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At least 181 records · Page 10Linked to original sources
PubMed1983

Identification of nonmitochondrial creatine kinase enzymatic activity in isolated sea urchin mitotic apparatus.

ATP-dependent calcium sequestration was previously localized in vesicles of mitotic apparatus isolated from sea urchins. We now demonstrate that the mitotic apparatus contains an ATP-regenerative system characterized as creatine kinase (EC 2.7.3.2). Mitotic apparatus isolated with vesicles intact converted ADP to ATP if phosphocreatine was present. Omission of ADP or phosphocreatine gave negligible ATP. When mitotic apparatus were washed with detergent-containing buffer to remove vesicles, their ability to produce ATP from ADP and phosphocreatine was reduced. Assays of creatine kinase activity using NADP+:glucose-6-phosphate dehydrogenase indicated that 70% of the creatine kinase activity was extractable with 0.5% Triton X-100. The insoluble residue containing the skeleton of the mitotic apparatus had the rest of the activity. Experiments with a luciferin/luciferase assay showed that Triton removed above 82% of the activity. Preparations of intact mitotic apparatus were free of cytochrome c oxidase (EC 1.9.3.1) activity and therefore free of mitochondria. About 10(8) mitotic apparatus (total volume about 1 liter) could produce 17 mmol of ATP/min when substrates were not limiting. The creatine kinase enzyme activity described herein and the previously described membrane vesicular calcium sequestration system are nonmitochondrial, integral constituents of the sea urchin mitotic apparatus.

Creatine Kinase↗
PubMed1993

The Golgi apparatus of motor neurons in amyotrophic lateral sclerosis.

The Golgi apparatus plays a key role in the posttranslational processing of polypeptides destined for secretion, incorporation into plasma membranes, and fast axoplasmic transport. Dispersion or fragmentation of the Golgi apparatus, experimentally induced by microtubule-disrupting agents, is associated with decreased secretion of immunoglobulins and insulin. The Golgi apparatus is also involved in targeting of lysosomal enzymes and in the endocytosis of certain hormones, receptors, and toxins. There is a paucity of information on this important organelle in human neuropathological conditions. Using an organelle-specific antiserum we have examined by immunocytochemistry the Golgi apparatus of motor neurons in the spinal cord in 4 patients with amyotrophic lateral sclerosis and 1 patient with Werdnig Hoffmann's disease, 1 with infantile neuronal degeneration, 1 with adult-type familial bulbospinal atrophy, 1 with mitochondrial myopathy with cytochrome c oxidase deficiency, 1 with centronuclear myopathy, and 1 with Duchenne's muscular dystrophy, and in 9 age-matched control subjects. In all motor neuronopathies examined and in the patient with mitochondrial myopathy, 20 to 85% of neurons counted had "fragmented" Golgi apparatus. In age-matched control subjects and the other 2 patients with myopathies, 0 to 1.65% of motor neurons had fragmented Golgi apparatus. These findings suggest that the Golgi apparatus of motor neurons is involved in patients with amyotrophic lateral sclerosis and related motor neuron diseases, and perhaps in patients with certain fatal primary myopathies.

Adolescent↗
PubMed1999

Cell-free transfer of the vesicular stomatitis virus G protein from an endoplasmic reticulum compartment of baby hamster kidney cells to a rat liver Golgi apparatus compartment for Man8-9 to Man5 processing.

