The Experts below are selected from a list of 53439 Experts worldwide ranked by ideXlab platform
Bruno Goud - One of the best experts on this subject based on the ideXlab platform.
-
a role for the rab6a gtpase in the inactivation of the mad2 spindle checkpoint
The EMBO Journal, 2006Co-Authors: Stephanie Misereylenkei, Anne Couedelcourteille, Elaine Del Nery, Sabine Bardin, Matthieu Piel, Victor Racine, Jeanbaptiste Sibarita, Franck Perez, Michel Bornens, Bruno GoudAbstract: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 p150Glued, 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 p150Glued and GAPCenA, may thus participate in a pathway involved in the metaphase/anaphase transition.
-
targeting of shiga toxin b subunit to retrograde Transport Route in association with detergent resistant membranes
Molecular Biology of the Cell, 2001Co-Authors: Thomas Falguieres, Bruno Goud, Frederic Mallard, Carole Baron, Daniel Hanau, Clifford A Lingwood, Jean Salamero, Ludger JohannesAbstract:In HeLa cells, Shiga toxin B-subunit is Transported from the plasma membrane to the endoplasmic reticulum, via early endosomes and the Golgi apparatus, circumventing the late endocytic pathway. We describe here that in cells derived from human monocytes, i.e., macrophages and dendritic cells, the B-subunit was internalized in a receptor-dependent manner, but retrograde Transport to the biosynthetic/secretory pathway did not occur and part of the internalized protein was degraded in lysosomes. These differences correlated with the observation that the B-subunit associated with Triton X-100-resistant membranes in HeLa cells, but not in monocyte-derived cells, suggesting that retrograde targeting to the biosynthetic/secretory pathway required association with specialized microdomains of biological membranes. In agreement with this hypothesis we found that in HeLa cells, the B-subunit resisted extraction by Triton X-100 until its arrival in the target compartments of the retrograde pathway, i.e., the Golgi apparatus and the endoplasmic reticulum. Furthermore, destabilization of Triton X-100-resistant membranes by cholesterol extraction potently inhibited B-subunit Transport from early endosomes to the trans-Golgi network, whereas under the same conditions, recycling of transferrin was not affected. Our data thus provide first evidence for a role of lipid asymmetry in membrane sorting at the interface between early endosomes and the trans-Golgi network.
-
evidence for a cop i independent Transport Route from the golgi complex to the endoplasmic reticulum
Nature Cell Biology, 1999Co-Authors: A Girod, Brian Storrie, Jeremy C Simpson, Ludger Johannes, Bruno Goud, Lynne M Roberts, Janet M Lord, Tommy Nilsson, Rainer PepperkokAbstract:The cytosolic coat-protein complex COP-I interacts with cytoplasmic 'retrieval' signals present in membrane proteins that cycle between the endoplasmic reticulum (ER) and the Golgi complex, and is required for both anterograde and retrograde Transport in the secretory pathway. Here we study the role of COP-I in Golgi-to-ER Transport of several distinct marker molecules. Microinjection of anti-COP-I antibodies inhibits retrieval of the lectin-like molecule ERGIC-53 and of the KDEL receptor from the Golgi to the ER. Transport to the ER of protein toxins, which contain a sequence that is recognized by the KDEL receptor, is also inhibited. In contrast, microinjection of anti-COP-I antibodies or expression of a GTP-restricted Arf-1 mutant does not interfere with Golgi-to-ER Transport of Shiga toxin/Shiga-like toxin-1 or with the apparent recycling to the ER of Golgi-resident glycosylation enzymes. Overexpression of a GDP-restricted mutant of Rab6 blocks Transport to the ER of Shiga toxin/Shiga-like toxin-1 and glycosylation enzymes, but not of ERGIC-53, the KDEL receptor or KDEL-containing toxins. These data indicate the existence of at least two distinct pathways for Golgi-to-ER Transport, one COP-I dependent and the other COP-I independent. The COP-I-independent pathway is specifically regulated by Rab6 and is used by Golgi glycosylation enzymes and Shiga toxin/Shiga-like toxin-1.
