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Nevalainen M, Metsikkö K. Fluvastatin delays propagation of viral infection in isolated rat FDB myofibers but does not affect exocytic membrane trafficking. Cell Biol Int 2015; 39:1307-16. [PMID: 26123964 DOI: 10.1002/cbin.10509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/25/2015] [Indexed: 11/06/2022]
Abstract
We have utilized the enveloped viral model to study the effect of fluvastatin on membrane trafficking in isolated rat myofibers. Our immunofluorescence studies constantly showed that infections in myofibers, which were treated with fluvastatin prior and during the infection with either vesicular stomatitis virus (VSV) or influenza A virus, propagated more slowly than in control myofibers without drug treatment. Experiments with a virus expressing Dad1 tagged with green fluorescent protein (GFP-Dad1) showed that fluvastatin did not affect its distribution within the ER/SR network and immunofluorescence staining for GM130 did not show any marked effect on the structure of the Golgi components. Furthermore, fluvastatin did not inhibit trafficking of the chimeric transport marker VSV temperature sensitive G protein (tsG-GFP) from the ER to the Golgi. We next subjected VSV infected myofibers for pulse-chase labeling experiments and found that fluvastatin did not slow down the ER-to-Golgi trafficking or Golgi to plasma membrane trafficking of the viral glycoprotein. These studies show that fluvastatin inhibited the propagation of viral infection in skeletal myofibers but no adverse effect on the exocytic trafficking could be demonstrated. These results suggest that other effects of statins rather than inhibition of ER-to-Golgi trafficking might be behind the myotoxic effects of the statins.
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Affiliation(s)
- Mika Nevalainen
- Division of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Faculty of Medicine, University of Oulu, Oulu, Finland.,Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA
| | - Kalervo Metsikkö
- Division of Cancer Research and Translational Medicine, Department of Anatomy and Cell Biology, Faculty of Medicine, University of Oulu, Oulu, Finland
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2
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Silván U, Boiteux C, Sütterlin R, Schroeder U, Mannherz HG, Jockusch BM, Bernèche S, Aebi U, Schoenenberger CA. An antiparallel actin dimer is associated with the endocytic pathway in mammalian cells. J Struct Biol 2011; 177:70-80. [PMID: 21970948 DOI: 10.1016/j.jsb.2011.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 09/15/2011] [Accepted: 09/21/2011] [Indexed: 10/17/2022]
Abstract
The dynamic rearrangement of the actin cytoskeleton plays a key role in several cellular processes such as cell motility, endocytosis, RNA processing and chromatin organization. However, the supramolecular actin structures involved in the different processes remain largely unknown. One of the less studied forms of actin is the lower dimer (LD). This unconventional arrangement of two actin molecules in an antiparallel orientation can be detected by chemical crosslinking at the onset of polymerization in vitro. Moreover, evidence for a transient incorporation of LD into growing filaments and its ability to inhibit nucleation of F-actin filament assembly implicate that the LD pathway contributes to supramolecular actin patterning. However, a clear link from this actin species to a specific cellular function has not yet been established. We have developed an antibody that selectively binds to LD configurations in supramolecular actin structures assembled in vitro. This antibody allowed us to unveil the LD in different mammalian cells. In particular, we show an association of the antiparallel actin arrangement with the endocytic compartment at the cellular and ultrastructural level. Taken together, our results strongly support a functional role of LD in the patterning of supramolecular actin assemblies in mammalian cells.
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Affiliation(s)
- Unai Silván
- M.E. Müller Institute for Structural Biology, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
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3
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Collado-Hilly M, Shirvani H, Jaillard D, Mauger JP. Differential redistribution of Ca2+-handling proteins during polarisation of MDCK cells: Effects on Ca2+ signalling. Cell Calcium 2010; 48:215-24. [PMID: 20932574 DOI: 10.1016/j.ceca.2010.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 09/03/2010] [Accepted: 09/07/2010] [Indexed: 10/19/2022]
Abstract
The spatial organisation of the Ca(2+) signal in microdomains enables the regulation of various processes in specific regions of the cell and is essential for the versatility of cell responses to various stimuli. Ca(2+) signals can be independently regulated in the cytoplasm and in the nucleoplasm. Increases in the concentration of Ca(2+) in the nucleus can have specific effects different from those due to increases of Ca(2+) in the cytoplasm. We investigated the influence of cell polarity on the subcellular distribution of molecules responsible for intracellular Ca(2+) homeostasis (Ca(2+) release channels, Ca(2+) pumps and Ca(2+) binding proteins) and its influence on the intracellular Ca(2+) signal in MDCK cells with respect to its cytoplasmic or nucleoplasmic localisation. The intracellular Ca(2+) store was largely reorganised during cell polarisation, with a differential redistribution of IP₃R, Ca(2+)-binding proteins and SERCA between the nuclear envelope and the periphery of the cell. This was accompanied by morphological changes in cell shape, which condense the cytoplasm around the nucleus, and in the shape of the nucleus, resulting in invaginations of the nuclear envelope. This facilitates Ca(2+) exchanges between the cytoplasm and the nucleoplasm, and preserves the ability to generate nucleoplasmic Ca(2+) transients in agonist-stimulated polarised MDCK cells.
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4
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Nevalainen M, Nissinen M, Kaakinen M, Metsikkö K. Influenza virus infection in multinucleated skeletal myofibers. Exp Cell Res 2010; 316:1784-94. [PMID: 20362571 DOI: 10.1016/j.yexcr.2010.03.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 03/23/2010] [Accepted: 03/26/2010] [Indexed: 11/29/2022]
Abstract
We examined the progression of the WSN influenza virus infection in isolated, multinucleated rat skeletal myofibers. Contrary to mononucleated cells, the adsorbed virions showed markedly delayed entry kinetics. Viral budding occurred on the sarcolemma, but the hemagglutinin envelope glycoprotein matured inefficiently and was poorly cleaved. Compatible with this, plaque assays indicated that infective viral particles were not formed. In situ hybridization studies showed that at low-dose infection, viral RNA production was restricted to one or a few nuclei within a myofiber. Dual in situ hybridization indicated that two different viral RNAs usually co-localized in the same nucleus or nuclei, suggesting that different viral genome segments replicated in the same nucleus. Newly synthesized viral ribonucleoprotein particles (vRNPs) did not re-enter virgin nuclei. Therefore, a single infected nucleus was able to support viral protein production, and notably, these proteins could reach hundreds of micrometers from the nucleus of origin. These results suggest that after viral disassembly in the endosome, the genome segments remained glued together and entered a myonucleus as a package. Spreading of the infection into virgin nuclei either by vRNPs or newly made virions did not occur, and thus the infection was abortive.
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Affiliation(s)
- Mika Nevalainen
- Institute of Biomedicine, Department of Anatomy and Cell Biology, PO Box 5000, FIN-90014 University of Oulu, Finland
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5
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Papponen H, Kaisto T, Myllylä VV, Myllylä R, Metsikkö K. Regulated sarcolemmal localization of the muscle-specific ClC-1 chloride channel. Exp Neurol 2005; 191:163-73. [PMID: 15589523 DOI: 10.1016/j.expneurol.2004.07.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Revised: 07/08/2004] [Accepted: 07/12/2004] [Indexed: 12/01/2022]
Abstract
The skeletal muscle-specific ClC-1 is a voltage-gated chloride channel protein. Specific antibodies against ClC-1 revealed in muscle sections a sarcolemmal staining that was absent in the myotonic arrested development of righting response (ADR) mouse muscle. The intensity of the sarcolemmal staining varied from one type of muscle to another and in lateral sections showed a typical mosaic pattern that colocalized with beta-dystroglycan and left the transverse tubule openings clear. Surprisingly, in isolated myofibers, the ClC-1 protein was absent from the sarcolemma. Instead, it localized to intracellular I band areas as soon as the myofibers were isolated. When the isolated myofibers were incubated with the kinase inhibitor staurosporine, the ClC-1 protein shifted back to the sarcolemma. Electric stimulation of the cultivated fibers had a similar effect. Also, myofibers infected with a recombinant Semliki Forest virus (SFV) expressing myc-tagged ClC-1 showed intracellular localization of the protein. The virally expressed mycClC-1 reached the Golgi apparatus but sarcolemmal staining remained nondetectable, and addition of staurosporine into the growth medium recruited the mycClC-1 to the sarcolemma. These data indicate that sarcolemmal targeting of the ClC-1 requires specific signals that are provided by the physiological environment.
