Mutations in the Rab33b protein that lead to the skeletal disease Smith-McCort dysplasia result in unstable proteins and altered autophagy function.

Although many studies of the Golgi apparatus structure have been performed by light and electron microscopy, the full shape of the Golgi apparatus remained unclear due to the technical limitations of the previously applied microscopy techniques. In this study, we used serial section scanning electron microscopy (SEM) for the morphological study of the Golgi apparatus. This method is useful for three-dimensional (3D) reconstruction of cellular structures without requiring specialized instruments, unlike focused ion beam SEM (FIB-SEM) and serial block face SEM (SBF-SEM). Using the serial section SEM method developed by our laboratory, we investigate the 3D shape of the osmium-impregnated Golgi apparatus in rat epididymal cells, pancreatic acinar cells and gonadotropes. The combination of serial section SEM and a 3D reconstruction technique enabled us to elucidate the entire shape of the Golgi apparatus in these cells. The full shape of the Golgi apparatus in epididymal cells formed a basket-like structure with oval-shaped cisterns, while the Golgi apparatus in an acinar cell from the pancreas was composed of elongated ribbon-like structures that were connected to each other, making a coarse network. The overall image of the Golgi apparatus cisterns from a gonadotrope looked like a spherical cage. This study has clearly shown that entire 3D shape of the Golgi apparatus varies depending on the cell type and that the Golgi cisterns network appears as a single mass located in the large region of the cytoplasm.

(1) The standard silver and osmium techniques show a typical Golgi apparatus in the epithelial cells of the stomach and intestine of the leech, Glossiphonia complanata. (2) Histochemical studies reveal the presence of lipoids in the Golgi region of these cells. In the stomach, part, at least, is lipine. (In the intestinal cells, the rest of the cytoplasm contains much lipine, but the Golgi apparatus little or none that can be shown by the method used.) (3) The Golgi apparatus in these cells appears to consist of rows of nonlipoidal spheres, each with a lipoid coat. In the stomach, this coat contains lipine.

The intracellular transport of the HSV-1 glycoproteins gA/gB, gC and gD has been followed by the indirect immunofluorescence technique (IIF). Infected tissue culture cells were stained with monoclonal antibodies made to the individual glycoproteins and with fluorochrome-coupled wheat germ agglutinin reacting specifically with Golgi apparatus of the cells. Staining of either infected, human fibroblasts or of VERO cells at 9 hours p.i. with antibodies to gA/gB showed a prominent ring-like nuclear fluorescence and distinct staining of the Golgi apparatus in the cells. Antibodies to gC and gD stained mainly the Golgi apparatus and areas close to or at the surface of the cells. By immunocytolysis of HSV-1-infected VERO cells the viral glycoproteins were demonstrable at the surface of cells but growth of infected cells in the presence of either TM or monensin inhibited the expression of most of the viral glycoproteins at the cell surface. Blocking of the glycosylation of the viral glycoproteins with tunicamycin (TM) was followed by accumulation of the core of the glycoproteins gA/gB and gD in granular structures close to the nucleus as seen by immunofluorescence microscopy. Antibodies to gC did also stain granules close to the nucleus but in addition the periphery of the cells were stained. Inhibition of intracellular transport from the Golgi apparatus by the carboxylic ionophore monensin was followed by accumulation of all the HSV-1 glycoproteins in vesicles derived from the Golgi apparatus in both human fibroblasts and VERO cells. Our data thus support the hypothesis that the HSV-1 glycoproteins are processed in the Golgi apparatus before the transport to and incorporation into the cell surface membrane of infected cells and into virion envelopes.

Nitric oxide scavenging causes remodeling of the endoplasmic reticulum, Golgi apparatus and mitochondria in pulmonary arterial endothelial cells

Precise Detection and Visualization of Cyclooxygenase-2 for Golgi Imaging by a Light-Up Aggregation-Induced Emission-Based Probe

α-Mannosidases involved in N-glycan processing show cell specificity and distinct subcompartmentalization within the Golgi apparatus of cells in the testis and epididymis

MG160, a Membrane Protein of the Golgi Apparatus Which Is Homologous to a Fibroblast Growth Factor Receptor and to a Ligand for E-selectin, Is Found Only in the Golgi Apparatus and Appears Early in Chicken Embryo Development

Editor's evaluation: Microcephaly-associated protein WDR62 shuttles from the Golgi apparatus to the spindle poles in human neural progenitors

The effects of vinblastine and colchicine on the Golgi apparatus of stomach surface mucoid and absorptive intestinal cells were compared by cytochemical analysis. The two epithelial cells were chosen because of their different specific functions in the formation of secretory granules, the production of lysosomes and the intensity of membrane traffic in the cytoplasm. For the analysis, adult mice were injected with 1 mg/100 g b.w. of vinblastine and 1 mg/100 g b.w. of colchicine. For the demonstration of cis and trans cisternae of the Golgi apparatus, prolonged osmification, thiamine pyrophosphatase and acid phosphatase activity identification were applied. After treatment with vinblastine or colchicine, polarity of stacks in the Golgi apparatus of surface mucoid cells is preserved although the number of cisternae with thiamine pyrophosphatase or acid phosphatase activity decreases. However, the Golgi apparatus of intestinal absorptive cells completely disintegrates and only a few separated cis or trans cisternae can be identified. The main effect seems to be a reduction of vesicles which can be cytochemically identified as parts of the Golgi apparatus and an accumulation of vesicles which probably originate from budding ER. Communication between the ER and the Golgi apparatus seems to be interrupted.

