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Results for “GOLGI APPARATUS”

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PubMed2002

Golgi apparatus dynamics during mouse oocyte in vitro maturation: effect of the membrane trafficking inhibitor brefeldin A.

We have studied Golgi apparatus dynamics during mouse oocyte in vitro maturation, employing both live imaging with the fluorescent lipid BODIPY-ceramide and immunocytochemistry using several specific markers (beta-COP, giantin, and TGN38). In germinal vesicle oocytes the Golgi consisted of a series of structures, possibly cisternal stacks, dispersed in the ooplasm, but slightly more concentrated in the interior than at the cortex. A similar pattern was detected in rhesus monkey germinal vesicle oocytes. These "mini-Golgis" were functionally active because they were reversibly disrupted by the membrane trafficking inhibitor brefeldin A. However, the drug had no visible effect if the oocytes had been previously microinjected with GTP-gamma-S. During in vitro maturation the large Golgi apparatus structures fragmented at germinal vesicle breakdown, and dispersed homogenously throughout the ooplasm, remaining in a fragmented state in metaphase-II oocytes. Similarly to what has been reported using protein synthesis inhibitors, the presence of brefeldin A blocked maturation at the germinal vesicle breakdown stage before the assembly of the metaphase-I spindle. These results suggest that progression of murine oocyte maturation may require functional membrane trafficking.

Animals↗

PubMed1996

Cloning and sequence analysis of the human MG160, a fibroblast growth factor and E-selectin binding membrane sialoglycoprotein of the Golgi apparatus.

The amino acid sequence of MG160, a membrane sialoglycoprotein of the medial cisternae of the rat Golgi apparatus, is more than 90% identical with CFR, a fibroblast growth factor (FGF) binding protein of chicken membranes, and with ESL-1, a ligand for E-selectin of plasma membranes of myeloid cells; furthermore, MG160, isolated by immunoaffinity chromatography from rat brain membranes, binds to basic FGF. The gene for MG160 has been assigned to human chromosome 16q22-23. To characterize this protein further in the human, its cDNA was cloned and sequenced. The protein has a large luminal domain composed of an initial proline-glutamine-rich segment, encoded by an uninterrupted exonic sequence of several CAG-CAA repeats. Expansion of CAG repeats has been implicated in the etiology of several neurodegenerative diseases. The proline-glutamine-rich segment is followed by 16 cysteine-rich repeats that contain five potential asparagine-linked glycosylation sites, which are conserved in the human, rat, mouse, and chicken. The large intralumenal domain of the protein is followed by a single transmembrane domain and a 13-amino-acid cytoplasmic carboxy-terminal tail, which is identical to that in the chicken, rat, and mouse. The overall amino acid identifies between MG160, CFR, and ESL-1 range from 88% to 95%. In several human fetal and adult tissues, three mRNA transcripts for MG160 of 10 kb, 5 kb, and 3.8 kb were identified by Northern blot analysis of poly(A)-selected mRNAs. These transcripts may represent alternatively spliced mRNAs of the protein or mRNAs encoding closely related proteins of the Golgi apparatus and/or plasma membranes.

Adult↗

PubMed1985

Dictyosome-like structures from guinea-pig testes lack galactosyltransferase, a Golgi apparatus marker.

More than twenty different enzyme activities of fractions containing dictyosome-like structures (DLS) as a dominant cell component were monitored. Plasma membrane vesicles were a major contaminant of the DLS fractions, which, presumably as a consequence, were enriched somewhat in plasma membrane markers. The lysosomal enzymes arylsulfatase and latent acid phosphatase were present in the DLS fractions as were the Golgi apparatus activities thiamine pyrophosphatase and nucleoside diphosphatase. The presence of the latter two enzymes in DLS, plus NADH-ferricyanide reductase, has been verified from cytochemistry. On the other hand, the Golgi apparatus marker, galactosyltransferase, was not enriched in DLS fractions and appeared to be absent. This latter finding, verified from cytochemistry with isolated DLS fractions and, in situ, from [3H]galactose incorporation by testis tubules with analysis by autoradiography, provides the first clear biochemical characteristic that serves unequivocally to distinguish DLS from conventional Golgi apparatus.

Animals↗

PubMed1983

Nerve growth factor induced changes in the Golgi apparatus of PC-12 rat pheochromocytoma cells as studied by ligand endocytosis, cytochemical and morphometric methods.