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Affiliation(s)
- H Papponen
- Department of Anatomy and Cell Biology, University of Oulu, PO Box 5000, FIN-90014, Finland
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6
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Campo C, Mason A, Maouyo D, Olsen O, Yoo D, Welling PA. Molecular mechanisms of membrane polarity in renal epithelial cells. Rev Physiol Biochem Pharmacol 2004; 153:47-99. [PMID: 15674648 DOI: 10.1007/s10254-004-0037-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Exciting discoveries in the last decade have cast light onto the fundamental mechanisms that underlie polarized trafficking in epithelial cells. It is now clear that epithelial cell membrane asymmetry is achieved by a combination of intracellular sorting operations, vectorial delivery mechanisms and plasmalemma-specific fusion and retention processes. Several well-defined signals that specify polarized segregation, sorting, or retention processes have, now, been described in a number of proteins. The intracellular machineries that decode and act on these signals are beginning to be described. In addition, the nature of the molecules that associate with intracellular trafficking vesicles to coordinate polarized delivery, tethering, docking, and fusion are also becoming understood. Combined with direct visualization of polarized sorting processes with new technologies in live-cell fluorescent microscopy, new and surprising insights into these once-elusive trafficking processes are emerging. Here we provide a review of these recent advances within an historically relevant context.
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Affiliation(s)
- C Campo
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Blom TS, Koivusalo M, Kuismanen E, Kostiainen R, Somerharju P, Ikonen E. Mass spectrometric analysis reveals an increase in plasma membrane polyunsaturated phospholipid species upon cellular cholesterol loading. Biochemistry 2001; 40:14635-44. [PMID: 11724577 DOI: 10.1021/bi0156714] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here we used electrospray ionization mass spectrometry for quantitative determination of lipid molecular species in human fibroblasts and their plasma membrane incorporated into enveloped viruses. Both influenza virus selecting ordered domains and vesicular stomatitis virus (VSV) depleted of such domains [Scheiffele, P., et al. (1999) J. Biol. Chem. 274, 2038-2044] were analyzed. The major difference between influenza and VSV was found to be a marked enrichment of glycosphingolipids in the former. The effect of chronic cholesterol loading on viral lipid composition was studied in Niemann-Pick type C (NPC) fibroblasts. Both NPC-derived influenza and VSV virions contained increased amounts of cholesterol. Furthermore, polyunsaturated phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine were enriched in NPC-derived virions at the expense of the monounsaturated ones. When normal fibroblasts were acutely loaded with cholesterol using cyclodextrin complexes, an adjustment toward increasingly unsaturated phospholipid species was observed, most clearly for phosphatidylcholine and sphingomyelin. Our results provide evidence that (1) glycosphingolipids are enriched in domains through which influenza virus buds, (2) chronic cholesterol accumulation increases the cholesterol content of both glycosphingolipid-enriched and intervening plasma membrane domains, and (3) an increase in membrane cholesterol content is accompanied by an increased level of polyunsaturated species of the major membrane phospholipids. We suggest that remodeling of phospholipids toward higher unsaturation may serve as both an acute and a long-term adaptive mechanism in human cellular membranes against cholesterol excess.
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Affiliation(s)
- T S Blom
- Department of Molecular Medicine, National Public Health Institute, Viikki Drug Discovery Technology Center, University of Helsinki, Helsinki, Finland
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8
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Noda Y, Okada Y, Saito N, Setou M, Xu Y, Zhang Z, Hirokawa N. KIFC3, a microtubule minus end-directed motor for the apical transport of annexin XIIIb-associated Triton-insoluble membranes. J Cell Biol 2001; 155:77-88. [PMID: 11581287 PMCID: PMC2150803 DOI: 10.1083/jcb.200108042] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have identified and characterized a COOH-terminal motor domain-type kinesin superfamily protein (KIFC), KIFC3, in the kidney. KIFC3 is a minus end-directed microtubule motor protein, therefore it accumulates in regions where minus ends of microtubules assemble. In polarized epithelial cells, KIFC3 is localized on membrane organelles immediately beneath the apical plasma membrane of renal tubular epithelial cells in vivo and polarized MDCK II cells in vitro. Flotation assay, coupled with detergent extraction, demonstrated that KIFC3 is associated with Triton X-100-insoluble membrane organelles, and that it overlaps with apically transported TGN-derived vesicles. This was confirmed by immunoprecipitation and by GST pulldown experiments showing the specific colocalization of KIFC3 and annexin XIIIb, a previously characterized membrane protein for apically transported vesicles (Lafont, F., S. Lecat, P. Verkade, and K. Simons. 1998. J. Cell Biol. 142:1413-1427). Furthermore, we proved that the apical transport of both influenza hemagglutinin and annexin XIIIb was partially inhibited or accelerated by overexpression of motor-domainless (dominant negative) or full-length KIFC3, respectively. Absence of cytoplasmic dynein on these annexin XIIIb-associated vesicles and distinct distribution of the two motors on the EM level verified the existence of KIFC3-driven transport in epithelial cells.
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Affiliation(s)
- Y Noda
- Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Hongo, Tokyo 113-0033, Japan
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9
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Abstract
Movement of proteins and lipids between the various compartments of eukaryotic cells is fundamental to the maintenance of cellular homeostasis, and an understanding of the molecular mechanisms that govern these processes remains a key goal of cell biological research. This aim has been greatly facilitated by the development of assays that recapitulate specific events in vitro. In the following article we provide an overview of some of the currently used assays that measure the movement of proteins within the exocytic and endocytic pathways, and provide a starting point for those wishing to establish their own systems to study other vesicular transport steps.
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Affiliation(s)
- N R Cook
- Wellcome Trust Centre for Molecular Mechanisms in Disease, University of Cambridge, Wellcome Trust/MRC Building, Addenbrookes Hospital, Hills Road, Cambridge, CB2 2XY, UK
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Verkade P, Harder T, Lafont F, Simons K. Induction of caveolae in the apical plasma membrane of Madin-Darby canine kidney cells. J Cell Biol 2000; 148:727-39. [PMID: 10684254 PMCID: PMC2169379 DOI: 10.1083/jcb.148.4.727] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In this paper, we have analyzed the behavior of antibody cross-linked raft-associated proteins on the surface of MDCK cells. We observed that cross-linking of membrane proteins gave different results depending on whether cross-linking occurred on the apical or basolateral plasma membrane. Whereas antibody cross-linking induced the formation of large clusters on the basolateral membrane, resembling those observed on the surface of fibroblasts (Harder, T., P. Scheiffele, P. Verkade, and K. Simons. 1998. J. Cell Biol. 929-942), only small ( approximately 100 nm) clusters formed on the apical plasma membrane. Cross-linked apical raft proteins e.g., GPI-anchored placental alkaline phosphatase (PLAP), influenza hemagglutinin, and gp114 coclustered and were internalized slowly ( approximately 10% after 60 min). Endocytosis occurred through surface invaginations that corresponded in size to caveolae and were labeled with caveolin-1 antibodies. Upon cholesterol depletion the internalization of PLAP was completely inhibited. In contrast, when a non-raft protein, the mutant LDL receptor LDLR-CT22, was cross-linked, it was excluded from the clusters of raft proteins and was rapidly internalized via clathrin-coated pits. Since caveolae are normally present on the basolateral membrane but lacking from the apical side, our data demonstrate that antibody cross-linking induced the formation of caveolae, which slowly internalized cross-linked clusters of raft-associated proteins.
