of the Rab6 GTPase, Rab6A and Rab6A', regulate a retrograde transport route connecting early endosomes and the endoplasmic reticulum via the Golgi complex in interphasic cells. Here we report that when Rab6A' function is altered cells are unable to progress normally through mitosis. Such cells are blocked in metaphase, despite displaying a normal Golgi fragmentation and with the Mad2-spindle checkpoint activated. Furthermore, the Rab6 effector p150(Glued), a subunit of the dynein/dynactin complex, remains associated with some kinetochores. A similar phenotype was observed when GAPCenA, a GTPase-activating protein of Rab6, was depleted from cells. Our results suggest that Rab6A' likely regulates the dynamics of the dynein/dynactin complex at the kinetochores and consequently the inactivation of the Mad2-spindle checkpoint. Rab6A', through its interaction with p150(Glued) and GAPCenA, may thus participate in a pathway involved in the metaphase/anaphase transition.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Bruno Goud
- UMR 144 CNRS/IC, Institut Curie, Paris, France
- UMR 144 CNRS/Institut Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France. Tel.: +33 1 4234 6398; Fax: +33 1 4234 6382; E-mail:
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Altan-Bonnet N, Sougrat R, Liu W, Snapp EL, Ward T, Lippincott-Schwartz J. Golgi inheritance in mammalian cells is mediated through endoplasmic reticulum export activities. Mol Biol Cell 2005; 17:990-1005. [PMID: 16314396 PMCID: PMC1356606 DOI: 10.1091/mbc.e05-02-0155] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Golgi inheritance during mammalian cell division occurs through the disassembly, partitioning, and reassembly of Golgi membranes. The mechanisms responsible for these processes are poorly understood. To address these mechanisms, we have examined the identity and dynamics of Golgi proteins within mitotic membranes using live cell imaging and electron microscopy techniques. Mitotic Golgi fragments, seen in prometaphase and telophase, were found to localize adjacent to endoplasmic reticulum (ER) export domains, and resident Golgi transmembrane proteins cycled rapidly into and out of these fragments. Golgi proteins within mitotic Golgi haze-seen during metaphase-were found to redistribute with ER markers into fragments when the ER was fragmented by ionomycin treatment. The temperature-sensitive misfolding mutant ts045VSVG protein, when localized to the Golgi at the start of mitosis, became trapped in the ER at the end of mitosis in cells shifted to 40 degrees C. Finally, reporters for Arf1 and Sar1 activity revealed that Arf1 and Sar1 undergo sequential inactivation during mitotic Golgi breakdown and sequential reactivation upon Golgi reassembly at the end of mitosis. Together, these findings support a model of mitotic Golgi inheritance that involves inhibition and subsequent reactivation of cellular activities controlling the cycling of Golgi components into and out of the ER.
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Affiliation(s)
- Nihal Altan-Bonnet
- Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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