Cells of the PC-12 rat pheochromocytoma cell line respond to nerve growth factor (NGF) by sprouting neurites and biochemically differentiating into sympathetic ganglion-like cells. NGF-stimulated ('differentiated') and unstimulated ('undifferentiated') cells were studied by cytochemical techniques for the localization of the enzymes acid phosphatase (ACPase) and thiamine pyrophosphatase (TPPase), and by a morphometric analysis of the distribution of endocytosed wheat-germ agglutinin labelled with horseradish peroxidase (WGA-HRP). Both cytochemical stains showed the enzymes to be distributed in lysosomes and certain cisternae of the Golgi apparatus in both NGF stimulated and unstimulated cells. ACPase was not confined to GERL (Golgi-endoplasmic reticulum-lysosome) as in certain other cells. The morphometric studies demonstrated that the reaction product of the internalized WGA-HRP occupied 4.7% of the cytoplasmic area in unstimulated cells and 4.5% in NGF-stimulated ones. Despite this similarity, the distribution of the WGA-HRP among the studied intracellular compartments in these two cell groups varied. In the NGF-stimulated cells 3.3% of the WGA-HRP reaction product was found in the innermost Golgi cisterna(e) while in unstimulated cells only 0.3% was seen in this compartment. Similarly, 4.3% of the WGA-HRP stain was found in small vesicles at the 'trans' aspect of the Golgi apparatus in stimulated cells, when only 0.3% of the stain occupied this compartment in 'undifferentiated' cells. The morphometric analysis also revealed that when the PC-12 cells were stimulated with NGF, the Golgi apparatus increased in area by approximately 70%. These findings are consistent with the hypothesis that NGF induced differentiation of PC-12 cells is coupled with enhanced endocytosis of WGA and probably of its 'receptor' to the innermost Golgi cisterna(e) and the closely associated vesicles.

Acid Phosphatase↗

PubMed1994

Concentration of intracellular hepatic apolipoprotein E in Golgi apparatus saccular distensions and endosomes.

The intrahepatic distribution of apolipoprotein E has been assessed by immunogold labeling of cryosections as well as by Western blotting of organelles isolated from liver homogenates. Both techniques supported the prior analytical fractionation studies of Wong (1989) who concluded that intrahepatic apoE was largely endosomal. All endosomal components decorated by gold particles indicative of apoE antigenicity in cryosections appeared filled with lipoprotein-like particles thereby accounting for this prominent morphological feature of isolated liver endosomes. The distribution of gold particles about the hepatic Golgi apparatus revealed a high content of apoE in closely apposed endosomes, ca. 400 nm in diameter, double labeled for apoE and internalized HRP. Remarkably, apoE (but not internalized HRP) was also observed within saccular distensions of all saccules of stacked Golgi cisternae but absent from the flattened saccular components as was also observed for apoB. This contrasted with albumin, the major secretory protein, which was uniformly distributed throughout the hepatic Golgi apparatus. These observations support a growing body of evidence for intra-Golgi sorting of secretory material in hepatic Golgi apparatus. The lack of any immunoreactive apoE or albumin in small 70-90 nm vesicles about the Golgi cisternae suggests limits to current models of vesicle-mediated intra-Golgi transport.

Albumins↗

PubMed1996

Ceramides are transported through the Golgi apparatus in human keratinocytes in vitro.

The intercellular lipid sheets of the stratum corneum constitute the epidermal permeability barrier that permits terrestrial life. Although lamellar granules are known to deliver the precursors of the stratum corneum lipids into the intercellular spaces, their site of origin remains unknown. Lamellar granules have characteristics of both secretory granules and lysosomes, which are known to originate from the Golgi apparatus in other cell types. Glucosylceramides, a major component of lamellar granule contents and the precursors of stratum corneum ceramides, have been found to be synthesized primarily in the early compartments of the Golgi apparatus in other cell types. We have investigated the transport and metabolism of a fluorescently labeled ceramide in human keratinocyte cultures using laser-scanning confocal microscopy and lipid analysis. We found that ceramide is metabolized to glucosylceramide and sphingomyelin as it passes through the Golgi apparatus and the metabolites are then delivered to the plasma membrane. Cold temperature, Brefeldin A, and monensin, all known to inhibit transport from the Golgi to the plasma membrane, prevented ceramide metabolites from appearing at the plasma membrane. Because glucosylceramides are one of the most important lipid constituents of lamellar granules, these results support the hypothesis that the Golgi is the origin of lamellar granules.