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Affiliation(s)
- Paul Verkade
- European Molecular Biology Laboratory, Cell Biology and Biophysics Programme, D-69117 Heidelberg, Germany
- Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Thomas Harder
- European Molecular Biology Laboratory, Cell Biology and Biophysics Programme, D-69117 Heidelberg, Germany
- Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Frank Lafont
- European Molecular Biology Laboratory, Cell Biology and Biophysics Programme, D-69117 Heidelberg, Germany
- Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Kai Simons
- European Molecular Biology Laboratory, Cell Biology and Biophysics Programme, D-69117 Heidelberg, Germany
- Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
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11
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Henkel JR, Gibson GA, Poland PA, Ellis MA, Hughey RP, Weisz OA. Influenza M2 proton channel activity selectively inhibits trans-Golgi network release of apical membrane and secreted proteins in polarized Madin-Darby canine kidney cells. J Cell Biol 2000; 148:495-504. [PMID: 10662775 PMCID: PMC2174804 DOI: 10.1083/jcb.148.3.495] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The function of acidification in protein sorting along the biosynthetic pathway has been difficult to elucidate, in part because reagents used to alter organelle pH affect all acidified compartments and are poorly reversible. We have used a novel approach to examine the role of acidification in protein sorting in polarized Madin-Darby canine kidney (MDCK) cells. We expressed the influenza virus M2 protein, an acid-activated ion channel that equilibrates lumenal and cytosolic pH, in polarized MDCK cells and examined the consequences on the targeting and delivery of apical and basolateral proteins. M2 activity affects the pH of only a subset of acidified organelles, and its activity can be rapidly reversed using ion channel blockers (Henkel, J.R., G. Apodaca, Y. Altschuler, S. Hardy, and O.A. Weisz. 1998. Mol. Biol. Cell. 8:2477-2490; Henkel, J.R., J.L. Popovich, G.A. Gibson, S.C. Watkins, and O.A. Weisz. 1999. J. Biol. Chem. 274:9854-9860). M2 expression significantly decreased the kinetics of cell surface delivery of the apical membrane protein influenza hemagglutinin, but not of the basolaterally delivered polymeric immunoglobulin receptor. Similarly, the kinetics of apical secretion of a soluble form of gamma-glutamyltranspeptidase were reduced with no effect on the basolaterally secreted fraction. Interestingly, M2 activity had no effect on the rate of secretion of a nonglycosylated protein (human growth hormone [hGH]) that was secreted equally from both surfaces. However, M2 slowed apical secretion of a glycosylated mutant of hGH that was secreted predominantly apically. Our results suggest a role for acidic trans-Golgi network pH in signal-mediated loading of apical cargo into forming vesicles.
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Affiliation(s)
- Jennifer R. Henkel
- Laboratory of Epithelial Cell Biology, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Gregory A. Gibson
- Laboratory of Epithelial Cell Biology, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Paul A. Poland
- Laboratory of Epithelial Cell Biology, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Mark A. Ellis
- Laboratory of Epithelial Cell Biology, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Rebecca P. Hughey
- Laboratory of Epithelial Cell Biology, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Ora A. Weisz
- Laboratory of Epithelial Cell Biology, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
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12
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Sattsangi S, Wonderlin WF. Isolation of transport vesicles that deliver ion channels to the cell surface. Methods Enzymol 1999; 294:339-50. [PMID: 9916237 DOI: 10.1016/s0076-6879(99)94021-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The squid giant axon provides a very simple preparation for the collection of bulk quantities of transport vesicles, and this greatly facilitates the physiologic study of ion channels incorporated into planar bilayers from these vesicles. However, this preparation is also limited in the repertoire of transport vesicles that can be studied, and it is not very convenient for some biochemical techniques, such as pulse-chase labeling experiments. Cultured N1E-115 cells, on the other hand, provide a preparation from which a larger repertoire of types of transport vesicles can be isolated, and many biochemical techniques can be applied in conjunction with physiologic studies. Further refinement of the techniques for isolating specific populations of vesicles from cultured cells will provide even greater insight into the role of vesicles in mediating ion channel trafficking.
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Affiliation(s)
- S Sattsangi
- Department of Pharmacology and Toxicology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown 26506-9223, USA
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13
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Scheiffele P, Rietveld A, Wilk T, Simons K. Influenza viruses select ordered lipid domains during budding from the plasma membrane. J Biol Chem 1999; 274:2038-44. [PMID: 9890962 DOI: 10.1074/jbc.274.4.2038] [Citation(s) in RCA: 349] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
During the budding of enveloped viruses from the plasma membrane, the lipids are not randomly incorporated into the envelope, but virions seem to have a lipid composition different from the host membrane. Here, we have analyzed lipid assemblies in three different viruses: fowl plague virus (FPV) from the influenza virus family, vesicular stomatitis virus (VSV), and Semliki Forest virus (SFV). Analysis of detergent extractability of proteins, cholesterol, phosphoglycerolipids, and sphingomyelin in virions showed that FPV contains high amounts of detergent-insoluble complexes, whereas such complexes are largely absent from VSV or SFV. Cholesterol depletion from the viral envelope by methyl-beta-cyclodextrin results in increased solubility of sphingomyelin and of the glycoproteins in the FPV envelope. This biochemical behavior suggests that so-called raft-lipid domains are selectively incorporated into the influenza virus envelope. The "fluidity" of the FPV envelope, as measured by the fluorescence polarization of diphenylhexatriene, was significantly lower than compared with VSV or SFV. Furthermore, influenza virus hemagglutinin incorporated into the envelope of recombinant VSV was largely detergent-soluble, indicating the depletion of raft-lipid assemblies from this membrane. The results provide a model for lipid selectivity during virus budding and support the view of lipid rafts as cholesterol-dependent, ordered domains in biological membranes.
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Affiliation(s)
- P Scheiffele
- Cell Biology Programme, European Molecular Biology Laboratory, Postfach 10 2209, D-69012 Heidelberg, Germany
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14
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Lafont F, Lecat S, Verkade P, Simons K. Annexin XIIIb associates with lipid microdomains to function in apical delivery. J Cell Biol 1998; 142:1413-27. [PMID: 9744874 PMCID: PMC2141766 DOI: 10.1083/jcb.142.6.1413] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A member of the annexin XIII sub-family, annexin XIIIb, has been implicated in the apical exocytosis of epithelial kidney cells. Annexins are phospholipid-binding proteins that have been suggested to be involved in membrane trafficking events although their actual physiological function remains open. Unlike the other annexins, annexin XIIIs are myristoylated. Here, we show by immunoelectron microscopy that annexin XIIIb is localized to the trans-Golgi network (TGN), vesicular carriers and the apical cell surface. Polarized apical sorting involves clustering of apical proteins into dynamic sphingolipid-cholesterol rafts. We now provide evidence for the raft association of annexin XIIIb. Using in vitro assays and either myristoylated or unmyristoylated recombinant annexin XIIIb, we demonstrate that annexin XIIIb in its native myristoylated form stimulates specifically apical transport whereas the unmyristoylated form inhibits this route. Moreover, we show that formation of apical carriers from the TGN is inhibited by an anti-annexin XIIIb antibody whereas it is stimulated by myristoylated recombinant annexin XIIIb. These results suggest that annexin XIIIb directly participates in apical delivery.