Georgia Drakakaki - One of the best experts on this subject based on the ideXlab platform.
-
A Hybrid Approach Enabling Large-Scale Glycomic Analysis of Post-Golgi Vesicles Reveals a Transport Route for Polysaccharides
The Plant Cell, 2019Co-Authors: Thomas Wilkop, Sivakumar Pattathil, Guangxi Ren, Destiny J. Davis, Wenlong Bao, Dechao Duan, Angelo Gabriel Peralta, David S. Domozych, Michael G. Hahn, Georgia DrakakakiAbstract:The plant endomembrane system facilitates the Transport of polysaccharides, associated enzymes, and glycoproteins through its dynamic pathways. Although enzymes involved in cell wall biosynthesis have been identified, little is known about the endomembrane-based Transport of glycan components. This is partially attributed to technical challenges in biochemically determining polysaccharide cargo in specific vesicles. Here, we introduce a hybrid approach addressing this limitation. By combining vesicle isolation with a large-scale carbohydrate antibody arraying technique, we charted an initial large-scale map describing the glycome profile of the SYNTAXIN OF PLANTS61 (SYP61) trans-Golgi network compartment in Arabidopsis (Arabidopsis thaliana). A library of antibodies recognizing specific noncellulosic carbohydrate epitopes allowed us to identify a range of diverse glycans, including pectins, xyloglucans (XyGs), and arabinogalactan proteins in isolated vesicles. Changes in XyG- and pectin-specific epitopes in the cell wall of an Arabidopsis SYP61 mutant corroborate our findings. Our data provide evidence that SYP61 vesicles are involved in the Transport and deposition of structural polysaccharides and glycoproteins. Adaptation of our methodology can enable studies characterizing the glycome profiles of various vesicle populations in plant and animal systems and their respective roles in glycan Transport defined by subcellular markers, developmental stages, or environmental stimuli.
Yong Mao - One of the best experts on this subject based on the ideXlab platform.
-
An adaptive scaled network for public Transport Route optimisation
Public Transport, 2019Co-Authors: Philipp Heyken Soares, Christine L. Mumford, Kwabena Amponsah, Yong MaoAbstract:We introduce an adaptive network for public Transport Route optimisation by scaling down the available street network to a level where optimisation methods such as genetic algorithms can be applied. Our scaling is adapted to preserve the characteristics of the street network. The methodology is applied to the urban area of Nottingham, UK, to generate a new benchmark dataset for bus Route optimisation studies. All travel time and demand data as well as information of permitted start and end points of Routes, are derived from openly available data. The scaled network is tested with the application of a genetic algorithm adapted for restricted Route start and end points. The results are compared with the real-world bus Routes.
Ludger Johannes - One of the best experts on this subject based on the ideXlab platform.
-
targeting of shiga toxin b subunit to retrograde Transport Route in association with detergent resistant membranes
Molecular Biology of the Cell, 2001Co-Authors: Thomas Falguieres, Bruno Goud, Frederic Mallard, Carole Baron, Daniel Hanau, Clifford A Lingwood, Jean Salamero, Ludger JohannesAbstract:In HeLa cells, Shiga toxin B-subunit is Transported from the plasma membrane to the endoplasmic reticulum, via early endosomes and the Golgi apparatus, circumventing the late endocytic pathway. We describe here that in cells derived from human monocytes, i.e., macrophages and dendritic cells, the B-subunit was internalized in a receptor-dependent manner, but retrograde Transport to the biosynthetic/secretory pathway did not occur and part of the internalized protein was degraded in lysosomes. These differences correlated with the observation that the B-subunit associated with Triton X-100-resistant membranes in HeLa cells, but not in monocyte-derived cells, suggesting that retrograde targeting to the biosynthetic/secretory pathway required association with specialized microdomains of biological membranes. In agreement with this hypothesis we found that in HeLa cells, the B-subunit resisted extraction by Triton X-100 until its arrival in the target compartments of the retrograde pathway, i.e., the Golgi apparatus and the endoplasmic reticulum. Furthermore, destabilization of Triton X-100-resistant membranes by cholesterol extraction potently inhibited B-subunit Transport from early endosomes to the trans-Golgi network, whereas under the same conditions, recycling of transferrin was not affected. Our data thus provide first evidence for a role of lipid asymmetry in membrane sorting at the interface between early endosomes and the trans-Golgi network.