Biological Transport↗

PubMed1995

Effects of brefeldin A on the three-dimensional structure of the Golgi apparatus in a sensitive strain of Saccharomyces cerevisiae.

BACKGROUND: Brefeldin A (BFA), when added to the medium of cultured mammalian cells, induces a reversible block of secretion and disrupts the Golgi apparatus whereas Golgi enzyme markers appear to redistribute into the endoplasmic reticulum (ER). It has been shown in addition that in mammalian cells, BFA would prevent the assembly of coatomer proteins (COP) onto membranes by inhibiting the GTP-dependent interaction of the ADP-ribosylation factor (ARF) with such membranes. The purpose of the present study is to analyze, by stereoelectron microscopy, the structural modifications of Golgi elements and of the ER-Golgi relationship in a BFA-sensitive yeast mutant, S. cerevisiae erg6. METHODS: S. cerevisiae erg6 cells were placed in a medium containing 100 micrograms/ml BFA dissolved in 1% alcohol and collected after exposures of 0.5, 1.5, 5, 10, 15, 20, 30, and 70 min to the drug. Yeasts placed in a BFA-free medium but containing 1% alcohol served as controls. After fixation in 2% glutaraldehyde, the cells were postfixed in reduced osmium and embedded in Epon. Then 0.08-0.2 microns thick sections stained with lead citrate were examined with the electron microscope. Photographs of the thicker sections, tilted at +/- 15 degrees from the 0 degree position of the goniometric stage, were used to prepare stereopairs from which the three-dimensional configuration of the organelles was visualized. Since BFA is known to prevent the interaction of ARF with membranes, the phenotype of the arf1 mutant deficient in this protein was also examined for comparative purposes. RESULTS: In control cells, as in wild-type strains, two types of Golgi elements were observed: small networks of fine tubules seen close and occasionally connected to ER cisternae and coarser tubular networks showing nodular distensions having a size comparable to that of secretion granules. The latter networks were considered as trans-Golgi elements and the former as cis-Golgi elements. Several networks of both types were distributed throughout the cytoplasm. At short time intervals (0.5-5 min) of BFA treatment, the trans-Golgi elements disappeared from the cytoplasm, while the ER-connected cis-Golgi elements developed and formed large spheroidal masses frequently showing concentrically arranged fine tubular networks. Such spheroidal, cage-like structures later disappeared, and after 30 min Golgi elements were no longer identifiable, while ER cisternae assumed pleomorphic configurations as the cells showed signs of degeneration. S. cerevisiae arf1 mutants presented a phenotype similar to that of BFA-treated S. cerevisiae erg6. CONCLUSIONS: It is therefore concluded that soon after exposure to BFA there is, in this sensitive yeast mutant, a transitory hypertrophy of the ER-connected cis-Golgi network presumably resulting from a block at the exit end of this compartment. At longer time intervals (i.e., after 30 min) the Golgi elements are no longer formed, and the cells present signs of cell degeneration.

ADP-Ribosylation Factor 1↗

PubMed1998

1998: the centenary of the discovery of the Golgi apparatus.

1998 is the year of the centenary of the discovery of the Golgi apparatus. This event is considered in its historical context: the first cell theory of 1838-1839, the first polemics in cytology and the research on the cell organelles at the turn of the century. The first approaches to clarify the physiological significance of the apparatus is traced from Golgi (1909) to Bowen (1929).

Biology↗

PubMed2006

Expanding the role of the dynein regulatory complex to non-axonemal functions: association of GAS11 with the Golgi apparatus.