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Affiliation(s)
- F Lafont
- European Molecular Biology Laboratory, Cell Biology and Biophysics Programme, D-69012 Heidelberg, Germany.
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15
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Hennig D, Scales SJ, Moreau A, Murley LL, De Mey J, Kreis TE. A formiminotransferase cyclodeaminase isoform is localized to the Golgi complex and can mediate interaction of trans-Golgi network-derived vesicles with microtubules. J Biol Chem 1998; 273:19602-11. [PMID: 9677386 DOI: 10.1074/jbc.273.31.19602] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A protein of 60 kDa (p60) has been identified using a quantitative in vitro vesicle-microtubule binding assay. Purified p60 induces co-sedimentation with microtubules of trans-Golgi network-derived vesicles isolated from polarized, perforated Madin-Darby canine kidney cells. Sequencing of the cDNA coding for this protein revealed that it is the chicken homologue of formiminotransferase cyclodeaminase (FTCD), a liver-specific enzyme involved in the histidine degradation pathway. Purified p60 from chicken liver has formiminotransferase activity, confirming that it is FTCD or an isoform of this enzyme. Isoforms of FTCD were identified in chicken hepatoma and HeLa cells, and immunolocalize to the region of the Golgi complex and vesicular structures in its vicinity. Furthermore, 58K, a previously identified microtubule-binding Golgi protein from rat liver (Bloom, G. S., and Brashear, T. A. (1989) J. Biol. Chem. 264, 16083-16092), is identical to FTCD. Both proteins co-purify with microtubules and co-localize with membranes of the Golgi complex. The capacity of FTCD to bind both to microtubules and Golgi-derived membranes may suggest that this protein, or one of its isoforms, might have in addition to its enzymatic activity, a second physiological function in mediating interaction of Golgi-derived membranes with microtubules.
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Affiliation(s)
- D Hennig
- Department of Supramolecular and Cell Biology, Institut Jacques Monod, 2 Place Jussieu, 75251 Paris, France
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16
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Wonderlin WF. The rate zonal separation of organelles from dilute suspensions: the problem of a large sample volume. Anal Biochem 1998; 258:74-9. [PMID: 9527851 DOI: 10.1006/abio.1998.2573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transport vesicles that deliver proteins to the cell surface can be isolated by incubating cells that have been permeabilized by mechanical or chemical techniques in a high-K medium containing an ATP regenerating system. The vesicles released from permeabilized cells are, however, obtained as a very dilute suspension in the incubation solution. This presents a problem for the preparative separation of specific populations of vesicles by velocity sedimentation, because the small sample volume capacity of traditional glycerol or sucrose velocity gradients requires that the vesicles first be concentrated by sedimentation or that very small amounts of vesicles be loaded onto a gradient. We have addressed the problem of the loss of zonal resolution produced by the loading of large sample volumes, and we propose that high-viscosity Ficoll gradients can be used effectively to restore the resolution of zones when substantially larger sample volumes of dilute suspensions must be loaded onto velocity gradients.
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Affiliation(s)
- W F Wonderlin
- Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia 26506-9223, USA
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17
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Abstract
Transport from the TGN to the basolateral surface involves a rab/N-ethylmaleimide-sensitive fusion protein (NSF)/soluble NSF attachment protein (SNAP)/SNAP receptor (SNARE) mechanism. Apical transport instead is thought to be mediated by detergent-insoluble sphingolipid-cholesterol rafts. By reducing the cholesterol level of living cells by 60-70% with lovastatin and methyl-beta-cyclodextrin, we show that the TGN-to-surface transport of the apical marker protein influenza virus hemagglutinin was slowed down, whereas the transport of the basolateral marker vesicular stomatitis virus glycoprotein as well as the ER-to-Golgi transport of both membrane proteins was not affected. Reduction of transport of hemagglutinin was accompanied by increased solubility in the detergent Triton X-100 and by significant missorting of hemagglutinin to the basolateral membrane. In addition, depletion of cellular cholesterol by lovastatin and methyl-beta-cyclodextrin led to missorting of the apical secretory glycoprotein gp-80, suggesting that gp-80 uses a raft-dependent mechanism for apical sorting. Our data provide for the first time direct evidence for the functional significance of cholesterol in the sorting of apical membrane proteins as well as of apically secreted glycoproteins.
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Affiliation(s)
- P Keller
- European Molecular Biology Laboratory, Cell Biology Programme, D-69012 Heidelberg, Germany
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18
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Rahkila P, Luukela V, Väänänen K, Metsikkö K. Differential targeting of vesicular stomatitis virus G protein and influenza virus hemagglutinin appears during myogenesis of L6 muscle cells. J Cell Biol 1998; 140:1101-11. [PMID: 9490723 PMCID: PMC2132697 DOI: 10.1083/jcb.140.5.1101] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Exocytic organelles undergo profound reorganization during myoblast differentiation and fusion. Here, we analyzed whether glycoprotein processing and targeting changed during this process by using vesicular stomatitis virus (VSV) G protein and influenza virus hemagglutinin (HA) as models. After the induction of differentiation, the maturation and transport of the VSV G protein changed dramatically. Thus, only half of the G protein was processed and traveled through the Golgi, whereas the other half remained unprocessed. Experiments with the VSV tsO45 mutant indicated that the unprocessed form folded and trimerized normally and then exited the ER. It did not, however, travel through the Golgi since brefeldin A recalled it back to the ER. Influenza virus HA glycoprotein, on the contrary, acquired resistance to endoglycosidase H and insolubility in Triton X-100, indicating passage through the Golgi. Biochemical and morphological assays indicated that the HA appeared at the myotube surface. A major fraction of the Golgi-processed VSV G protein, however, did not appear at the myotube surface, but was found in intracellular vesicles that partially colocalized with the regulatable glucose transporter. Taken together, the results suggest that, during early myogenic differentiation, the VSV G protein was rerouted into developing, muscle-specific membrane compartments. Influenza virus HA, on the contrary, was targeted to the myotube surface.
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Affiliation(s)
- P Rahkila
- Department of Anatomy, University of Oulu, FIN-90220 Oulu, Finland
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19
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Camus G, Jasmin BJ, Cartaud J. Polarized sorting of nicotinic acetylcholine receptors to the postsynaptic membrane in Torpedo electrocyte. Eur J Neurosci 1998; 10:839-52. [PMID: 9753152 DOI: 10.1046/j.1460-9568.1998.00091.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Several regulatory mechanisms contribute to the accumulation and maintenance of high concentrations of acetylcholine receptors (AChR) at the postsynaptic membrane of the neuromuscular junction, including compartmentalized gene transcription, targeting, clustering and anchoring to the cytoskeleton. The targeting of the AChR to the postsynaptic membrane is likely to involve a polarized sorting in the exocytic pathway. In this work, we used the electrocyte of Torpedo marmorata electric organ to study the intracellular trafficking of neosynthesized AChR and its delivery to the postsynaptic membrane. Gradient centrifugation and immunoisolation techniques have led to the isolation of two populations of post-Golgi transport vesicles (PGVs) enriched in proteins of either the innervated (AChR) or non-innervated (Na,K-ATPase) membrane domains of the cell. Immunolabelling of these vesicles at the EM level disclosed that very few PGVs contained both proteins. In AChR-enriched vesicles, high sialylation of AchR molecules, an expected post-translational modification of proteins exiting the trans-Golgi network, and the presence of a marker of the exocytic pathway (Rab6p), indicate that these vesicles are carriers engaged in the Golgi-to-plasma membrane transport. These data suggest that AChR and Na,K-ATPase are sorted intracellularly most likely within the trans-Golgi network. Furthermore, EM analysis and immunogold-labelling experiments provided in situ evidence that the AChR-containing PGVs are conveyed to the postsynaptic membrane, possibly by a microtubule-dependent transport mechanism. Our data therefore provide the first evidence that the targeting of receptors for neurotransmitters to synaptic sites could be contributed by intracellular sorting and polarized delivery in the exocytic pathway.