We report the reconstitution of the transfer of a membrane glycoprotein (vesicular stomatitis virus glycoprotein, VSV-G protein) from endoplasmic reticulum to Golgi apparatus and its subsequent Man8-9GlcNAc2 to Man5GlcNAc2 processing in a completely cell-free system. The acceptor was Golgi apparatus from rat liver immobilized on nitrocellulose. The endoplasmic reticulum donor was from homogenates of VSV-G-infected BHK cells. Nucleoside triphosphate plus cytosol-dependent transfer and processing of radiolabeled VSV-G protein was observed with donor from BHK cells infected at 37 degrees C with wild-type VSV or at the permissive temperature of 34 degrees C with the ts045 mutant. With Golgi apparatus as acceptor, specific transfer at 37 degrees C in the presence of nucleoside triphosphate was eightfold that at 4 degrees C or in the absence of ATP. About 40% of the VSV-G protein transferred was processed to the Man5GlcNAc2 form. Processing was specific for cis Golgi apparatus fractions purified by preparative free-flow electrophoresis. Fractions derived from the trans Golgi apparatus were inactive in processing. With the ts045 temperature-sensitive mutant, transfer and processing were much reduced even in the complete system when microsomes were from cells infected with mutant virus and incubated at the restrictive temperature of 39.5 degrees C but were able to proceed at the permissive temperature of 34 degrees C. Thus, Man8-9GlcNAc2 to Man5GlcNAc2 processing of VSV-G protein occurs following transfer in a completely cell-free system using immobilized intact Golgi apparatus or cis Golgi apparatus cisternae as the acceptor and shows temperature sensitivity, donor specificity, requirement for ATP, and response to inhibitors similar to those exhibited by transfer and processing of VSV-G protein in vivo.

Adenosine Triphosphate↗
PubMed1993

Ceramide excluded from cell-free vesicular lipid transfer from endoplasmic reticulum to Golgi apparatus. Evidence for lipid sorting.

The distribution and cell-free transfer of ceramide and other lipids were compared using highly purified fractions of endoplasmic reticulum, transitional endoplasmic reticulum, transition vesicles and Golgi apparatus from rat liver. Ceramides were present in both endoplasmic reticulum and Golgi apparatus where they represented between 0.3 and 1% of the total lipids. Ceramides, however, were much reduced or absent (< 0.05%) from transition vesicles. Transition vesicles were induced to form from transitional endoplasmic reticulum by incubation with ATP and a cytosol fraction. When transfer of [14C]choline-labeled phosphatidylcholine from transitional endoplasmic reticulum to Golgi apparatus was followed, transition vesicles were more efficient in transfer than the transitional endoplasmic reticulum from which they were derived. This transfer was temperature- and ATP-dependent and inhibited by N-ethylmaleimide. When transfer of [3H]ceramide was followed, there was little or no transfer via transition vesicles and that transfer which occurred was temperature-, ATP- and N-ethylmaleimide independent. Transfer of ceramide in the cell-free system did occur from endoplasmic reticulum to Golgi apparatus but via a non-vesicular mechanism that was temperature-dependent but not dependent on ATP or cytosol, alone, or in combination, nor was it inhibited by N-ethylmaleimide. A component of phosphatidylcholine transfer exhibited similar characteristics. The results provide evidence for two distinct mechanisms for cell-free transfer of lipids from endoplasmic reticulum to Golgi apparatus. The first is via 50 to 70 nm transition vesicles which is temperature- and ATP-dependent, inhibited by N-ethylmaleimide and from which ceramides are excluded. The second is non-vesicular, temperature-dependent, and neither ATP- nor cytosol-dependent. It accounts for the bulk of the ceramide transfer. As a result during cell-free lipid transfer from endoplasmic reticulum to Golgi apparatus, lipid sorting occurs such that ceramides are largely absent from the transition vesicles and, apparently are delivered to the Golgi apparatus by another mechanism.

Animals↗
PubMed1991

Distribution of glycosyltransferases among Golgi apparatus subfractions from liver and hepatomas of the rat.