Apolipoprotein (apo) E4 is the major genetic risk factor for Alzheimer disease (AD) and likely contributes to neuropathology through various pathways. Here we report that the intracellular trafficking of apoE4 is impaired in Neuro-2a cells and primary neurons, as shown by measuring fluorescence recovery after photobleaching. In Neuro-2a cells, more apoE4 than apoE3 molecules remained immobilized in the endoplasmic reticulum (ER) and the Golgi apparatus, and the lateral motility of apoE4 was significantly lower in the Golgi apparatus (but not in the ER) than that of apoE3. Likewise, the immobile fraction was larger, and the lateral motility was lower for apoE4 than apoE3 in mouse primary hippocampal neurons. ApoE4 with the R61T mutation, which abolishes apoE4 domain interaction, was less immobilized, and its lateral motility was comparable with that of apoE3. The trafficking impairment of apoE4 was also rescued by disrupting domain interaction with the small-molecule structure correctors GIND25 and PH002. PH002 also rescued apoE4-induced impairments of neurite outgrowth in Neuro-2a cells and dendritic spine development in primary neurons. ApoE4 did not affect trafficking of amyloid precursor protein, another AD-related protein, through the secretory pathway. Thus, domain interaction renders more newly synthesized apoE4 molecules immobile and slows their trafficking along the secretory pathway. Correcting the pathological structure of apoE4 by disrupting domain interaction is a potential therapeutic approach to treat or prevent AD related to apoE4.

Histochemical studies using cryostat sections of fixed rodent fetal and newborn tissues indicated that acid phosphatase (APase) staining of the Golgi apparatus (GA) of cells secreting matrix for hard tissue formation was a general phenomenon. The enzyme was chiefly observed in the GA of tall secretory ameloblasts involved in enamel formation and in the GA of odontoblasts forming dentine; lysosome-like granules reactive for this enzyme were also observed in these cells. Activity was also intense in the GA and lysosomes of osteoblasts involved in intramembranous and endochondral bone formation. High levels of APase in the GA of extracellular matrix-forming cells appeared to correlate with secretory activity. The GA of most other cells, even chondroblasts forming cartilage matrix, had much less marked APase activity. Contrary to previous suggestions, it appears that APase may have a more direct role in osteogenesis than the osteolytic or resorptive action usually cited.

1. The Golgi apparatus of nerve cells of spinal ganglion in the guinea pig was demonstrated by means of the present author's protease-Nile blue sulphate technique.2. The Golgi apparatus thus demonstrated accords fully to those prepared after the classical osmium-impregnation methods when employed properly. This fact proves that the Golgi apparatus of nerve cells assumes, at least in the fixed condition, the reticular feature which is familiar to us in the classical works.3. As fixatives before the digestion procedures various reagents, simple or mixed, were employed. The results obtained from these attempts are summarized in Table I in the section of material and methods. The most excellent fixatives found by this attempts proved to be the combinating techniques as follows: formalin-trypsin, osmic acid-trypsin, Champy's fluid-pepsin, Champy's fluid-trypsin, corrossive sub-limate-trypsin, potassium bichromate-pepsin, potassium bicromate-trypsin, picric acid-trypsin, and picric acid-pepsin. The percentages of the reagents and of the enzymes, and the reaction times are detailed in Table 1.4. The Nissl bodies and the mitochondria were frequently impregnated by the osmium impregnation. This phenomenon seems to be indicative of the special physiological condition of the cytoplasm in which the lipoid is unmasked from the protein.5. The mitochondria seem to be dissolved by these techniques without an exception. The Nissl bodies remain undigested by formalin-trypsin, formalin-pepsin, corrossive sublimate-trypsin technique. Their capacity of blackening by the osmic acid and their demonstrability by the pro-tease-Nile blue sulphate techniques are suggesting the existence of lipoidal substances in them. This assumption is on the other hand supported by various experimental data appeared in the literature, e.g. the experiment of axon section made by Legendre (1910) etc.6. The vital staining of the genuine Golgi apparatus has been attempted. Applying Nile blue sulphate and crysoidin upon the fresh material sectioned by means of frozen method the net-like Golgi apparatus which fully corresponds to that impregnated with osmic acid was observed stained with a considerable clearness. Here, the nerve cells in the frozen sections were surmised to be still living from the fact that their nuclei were quite free from staining and their cytoplasm showed no symptoms of death as vacuolation or granulation.7. The solubility of the Golgi substance was studied. Likewise those in other tissue cells known in the foregoing works made by the present author, the Golgi apparatus of nerve cells in the guinea pig, contains the protein digestible by trypsin and the lipoid soluble in aceton. The idea that the Golgi apparatus contains the lecithin has been denied by this study of solubility.