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Affiliation(s)
- G Camus
- Département de Biologie Supramoléculaire et Cellulaire, Institut Jacques Monod, CNRS, Université Denis Diderot, Paris, France
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20
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Nakata T, Terada S, Hirokawa N. Visualization of the dynamics of synaptic vesicle and plasma membrane proteins in living axons. J Cell Biol 1998; 140:659-74. [PMID: 9456325 PMCID: PMC2140163 DOI: 10.1083/jcb.140.3.659] [Citation(s) in RCA: 262] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/1997] [Revised: 12/04/1997] [Indexed: 02/06/2023] Open
Abstract
Newly synthesized membrane proteins are transported by fast axonal flow to their targets such as the plasma membrane and synaptic vesicles. However, their transporting vesicles have not yet been identified. We have successfully visualized the transporting vesicles of plasma membrane proteins, synaptic vesicle proteins, and the trans-Golgi network residual proteins in living axons at high resolution using laser scan microscopy of green fluorescent protein-tagged proteins after photobleaching. We found that all of these proteins are transported by tubulovesicular organelles of various sizes and shapes that circulate within axons from branch to branch and switch the direction of movement. These organelles are distinct from the endosomal compartments and constitute a new entity of membrane organelles that mediate the transport of newly synthesized proteins from the trans-Golgi network to the plasma membrane.
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Affiliation(s)
- T Nakata
- Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Hongo, Tokyo, Japan, 113
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21
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Fath KR, Trimbur GM, Burgess DR. Molecular motors and a spectrin matrix associate with Golgi membranes in vitro. J Cell Biol 1997; 139:1169-81. [PMID: 9382864 PMCID: PMC2140197 DOI: 10.1083/jcb.139.5.1169] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Cytoplasmic dynein is a microtubule minus-end-directed motor that is thought to power the transport of vesicles from the TGN to the apical cortex in polarized epithelial cells. Trans-Golgi enriched membranes, which were isolated from primary polarized intestinal epithelial cells, contain both the actin-based motor myosin-I and dynein, whereas isolated Golgi stacks lack dynein but contain myosin-I (Fath, K.R., G.M. Trimbur, and D.R. Burgess. 1994. J. Cell Biol. 126:661-675). We show now that Golgi stacks in vitro bind dynein supplied from cytosol in the absence of ATP, and bud small membranes when incubated with cytosol and ATP. Cytosolic dynein binds to regions of stacks that are destined to bud because dynein is present in budded membranes, but absent from stacks after budding. Budded membranes move exclusively towards microtubule minus-ends in in vitro motility assays. Extraction studies suggest that dynein binds to a Golgi peripheral membrane protein(s) that resists extraction by ice-cold Triton X-100. In the presence of cytosol, these membrane ghosts can move towards the minus-ends of microtubules. Detergent-extracted Golgi stacks and TGN-containing membranes are closely associated with an amorphous matrix composed in part of spectrin and ankyrin. Although spectrin has been proposed to help link dynein to organellar membranes, we found that functional dynein may bind to extracted membranes independently of spectrin and ankyrin.
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Affiliation(s)
- K R Fath
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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22
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Fiedler K, Kellner R, Simons K. Mapping the protein composition of trans-Golgi network (TGN)-derived carrier vesicles from polarized MDCK cells. Electrophoresis 1997; 18:2613-9. [PMID: 9527491 DOI: 10.1002/elps.1150181417] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In polarized MDCK cells, proteins and lipids are sorted in the trans-Golgi network /TGN) and packaged into different vesicular carriers that are delivered to the apical or basolateral cell surface. To gain insight into the sorting and trafficking machinery, we have previously isolated TGN-derived carrier vesicles from perforated MDCK cells. The composition of immuno-isolated apical and basolateral carriers was mapped by two-dimensional (2-D) gel electrophoresis. Here we describe the identification of several components of the vesicle fraction by using three different methods. 2-D gel comigration was performed with carrier vesicles isolated from metabolically labeled MDCK cells and human epidermal keratinocyte lysates. This allowed us to assign eleven known components by a comparison with the comprehensive keratinocyte 2-D gel database. These comprised two members of the 14-3-3 family of proteins that have been implicated in vesicular trafficking. Five proteins were purified from preparative 2-D gels and identified by peptide microsequencing, including the beta1 and beta2 subunit of trimeric G proteins and an annexin II variant. A member of the SNARE family of proteins was identified by immunoblotting. The combination of 2-D gel electrophoresis and 2-D gel databases allows the rapid assessment of the purity of subcellular fractions and to characterize components involved in vesicular transport.
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Affiliation(s)
- K Fiedler
- Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
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23
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Aaku-Saraste E, Oback B, Hellwig A, Huttner WB. Neuroepithelial cells downregulate their plasma membrane polarity prior to neural tube closure and neurogenesis. Mech Dev 1997; 69:71-81. [PMID: 9486532 DOI: 10.1016/s0925-4773(97)00156-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cell differentiation often involves changes in cell polarity. In this study we show that neuroepithelial cells, the progenitors of all neurons and macroglial cells of the vertebrate central nervous system, downregulate the polarized delivery to the apical and basolateral plasma membrane domains during development. Upon infection of the neuroepithelium of mouse embryos with fowl plague virus (FPV), polarized delivery of the viral envelope hemagglutinin, an apical marker, occurred at the neural plate stage (E8), but was downregulated at the open neural tube stage (E9). Upon infection with vesicular stomatitis virus, the viral envelope G protein, a basolateral marker, showed an unpolarized delivery not only at the open neural tube stage, but already at the neural plate stage. These results show that a progressive downregulation of plasma membrane polarity of neuroepithelial cells precedes neural tube closure and the onset of neurogenesis.
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Affiliation(s)
- E Aaku-Saraste
- Department of Neurobiology, University of Heidelberg, Germany
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24
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Shevchenko A, Keller P, Scheiffele P, Mann M, Simons K. Identification of components of trans-Golgi network-derived transport vesicles and detergent-insoluble complexes by nanoelectrospray tandem mass spectrometry. Electrophoresis 1997; 18:2591-600. [PMID: 9527489 DOI: 10.1002/elps.1150181415] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Epithelial cells have to deliver newly synthesized proteins to the apical and the basolateral plasma membrane domains of the polarized cell surface. Sorting takes place in the trans-Golgi network and at least two vesicular carriers exist for apical and basolateral delivery. After immuno-isolation, the composition of these vesicle preparations was analyzed by two-dimensional (2-D) gel electrophoresis and detergent extraction. In this paper we compare the constituents of detergent-insoluble complexes in different cell lines of polarized or nonpolarized origin and present the identification of five previously uncharacterized proteins. We show that our protein identification strategy can be successfully applied to the problem of small hydrophobic proteins from organisms that have not been substantially sequenced. The high sensitivity of nanoelectrospray tandem mass spectrometry allowed us to identify two proteins that belong to the p23/p24 family of putative cargo receptors for vesicular trafficking. Furthermore we have mapped CD9 and CD81, two members of a large family of proteins consisting of highly hydrophobic four transmembrane proteins. In addition we have identified caveolin-2 as a constituent of basolateral transport vesicles. We have also extended our analysis of immuno-isolated vesicles to a more basic pI range and show that this region on 2-D gels is devoid of proteins. With these approaches and with the previously published data we have now identified most of the major low molecular weight proteins recovered in detergent-insoluble glycolipid-enriched complexes.