Glycosyltransferase activities of highly purified fractions of Golgi apparatus, plasma membrane and endoplasmic reticulum, all from the same homogenates, were analyzed and compared. Additionally, Golgi apparatus were unstacked and the individual cisternae separated into fractions enriched in cis, median and trans elements using the technique of preparative free-flow electrophoresis. Golgi apparatus from both liver and hepatomas were enriched in all glycosyltransferases compared to endoplasmic reticulum and plasma membranes. However, Golgi apparatus from hepatomas showed both elevated fucosyltransferase and galactosyltransferase activities but reduced sialyltransferase and dipeptidyl peptidase IV (DPP IV) activities compared to liver. Activity of N-acetylglucosaminyltransferase was approximately the same in both liver and hepatoma Golgi apparatus. With normal liver, sialyl- and galactosyltransferase activities and DPP IV showed a marked cis-to-trans gradient of activity. Fucosyltransferase was concentrated in two regions of the electrophoretic separations, one corresponding to cis cisternae and one corresponding to trans cisternae. N-Acetylglucosaminyltransferase activity was more widely distributed but the endogenous acceptor activity was predominantly cis. With hepatoma Golgi apparatus, the pattern for DPP IV was similar to that for liver but those of sialyl- and galactosyltransferases differed markedly from liver. Instead of activity increasing cis to trans, the activities for sialyl- and galactosyltransferases decreased. For fucosyltransferases, activity dependent on exogenous acceptor was medial whereas with endogenous acceptor, two activity peaks, cis and trans, still were observed. For N-acetylglucosaminyltransferase the pattern for hepatoma was similar to that for liver. The results indicate alterations in the distribution of glycosyltransferase activities within the Golgi apparatus in hepatotumorigenesis that may reflect altered cell surface glycosylation patterns.

Animals↗
PubMed1992

Temperature- and acceptor-specificity of cell-free vesicular transfer from transitional endoplasmic reticulum to the cis Golgi apparatus.

The temperature dependence and specificity of transfer of membrane constituents from donor transitional endoplasmic reticulum to the cis Golgi apparatus were investigated using a cell-free system from rat liver. The radiolabelled transitional endoplasmic reticulum donors were prepared from slices of rat liver prelabelled with [14C]leucine. The acceptor Golgi apparatus elements were unlabelled and immobilized on nitrocellulose. When Golgi apparatus stacks were separated by preparative free-flow electrophoresis into subfractions enriched in cisternae derived from the cis, medial and trans portions of the stack respectively, efficient specific transfer was observed only to cis elements. Trans elements were devoid of specific acceptor capacity. Similarly, when transfer was determined as a function of temperature, a transition was observed in transfer activity between 12 degrees C and 18 degrees C similar to that seen in vivo for formation of the so-called 16 degrees C cis Golgi-located membrane compartment. Transfer at temperatures below 16 degrees C and transfer to trans Golgi apparatus compartments at temperatures either above or below 16 degrees C was similar and unspecific. The unspecific transfer at low temperature was pH independent, whereas specific transfer was greatest at the physiological pH of 7, and was reduced to 10% and 18% of that occurring at pH 8 and pH 5.5 respectively. These findings show that the cell-free system derived from rat liver exhibits a high degree of fidelity to transfer in vivo, an efficiency approaching that observed in vivo, and a nearly absolute acceptor specificity for cis Golgi apparatus. The acceptor-, temperature- and pH-specificity of the cell-free transfer, as well as the saturation kinetics exhibited with respect to acceptor Golgi apparatus, support the concept of transition-vesicle-specific docking sites of finite number associated with cis Golgi apparatus cisternae.

Adenosine Triphosphate↗
PubMed1970

Isolation of a Golgi apparatus-rich fraction from rat liver. II. Enzymatic characterization and comparison with other cell fractions.