The mammalian GAS11 gene is a candidate tumor suppressor of unknown function that was previously identified as one of several genes upregulated upon growth arrest. Interestingly, although GAS11 homologs in Trypanosoma brucei (trypanin) and Chlamydomonas reinhardtii (PF2) are integral components of the flagellar axoneme and are necessary for regulating flagellar beat, the GAS11 gene was discovered based on its expression in cells that do not assemble a motile cilium. This suggests that GAS11 function might not be restricted to the cilium. To investigate this possibility, we generated GAS11-specific antibodies and demonstrate here that GAS11 is expressed in a variety of mammalian cells that lack a motile cilium. In COS7 cells, GAS11 is associated with the detergent-insoluble cytoskeleton and exhibits a juxtanuclear localization that overlaps with the pericentrosomal Golgi apparatus. This localization is dependent upon intact microtubules and is cell-cycle regulated, such that GAS11 is dispersed throughout the cytoplasm as cells progress through mitosis. GAS11 remains associated with Golgi fragments following depolymerization of cytoplasmic microtubules but is dispersed upon disruption of the Golgi with brefeldin A. These data suggest that GAS11 is associated with the Golgi apparatus. In support of this, recombinant GAS11 binds Golgi membranes in vitro. In growth-arrested mIMCD3 cells, GAS11 co-localizes with gamma-tubulin at the base of the primary cilium. The pericentrosomal Golgi apparatus and base of the cilium both represent convergence points for microtubule minus ends and correspond to sites where dynein regulation is required. The algal GAS11 homolog functions as part of a dynein regulatory complex (DRC) in the axoneme (Rupp and Porter. J Cell Biol 2003;162:47-57) and our findings suggest that components of this axonemal dynein regulatory system have been adapted in mammalian cells to participate in non-axonemal functions.

Animals↗

PubMed2004

The Ca2+/Mn2+ pumps in the Golgi apparatus.

Recent evidence highlights the functional importance of the Golgi apparatus as an agonist-sensitive intracellular Ca(2+) store. Besides Ca(2+)-release channels and Ca(2+)-binding proteins, the Golgi complex contains Ca(2+)-uptake mechanisms consisting of the well-known sarco/endoplasmic reticulum Ca(2+)-transport ATPases (SERCA) and the much less characterized secretory-pathway Ca(2+)-transport ATPases (SPCA). SPCA supplies the Golgi compartments and, possibly, the more distal compartments of the secretory pathway with both Ca(2+) and Mn(2+) and, therefore, plays an important role in the cytosolic and intra-Golgi Ca(2+) and Mn(2+) homeostasis. Mutations in the human gene encoding the SPCA1 pump (ATP2C1) resulting in Hailey-Hailey disease, an autosomal dominant skin disorder, are discussed.

Calcium-Transporting ATPases↗

PubMed2005

AtUTr2 is an Arabidopsis thaliana nucleotide sugar transporter located in the Golgi apparatus capable of transporting UDP-galactose.

The synthesis of noncellulosic polysaccharides and glycoproteins in the plant cell Golgi apparatus requires UDP-galactose as a substrate. We have cloned and characterized a nucleotide sugar transporter from Arabidopsis thaliana (L.) Heynh. named AtUTr2. Expression in tobacco and Saccharomyces cerevisiae and subsequent biochemical characterization indicate that AtUTr2 transports UDP-galactose, but not UDP-glucose, UDP-N-acetyl glucosamine, UDP-xylose, UDP-glucuronic acid, GDP-fucose or GDP-mannose. Experiments expressing an AtUTr2-GFP fusion protein in onion epidermal cells suggest that AtUTr2 is located in the Golgi apparatus. Finally, northern analysis indicates that the AtUTr2 transcript was more abundant in roots and calli although it was also present in other Arabidopsis organs but at lower levels. Therefore, AtUTr2 is a nucleotide sugar transporter capable of transporting UDP-galactose that may play an important role in the synthesis of galactose-containing glycoconjugates in Arabidopsis.

Amino Acid Sequence↗

PubMed1993

Structure of the Golgi apparatus in stimulated and nonstimulated acinar cells of mammary glands of the rat.

The structural features of the Golgi apparatus of acinar cells of mammary glands were examined with the electron microscope in 3 groups of rats: (1) in lactating female animals at 8 days postpartum, which served as controls; (2) in female rats sacrificed at various intervals from 2 to 30 hours following separation from their 8-day old pups; and (3) in females separated from their 8-day-old pups for a period of 12 hours and returned to their litters for durations of 1, 2, 4, and 8 hours. In animals of group 2, the Golgi stacks remained identical to that of controls between 2 and 8 hours. At 12 hours and later, the Golgi stacks decreased progressively in size, but the number of elements composing the stacks remained similar to that of lactating females and all contained casein submicelles. At 24 and 30 hours, typical secretory granules containing casein micelles disappeared from the trans aspect of the stacks. The earliest and most striking changes observed in the Golgi apparatus of the rats of group 2 took place at 12 hours. At this time, the prosecretory and secretory granules decreased considerably in volume and lost most of their electron-lucent content. This indicated that the delivery of small molecules, i.e., lactose and H2O, to these structures was soon altered following arrest of the sucking stimulus. In animals of group 3, the size of prosecretory and secretory granules and the amount of their electron-lucent content reverted to normal at 4 hours. Thus the influx of lactose and H2O into these structures appears to be rapidly restored after returning the pups to their mothers. The decrease in size of the Golgi stacks noted at 12, 18, and 24 hours following arrest of lactation (group 2), was accompanied by an increase in number of small vesicles that formed clusters next to the Golgi stacks and in "wells." Thus in these regressing Golgi stacks, many of the associated small vesicles appear to arise by vesiculation of the saccules.