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Affiliation(s)
- A Shevchenko
- Peptide and Protein Group, European Molecular Biology Laboratory, Heidelberg, Germany
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25
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Grimes ML, Beattie E, Mobley WC. A signaling organelle containing the nerve growth factor-activated receptor tyrosine kinase, TrkA. Proc Natl Acad Sci U S A 1997; 94:9909-14. [PMID: 9275225 PMCID: PMC23291 DOI: 10.1073/pnas.94.18.9909] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/1997] [Accepted: 07/03/1997] [Indexed: 02/05/2023] Open
Abstract
The topology of signal transduction is particularly important for neurons. Neurotrophic factors such as nerve growth factor (NGF) interact with receptors at distal axons and a signal is transduced by retrograde transport to the cell body to ensure survival of the neuron. We have discovered an organelle that may account for the retrograde transport of the neurotrophin signal. This organelle is derived from endocytosis of the receptor tyrosine kinase for NGF, TrkA. In vitro reactions containing semi-intact PC12 cells and ATP were used to enhance recovery of a novel organelle: small vesicles containing internalized NGF bound to activated TrkA. These vesicles were distinct from clathrin coated vesicles, uncoated primary endocytic vesicles, and synaptic vesicles, and resembled transport vesicles in their sedimentation velocity. They contained 10% of the total bound NGF and almost one-third of the total tyrosine phosphorylated TrkA. These small vesicles are compelling candidates for the organelles through which the neurotrophin signal is conveyed down the axon.
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Affiliation(s)
- M L Grimes
- Department of Biochemistry, Massey University, Palmerston North, New Zealand.
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26
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Rahkila P, Alakangas A, Väänänen K, Metsikkö K. Transport pathway, maturation, and targetting of the vesicular stomatitis virus glycoprotein in skeletal muscle fibers. J Cell Sci 1996; 109 ( Pt 6):1585-96. [PMID: 8799845 DOI: 10.1242/jcs.109.6.1585] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have infected isolated skeletal muscle fibers with the vesicular stomatitis virus or the mutant tsO45, whose glycoprotein is blocked in the endoplasmic reticulum at 39 degrees C. Immunofluorescence analysis for the viral glycoprotein indicated that the fibers were infected over their entire length at a virus dose of 10(9)/ml. When we infected the myofibers with the tsO45 mutant at 39 degrees C, the viral glycoprotein appeared to be localised to the terminal cisternae of the sarcoplasmic reticulum. Upon shifting the cultures to the permissive temperature, 32 degrees C, in the presence of dinitrophenol, which blocks vesicular transport, the viral glycoprotein proceeded to completely fill the sarcoplasmic reticulum. Thus, both the endoplasmic reticulum located at the terminal cisternae of the sarcoplasmic reticulum, and the entire endoplasmic and sarcoplasmic reticulum appeared to be continuous. Shifting the culture temperature from 39 degrees C to 20 degrees C, resulted in prominent perinuclear staining throughout the fibers, accompanied by the appearance of distinct bright dots between the nuclei. Electron microscopic immunoperoxidase labeling indicated that these bright structures represented the Golgi apparatus. When either the tsO45-infected or wild-type virus-infected fibers were incubated at 32 degrees C, the viral glycoprotein showed a staining pattern that consisted of double rows of punctate fluorescence. Immunogold labeling showed that the viral glycoprotein was present in both the transverse tubules as well as the endoplasmic/sarcoplasmic reticulum endomembranes. In addition, extensive viral budding was observed in the transverse tubules. Metabolic labeling experiments revealed that only half of the glycoprotein was processed in the Golgi, and this processed form had become incorporated into the budding viral particles. Thus, the processed viral glycoprotein was targeted to the transverse tubules. The other half of the glycoprotein remained endoglycosidase H-sensitive, suggesting its retention in the endoplasmic/sarcoplasmic reticulum endomembranes.
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Affiliation(s)
- P Rahkila
- Biocenter, University of Oulu, Finland
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27
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Austin CD, Shields D. Prosomatostatin processing in permeabilized cells. Calcium is required for prohormone cleavage but not formation of nascent secretory vesicles. J Biol Chem 1996; 271:1194-9. [PMID: 8557650 DOI: 10.1074/jbc.271.2.1194] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Our laboratory has been using a permeabilized cell system derived from rat anterior pituitary GH3 cells expressing prosomatostatin (pro-SRIF) to study prohormone processing and nascent secretory vesicle formation in vitro. Because calcium is necessary for prohormone processing enzyme activity, secretory granule fusion with the plasma membrane, and possibly sorting to the regulated pathway, we treated permeabilized cells with the calcium ionophore A23187 to determine the role of calcium in pro-SRIF cleavage and nascent vesicle formation from the trans-Golgi network (TGN). Here we demonstrate that pro-SRIF cleavage was markedly inhibited when lumenal free calcium was chelated with EGTA in the presence of A23187. Surprisingly, submillimolar free calcium (approximately 15 microM) was sufficient to maintain prohormone cleavage efficiency, a value far lower than that estimated for total calcium levels in the TGN and secretory granules. Experiments using both A23187 and the protonophore CCCP revealed that free calcium is absolutely required for efficient pro-SRIF cleavage, even at the optimal pH of 6.1. Secretory vesicle formation by contrast was not inhibited by calcium chelation but rather by millimolar extralumenal free calcium. Together, these observations demonstrate that pro-SRIF processing and budding of nascent secretory vesicles from the TGN can be uncoupled and therefore have distinct biochemical requirements. Interestingly, our data using intact GH3 cells demonstrate that basal secretion of SRIF-related material is largely calcium-dependent and therefore cannot be equated with constitutive pathway secretion. These results underscore the importance of determining calcium requirements before assigning a secretion event to either the constitutive or regulated secretory pathway.
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Affiliation(s)
- C D Austin
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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28
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29
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Fiedler K, Simons K. Characterization of VIP36, an animal lectin homologous to leguminous lectins. J Cell Sci 1996; 109 ( Pt 1):271-6. [PMID: 8834812 DOI: 10.1242/jcs.109.1.271] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
VIP36 was isolated from MDCK cells as a component of glycolipid-enriched detergent-insoluble complexes. The protein is localized to the Golgi apparatus and the cell surface, and belongs to a new family of legume lectin homologues in the animal secretory pathway that might be involved in the trafficking of glycoproteins, glycolipids or both. Here we show that VIP36 is N-glycosylated and expressed in organs abundant in epithelial cells as well as in non-epithelial organs. Our studies demonstrate that the recombinant exoplasmic/luminal domain of VIP36 binds Ca2+ and that the protein decorates internal membrane structures of MDCK cells in vitro that are distinct from the Golgi apparatus. This binding requires Ca2+ and can be specifically inhibited by N-acetyl-D-galactosamine. The recombinant protein was used for affinity chromatography. Glycopeptides obtained from [3H]galactose-labelled cells bind to VIP36 and can be eluted with N-acetyl-D-galactosamine. Our data imply that VIP36 functions as a lectin in post-Golgi trafficking.