Enzymatic activities associated with Golgi apparatus-, endoplasmic reticulum-, plasma membrane-, mitochondria-, and microbody-rich cell fractions isolated from rat liver were determined and used as a basis for estimating fraction purity. Succinic dehydrogenase and cytochrome oxidase (mitochondria) activities were low in the Golgi apparatus-rich fraction. On the basis of glucose-6-phosphatase (endoplasmic reticulum) and 5'-nucleotidase (plasma membrane) activities, the Golgi apparatus-rich fraction obtained directly from sucrose gradients was estimated to contain no more than 10% endoplasmic reticulum- and 11% plasma membrane-derived material. Total protein contribution of endoplasmic reticulum, mitochondria, plasma membrane, microbodies (uric acid oxidase), and lysosomes (acid phosphatase) to the Golgi apparatus-rich fraction was estimated to be no more than 20-30% and decreased to less than 10% with further washing. The results show that purified Golgi apparatus fractions isolated routinely may exceed 80% Golgi apparatus-derived material. Nucleoside di- and triphosphatase activities were enriched 2-3-fold in the Golgi apparatus fraction relative to the total homogenate, and of a total of more than 25 enzyme-substrate combinations reported, only thiamine pyrophosphatase showed a significantly greater enrichment.

Animals↗
PubMed1971

Isolation of a Golgi apparatus-rich fraction from rat liver. IV. Thiamine pyrophosphatase.

The thiamine pyrophosphatase (the enzyme [s] catalyzing the release of inorganic phosphate with thiamine pyrophosphate as the substrate) activities of Golgi apparatus-, plasma membrane-, endoplasmic reticulum-, and mitochondria-rich fractions from rat liver were compared at pH 8. Activity was concentrated in the Golgi apparatus fractions, which, on a protein basis, had a specific activity six to eight times that of the total homogenates or purified endoplasmic reticulum fractions. However, only 1-3% of the total activity was recovered in the Golgi apparatus fractions under conditions where 30-50% of the UDPgalactose:N-acetylglucosamine-galactosyl transferase activity was recovered. Considering both recovery of galactosyl transferase and fraction purity, we estimate that approximately 10% of the total thiamine pyrophosphatase activity of the liver was localized within the Golgi apparatus, with a specific activity of about ten times that of the total homogenate. Cytochemically, reaction product was found in the cisternae of the endoplasmic reticulum as well as in the Golgi apparatus. This is in contrast to results obtained in most other tissues, where reaction product was restricted to the Golgi apparatus. Thus, enzymes of rat liver catalyzing the hydrolysis of thiamine pyrophosphate, although concentrated in the Golgi apparatus, are widely distributed among other cell components in this tissue.

Animals↗
PubMed1971

Isolation of germ cell Golgi apparatus from seminiferous tubules of rat testes.

Intact Golgi apparatus have been isolated with good purity from rat testis by a simplified sucrose gradient technique. The procedure is inherently selective in that most of the Golgi apparatus in the isolate are from germ cells in late spermatocyte or early spermatid development. No Sertoli cell Golgi apparatus are present in the fraction. Biochemical analyses showed that the enzyme N-acetylglucosamine galactosyltransferase is enhanced in the band containing Golgi apparatus. Because they are easy to isolate, and because they are involved with the formation of a specific internal cellular component (the acrosome), these Golgi apparatus will be useful objects for comparison with other kinds of Golgi apparatus and for other studies leading to a better understanding of the basic functioning of Golgi apparatus.

Animals↗
PubMed1984

Role of microtubules in the organization and localization of the Golgi apparatus.