The three-dimensional ultrastructure of the Golgi apparatus in different cells of the rat - epithelial principal cells in the epididymal duct, goblet cells in the jejunum, gonadotrophs in the pituitary gland and dorsal root ganglion cells - was studied by scanning electron microscopy (SEM) of osmium-macerated tissues. The Golgi apparatus in the epididymal principal cells took the shape of a candle flame with irregular-shaped cisterns, while those in the goblet cells of the jejunum were cup-shaped or cylindrical with flat cisterns. Gonadotrophs had a large spherical Golgi apparatus; this apparatus was composed of several concentric cisterns with large round windows through which the rough endoplasmic reticulum (rER) and mitochondria extended into the center of the globular Golgi apparatus. Dorsal root ganglion cells had several small Golgi stacks scattered in the cytoplasm. In all Golgi apparatuses of the different cells examined in the present study, the cis-most cistern was generally composed of a flattened sheet with numerous small fenestrations on its wall. On the other hand, the shape of the trans-most cistern varied by cell type; it was generally composed of tubules and/or small sheets which were sometimes connected with each other to form a rather complicated structure. The cis-most cistern and the trans-most cistern were often closely associated with the rER although no direct communication was found between them. These findings indicate that the structure of the Golgi apparatus, especially its overall shape and the ultrastructure of the trans-most cistern, varies by cell type, a point to be considered in relation to the function of the individual cells.

Microtubules, actin filaments, and Golgi apparatus are connected both directly and indirectly, but it is manifested differently depending on the cell organization and specialization, and these connections are considered in many original studies and reviews. In this review we would like to discuss what underlies differences in the structural organization of the Golgi apparatus in animal and plant cells: specific features of the microtubule cytoskeleton organization, the use of different cytoskeleton components for Golgi apparatus movement and maintenance of its integrity, or specific features of synthetic and secretory processes. We suppose that a dispersed state of the Golgi apparatus in higher plant cells cannot be explained only by specific features of the microtubule system organization and by the absence of centrosome as an active center of their organization because the Golgi apparatus is organized similarly in the cells of other organisms that possess the centrosome and centrosomal microtubules. One of the key factors determining the Golgi apparatus state in plant cells is the functional uniformity or functional specialization of stacks. The functional specialization does not suggest the joining of the stacks to form a ribbon; therefore, the disperse state of the Golgi apparatus needs to be supported, but it also can exist "by default". We believe that the dispersed state of the Golgi apparatus in plants is supported, on one hand, by dynamic connections of the Golgi apparatus stacks with the actin filament system and, on the other hand, with the endoplasmic reticulum exit sites distributed throughout the endoplasmic reticulum.

BackgroundEndothelial nitric oxide synthase (eNOS) is primarily localized on the Golgi apparatus and plasma membrane caveolae in endothelial cells. Previously, we demonstrated that protein S-nitrosylation occurs preferentially where eNOS is localized. Thus, in endothelial cells, Golgi proteins are likely to be targets for S-nitrosylation. The aim of this study was to identify S-nitrosylated Golgi proteins and attribute their S-nitrosylation to eNOS-derived nitric oxide in endothelial cells.MethodsGolgi membranes were isolated from rat livers. S-nitrosylated Golgi proteins were determined by a modified biotin-switch assay coupled with mass spectrometry that allows the identification of the S-nitrosylated cysteine residue. The biotin switch assay followed by Western blot or immunoprecipitation using an S-nitrosocysteine antibody was also employed to validate S-nitrosylated proteins in endothelial cell lysates.ResultsSeventy-eight potential S-nitrosylated proteins and their target cysteine residues for S-nitrosylation were identified; 9 of them were Golgi-resident or Golgi/endoplasmic reticulum (ER)-associated proteins. Among these 9 proteins, S-nitrosylation of EMMPRIN and Golgi phosphoprotein 3 (GOLPH3) was verified in endothelial cells. Furthermore, S-nitrosylation of these proteins was found at the basal levels and increased in response to eNOS stimulation by the calcium ionophore A23187. Immunofluorescence microscopy and immunoprecipitation showed that EMMPRIN and GOLPH3 are co-localized with eNOS at the Golgi apparatus in endothelial cells. S-nitrosylation of EMMPRIN was notably increased in the aorta of cirrhotic rats.ConclusionOur data suggest that the selective S-nitrosylation of EMMPRIN and GOLPH3 at the Golgi apparatus in endothelial cells results from the physical proximity to eNOS-derived nitric oxide.