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Affiliation(s)
- K Fiedler
- Cell Biology Programme, European Molecular Biology Laboratory, Heidelberg, Germany
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30
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Zacchetti D, Peränen J, Murata M, Fiedler K, Simons K. VIP17/MAL, a proteolipid in apical transport vesicles. FEBS Lett 1995; 377:465-9. [PMID: 8549777 DOI: 10.1016/0014-5793(95)01396-2] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
VIP17 is a proteolipid enriched in the CHAPS-insoluble complexes from MDCK cells, and a candidate component of the molecular machinery responsible for the sorting and targeting of proteins to the apical surface. Cloning and sequencing of the cDNA encoding the protein revealed that it is the canine homolog of the human and rat MAL proteins. Analysis by immunofluorescence microscopy of epitope-tagged VIP17/MAL expressed transiently in BHK cells and stably in MDCK cells revealed a perinuclear, vesicular, and plasmalemmal staining. In MDCK cells the distribution was mainly in vesicular structures in the apical cytoplasm. These and other results suggest that VIP17/MAL is an important component in vesicular trafficking cycling between the Golgi complex and the apical plasma membrane.
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Affiliation(s)
- D Zacchetti
- Cell Biology Programme, European Molecular Biology Laboratory, Heidelberg, Germany
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31
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Luján HD, Marotta A, Mowatt MR, Sciaky N, Lippincott-Schwartz J, Nash TE. Developmental induction of Golgi structure and function in the primitive eukaryote Giardia lamblia. J Biol Chem 1995; 270:4612-8. [PMID: 7876232 DOI: 10.1074/jbc.270.9.4612] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A fundamental characteristic of eukaryotic cells is the presence of membrane-bound compartments and membrane transport pathways in which the Golgi complex plays a central role in the selective processing, sorting, and secretion of proteins. The parasitic protozoan Giardia lamblia belongs to the earliest identified lineage among eukaryotes and therefore offers unique insight into the progression from primitive to more complex eukaryotic cells. Here, we report that Giardia trophozoites undergo a developmental induction of Golgi enzyme activities, which correlates with the appearance of a morphologically identifiable Golgi complex, as they differentiate to cysts. Prior to this induction, no morphologically or biochemically identifiable Golgi complex exists within nonencysting cells. Remarkably, protein secretion in both nonencysting and encysting trophozoites is inhibited by brefeldin A, and brefeldin A-sensitive membrane association of ADP-ribosylation factor and beta-COP is observed. These results suggest that the secretory machinery of Giardia resembles that of higher eukaryotes despite the absence of a Golgi complex in nonencysting trophozoites. These findings have implications both for defining the minimal machinery for protein secretion in eukaryotes and for examining the biogenesis of Golgi structure and function.
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Affiliation(s)
- H D Luján
- Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892
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32
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Moreau P, Cassagne C. Phospholipid trafficking and membrane biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1197:257-90. [PMID: 7819268 DOI: 10.1016/0304-4157(94)90010-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- P Moreau
- URA 1811 CNRS, IBGC, University of Bordeaux II, France
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33
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34
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Esparís-Ogando A, Zurzolo C, Rodriguez-Boulan E. Permeabilization of MDCK cells with cholesterol binding agents: dependence on substratum and confluency. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 267:C166-76. [PMID: 8048477 DOI: 10.1152/ajpcell.1994.267.1.c166] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We studied systematically the susceptibility of Madin-Darby canine kidney (MDCK) cells to permeabilization by two cholesterol binding agents, digitonin and streptolysin-O (SLO), under different culture conditions. Monolayers grown on polycarbonate filter chambers (Transwells) required twice the concentration of digitonin effective on monolayers grown on glass or plastic (80 vs. 40 micrograms/ml) to allow antibody penetration or the release of 90% of the cytosolic protein lactate dehydrogenase (LDH). Neither the apical nor the basolateral surface showed preferential susceptibility to digitonin. Confluent MDCK cells, cultured either on filters or on impermeable substrates, showed poor antibody permeability after addition of commercial SLOs, even when used at concentrations 100 times higher (20 U/ml) than those effective on nonepithelial Chinese hamster ovary cells. Surprisingly, culture conditions that prevent tight junction formation and the acquisition of a polarized phenotype (< 10 microM Ca2+) increased dramatically the susceptibility to permeabilization by SLO. On restoration of normal Ca2+ levels, susceptibility to SLO quickly decreased. Thus conditions that lead to the full establishment of polarity result in decreased sensitivity to disruption by digitonin and SLO.
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Affiliation(s)
- A Esparís-Ogando
- Department of Cell Biology and Anatomy, Cornell University Medical College, New York, New York 10021
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35
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Abstract
VIP21-Caveolin is a component of the filamentous coat surrounding the invaginations of the plasma membrane called caveolae. Unlike the vesicular coat proteins identified so far, VIP21-Caveolin can be classified as an integral membrane protein. Furthermore, it is found in high molecular mass oligomers. Based on its localisation in specialised membrane subdomains, a role for VIP21-Caveolin in membrane protein sorting has been proposed.
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Affiliation(s)
- T V Kurzchalia
- Department of Cell Biology, Max-Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany
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36
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Bomsel M, Mostov KE. Possible role of both the alpha and beta gamma subunits of the heterotrimeric G protein, Gs, in transcytosis of the polymeric immunoglobulin receptor. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)74464-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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37
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Vega-Salas DE, San Martino JA, Salas PJ, Baldi A. Vacuolar apical compartment (VAC) in breast carcinoma cell lines (MCF-7 and T47D): failure of the cell-cell regulated exocytosis mechanism of apical membrane. Differentiation 1993. [DOI: 10.1111/j.1432-0436.1993.tb01596.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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Vega-Salas DE, San Martino JA, Salas PJ, Baldi A. Vacuolar apical compartment (VAC) in breast carcinoma cell lines (MCF-7 and T47D): failure of the cell-cell regulated exocytosis mechanism of apical membrane. Differentiation 1993; 54:131-41. [PMID: 8243890 DOI: 10.1111/j.1432-0436.1993.tb00716.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have previously shown that an integral plasma membrane glycoprotein (AP2) is highly polarized to the apical domain in confluent Madin-Darby canine kidney (MDCK) epithelial cells. However, when the monolayers are prevented from forming intercellular contacts, approximately 60% of the AP2 cellular content is stored in the intracellular vacuolar apical compartment (VAC). In the current work we found that AP2 was present in the non-tumorigenic human mammary epithelial cell line MCF-10A, in the breast carcinoma cell lines MCF-7 and T47D, and in breast ductal carcinomas in vivo. By radioimmunoassay, an intracellular compartment of AP2 was identified in the mammary cell lines in culture. In MCF-10A, this compartment behaved as in MDCK cells; namely it was observed only when the cells cannot form cell-cell contacts. However, in the carcinoma cell lines MCF-7 and T47D, a significant AP2 intracellular compartment was observed also under conditions permissive for the formation of intercellular contacts. These results were confirmed by immunofluorescence and immunoelectron microscopy experiments that showed VACs in MCF-7 and T47D, even in cells with extensive intercellular contacts. In MCF-7 cells, the addition of serum caused a partial decrease of the AP2 intracellular compartment. The exocytosis of VACs occurred towards the center of multi-cellular groups, forming intercellular lumens, similar to those transiently observed in MDCK cells and to structures described by others during embryo development. Altogether, these results suggest that VAC exocytosis is controlled by cell-cell contact signalling, which may be defective in carcinoma cells.