Normal interphase PtK2 and A549 cells display long microtubules radiating from the microtubule-organizing center (MTOC) to the plasma membrane. Both MTOC and Golgi apparatus are contained in the same perinuclear area. Treatment of cells with 1 microM colcemid for 2 h results in microtubule depolymerization and fragmentation of the Golgi apparatus into elements scattered throughout the cytoplasm. Both normal microtubules and the Golgi apparatus assemble again following removal of colcemid. Injection of the alpha, beta-nonhydrolyzable GTP analog, guanosine 5'(alpha, beta-methylene)diphosphate [pp(CH2)pG], into interphase cells growing in normal medium results in the formation of microtubule bundles resistant to colcemid and prevents the fragmentation of the Golgi apparatus. Injection of pp(CH2)pG into cells incubated with colcemid results in substitution of tubulin ribbons for microtubules and has no effect on the Golgi-derived elements scattered throughout the cytoplasm. Removal of colcemid 1 h after the injection of pp(CH2)pG results in polymerization of large numbers of short, single randomly oriented microtubules, whereas the Golgi apparatus remains fragmented. Treatment of cells with 10 microM taxol for 3 h results both in polymerization of microtubule bundles without relation to the MTOC in the cell periphery and fragmentation of the Golgi apparatus. The Golgi-derived fragments are present exclusively in regions of the peripheral cytoplasm enriched in microtubules. The codistribution of microtubules and Golgi elements can be reversed in taxol-treated cells by injection of a monoclonal (YL 1/2) antibody reacting specifically with the tyrosylated form of alpha-tubulin. Cells incubated with colcemid after treatment with taxol have large numbers of Golgi-derived elements in close association with colcemid-resistant microtubule bundles. Incubation of cells with 50 microM vinblastine for 90 min results in microtubule dissembly, formation of tubulin paracrystals, and fragmentation of the Golgi apparatus into elements without relation to the tubulin paracrystals.

Alkaloids↗
PubMed1991

Cyclic localization change of Golgi apparatus in Sertoli cells induced by mature spermatids in rats.

Previously we reported that the intracellular localization of the Golgi apparatus of rat Sertoli cells changes during the seminiferous epithelial cycle, and that the cyclic changes seem to be correlated to specific generations of germ cells. To ascertain which generations of germ cells are responsible for the cyclic changes, we determined the relative volume of the Golgi apparatus within the basal, mid, and apical cytoplasm of Sertoli cells in testes with and without mature spermatids. In normal adult rats, the Golgi apparatus was usually localized exclusively in the basal cytoplasm, whereas at stages VII-IX it increased remarkably in mid and apical cytoplasm, with a concomitant decrease in the basal cytoplasm. In young adult testes without spermatids at steps 15-19 of spermiogenesis (2nd layer spermatids), the Golgi apparatus was localized in the basal cytoplasm throughout the seminiferous epithelial cycle. Orchiopexy maintained for 35 days following 60 days of cryptorchidism allowed germ cells to regenerate to spermatids at steps 1-14 of sperminogenesis (1st layer spermatids), but failed to change the intracellular localization of the Golgi apparatus in Sertoli cells. At 50 days after orchiopexy, when all generations of germ cells appeared in the tubules, the cyclic changes in localization of the Golgi apparatus were restored similar to those in normal adult testes. These findings indicate that the cyclic change in localization of the Golgi apparatus in Sertoli cells is evoked by the presence of 2nd layer spermatids.

Animals↗
PubMed1995

On the significance and reproducibility of the fragmentation of the Golgi apparatus of motor neurons in human spinal cords.

Recent immunocytochemical and morphometric studies with an organelle-specific antiserum against MG-160, an intrinsic membrane sialoglycoprotein of the Golgi apparatus, have shown in several patients with sporadic amyotrophic lateral sclerosis (ALS), and in a few patients with related conditions, a fragmentation of the Golgi apparatus of spinal cord motor neurons which resembles the dispersion of the organelle observed in cells treated with microtubule depolymerizing agents. In the present study we examined by morphometry the effect of tissue fixation and processing on the immunocytochemical morphology of the Golgi apparatus of motor neurons from spinal cords of five controls and in one patient with leptomeningeal lymphoma. Qualitative studies of the Golgi apparatus of spinal cord motor neurons were also carried out in two more individuals with lymphoma or leukemia with leptomeningeal involvement and in one patient with multiple myeloma associated with a chronic inflammatory demyelinating polyneuropathy. The results of this study show that it is possible to obtain optimal immunocytochemical preparations of the Golgi apparatus of spinal cord motor neurons in routinely fixed and processed tissues obtained at autopsy. This study also provides baseline values of the Golgi apparatus in normal individuals which may be useful in future studies of the organelle in human neuropathologic conditions affecting the lower motor neuron unit. Lastly, this study shows that the fragmentation of the neuronal Golgi apparatus is not limited to ALS and related disorders.