Animals↗

PubMed2003

Association of cPLA2-alpha and COX-1 with the Golgi apparatus of A549 human lung epithelial cells.

Cytosolic phospholipase A2-alpha (cPLA2-alpha) is an 85 kDa, Ca2+-sensitive enzyme involved in receptor-mediated prostaglandin synthesis. In airway epithelial cells, the release of prostaglandins is crucial in regulating the inflammatory response. Although prostaglandin release has been studied in various epithelial cell models, the subcellular location of cPLA2-alpha in these cells is unknown. Using high-resolution confocal microscopy of the human A549 lung epithelial cell line, we show that cPLA2-alpha relocates from the cytosol and nuclei to a juxtanuclear region following stimulation with the Ca2+ ionophore A23187. Double staining with rhodamine-conjugated wheat germ agglutinin confirmed this region to be the Golgi apparatus. Markers specific for Golgi subcompartments revealed that cPLA2-alpha is predominantly located at the trans-Golgi stack and the trans-Golgi network following elevation of cytosolic Ca2+. Furthermore, treatment of cells with the Golgi-disrupting agent brefeldin A caused a redistribution of cPLA2-alpha, confirming that cPLA2-alpha associates with Golgi-derived membranes. Finally, a specific co-localization of cPLA2-alpha with cyclooxygenase-1 but not cyclooxygenase-2 was evident at the Golgi apparatus. These results, combined with recent data on the role of PLA2 activity in maintaining Golgi structure and function, suggest that Golgi localization of cPLA2-alpha may be involved in membrane trafficking in epithelial cells.

Biomarkers↗

PubMed2002

ZnT7, a novel mammalian zinc transporter, accumulates zinc in the Golgi apparatus.

ZnT7, a novel member of the zinc transporter (ZnT) family, was identified by searching the expressed sequence tag (EST) databases with the amino acid sequence of ZnT1. Like the other ZnT proteins, the protein (387 amino acids) predicted from this gene contains six transmembrane domains and a histidine-rich loop between transmembrane domains IV and V. We show that Znt7 is widely transcribed in mouse tissues with abundant expression in the liver and small intestine and moderate expression in the kidney, spleen, brain, and lung. An affinity-purified antibody raised against the amino acids 299-315 of mouse ZnT7 specifically reacted with the proteins with apparent molecular masses of 85, 43, and 65 kDa in small intestine and lung tissues by Western blot analysis. Immunofluorescence microscope analysis reveals that ZnT7 is localized in the Golgi apparatus and cytoplasmic vesicles. Exposure of the ZnT7-expressing Chinese hamster ovary (CHO) cells to zinc causes an accumulation of zinc in the Golgi apparatus, suggesting that ZnT7 facilitates zinc transport from the cytoplasm into the Golgi apparatus.

Amino Acid Sequence↗

PubMed2006

ARL1 plays a role in the binding of the GRIP domain of a peripheral matrix protein to the Golgi apparatus in plant cells.

ARF GTPases play a central role in regulating membrane dynamics and protein transport in eukaryotic cells. ARF-like (ARL) proteins are close relatives of the ARF regulators of vesicular transport, but their function in plant cells is poorly characterized. Here, by means of live cell imaging and site-directed mutagenesis, we have investigated the cellular function of the plant GTPase ARL1. We provide direct evidence for a role of this ARL family member in the association of a plant golgin with the plant Golgi apparatus. Our data reveal the existence of key residues within the conserved GRIP-domain of the golgin and within the GTPase ARL1 that are central to ARL1-GRIP interaction. Mutations of these residues abolish the interaction of GRIP with the GTP-bound ARL1 and induce a redistribution of GRIP into the cytosol. This indicates that the localization of GRIP to the Golgi apparatus is strongly influenced by the interaction of GRIP with Golgi-localized ARL1. Our results assign a cellular role to a member of the Arabidopsis ARL family in the plant secretory pathway and propose mechanisms for localization of peripheral golgins to the plant Golgi apparatus.