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Affiliation(s)
- D E Vega-Salas
- Instituto de Investigaciones Bioquímicas, Fundación Campomar, Buenos Aires, Argentina
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39
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Fiedler K, Kobayashi T, Kurzchalia TV, Simons K. Glycosphingolipid-enriched, detergent-insoluble complexes in protein sorting in epithelial cells. Biochemistry 1993; 32:6365-73. [PMID: 8518282 DOI: 10.1021/bi00076a009] [Citation(s) in RCA: 202] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In simple epithelial cells, the delivery of apical and basolateral proteins to the cell surface is mediated by sorting in the trans-Golgi network and transport via separate vesicular carriers. In order to identify the molecular machinery involved in protein sorting, we have recently studied a detergent-insoluble complex in Madin-Darby canine kidney (MDCK) cells, following CHAPS extraction of exocytic carrier vesicles, specifically including the apical marker protein influenza hemagglutinin (HA). Previously, a Triton X-100 insoluble membrane residue that was enriched in glycosylphosphatidylinositol-anchored (GPI) proteins and glycolipids was characterized and implicated in transport to the apical cell surface [Brown, D., & Rose, J. (1991) Cell 68, 533-544]. In this report, the protein compositions of the CHAPS and Triton complexes have been compared by two-dimensional gel analysis. Only a few major membrane proteins are found in the complexes. The protein compositions are qualitatively similar, but differ quantitatively in the individual components. The CHAPS complex is depleted of GPI-linked proteins and retains a minor fraction of lipids similar in composition to that of the Triton X-100 insoluble complex. We propose that in vivo the complexes form part of a sorting platform that mediates protein segregation and delivery to the apical cell surface.
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Affiliation(s)
- K Fiedler
- Cell Biology Programme, European Molecular Biology Laboratory, Heidelberg, Germany
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40
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Kagiwada S, Murata M, Hishida R, Tagaya M, Yamashina S, Ohnishi S. In vitro fusion of rabbit liver Golgi membranes with liposomes. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)54093-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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41
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Affiliation(s)
- D Allan
- Department of Physiology, University College London Medical School, U.K
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42
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Grimes M, Kelly RB. Sorting of chromogranin B into immature secretory granules in pheochromocytoma (PC12) cells. Ann N Y Acad Sci 1992; 674:38-52. [PMID: 1288369 DOI: 10.1111/j.1749-6632.1992.tb27475.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two tyrosine sulfated proteins, chromogranin B and secretogranin II, are targeted into regulated secretory granules, which are stored until stimulation causes them to fuse with the plasma membrane. In PC12 cells, [35S]-sulfate labels chromogranin B, secretogranin II and proteoglycans just before they are sorted into the regulated and constitutive secretory pathways. Chromogranin B was secreted by both the regulated and constitutive secretory pathways. In contrast, very little secretogranin II was secreted constitutively. Formation of regulated and constitutive secretory vesicles from the trans Golgi network was reconstituted in vitro. Mechanically permeabilized PC12 cells released regulated and constitutive vesicles containing sulfated markers. At early chase times, chromogranin B was predominantly released from permeabilized cells in small vesicles that comigrated with constitutive secretory vesicles containing proteoglycans. At intermediate chase times the vesicles containing chromogranin B resembled immature secretory granules containing secretogranin II. At very long chase times chromogranin B and secretogranin II were found in mature secretory granules that did not escape the permeabilized cells in vitro. We conclude that chromogranin B is sorted into immature regulated secretory granules with lower efficiency than secretogranin II.
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Affiliation(s)
- M Grimes
- Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448
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43
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44
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Abstract
A number of proteins that are necessary for membrane transport have been identified using cell-free assays and yeast genetics. Although our knowledge of transport mechanisms remains limited, common themes are clearly emerging. In particular, specific GTP-binding proteins appear to be involved, not only at all steps of membrane traffic but also at more than one check-point within each step. The ordered sequence of events occurring during vesicle formation, targeting and fusion may be regulated in a stepwise manner by specific GTP-dependent switches, which act as modular elements of the transport mechanism.
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Affiliation(s)
- J Gruenberg
- European Molecular Biology Laboratory, Heidelberg, Germany
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45
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Jasmin BJ, Goud B, Camus G, Cartaud J. The low molecular weight guanosine triphosphate-binding protein Rab6p associates with distinct post-Golgi vesicles in Torpedo marmorata electrocytes. Neuroscience 1992; 49:849-55. [PMID: 1436484 DOI: 10.1016/0306-4522(92)90361-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Rab genes have recently been cloned and sequenced in mammals, and their products represent good candidates for low molecular weight guanosine triphosphate-binding proteins involved in the regulation of intracellular transport of vesicles in higher eukaryotes. Remarkably, each of the Rab proteins appears to be associated with a distinct step of either the exocytic or endocytic pathway. In particular, Rab6p has been localized to the outermost Golgi cisternae in normal rat kidney cells, where its function remains unclear. In this work, we have carried out a series of immunocytochemical analyses of the subcellular distribution of Rab6p in a polarized cell, the electrocyte of Torpedo marmorata, to elucidate the molecular mechanisms involved in the sorting and targeting of synaptic proteins. We report that, aside from its Golgi localization, the bulk of Rab6p associates with clusters of post-Golgi vesicles, primarily those located at the cytoplasmic face of the innervated membrane of the electrocyte. Consequently, Rab6p presents a polarized distribution in this cell. Furthermore, we show that this distribution is dependent upon the integrity of the microtubule network of the electrocyte. These data are coherent with the notion that Rab6p is involved in the regulation of membrane traffic from the trans-Golgi network to the innervated plasma membrane, delivering, by way of a microtubule-based organelle transport mechanism, synaptic proteins to their appropriate locations.
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Affiliation(s)
- B J Jasmin
- Institut Jacques Monod, CNRS, Université Paris 7, France
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46
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Kobayashi T, Pimplikar SW, Parton RG, Bhakdi S, Simons K. Sphingolipid transport from the trans-Golgi network to the apical surface in permeabilized MDCK cells. FEBS Lett 1992; 300:227-31. [PMID: 1555649 DOI: 10.1016/0014-5793(92)80851-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have measured the transport of de novo synthesized fluorescent analogs of sphingomyelin and glucosylceramide from the trans-Golgi network (TGN) to the apical membrane in basolaterally permeabilized Madin-Darby canine kidney (MDCK) cells. Sphingolipid transport was temperature, ATP and cytosol dependent. Introduction of bovine serum albumin (BSA), which binds fluorescent sphingolipid monomer, into the permeabilized cells, did not affect lipid transport to the apical membrane. Both fluorescent sphingomyelin and glucosylceramide analogs were localized to the lumenal bilayer leaflet of isolated TGN-derived vesicles. These results strongly suggest that both sphingolipids are transported from the TGN to the apical membrane via vesicular traffic.
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Affiliation(s)
- T Kobayashi
- European Molecular Biology Laboratory, Heidelberg, Germany
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47
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Podbiliewicz B, Mellman I. Reconstitution of endocytosis and recycling using perforated Madin-Darby canine kidney cells. Methods Enzymol 1992; 219:198-211. [PMID: 1487993 DOI: 10.1016/0076-6879(92)19022-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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48
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Tooze SA, Huttner WB. Cell-free formation of immature secretory granules and constitutive secretory vesicles from trans-Golgi network. Methods Enzymol 1992; 219:81-93. [PMID: 1488016 DOI: 10.1016/0076-6879(92)19012-u] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- S A Tooze
- Department of Cell Biology, European Molecular Biology Laboratory, Heidelberg, Germany
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49
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Casanova J, Mishumi Y, Ikehara Y, Hubbard A, Mostov K. Direct apical sorting of rat liver dipeptidylpeptidase IV expressed in Madin-Darby canine kidney cells. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54246-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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50
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Miller SG, Moore HP. Biochemical analysis of constitutive secretion in a semiintact cell system. CELL BIOPHYSICS 1991; 19:35-43. [PMID: 1726886 DOI: 10.1007/bf02989877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- S G Miller
- Department of Molecular and Cell Biology, University of California, Berkeley 94720
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