-
evidence for a cop i independent Transport Route from the golgi complex to the endoplasmic reticulum
Nature Cell Biology, 1999Co-Authors: A Girod, Brian Storrie, Jeremy C Simpson, Ludger Johannes, Bruno Goud, Lynne M Roberts, Janet M Lord, Tommy Nilsson, Rainer PepperkokAbstract:The cytosolic coat-protein complex COP-I interacts with cytoplasmic 'retrieval' signals present in membrane proteins that cycle between the endoplasmic reticulum (ER) and the Golgi complex, and is required for both anterograde and retrograde Transport in the secretory pathway. Here we study the role of COP-I in Golgi-to-ER Transport of several distinct marker molecules. Microinjection of anti-COP-I antibodies inhibits retrieval of the lectin-like molecule ERGIC-53 and of the KDEL receptor from the Golgi to the ER. Transport to the ER of protein toxins, which contain a sequence that is recognized by the KDEL receptor, is also inhibited. In contrast, microinjection of anti-COP-I antibodies or expression of a GTP-restricted Arf-1 mutant does not interfere with Golgi-to-ER Transport of Shiga toxin/Shiga-like toxin-1 or with the apparent recycling to the ER of Golgi-resident glycosylation enzymes. Overexpression of a GDP-restricted mutant of Rab6 blocks Transport to the ER of Shiga toxin/Shiga-like toxin-1 and glycosylation enzymes, but not of ERGIC-53, the KDEL receptor or KDEL-containing toxins. These data indicate the existence of at least two distinct pathways for Golgi-to-ER Transport, one COP-I dependent and the other COP-I independent. The COP-I-independent pathway is specifically regulated by Rab6 and is used by Golgi glycosylation enzymes and Shiga toxin/Shiga-like toxin-1.
Mark Zuidgeest - One of the best experts on this subject based on the ideXlab platform.
-
the formulation and evaluation of Transport Route planning alternatives a spatial decision support system for the via baltica project poland
Journal of Transport Geography, 2009Co-Authors: S S Keshkamat, J Looijen, Mark ZuidgeestAbstract:Abstract Transport planning plays an undeniably key role in the economic growth of any region. However, when done heedlessly this planning can be detrimental to the biophysical and social environment of the region. In Transport Route planning generally one or a few alternative Routes are proposed, usually representing the interest of the proponent. If required, an environmental impact assessment is carried out on these alternatives. Although, EIA and SEA are meant to be effective in taking informed decisions about the proposed Route, these alternatives – the heart of impact assessment – are themselves devised in a subjective and non-spatial manner. Such an approach may easily overlook Routes, which could otherwise have been more suitable. A planning system that directly takes into account environmental and socio-economic considerations in selecting alternative Routes facilitates sustainable development. This paper presents a holistic and coherent spatial multi-criteria network analysis method for the generation of optimal routing alternatives under different policy visions, in a network of existing roads. The presented methodology was case-tested for the highly contested 340 km portion of the Via Baltica corridor in Poland, a part of the trans-European Transport network (TEN-T) program. The methodology shows its ability to serve as a versatile effect-based decision support system for Transport Route planning at a strategically higher level of planning, particularly for (geographically) large-scale investment schemes.