Amino Acid Motifs↗

PubMed1995

Decreased protein synthetic activity of the hypothalamic tuberomamillary nucleus in Alzheimer's disease as suggested by smaller Golgi apparatus.

The nucleus tuberalis lateralis (NTL) and tuberomamillary nucleus (TM), which are located close together in the tuberal region of the human hypothalamus, are differentially affected by Alzheimer's disease (AD), In the AD, the NTL shows only early cytoskeletal alterations, i.e. pre-tangle stages, while the TM is characterised by advanced Alzheimer's changes, e.g. neurofibrillary degeneration, senile plaques and amyloid deposition. Earlier we showed that the early cytoskeletal alterations in the NTL are not accompanied by changes in protein synthetic activity. The present study was carried out in order to measure the protein synthetic activity of the neighbouring area, the TM, which is severely affected by advanced Alzheimer changes. A polyclonal antibody against MG-160, a conserved membrane sialoglycoprotein of the Golgi apparatus, was used to stain this organelle and using an image analysis system, the size of the Golgi apparatus was measured as an index for synthetic and secretory activity in 15 Alzheimer patients and 21 controls. A significant decrease in the size of the Golgi apparatus was found in the TM neurons in AD, although the cell profile area remained unchanged. These data suggest that the protein synthetic and secretory activity of TM neurons is indeed decreased in AD.

Aged↗

PubMed1986

A microtubule-binding protein associated with membranes of the Golgi apparatus.

A monoclonal antibody (M3A5), raised against microtubule-associated protein 2 (MAP-2), recognized an antigen associated with the Golgi complex in a variety of non-neuronal tissue culture cells. In double immunofluorescence studies M3A5 staining was very similar to that of specific Golgi markers, even after disruption of the Golgi apparatus organization with monensin or nocodazole. M3A5 recognized one band of Mr approximately 110,000 in immunoblots of culture cell extracts; this protein, designated 110K, was enriched in Golgi stack fractions prepared from rat liver. The 110K protein has been shown to partition into the aqueous phase by Triton X-114 extraction of a Golgi-enriched fraction and was eluted after pH 11.0 carbonate washing. It is therefore likely to be a peripheral membrane protein. Proteinase K treatment of an isolated Golgi stack fraction resulted in complete digestion of the 110K protein, both in the presence and absence of Triton X-100. A the 110K protein is accessible to protease in intact vesicles in vitro, it is presumably located on the cytoplasmic face of the Golgi membrane in vivo. The 110K protein was able to interact specifically with taxol-polymerized microtubules in vitro. These results suggest that the 110K protein may serve to link the Golgi apparatus to the microtubule network and so may belong to a novel class of proteins: the microtubule-binding proteins.

Animals↗

PubMed2003

Proteasome inhibition induces inclusion bodies associated with intermediate filaments and fragmentation of the Golgi apparatus.

The ubiquitin-proteasome system is involved in a variety of biological processes. Inclusion bodies associated with intermediate filaments (IFs) and ubiquitin are observed in various diseases; however, the precise mechanisms of formation and the pathological significance of inclusion bodies have not been fully understood. We examined the effect of proteasome inhibitors on the structure of IF using anti-cytokeratin antibodies or transfection of green fluorescent protein-fused cytokeratin 18 in a hepatoma cell line, Huh7. Intracellular organelles were visualized by immunofluorescent and electron microscopies. Proteasome inhibitors induced IF inclusions associated with ubiquitin. Electron microscopic examination revealed inclusion bodies surrounded by filamentous structures. Autophagic vacuoles and lysosomes were frequently observed, and the organization of the Golgi apparatus was disrupted in these cells. After the removal of the proteasome inhibitors, the IF network and organization of the Golgi apparatus were restored. The IF inclusions could be induced by inhibition of the proteasome function. IF inclusions induced fragmentation of the Golgi apparatus and might inhibit the function of this important station of membrane traffic. The IF inclusions disappeared by restoring proteasome function, and autophagy and lysosomal degradation might be, at least in part, associated with the elimination of inclusion bodies.

Autophagy↗