Adult↗
PubMed1983

A quantitative study of the position of the Golgi apparatus in the developing chick myocardium. Effects of colchicine administration.

This paper presents a quantitative study of the position of the Golgi apparatus in the developing chick myocardium between stages 8+ and 13+. In addition we have studied the effects of colchicine on the position and structure of the Golgi apparatus. During the formation of the heart tube and loop the position of the Golgi apparatus in the myocytes situated in the vicinity of the dorsal mesocardium is related to that found in the cells of the precardiac mesoderm, but it is completely different from that found in the bulk of myocytes of the heart tube and loop. The position of the Golgi apparatus in both pre- and myocardial cells shows clear significative patterns of polarity. The possible significance of the Golgi apparatus polarity is discussed. After colchicine treatment microtubules disappear, the Golgi apparatus loses its polarization and vacuoles filled with amorphous material and/or collagen fibrils are observed. A possible role of the microtubular system in the maintenance of the structure and polarity of the Golgi apparatus and in the intracytoplasmic transport of the cardiac jelly materials is proposed.

Animals↗
PubMed2002

Selective regulation of the Rab9-independent transport of ricin to the Golgi apparatus by calcium.

Transport of ricin from endosomes to the Golgi apparatus occurs, in contrast to the transport of the mannose 6-phosphate receptor, by a Rab9-independent process. To characterize the pathway of ricin transport to the Golgi apparatus, we investigated whether it was regulated by calcium. As shown here, our data indicate that calcium is selectively involved in the regulation of ricin transport to the Golgi apparatus. Thapsigargin, which inhibits calcium transport into the ER, and the calcium ionophore A23187 both increased the transport of ricin to the Golgi apparatus by a factor of 20. By contrast, transport of the mannose 6-phosphate receptor to the Golgi apparatus was unaffected. Ricin and mannose 6-phosphate receptor transport were measured by quantifying the sulfation of modified forms of ricin and the mannose 6-phosphate receptor. The increased transport of ricin was reduced by wortmannin and LY294002, suggesting that phosphoinositide 3-kinase might be involved in transport of ricin to the Golgi apparatus. Together, these findings indicate that the different pathways to the Golgi apparatus utilized by ricin and the mannose 6-phosphate receptor are regulated by different mechanisms.

Androstadienes↗
PubMed1992

Fragmentation of the Golgi apparatus of motor neurons in amyotrophic lateral sclerosis.

The Golgi apparatus (complex) is at the center stage of important functions of processing and transport of plasma membrane, lysosomal, and secreted proteins. The involvement of the Golgi apparatus in the pathogenesis of chronic degenerative diseases of neurons is virtually unknown. In the present study, fragmentation and atrophy of the Golgi apparatus of motor neurons in amyotrophic lateral sclerosis (ALS), has been detected with organelle specific antibodies. Approximately 30% of motor neurons in five ALS patients showed a fragmented Golgi apparatus whereas only about 1% of motor neurons from seven controls with neurologic or systemic disease showed a similar change. Morphometric studies are consistent with the hypothesis that the alteration of the Golgi apparatus is an early event in the pathogenesis of the neuronal degeneration in ALS. Immunocytochemical studies with antibodies against alpha tubulin, tau, and phosphorylated subunits of neurofilament polypeptides did not disclose differences in the staining of neurons with fragmented or normal Golgi apparatus, suggesting that the alteration of the organelle is not secondary to a gross lesion of the cytoskeleton. However, these observations do not rule out the hypothesis that the fragmentation of the Golgi apparatus is secondary to subtle changes of the polypeptides involved in the attachment of membranes of the organelle to the cytoskeleton.

Amyotrophic Lateral Sclerosis↗
PubMed1990

Movement of interphase Golgi apparatus in fused mammalian cells and its relationship to cytoskeletal elements and rearrangement of nuclei.

Virus-induced Vero cell fusion was used to analyze the rearrangement of Golgi apparatus during the development of syncytia. Individual Golgi apparatus, associated initially with the separate microtubule-organizing centers in the perinuclear area of fused cells, congregated in the center of the syncytia and formed an extended Golgi complex within 3 to 5 h. The relocation of the Golgi apparatus, but not of nuclei, depended on the presence of an intact microtubule network, since both the microtubule depolymerizing drug nocodazole and the microtubule-stabilizing drug taxol interfered with the formation of an extended Golgi complex. Depolymerization of microfilaments with cytochalasin D and the complete collapse of intermediate filaments induced by microinjected monoclonal antibodies against vimentin had no effect on these processes. Cooling cells to 20 degrees C inhibited both congregation of Golgi apparatus and relocation of nuclei. Visualization of the movement of Golgi apparatus labeled in living cells with fluorescent metabolites of C6-NBD-ceramide showed that relocation of the Golgi apparatus was a process in which congregation and coalescence of the intact organelles was seen, rather than dispersal and reassembly of smaller Golgi elements in the center of the polykaryons. Thus, movement of intact Golgi apparatus in fused interphase cells depends on an undisturbed microtubule network and occurs independently of the relocation of nuclei.

Actin Cytoskeleton↗
PubMed1987

Golgi apparatus cisternae of monensin-treated cells accumulate in the cytoplasm of liver slices.

Protein transport via the endoplasmic reticulum Golgi apparatus-cell surface export route was blocked when slices (6-15 cells thick) of livers of 10-day-old rats were incubated with 1 microM monensin. Production of secretory vesicles by Golgi apparatus was reduced or eliminated and, in their place, swollen cisternae accumulated in the cytoplasm at the trans Golgi apparatus face. The swelling response was restricted to the six external cell layers of the liver slices, and the number of cells showing the response was little increased by either a greater concentration of monensin or by longer times of incubation. When monensin was added post-chase to the slices, flux of radioactive proteins to the cell surface was inhibited by about 80% as determined from standard pulse-chase analyses with isolated cell fractions. Radioactive proteins accumulated in both endoplasmic reticulum and Golgi apparatus and in a fraction that may contain monensin-blocked Golgi apparatus cisternae released from the stack. The latter fraction was characterized by galactosyltransferase/thiamine pyrophosphatase ratios similar to those of Golgi apparatus from control slices. The use of monensin with the tissue slice system may provide an opportunity for the cells to accumulate monensin-blocked Golgi apparatus cisternae in sufficient quantities to permit their isolation and purification by conventional cell fractionation methods.

Animals↗
PubMed1994

Rous-Whipple Award Lecture. Contributions to the physiology and pathology of the Golgi apparatus.

The importance of the Golgi apparatus in the transport, processing, and targeting of proteins destined for secretion, plasma membranes, and lysosomes has emerged from numerous studies. In this paper we review studies from our laboratory dealing with 1) the Golgi apparatus during mitosis and the role of microtubules in maintaining the structure of the organelle, 2) the endocytosis of antibodies, exogenous lectins, and toxins into the Golgi apparatus of several cells including neurons in vivo and in vitro, 3) the traffic of MG-160, a membrane sialoglycoprotein of the medial cisternae of the Golgi apparatus, from the trans-Golgi network to the Golgi cisternae, and 4) the involvement of the Golgi apparatus of motor neurons in the pathogenesis of amyotrophic lateral sclerosis. We conclude with a summary of ongoing work on the primary structure of MG-160 and introduce evidence suggesting that this intrinsic membrane protein of the Golgi apparatus may be involved in the regulation of endogenous, autocrine, basic fibroblast growth factor. We hope that this review will stimulate studies on the Golgi apparatus of neurons, which may lead to the discovery of neuron-specific properties of this important organelle and its involvement in the pathogenesis of neurodegenerative disorders.

Amyotrophic Lateral Sclerosis↗